CN114339643B

CN114339643B - Policy rule providing method and session management network element

Info

Publication number: CN114339643B
Application number: CN202011052641.3A
Authority: CN
Inventors: 周晓云; 吴义壮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2023-09-22
Anticipated expiration: 2040-09-29
Also published as: WO2022068502A1; CN114339643A

Abstract

The embodiment of the application discloses a policy rule providing method and a session management network element, which are used for acquiring a policy rule for UPF detection data packets when SMF cannot directly interact with PCF. The method of the embodiment of the application comprises the following steps: the first SMF sends data description information to a second SMF which can interact with the PCF, the second SMF acquires corresponding PCC rules from the PCF according to the data description information, and then generates corresponding policy rules to send to the first SMF, so that the first SMF can acquire the policy rules for UPF detection data packets according to the PCC rules.

Description

Policy rule providing method and session management network element

Technical Field

The embodiment of the application relates to the field of communication, in particular to a policy rule providing method and a session management network element.

Background

In the communication protocols that may occur in the 4G, 5G and future, one of the functions of the session management function (SMF, session management function) is to implement separation of the user plane and the control plane, and to take charge of the function of the control plane, i.e. to provide policy rules for the user plane function (UPF, user plane function).

When an application needs to subscribe to an event related to data transmitted by the application and the UE, and a UPF needs to detect a data packet transmitted by the UE (for example, when the subscribed event is that the data packet is buffered, the UPF needs to buffer the data packet and report the event that the data packet is buffered), the SMF needs to request policy control and charging (PCC, policy control and charging) rules from the PCF, generate a policy rule for detecting a state of the data packet according to the PCC rule, and the UPF realizes detection and event report of the corresponding data packet according to the policy rule, thereby realizing event report of the event subscription.

When the SMF cannot directly interact with the PCF, the SMF cannot acquire the PCC rule, and the SMF cannot correctly formulate a policy rule for the UPF to detect the packet. For example, in roaming scenarios or scenarios where an intermediate session management function (I-SMF) is present, V-SMF and I-SMF cannot properly formulate policy rules for UPF detection packets because the visited session management function (V-SMF) and the I-SMF cannot interact directly with the PCF and cannot acquire PCC rules.

Disclosure of Invention

The embodiment of the application provides a policy rule providing method, which is used for acquiring PCC rules when SMF can not interact with PCF directly, so as to acquire policy rules for UPF detection data packets.

An embodiment of the present application provides a method for providing policy rules, where the method includes:

after the user equipment UE accesses the network and establishes the PDU session, the application may request to create a subscription for a first event, the first event being related to data transmitted by the application and the UE, the data packet transmitted by the UE may be detected by the UPF, and the data packet may include data received by the UE.

When an application requests to subscribe to a first event, the first session management network element SMF may receive a first message, where the first message is used to request to create subscription of the first event, and the first message may include first description information of data, where the data is data received by the UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

The first SMF may send a second message to the second session management network element SMF according to request policy indication information, where the request policy indication information is used to instruct the first SMF to obtain, from the PCF, a policy rule corresponding to a subscription event, the second message includes first description information, and the second message is used to request a first policy rule corresponding to the first description information;

the first SMF receives a first policy rule sent by the second SMF;

the first SMF determines a second policy rule according to the first policy rule;

the first SMF sends a second policy rule to the user plane function, UPF, to enable the UPF to process the data.

In the embodiment of the application, the first SMF which cannot directly interact with the PCF sends the first description information to the second SMF which can directly interact with the PCF, and receives the first policy rule generated by the second SMF according to the first description information, so as to generate the corresponding policy rule. The first SMF completes subscription of the event under the condition that the first SMF cannot be directly connected with the PCF.

With reference to the first aspect, in a first implementation manner of the first aspect of the embodiment of the present application, when updating the first event subscription, a corresponding policy rule may be provided:

specifically, the second message may further include a first identifier, where the first identifier is used to identify a transaction between the first SMF and the second SMF, the first identifier corresponds to a subscription of the first event, and the corresponding transaction and the corresponding policy rule may be determined according to the first identifier;

After the first SMF sends the first message to the second SMF, the method further comprises:

the first SMF receives a third message, where the third message is used to request updating of subscription of the first event, and the third message includes second description information of the data, and in the embodiment of the present application, the second description information may also be referred to as second data description information;

the first SMF sends a fourth message to the second SMF, wherein the fourth message is used for requesting the second SMF to update the first policy rule, and the fourth message comprises a first identifier and second description information;

the first SMF receives a fourth policy rule sent by the second SMF, wherein the fourth policy rule is a policy rule obtained after updating the first policy rule according to the second description information;

and the first SMF updates the second policy rule according to the fourth policy rule, and obtains the policy rule corresponding to the second descriptive information at the first SMF.

In the embodiment of the application, the first SMF sends the second description information and the first identifier to the second SMF, so that the second SMF updates the first policy rule according to the second description information to obtain a fourth policy rule, and receives the fourth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the first implementation manner of the first aspect, in a second implementation manner of the first aspect of the embodiment of the present application, after the first SMF sends the fourth message to the second SMF, the method further includes:

the first SMF receives a tenth message, where the tenth message is used to request updating of subscription of the first event, and the tenth message includes third description information of the data, where in the embodiment of the present application, the third description information may also be referred to as third data description information;

the first SMF sends an eleventh message to the second SMF, wherein the eleventh message is used for requesting the second SMF to update the fourth policy rule, and the eleventh message comprises a first identifier and third description information;

the first SMF receives a sixth policy rule sent by the second SMF, wherein the sixth policy rule is a policy rule obtained after updating the fourth policy rule according to the third description information;

the first SMF updates the policy rules related to the first event at the first SMF according to the sixth policy rules, and obtains the policy rules corresponding to the third description information at the first SMF.

In the embodiment of the application, the first SMF sends the third description information and the first identifier to the second SMF, so that the second SMF updates the fourth policy rule according to the third description information to obtain a sixth policy rule, and receives the sixth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the third description information. After the update of the event subscription is realized, the update of the event subscription is performed again.

With reference to the first aspect, in a third implementation manner of the first aspect of the embodiment of the present application, deletion of the subscription to the first event may also be implemented:

specifically, the first message may further include a first identifier, where the first identifier is used to identify a transaction between the first SMF and the second SMF, and the corresponding transaction and the corresponding policy rule may be determined according to the first identifier;

specifically, in this embodiment, the first identifier may represent the first event between the first SMF and the second SMF;

the first SMF receives a fifth message, wherein the fifth message is used for requesting to delete subscription of the first event;

the first SMF sends a sixth message to the second SMF requesting deletion of the first policy rule, the sixth message including the first identification and the deletion indication.

In the embodiment of the application, the first SMF sends the deletion instruction and the first identifier to the second SMF, so that the second SMF deletes the first policy rule according to the deletion instruction. And deleting the event subscription after the event subscription is completed.

With reference to the first implementation manner of the first aspect, in a fourth implementation manner of the first aspect of the embodiment of the present application, deletion of the updated first event subscription may also be implemented:

Specifically, after the first SMF sends the fourth message to the second SMF, the method further includes:

the first SMF receives a twelfth message, wherein the twelfth message is used for requesting to delete subscription of the first event;

the first SMF sends a thirteenth message to the second SMF requesting deletion of the fourth policy rule, the thirteenth message including the first identification and the deletion indication.

In the embodiment of the application, the first SMF sends the deletion instruction and the first identifier to the second SMF, so that the second SMF deletes the fourth policy rule according to the deletion instruction. And deleting the updated event subscription.

With reference to the first aspect, the first implementation manner of the first aspect, or any one of the fourth implementation manners of the first aspect, in a fifth implementation manner of the first aspect of the embodiment of the present application,

before the first SMF sends the second message to the second SMF according to the request policy indication information, the method further includes:

the first SMF receives request strategy indication information sent by the second SMF.

According to the request policy indication information, the first SMF can know that the request policy indication information is needed, so that the policy rule corresponding to the subscription of the first event is obtained.

With reference to the first aspect, the first implementation manner of the first aspect, or any one of the fifth implementation manners of the first aspect, in a sixth implementation manner of the first aspect of the embodiment of the present application,

the request policy indication information includes at least one of indication information of policy charging control applied to the UE, indication information of reporting reception of a downlink data notification event subscription, or indication information of reporting reception of data description information.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the sixth implementation manner of the first aspect, in a seventh implementation manner of the first aspect of the embodiment of the present application,

the first message further includes event subscription type indication information for indicating a type of subscription of the first event.

In the embodiment of the application, the second SMF can determine the subscription type of the first event according to the event subscription type indication information, and when PCC rules are requested to PCF, the corresponding downlink data notification event subscription trigger can be determined according to the indication information, and the corresponding trigger is not required to be determined through the subscription of the event, so that the operation resources of the second SMF are saved.

With reference to the seventh implementation manner of the first aspect, in an eighth implementation manner of the first aspect of the embodiments of the present application,

the first policy rule that the first SMF receives the second SMF transmission includes:

the first SMF receives a first policy rule and notification control indication information sent by the second SMF, and the notification control indication information is determined according to the event subscription type indication information;

the first SMF determining a second policy rule from the first policy rule includes:

the first SMF determines a second policy rule according to the first policy rule and the notification control instruction information.

In the embodiment of the application, the first SMF can directly determine the second policy rule according to the first policy rule and the notification control instruction information, the first event corresponding to the first policy rule does not need to be determined, and then the second policy rule is determined according to the first event, so that the operation resource and time delay of the first SMF are saved, and the efficiency is improved.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the seventh implementation manner of the first aspect, in a ninth implementation manner of the first aspect of the embodiment of the present application,

The first SMF determines a second policy rule based on the first policy rule and the subscription of the first event.

In the embodiment of the application, the first SMF determines the second policy rule according to the first policy rule and the subscription of the first event, and event subscription type indication information and notification control indication information are not required to be carried in the information sent and received by the second SMF, so that the operation resources and network bandwidth resources of network elements which need to send and determine the two indication information in a network are saved.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the ninth implementation manner of the first aspect, in a tenth implementation manner of the first aspect of the embodiment of the present application,

after the first SMF sends the second policy rule to the UPF, the method further comprises:

the first SMF receives a second event reported by the UPF after the data is processed;

the first SMF determines a first event from the second event and reports the first event to an event receiving network element, the event receiving network element being configured to receive a report related to the first event.

With reference to the tenth implementation manner of the first aspect, in an eleventh implementation manner of the first aspect of the embodiment of the present application,

the second event includes an event that the data is buffered or an event that the data is lost.

With reference to the first aspect, the first implementation manner of the first aspect, or any one of the eleventh implementation manners of the first aspect, in a twelfth implementation manner of the first aspect of the embodiment of the present application,

the first event includes a downlink data notification failure event or a downlink data transmission status event.

With reference to the first aspect, the first implementation manner of the first aspect, and any one of the twelfth implementation manners of the first aspect, in a thirteenth implementation manner of the first aspect of the embodiment of the present application, the first policy rule is first N4 information.

With reference to the first aspect, the first implementation manner of the first aspect, and any one of the thirteenth implementation manners of the first aspect, in a fourteenth implementation manner of the first aspect of the embodiment of the present application, the second policy rule is second N4 information.

With reference to the eighth implementation manner of the first aspect, in a fifteenth implementation manner of the first aspect of the embodiment of the present application, the notification control instruction information is included in the first policy rule.

In the embodiment of the application, the notification control instruction information is included in the first policy rule, and in the process of forwarding and determining the second policy rule according to the first policy rule, the notification control instruction information is included in the first policy rule, so that independent processing of the notification control instruction information is not needed, and the operation resources of the equipment are saved.

With reference to the first implementation manner of the first aspect, in a sixteenth implementation manner of the first aspect of the embodiment of the present application, a third identifier is further included in the third message, where the third identifier is used to identify a subscription of the first event.

With reference to the sixteenth implementation manner of the first aspect, in a seventeenth implementation manner of the first aspect of the embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to any one of the first implementation manner of the first aspect to the fourth implementation manner of the first aspect, in an eighteenth implementation manner of the first aspect of the embodiment of the present application, the first identifier is a transaction identifier, which indicates a transaction between the first SMF and the second SMF, and corresponds to a subscription of the first event.

With reference to the eighteenth implementation manner of the first aspect, in a nineteenth implementation manner of the first aspect of the embodiment of the present application, the transaction identifier is a NEF notification association identifier, and the NEF notification association identifier is used to identify a subscription of the first event.

A second aspect of an embodiment of the present application provides a method for providing policy rules, where the method includes:

When an application requests to subscribe to a first event, the second SMF may receive a second message sent by the first SMF, where the second message includes first description information and event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, that is, a type of the first event, and the first description information is used to identify data received by the UE;

the second SMF sends a seventh message to the policy control network element PCF, wherein the seventh message is used for requesting a third policy rule corresponding to the first description information, the seventh message comprises the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

the second SMF receives the third policy rules sent by the PCF;

the second SMF determines a first policy rule according to the third policy rule;

the second SMF sends a first policy rule to the first SMF.

In the embodiment of the application, the second SMF which can directly interact with the PCF receives the first description information and the event subscription type indication information sent by the first SMF which cannot directly interact with the PCF, requests the PCF for the third policy rule generated according to the first description information, so as to generate the corresponding first policy rule, and then sends the first policy rule to the first SMF, so that the first SMF obtains the first policy rule generated according to the third policy rule.

With reference to the second aspect, in a first implementation manner of the second aspect of the embodiment of the present application,

before the second SMF receives the second message sent by the first SMF, the method further includes:

the second SMF receives first request strategy indication information sent by the PCF, wherein the first request strategy indication information comprises indication information for reporting that a downlink data notification event subscription is received;

the second SMF sends second request strategy indication information to the first SMF, wherein the second request strategy indication information comprises at least one of indication information of strategy charging control applied to the UE, indication information of the report received downlink data notification event subscription or indication information of report received data description information; the second request policy indication information is used for indicating the first SMF to acquire a policy rule corresponding to the subscription event.

In the embodiment of the application, the second SMF sends the second request policy indication information to the first SMF, and notifies the first SMF to acquire the policy rules corresponding to the subscription event from the PCF, so that the first SMF acquires the policy rules generated by the PCF through the second SMF, and thus acquires the policy rules required by the event subscription.

With reference to the second aspect and the first implementation manner of the second aspect, in a second implementation manner of the second aspect of the embodiment of the present application,

The third policy rule sent by the PCF is received by the second SMF, where the third policy rule includes:

the second SMF receives a third policy rule and notification control instruction information sent by the PCF, and the notification control instruction information is determined according to the downlink data notification event subscription trigger;

the second SMF sending the first policy rule to the first SMF includes:

the second SMF transmits the first policy rule and notification control indication information to the first SMF.

In the embodiment of the application, the second SMF sends the first policy rule and the notification control indication information to the first SMF, and the first SMF can directly determine the second policy rule according to the first policy rule and the notification control indication information without determining the first event corresponding to the first policy rule, and then determine the second policy rule according to the first event, thereby saving the operation resource and time delay of the first SMF and improving the efficiency.

With reference to the second aspect and any one of the first implementation manner to the second implementation manner of the second aspect, in a third implementation manner of the second aspect of the embodiment of the present application, when updating the first event subscription, a corresponding policy rule may be provided:

the second message further comprises a first identifier, wherein the first identifier is used for identifying a transaction between the second SMF and the first SMF and corresponds to subscription of a first event;

After the second SMF sends the seventh message to the PCF, the method further comprises:

the second SMF receives a fourth message sent by the first SMF, wherein the fourth message comprises a first identifier and second description information of the data, and the fourth message is used for requesting to update the subscription of the first event;

the second SMF sends an eighth message to the PCF, wherein the eighth message comprises a second identifier and second description information, the eighth message is used for requesting to update a third policy rule, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the first identifier;

the second SMF receives a fifth policy rule sent by the PCF, wherein the fifth policy rule is obtained by updating the third policy rule according to the second description information;

the second SMF updates the first strategy rule according to the fifth strategy rule to obtain a fourth strategy rule;

the second SMF sends a fourth policy rule to the first SMF.

In the embodiment of the application, the second SMF updates the first policy rule according to the second description information to obtain a fourth policy rule, and sends the fourth policy rule to the first SMF, so that the first SMF generates the policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the third implementation manner of the second aspect, in a fourth implementation manner of the second aspect of the embodiment of the present application, after the second SMF receives the fourth message sent by the first SMF, the method further includes:

the second SMF receives an eleventh message sent by the first SMF, wherein the eleventh message is used for requesting the second SMF to update the fourth policy rule, and the eleventh message comprises a first identifier and third description information of the data, and the third description information can also be called third data description information;

the second SMF sends a second identifier and third description information to the PCF so as to request the PCF to update the fifth policy rule according to the third description information;

the second SMF receives a seventh policy rule sent by the PCF, wherein the seventh policy rule is obtained by updating the fifth policy rule according to the third description information;

the second SMF updates the fourth policy rule according to the seventh policy rule to obtain a sixth policy rule;

the second SMF sends a sixth policy rule to the first SMF.

In the embodiment of the application, the second SMF sends the third description information and the second identifier to the PCF, so that the PCF updates the fifth policy rule according to the third description information to obtain a seventh policy rule, and receives the seventh policy rule sent by the PCF, thereby generating a sixth policy rule corresponding to the third description information. After the update of the event subscription is realized, the update of the event subscription is performed again.

With reference to the second aspect and any one of the first implementation manner to the fourth implementation manner of the second aspect, in a fifth implementation manner of the second aspect of the embodiment of the present application, deletion of an event subscription may also be implemented:

the second message also comprises a first identifier, wherein the first identifier is used for identifying a transaction between the second SMF and the first SMF and corresponds to subscription of a first event;

the second SMF receives a sixth message sent by the first SMF, wherein the sixth message comprises the first identifier and the deletion indication;

the second SMF sends a ninth message to the PCF, wherein the ninth message is used for requesting to delete the third policy rule, the ninth message comprises a second identifier, the second identifier is the identification information of the third policy rule, and the second identifier is determined according to the first identifier.

In the embodiment of the application, the second SMF sends the ninth message to the PCF, so that the PCF deletes the third policy rule according to the second identifier in the ninth message, and the deletion of the event subscription is realized.

With reference to the third implementation manner of the second aspect, in a sixth implementation manner of the second aspect of the embodiment of the present application, deletion of the updated event subscription may also be implemented:

After the second SMF sends the second identifier and the third description information to the PCF, the method further includes:

the second SMF receives a thirteenth message sent by the first SMF, wherein the thirteenth message comprises the first identifier and the deletion indication;

the second SMF sends a fourteenth message to the PCF, where the fourteenth message is used to request deletion of the fifth policy rule, and the fourteenth message includes a second identifier, where the second identifier is used to identify the fifth policy rule.

In the embodiment of the application, the second SMF sends the fourteenth message to the PCF, so that the PCF deletes the fifth policy rule according to the second identifier in the fourteenth message, and the deletion of the updated event subscription is realized.

With reference to the second aspect, any one of the first implementation manner of the second aspect to the sixth implementation manner of the second aspect, in a seventh implementation manner of the second aspect of the embodiment of the present application,

With reference to the second aspect, or any one of the first implementation manner to the seventh implementation manner of the second aspect, in an eighth implementation manner of the second aspect of the embodiment of the present application, the third policy rule is a PCC rule.

With reference to the second aspect, any one of the first implementation manner of the second aspect to the eighth implementation manner of the second aspect, in a ninth implementation manner of the second aspect of the embodiment of the present application, the first policy rule is first N4 information.

With reference to the second implementation manner of the second aspect, in a tenth implementation manner of the first aspect of the embodiment of the present application, the notification control instruction information is included in the third policy rule.

In the embodiment of the application, the notification control instruction information is included in the third policy rule, and in the process of forwarding and using the first policy rule, the notification control instruction information is included in the third policy rule, so that independent processing of the notification control instruction information is not needed, and the operation resource of the equipment is saved.

With reference to the second implementation manner of the second aspect, in an eleventh implementation manner of the second aspect of the embodiment of the present application, the notification control instruction information is included in the first policy rule.

In the embodiment of the application, the notification control instruction information is included in the first policy rule, and in the process of forwarding and using the first policy rule, the notification control instruction information is included in the first policy rule, so that independent processing of the notification control instruction information is not needed, and the operation resource of the equipment is saved.

With reference to any one of the third implementation manner of the second aspect to the sixth implementation manner of the second aspect, in a twelfth implementation manner of the second aspect of the embodiment of the present application, the first identifier is a transaction identifier, which indicates a transaction between the first SMF and the second SMF, and corresponds to a subscription of the first event.

With reference to the twelfth implementation manner of the second aspect, in a thirteenth implementation manner of the second aspect of the embodiment of the present application, the transaction identifier is a NEF notification association identifier, and the NEF notification association identifier is used to identify a subscription of the first event.

A third aspect of an embodiment of the present application provides a session management network element, including:

a first receiving unit, configured to receive a first message, where the first message is used to request to create a subscription of a first event, where the subscription of the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is received by the UE;

a first sending unit, configured to send a second message to a second session management network element SMF according to request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

A second receiving unit, configured to receive the first policy rule sent by the second SMF;

the first determining unit is used for determining a second strategy rule according to the first strategy rule;

and the second sending unit is used for sending the second policy rule to a user plane function network element UPF so that the UPF processes the data.

The session management network element is configured to perform the method of the aforementioned first aspect.

A fourth aspect of an embodiment of the present application provides a session management network element, including:

a seventh receiving unit, configured to receive a second message sent by a first session management network element SMF, where the first message includes first description information and event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, where the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

a fifth sending unit, configured to send a seventh message to a policy control network element PCF, where the seventh message is configured to request a third policy rule corresponding to the first description information, where the seventh message includes the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

An eighth receiving unit, configured to receive the third policy rule sent by the PCF;

a second determining unit, configured to determine a first policy rule according to the third policy rule;

and a sixth sending unit, configured to send the first policy rule to the first SMF.

The session management network element is adapted to perform the method of the aforementioned second aspect.

A fifth aspect of an embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor, the memory and the input and output equipment are connected with the bus;

the processor is used for executing the following steps:

receiving a first message, wherein the first message is used for requesting to create a subscription of a first event, the subscription of the first event is an event subscription for User Equipment (UE), the first message comprises first description information of data, and the data is received by the UE;

sending a second message to a second session management network element SMF according to the request policy indication information, wherein the second message comprises the first description information, and the second message is used for requesting a first policy rule corresponding to the first description information;

receiving the first policy rule sent by the second SMF;

Determining a second policy rule according to the first policy rule;

and sending the second policy rule to a User Plane Function (UPF) so that the UPF processes the data.

A sixth aspect of an embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor is used for executing the following steps:

receiving a second message sent by a first session management network element (SMF), wherein the first message comprises first description information and event subscription type indication information, the event subscription type indication information is used for indicating the type of event subscription, the event subscription is an event subscription for User Equipment (UE), and the first description information is used for identifying data received by the UE;

a seventh message is sent to a policy control network element PCF, wherein the seventh message is used for requesting a third policy rule corresponding to the first description information, the seventh message comprises the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

Receiving the third policy rule sent by the PCF;

determining a first policy rule according to the third policy rule;

and sending the first policy rule to the first SMF.

A seventh aspect of the embodiment of the present application provides a method for providing policy rules, where the method includes:

When the application requests to subscribe to the first event, the first session management network element SMF may receive a first policy rule sent by the second SMF, where the first policy rule is generated according to first description information of data, where the data is data received by the UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

In the embodiment of the application, the first SMF which cannot directly interact with the PCF generates the corresponding policy rule by receiving the first policy rule generated by the second SMF according to the first description information. The first SMF completes subscription of the event under the condition that the first SMF cannot be directly connected with the PCF.

With reference to the seventh aspect, in a first implementation manner of the seventh aspect of the embodiment of the present application, when updating the first event subscription, a corresponding policy rule may be provided:

specifically, after the first SMF receives the first policy rule sent by the second SMF,

the first SMF receives a fourth policy rule sent by the second SMF, wherein the fourth policy rule is a policy rule obtained after updating the first policy rule according to the second description information of the data;

In the embodiment of the application, the second SMF updates the first policy rule according to the second description information to obtain the fourth policy rule, and the first SMF receives the fourth policy rule sent by the second SMF so as to generate the policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the first implementation manner of the seventh aspect, in a second implementation manner of the seventh aspect of the embodiment of the present application, after the first SMF receives the fourth policy rule sent by the second SMF, the method further includes:

the first SMF receives a sixth policy rule sent by the second SMF, wherein the sixth policy rule is a policy rule obtained after updating the fourth policy rule according to third description information of the data;

In the embodiment of the application, the second SMF updates the fourth policy rule according to the third description information to obtain a sixth policy rule, and the first SMF receives the sixth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the third description information. After the update of the event subscription is realized, the update of the event subscription is performed again.

With reference to the seventh aspect, in a third implementation manner of the seventh aspect of the embodiment of the present application, deletion of an event subscription may further be implemented:

the first SMF receives an instruction sent by the second SMF to delete the first policy rule;

The first SMF deletes the first policy rule and sends an indication to the UPF to delete the second policy rule.

In the embodiment of the application, the first SMF receives the indication of deleting the first policy rule sent by the second SMF, and deletes the first policy rule according to the indication. And deleting the event subscription is realized.

With reference to the first implementation manner of the seventh aspect, in a fourth implementation manner of the seventh aspect of the embodiment of the present application, deletion of the updated first event subscription may also be implemented:

specifically, after the first SMF receives the fourth policy rule sent by the second SMF,

the first SMF receives an instruction sent by the second SMF to delete the fourth policy rule;

the first SMF deletes the fourth policy rule and sends an indication to the UPF to delete the policy rule associated with the first event.

In the embodiment of the present application, the first SMF receives an instruction for deleting the fourth policy rule sent by the second SMF, and deletes the fourth policy rule according to the instruction. And deleting the updated event subscription.

With reference to the seventh aspect, any one of the first implementation manner of the seventh aspect to the fourth implementation manner of the seventh aspect, in a fifth implementation manner of the seventh aspect of the embodiment of the present application,

the first SMF receives a first policy rule and notification control instruction information sent by the second SMF, and the notification control instruction information is determined according to the subscription of the first event;

With reference to the seventh aspect, any one of the first implementation manner of the seventh aspect to the fourth implementation manner of the seventh aspect, in a sixth implementation manner of the seventh aspect of the embodiment of the present application,

In the embodiment of the application, the first SMF determines the second policy rule according to the first policy rule and the subscription of the first event, and notification control indication information is not required to be carried in the information sent and received by the second SMF, so that the operation resources and network bandwidth resources of network elements which need to send and determine the indication information in a network are saved.

With reference to the seventh aspect, any one of the first implementation manner of the seventh aspect to the sixth implementation manner of the seventh aspect, in a seventh implementation manner of the seventh aspect of the embodiment of the present application,

With reference to the seventh implementation manner of the seventh aspect, in an eighth implementation manner of the seventh aspect of the embodiment of the present application,

With reference to the seventh aspect, or any one of the first implementation manner of the seventh aspect to the eighth implementation manner of the seventh aspect, in a ninth implementation manner of the seventh aspect of the embodiment of the present application,

With reference to the seventh aspect, any one of the first implementation manner of the seventh aspect to the ninth implementation manner of the seventh aspect, in a tenth implementation manner of the seventh aspect of the embodiment of the present application, the first policy rule is first N4 information.

With reference to the seventh aspect, or any one of the first implementation manner of the seventh aspect to the tenth implementation manner of the seventh aspect, in an eleventh implementation manner of the seventh aspect of the embodiment of the present application, the second policy rule is second N4 information.

With reference to the seventh aspect, any one of the first implementation manner of the seventh aspect to the eleventh implementation manner of the seventh aspect, in a twelfth implementation manner of the seventh aspect of the present application, specifically, before the first SMF receives the first policy rule sent by the second SMF, the first SMF sends, to the second SMF, an indication that data is cached in the UPF or an indication that a policy rule is needed.

With reference to the fifth implementation manner of the seventh aspect, in a thirteenth implementation manner of the seventh aspect of the embodiment of the present application, the notification control indication information is included in the first policy rule.

An eighth aspect of the present application provides a method for providing policy rules, where the method includes:

When the application requests to subscribe to the first event, the second SMF may send a seventh message to the PCF according to the first request policy indication information, where the seventh message includes first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, that is, a type of the first event, and the first description information is used to identify data received by the UE;

the second SMF receives the third policy rules sent by the PCF;

the second SMF sends a first policy rule to the first SMF.

In the embodiment of the application, the second SMF which can directly interact with the PCF requests the PCF for the third policy rule generated according to the first description information, so as to generate the corresponding first policy rule, and then the first policy rule is sent to the first SMF, so that the first SMF obtains the first policy rule generated according to the third policy rule.

With reference to the eighth aspect, in a first implementation manner of the eighth aspect of the embodiment of the present application,

before the second SMF sends the seventh message to the PCF according to the first request policy indication information, the method further comprises:

in the embodiment of the application, the second SMF receives the first request policy indication information sent by the PCF, so that the second SMF can acquire the policy rules corresponding to the subscription event from the PCF, and the first SMF acquires the policy rules generated by the PCF through the second SMF, thereby acquiring the policy rules required by the event subscription.

With reference to the eighth aspect and the first implementation manner of the eighth aspect, in a second implementation manner of the eighth aspect of the embodiment of the present application,

the second SMF receives a third policy rule and notification control indication information sent by the PCF, and the notification control indication information is determined according to the event subscription type indication information;

the second SMF sending the first policy rule to the first SMF includes:

With reference to the eighth aspect and any one of the first implementation manner to the second implementation manner of the eighth aspect, in a third implementation manner of the eighth aspect of the embodiment of the present application, when updating the first event subscription, a corresponding policy rule may be provided:

the second SMF receives a third identifier and second description information of the data, wherein the second description information is used for updating the subscription of the first event, and the third identifier is used for identifying the subscription of the first event;

the second SMF sends an eighth message to the PCF, wherein the eighth message comprises a second identifier and second description information, the eighth message is used for requesting to update a third policy rule, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the third identifier;

the second SMF sends a fourth policy rule to the first SMF.

With reference to the third implementation manner of the eighth aspect, in a fourth implementation manner of the eighth aspect of the embodiment of the present application, after the second SMF receives the third identifier and the second description information, the method further includes:

the second SMF receives a third identifier and third description information of the data, where the third description information may also be called third data description information, and the third identifier is used to identify a subscription of the first event;

the second SMF sends a sixth policy rule to the first SMF.

With reference to the eighth aspect and any one of the first implementation manner to the fourth implementation manner of the eighth aspect, in a fifth implementation manner of the eighth aspect of the embodiment of the present application, deletion of an event subscription may further be implemented:

the second SMF receives a third identifier and a deletion instruction, wherein the third identifier is used for identifying the subscription of the first event;

the second SMF sends a ninth message to the PCF, wherein the ninth message is used for requesting to delete the third policy rule, and the ninth message comprises a second identifier, and the second identifier is used for identifying the third policy rule.

With reference to the third implementation manner of the eighth aspect, in a sixth implementation manner of the eighth aspect of the embodiment of the present application, deletion of the updated event subscription may also be implemented:

the second SMF sends a fourteenth message to the PCF, wherein the fourteenth message is used for requesting to delete the fifth policy rule, the fourteenth message comprises a second identifier, and the second identifier is used for identifying the fifth policy rule;

the second SMF sends an indication to the first SMF to delete the fourth policy rule.

In the embodiment of the application, the second SMF deletes the fifth policy rule according to the second identifier in the fourteenth message to the PCF, and sends an instruction for deleting the fourth policy rule to the first SMF so that the first SMF deletes the fourth policy rule, thereby realizing deletion of the event subscription after updating.

With reference to the eighth aspect, any one of the first implementation manner of the eighth aspect to the sixth implementation manner of the eighth aspect, in a seventh implementation manner of the eighth aspect of the embodiment of the present application,

With reference to the eighth aspect, any one of the first implementation manner of the eighth aspect to the seventh implementation manner of the eighth aspect, in an eighth implementation manner of the eighth aspect of the embodiment of the present application, the first policy rule is first N4 information.

With reference to the eighth aspect, any one of the first implementation manner of the eighth aspect to the eighth implementation manner of the eighth aspect, in a ninth implementation manner of the eighth aspect of the embodiment of the present application, the third policy rule is a PCC rule.

With reference to the eighth aspect, any one of the first implementation manner of the eighth aspect to the ninth implementation manner of the eighth aspect, in a tenth implementation manner of the seventh aspect, specifically, before the second SMF sends the seventh message to the PCF according to the first request policy indication information, the second SMF receives an indication that data sent by the first SMF is buffered in the UPF or an indication that a policy rule is required.

With reference to the third implementation manner of the eighth aspect, in an eleventh implementation manner of the eighth aspect of the embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to the second implementation manner of the eighth aspect, in a twelfth implementation manner of the eighth aspect of the embodiment of the present application, notification control instruction information is included in the third policy rule.

With reference to the second implementation manner of the eighth aspect, in a thirteenth implementation manner of the first aspect of the embodiment of the present application, the notification control indication information is included in the first policy rule.

With reference to the third implementation manner of the eighth aspect, in a fourteenth implementation manner of the first aspect of the embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to the third implementation manner of the eighth aspect, in a fourteenth implementation manner of the first aspect of the embodiment of the present application, the third identifier is a NEF subscription association identifier.

A ninth aspect of an embodiment of the present application provides a session management network element, including:

the first receiving unit is configured to receive a first policy rule sent by the second SMF, where the first policy rule is generated according to first description information of data, where the data is data received by the UE, and in the embodiment of the present application, the first description information may also be referred to as first data description information;

a first determining unit, configured to determine a second policy rule according to the first policy rule;

and the first sending unit is used for sending the second policy rule to the user plane function network element UPF so that the UPF processes the data.

The session management network element is configured to perform the method of the seventh aspect described above.

A tenth aspect of an embodiment of the present application provides a session management network element, including:

the second sending unit is configured to send a seventh message to the PCF according to the first request policy indication information, where the seventh message includes first description information and a downlink data notification event subscription trigger, where the downlink data notification event subscription trigger is determined according to event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, that is, a type of the first event, and the first description information is used to identify data received by the UE;

A second receiving unit, configured to receive the third policy rule sent by the PCF;

the second determining unit is used for determining the first policy rule according to the third policy rule;

and the third sending unit is used for sending the first policy rule to the first SMF.

The session management network element is configured to perform the method of the foregoing eighth aspect.

An eleventh aspect of the embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor is used for executing the following steps:

receiving a first policy rule sent by a second SMF, the first policy rule being generated according to first description information of data, where the data is data received by a UE, and in the embodiment of the present application, the first description information may also be referred to as first data description information;

determining a second policy rule according to the first policy rule;

and sending a second policy rule to the user plane function network element UPF so that the UPF processes the data.

A twelfth aspect of an embodiment of the present application provides a session management network element, including:

A processor, a memory, an input-output device, and a bus;

the processor is used for executing the following steps:

a seventh message is sent to the PCF according to the first request policy indication information, wherein the seventh message comprises first description information and a downlink data notification event subscription trigger, the downlink data notification event subscription trigger is determined according to event subscription type indication information, the event subscription type indication information is used for indicating the type of event subscription, namely the type of a first event, the first description information is used for identifying data received by the UE, and in the embodiment of the application, the first description information can be also called as first data description information;

receiving the third policy rule sent by the PCF;

determining a first policy rule according to the third policy rule;

and sending a first policy rule to the first SMF.

A thirteenth aspect of the embodiments of the present application provides a computer-readable storage medium having a program stored therein, which when executed by a computer, performs the methods of the foregoing first, second, seventh and eighth aspects.

A fourteenth aspect of the embodiments of the present application provides a computer program product which, when executed on a computer, performs the methods of the first, second, seventh and eighth aspects described above.

Drawings

FIG. 1 is a schematic diagram of a network framework with open business capabilities;

FIG. 2 is a flowchart of a method for providing policy rules according to an embodiment of the present application;

FIG. 3 is a flowchart of a method for providing policy rules according to an embodiment of the present application;

FIG. 4a is a schematic diagram of another flow chart of a method for providing policy rules according to an embodiment of the present application;

FIG. 4b is a flowchart illustrating another method for providing policy rules according to an embodiment of the present application;

FIG. 5a is a schematic diagram of another flow chart of a method for providing policy rules according to an embodiment of the present application;

FIG. 5b is a flowchart illustrating another method for providing policy rules according to an embodiment of the present application;

FIG. 6 is a flowchart illustrating another method for providing policy rules according to an embodiment of the present application;

FIG. 7 is a flowchart of another method for providing policy rules according to an embodiment of the present application;

FIG. 8a is a schematic diagram of another flow chart of a method for providing policy rules according to an embodiment of the application;

FIG. 8b is a flowchart illustrating another method for providing policy rules according to an embodiment of the present application;

FIG. 9a is a schematic diagram of another flow chart of a method for providing policy rules according to an embodiment of the application;

FIG. 9b is a flowchart illustrating another method for providing policy rules according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a session management network element according to an embodiment of the present application;

fig. 11 is a schematic diagram of another structure of a session management network element according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a session management network element according to an embodiment of the present application;

fig. 13 is another schematic structural diagram of a session management network element according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of a session management network element according to an embodiment of the present application.

Detailed Description

Referring to fig. 1, fig. 1 is a block diagram of service capability opening (SCEF, service capability exposure function) (NEF, network exposure function) supporting 4G/5G and next generation mobile communication network interworking. Based on this architecture, the 3GPP network is able to securely provide service capabilities to the application functions (AF, application function) of the third party application service provider (3drd party ASP,3drd party application service provider). The network opening function (NEF, network exposure function) is a core network element in the architecture enabling the 3GPP network to securely provide service capabilities to a third party service provider service capability server (SCS, services capability server) or application server (AS, application server). The unified data management function (UDM, unified data management) is a unified data management network element, which stores subscription information of the user. The core network access and mobility management function (AMF, core access and mobility management function) is a network element responsible for mobility management of UEs in 5G and next generation mobile communication networks. The session management function (SMF, session management function) is a network element responsible for managing PDU sessions of User Equipments (UEs) in 5G and next generation mobile communication networks. The AF invokes the service capabilities provided by the NEF through the API interface of the Nnef service.

In one example, when an application subscribes to an event that requires detection of data transmission at the UPF, a corresponding policy to be executed at the UPF needs to be generated according to PCC rules. The policy may be a packet detection rule (PDR, packet detection rule), or other rules related to packet transmission, such as forwarding action rule (FAR, forwarding action rule), usage reporting rule (URR, usage reporting rule), etc., which are not limited herein.

In the embodiment of the present application, all messages including subscription request messages, update context request messages, update request messages, acknowledgement messages, and the like are examples of sending messages, and are not limited to the messages, and as long as they carry the data described in the embodiment of the present application, they are considered as messages described in the embodiment of the present application, and are not limited in this specific application.

The embodiment of the application provides a method for acquiring PCC rules through a second SMF capable of directly interacting with PCF, so as to formulate policy rules for UPF detection data packets according to the PCC rules.

In the embodiment of the present application, the V-SMF may also be referred to as a first SMF, where the first SMF cannot interact with the PCF, and other first SMFs, such as I-SMF, that cannot interact with the PCF may be used in the embodiment of the present application, and in particular, the embodiment of the present application uses the V-SMF as an example and does not limit the first SMF.

In the embodiment of the application, the first and second are only used for distinguishing similar subjects, such as a first SMF which is used for distinguishing UPF interaction but can not be directly interacted with PCF and a second SMF which can be directly interacted with PCF; or for distinguishing between the first data description information provided at the time of event subscription and the second data description information provided at the time of event update, the first and second do not pose a limitation on the similar body.

In embodiments of the present application, the triplet information may also be referred to as data descriptive information (traffic descriptors). The data description information may also be referred to as description information, and is used to identify downlink data of an application. In addition to the triplet information, the data description information may also be other information, such as a MAC address or VLAN ID that identifies the application server, and the like, which is not limited herein. The embodiment of the application takes the triplet information as an example and does not limit the description information of the data.

Specifically, the triplet information is IP triplet information for identifying an address, a port number, and a protocol type of the application server.

Specifically, in the embodiment of event subscription, for example, in the embodiment shown in fig. 2, 3, 6 or 7, the triplet information is first data description information; in the event update embodiment, such as the embodiment shown in fig. 4a, 4b, 8a or 8b, the triplet information is the second data descriptive information.

The application may subscribe to the network for different events, such as a reachable event after a failure of the downstream data transfer, or may be other events, such as a downstream data transfer status event, as is not limited herein. The process of providing policy rules for different events will be exemplified below.

1. Obtaining a policy rule of an reachable event after the failure of the downlink data notification:

1. reachable events after failure to subscribe to downstream data notification:

in the embodiment of the present application, the post-failure reachable event (availability after downlink data notification failure event) of the downlink data notification may also be referred to as a post-failure reachable event of the downlink data transmission or a post-failure reachable event of the downlink data transmission.

In the embodiment of the present application, the first SMF may request the PCC rule from the PCF, or the second SMF may request the PCC rule from the PCF, and these two cases will be respectively described below:

1.1, the first SMF requests PCC rules from the PCF:

referring to fig. 2, when the UE is in a roaming state, i.e., the V-SMF cannot interact directly with the PCF, the AF subscribes to a reachable event after the downlink data delivery fails, and the first SMF requests the PCC rule from the PCF. For the scenario where there is an I-SMF for the PDU session, the V-SMF may be replaced with an I-SMF, which is not limited herein. One flow of providing policy rules in the embodiment of the application includes:

201. The UE accesses the network and establishes a PDU session:

the UE accesses the network and establishes a PDU session that establishes a UE-to-UPF data path. The UE may interact with the application server through this data channel.

Optionally, during PDU session establishment or modification, the PCF may send a policy control request trigger (PCRT, policy control request trigger) to the second SMF, which notifies the failure event subscription for downstream data carrying the data description (downlink data notification failure event subscribed with traffic descriptor). The PCRF is configured to instruct the second SMF to request PCC rules from the PCF when receiving a downlink data notification failure event subscription carrying a data description. In the embodiment of the present application, the PCRT is also referred to as a downlink data notification event subscription trigger.

Optionally, during PDU session establishment or modification, the PCF may send an indication to the second SMF reporting receipt of the downlink data notification event subscription. In the embodiment of the present application, the indication information is also referred to as first request policy indication information.

Further, the second SMF may send, to the V-SMF, indication information for determining that policy charging control is applied to the UE, indication information for reporting that the downlink data notification failure event is received, or indication information for reporting that the data description information is received, according to the PCRT for carrying the downlink data notification failure event subscription described by the data.

In the embodiment of the present application, the indication information may also be referred to as request policy indication information or second request policy indication information, which is used to instruct the first SMF to obtain a policy rule corresponding to a subscription event.

In the embodiment of the present application, the downlink data notification failure event (downlink data notification failure event) may also be referred to as a downlink data transmission failure event or a downlink data transmission failure event, and in the embodiment of the present application, the event is also referred to as a first event.

202. AF sends subscription request message to NEF:

AF sends a Nnef_EventExposure_ Subscribe Request message to NEF, subscribing to the event reachable after failure of downstream data transfer (availability after downlink data notification failure).

The message carries an event identification (event id), an AF notification endpoint (AF notification endpoint), an external identification of the user or an external user group identification, and triple information.

In the embodiment of the application, the data description information provided during event subscription is called first data description information, and the data description information provided during event update is called second data description information. In this embodiment or the embodiment shown in fig. 3, the data description information is first data description information.

Event identification (event id) represents a subscribed event, in this embodiment, an identification of an reachable event after failure of downstream data notification.

The AF notification endpoint is for indicating an endpoint of the AF reception event notification, and the AF notification endpoint may include an AF notification target address (AF notification target address). When the AF assigns the same AF notification target address to a plurality of subscription notifications, the different subscriptions can be distinguished by an AF notification association identification, at which point the AF notification endpoint includes the AF notification target address (AF notification target address) and the AF notification association identification (AF notification correlation Id).

203. The NEF sends a subscription request message to the UDM:

the NEF sends a Nudm_EventExposure_ Subscribe Request message to the UDM, and subscribes to reachable events after the downlink data notification fails.

The message carries the event identification, the triplet information and the external identification of the user or the external user group identification received in step 202, and a NEF notification endpoint (NEF notification endpoint) for receiving the subscription notification.

The NEF notification endpoint is configured to instruct the NEF to receive an endpoint of the subscription notification, and is configured to identify to which NEF network element the detected downstream data notification fails and to which the reachable event is fed back, and may include a NEF notification destination address (NEF notification target address) and a NEF notification association identifier (NEF notification correlation Id). When the NEF assigns the same NEF notification target address to multiple subscription notifications, different events may be distinguished by the NEF notification association identification.

204. The UDM sends a subscription request message to the AMF registered by the UE:

the UDM receives the external user identity in step 203 and can determine the internal user identity from the external identity.

In the embodiment of the present application, when the event subscription is specific to a plurality of users, the external identifier of the user in steps 202 and 203 may also be an external user group identifier, where the external user group identifier represents each of the users, and the internal identifier of each of the users may be determined according to the external user group identifier, which is not limited herein.

The UDM may determine the AMF registered by the UE according to the local correspondence stored in the UDM and the internal identifier of the user, and send a namf_eventExposure_ Subscribe Request message to the AMF registered by the UE, to subscribe to the reachable event after the failure of the downlink data notification.

The message carries the event identifier, the triplet information, the NEF notification endpoint, and the user internal identifier received in step 203.

If a user group identity is received in step 203, the UDM may send the above message to the AMF registered by the UE for each UE in the user group.

205. The AMF returns an acknowledgement message to the UDM:

the AMF assigns an AMF subscription association identifier (AMF subscription correlation id) according to the event identifier received in step 204, where the AMF subscription association identifier is used to identify a subscription for an reachable event after failure of the downstream data notification, indicating that the event has been subscribed successfully at the AMF.

The AMF stores the received information and returns a confirmation message to the UDM, wherein the message carries the AMF subscription association identification.

206. The UDM returns an acknowledgement message to the NEF:

the UDM assigns a UDM subscription association identifier (UDM subscription correlation id) to the event subscription, the UDM subscription association identifier being used to identify an event reachable after failure of the downstream data notification, indicating that the event has been subscribed successfully at the UDM.

The UDM returns a confirmation message to the NEF, wherein the confirmation message carries the UDM subscription association identification.

207. The NEF returns an acknowledgement message to the AF:

the NEF assigns a NEF subscription association identifier (NEF subscription correlation id) to the event subscription, the NEF subscription association identifier being used to identify reachable events after failure of the downstream data notification, indicating that the event subscription has been successful at the NEF.

The NEF stores the received information and returns a confirmation message to the AF, wherein the confirmation message carries the NEF subscription association identification.

In an embodiment of the present application, step 206 may be performed before step 205 or 204, as long as it is performed after step 203; step 207 may be performed before any of steps 203 to 206, so long as it is performed after step 202, and is not specifically limited herein.

Steps 208 to 214 have two implementations, specifically as follows:

A: the message carries notification control indication information and is used for generating a corresponding policy rule, and the specific implementation mode is as follows:

208. the AMF sends a first message to the V-SMF:

the AMF may generate notification indication information of the failure to notify the downlink data notification (downlink data notification failure) according to the subscription of the event in step 204, where the indication information is used to indicate the type of the event subscription, specifically may be an event identifier of the failure event to notify the downlink data notification, or other identifiers allocated by the AMF, and is not limited herein.

AMF sends Nsmf_PDUSion_ UpdateSMContext Request message to V-SMF, subscribes to failure event of notifying downlink data. In this embodiment, the message may also be referred to as a first message. In the embodiment of the present application, the first message is used to request the V-SMF to create the subscription of the event, for example, in the embodiment, the first message is used to request the subscription of the event of failure to create the downlink data notification; in other embodiments, it may also be used to request the creation of subscriptions to other events; the first message may also be other forms of messages, and the examples herein are not meant to limit the first message.

The message carries the NEF notification association identifier, the triplet information and the downlink data notification failure notification indication information received in step 204.

209. The V-SMF returns an acknowledgement message to the AMF.

210. The V-SMF determines that a policy rule for processing data needs to be requested and sends a second message to the second SMF:

in step 201, when the V-SMF receives indication information that policy charging control is applied to the UE, reports indication information that a downlink data notification failure event subscription is received, or reports indication information that data description information is received, the V-SMF may determine that PCC is applied to the PDU session, and when the V-SMF determines that data needs to be buffered in the UPF, it may also determine that the received event subscription needs to be reported to the second SMF and a policy for processing the data in the UPF is requested.

The V-SMF may assign a Transaction identifier (Transaction Id) to the event, the Transaction identifier being used to represent a Transaction between the V-SMF and the second SMF for subsequent modification and deletion operations, the Transaction identifier also being used to identify a policy rule request subscribed to for the first event. In the embodiment of the application, the transaction identifier may also be referred to as first identification information. In an embodiment of the application, the transaction identification corresponds to a subscription for the first event. In this embodiment, the transaction identifier corresponds to a subscription to a downstream data notification failure event.

The V-SMF may further allocate ddn_failure indication information according to the subscription of the event in step 208, where the ddn_failure indication information is used to indicate that the received event subscription type is a downlink data notification failed subscription.

The ddn_failure indication information is also referred to as event subscription type indication information in the present embodiment. In the embodiment of the present application, the event subscription type indication information is used to indicate the type of event subscription, and is generated according to the event subscription, and in the subscription of other events, the event subscription type indication information may be used to indicate the event subscription of other events, for example, the event subscription of the downlink data transfer state event, which is not limited herein.

Specifically, the event subscription type indication information may be generated according to the indication information indicating the event subscription type in step 208, or may be the indication information indicating the event subscription type in step 208, which is not limited herein.

Specifically, the V-SMF sends an nsmf_pduse_update Request message to the second SMF, reporting the received event subscription, requesting a policy for detecting data. The message carries triplet information, the Transaction identifier (Transaction Id) and the ddn_failure indication information. In this embodiment, the message may also be referred to as a second message. In the embodiment of the application, the second message is used for requesting the second SMF for the policy rule corresponding to the subscription event and used for processing the data.

In the embodiment of the present application, step 210 may also be performed before step 209, so long as it is performed after step 208, which is not limited herein.

211. The second SMF sends a seventh message to the PCF:

the second message received by the second SMF in step 210 includes both the triplet information and the transaction identification.

Upon receiving the transaction identifier, the second SMF needs to request the PCF for a PCC rule for detecting a downlink data delivery failure event, and since the PCF has provided a PCRT carrying a downlink data notification failure event subscription of a data description before, the second SMF may send an npcf_smpolicy control_update request message to the PCF. In this embodiment, this message may also be referred to as a seventh message. In the embodiment of the application, the seventh message is used for requesting PCC rules from the PCF.

The second SMF determines, according to the ddn_failure indication information in the second message, that the message is used to request a PCC rule for detecting a downlink data transmission Failure event, and the second SMF may find the PCRT corresponding to the event received in step 201.

The message carries the triplet information received in step 210 and the PCRT described above.

Optionally, an operation indication Create may also be carried in the message, indicating that the message is used to request a new PCC rule.

212. The PCF formulates PCC rules and sends third policy rules to the second SMF:

the PCF formulates a PCC rule (PCC rule) according to the triplet information received in step 211, i.e. includes the triplet information in a filter template in the PCC rule, and sets a high priority, where the PCC rule includes a PCC rule identifier (PCC rule Id), and the PCC rule identifier is used to represent the PCC rule, and when the PCC rule is updated or deleted later, the corresponding PCC rule may be determined according to the PCC rule identifier, so as to make a change to the PCC rule. In the embodiment of the present application, the PCC rule identifier may also be referred to as second identification information.

The PCF may also determine DDN Failure notification control indication information indicating that DNN Failure notification needs to be performed according to the PCRT received in step 211. The DDN Failure notification control indication information may be included in a PCC rule for indicating that the PCC rule is used to detect a downlink data notification Failure event.

The ddn_failure notification control instruction information is also referred to as notification control instruction information in the present embodiment. In the embodiment of the application, the notification control instruction information is used for indicating the action corresponding to the event subscription and is generated according to the event subscription type instruction information.

The PCF returns an acknowledgement message to the second SMF, wherein the PCC rule is carried in the message. In the embodiment of the present application, the PCC rule generated in the event subscription process may also be referred to as a third policy rule.

Alternatively, the DDN Failure notification control indication information may not be included in the PCC rule, but may be carried in the acknowledgement message, which is not limited herein.

213. The second SMF receives the third policy rule, generates first N4 information (N4 information), and transmits the first policy rule to the V-SMF:

when the second SMF receives the PCC rule (third policy rule) of step 212, since the second message in step 210 includes both the triplet information and the transaction identifier, and the PCC rule is generated according to the triplet information, the second SMF may determine and store the correspondence between the transaction identifier and the PCC rule identifier according to the same. When the subsequent updating or deleting of the failed subscription of the downlink data notification is performed, the PCC rule identifier corresponding to the event can be searched according to the corresponding relation, so that a corresponding instruction is sent to the PCF, and the PCF updates or deletes the PCC rule corresponding to the PCC rule identifier.

The second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgement message in step 212 includes DDN Failure notification control indication information, so that the first N4 information may also include DDN Failure notification control indication information, where the first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. In the embodiment of the present application, the first N4 information generated in the event subscription process may also be referred to as a first policy rule.

Alternatively, the DDN Failure notification control indication information may not be included in the first N4 information, but may be carried in the acknowledgement message, which is not limited herein.

214. V-SMF sends second N4 information (second policy rule) to UPF:

since the first N4 information or the acknowledgement message in step 213 includes DDN Failure notification control indication information, the V-SMF may determine that the first N4 information is used to detect a downlink data notification Failure event;

the V-SMF determines second N4 information from the first N4 information. The method comprises the following steps:

when the V-SMF receives a UE-unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR and includes the same filter templates and priority information as the first PDR. The V-SMF may determine an associated FAR from the DDN Failure notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard and report packets that match the second PDR.

When the V-SMF receives a notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR according to the first PDR, where the second PDR is generated according to the first PDR and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the DDN Failure notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard buffered data matching the second PDR, and the URR is used to instruct the UPF to report when buffered data packets matching the second PDR are discarded.

Specifically, the process of generating the second PDR may directly use the first PDR as the second PDR, or may generate the second PDR by other manners, for example, format conversion of the first PDR, which is not limited herein.

The V-SMF sends second N4 information (N4 information) to the UPF, the second N4 information including the second PDR, FAR, and URR described above. In the embodiment of the present application, the second N4 information generated in the event subscription process may also be referred to as a second policy rule.

B: the message does not carry notification control indication information, and a corresponding policy rule is generated according to the subscription of the event, and the specific implementation mode is as follows:

208. the AMF sends a first message to the V-SMF:

AMF sends Nsmf_PDUSion_ UpdateSMContext Request message to V-SMF, subscribes to failure event of notifying downlink data. In this embodiment, the message may also be referred to as a first message.

The message carries the NEF notification association identification and the triplet information received in step 204.

209. The V-SMF returns an acknowledgement message to the AMF.

Specifically, the V-SMF sends an nsmf_pduse_update Request message to the second SMF, reporting the received event subscription, requesting a policy for detecting data. The message carries the triplet information and the Transaction identifier (Transaction Id). In this embodiment, the message may also be referred to as a second message.

211. The second SMF sends a seventh message to the PCF:

The second SMF determines first N4 information carrying the first PDR according to the PCC rule. The first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information and the transaction identifier. In the embodiment of the present application, the first N4 information generated in the event subscription process may also be referred to as a first policy rule.

214. V-SMF sends second N4 information (second policy rule) to UPF:

since the V-SMF assigns a transaction identifier to the downlink data notification failure event in step 210, the V-SMF may associate the first N4 information in the message with the downlink data notification failure event subscription according to the transaction identifier in the message in step 213, and determine that the first N4 information is used to detect the downlink data notification failure event.

The V-SMF determines second N4 information according to the first N4 information and the downlink data notification failure event subscription. The method comprises the following steps:

when the V-SMF receives a UE-unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR and includes the same filter templates and priority information as the first PDR. The V-SMF may determine the associated FAR from the downstream data notification failure event subscription and the second PDR.

When the V-SMF receives a notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR according to the first PDR, where the second PDR is generated according to the first PDR and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the downstream data notification failure event subscription and the second PDR. The FAR is used to instruct the UPF to discard buffered data matching the second PDR, and the URR is used to instruct the UPF to report when buffered data packets matching the second PDR are discarded.

215. The UPF informs the V-SMF that the matched packet is discarded:

under the condition that the UE is not reachable, the UPF matches the data packet according to the second PDR, discards the data packet matched with the second PDR according to the FAR, and then notifies the V-SMF that the matched data packet is discarded; or,

and under the condition that the UE is in an idle state, the UPF matches the data packet according to the second PDR, and caches the data packet matched with the second PDR according to the FAR. When the number of buffered packets exceeds a certain threshold, the UPF discards the data. At this point the V-SMF matched packets are notified to be dropped according to URR.

In an embodiment of the present application, the event of discarding the data in step 215 may also be referred to as a second event, and the first SMF may determine the first event according to the second event. For example, in this embodiment, the downlink data transmission failure event may be determined according to the event of discarding data.

216. The V-SMF informs the AMF of the downlink data transfer failure:

after receiving the discarded message of the data packet fed back by the UPF, the V-SMF can send an Nsmf_PDUSion_SMContextStatusNotify message to the AMF to inform the AMF of the downlink data transmission failure.

The message includes the NEF notification association identification that the SMF received in step 208.

In the embodiment of the present application, the AMF may also be referred to as an event receiving network element, where the event receiving network element is configured to receive a report related to the first event, in this embodiment, a report of a downlink data transmission failure event.

217. AMF judges that the UE is reachable:

if the AMF receives the downlink data notification failure message of the V-SMF, the UE is still unreachable, and the AMF sets a notification-after-failure (notification-on-available-after-DDN-failure) flag bit.

When the AMF detects that the UE is reachable, the AMF may determine that a downlink data delivery failure reachability-DDN-failure (dl-reachable) event report needs to be sent according to the downlink data delivery failure reachability notification flag.

218. The AMF informs the NEF that the UE is reachable:

the AMF sends a reachable event report after the downlink data transfer failure to the NEF. Specifically, the AMF may send a namf_eventExposure_notify Request message to the NEF, where the message carries the event identifier received in step 204 and the NEF notification endpoint.

219. The NEF informs the AF that the UE is reachable:

the NEF sends an nnef_eventExposure_notify Request message to the AF, which carries the event identification received in step 203 and the AF notification endpoint.

In an embodiment of the present application, the first SMF (which may be V-SMF or I-SMF) requests a policy for detecting a downlink data state from the SMF, and the SMF further requests a PCC rule from the PCF. Thereby enabling detection of the data packet of the subscription event by the first SMF.

In the embodiment of the application, the second SMF may also initiate a request PCC rule, and then send N4 information to the first SMF (which may be V-SMF or I-SMF). The flow of requesting PCC rules from the PCF by the second SMF and providing N4 information will be described as follows:

1.2, the second SMF requests PCC rules from the PCF:

referring to fig. 3, when the UE is in a roaming state, the AF subscribes to a reachable event after downlink data delivery failure, and the second SMF requests the PCC rule from the PCF. For the scene that the PDU session exists I-SMF, the V-SMF is replaced by the I-SMF. One flow of providing policy rules in the embodiment of the application includes:

301-307：

steps 301 to 307 are similar to steps 201 to 207 of the embodiment shown in fig. 2 and will not be described again.

308. The AMF sends an update context request message to the V-SMF:

the AMF may generate notification indication information of a downlink data notification failure (downlink data notification failure) according to the subscription of the event in step 304, where the indication information is used to indicate that the event is reported when the downlink data notification failure event occurs.

AMF sends Nsmf_PDUSion_ UpdateSMContext Request message to V-SMF, subscribes to failure event of notifying downlink data.

The message carries the NEF notification association identifier, the triplet information and the notification indication information of the failure (downlink data notification failure) of the downlink data notification received in step 304. In the present embodiment, the downlink data notification failure notification indication information may also be referred to as event subscription type indication information.

309. The V-SMF sends an update request message to the second SMF:

when the V-SMF determines that data needs to be buffered in the UPF, the V-SMF may determine that PCC rules need to be requested from the PCF, at which point the V-SMF may generate an indication of the UPF to buffer the data or an indication of the requesting PCC.

V-SMF sends Nsmf_PDUSion_Update Request message to SMF, and subscribes to failure event of notifying downlink data.

The message carries the NEF notification association identifier, the triplet information and the notification indication information of failure (downlink data notification failure) of downlink data notification received in step 308, and the indication of the UPF buffered data or the indication of the request PCC.

310. The second SMF returns an acknowledgement message to the V-SMF:

311. the V-SMF returns an acknowledgement message to the AMF:

there are two implementations of steps 312 to 315, specifically as follows:

312. the second SMF determines that a policy rule for processing data needs to be requested and sends an update request message to the PCF:

the second SMF may determine that a PCC rule needs to be requested from the PCF due to receiving an indication of UPF buffered data or an indication of requesting PCC in step 309. And the PCF provided a PCRT carrying a downstream data notification failure event subscription of the data description, the second SMF may send an npcf_smpolicy control_update request to the PCF requesting policy rules for processing the data. The message carries the triplet information received in step 309 and the PCRT to which the downlink data notification failure event is subscribed, which carries the description of the data.

In the embodiment of the present application, the PCRT may also be referred to as event subscription type indication information, where the event subscription type indication information is used to indicate the type of event subscription.

In the embodiment of the present application, step 312 may also be performed before step 310 or step 311, so long as it is performed after step 309, which is not limited herein.

313. The PCF formulates PCC rules and sends third policy rules to the second SMF:

the a implementation of step 313 is similar to the a implementation of step 212 of the example implemented in fig. 2, and will not be described here again.

314. The second SMF receives the third policy rule, generates first N4 information (N4 information), and transmits the first policy rule to the V-SMF:

the second SMF receives the PCC rule (third policy rule) in step 313, and since the PCC rule is generated according to the triplet information in the message in step 312, and the triplet information is obtained together with the NEF notification association identifier when the update context request message is received in step 309, the second SMF may determine and store the correspondence between the NEF notification association identifier and the PCC rule identifier according to the same. When the subsequent updating or deleting of the failed subscription of the downlink data notification is performed, the PCC rule identifier corresponding to the event can be searched according to the corresponding relation, so that a corresponding instruction is sent to the PCF, and the PCF updates or deletes the PCC rule corresponding to the PCC rule identifier.

The second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgement message in step 313 includes DDN Failure notification control indication information, so that the first N4 information may also include DDN Failure notification control indication information, where the first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

315. V-SMF sends second N4 information (second policy rule) to UPF:

the a implementation of step 315 is similar to the a implementation of step 214 of the example implemented in fig. 2, and will not be described again here.

Since the PCF provided the PCRT carrying the data description of the downstream data notification failure event subscription before, the second SMF may send an npcf_smplicycontrol_update request to the PCF requesting policy rules for processing the data. The message carries the triplet information received in step 309 and the PCRT to which the downlink data notification failure event is subscribed, which carries the description of the data.

the B implementation of step 313 is similar to the B implementation of step 212 of the example implemented in fig. 2 and will not be described here again.

315. V-SMF sends second N4 information (second policy rule) to UPF:

the B implementation of step 315 is similar to the B implementation of step 214 of the example implemented in fig. 2 and will not be described again here.

316-320：

Steps 316 to 320 are similar to steps 215 to 219 of the embodiment shown in fig. 2 and are not described in detail herein.

In addition to subscribing to the event, the embodiment of the application also provides updating and deleting the event after successful subscription, and the updating and deleting process is described as follows:

2. event reachable after failure to update downlink data notification:

in the embodiment of the application, the data description information provided during event updating is called second data description information. In this embodiment or the embodiment shown in fig. 4b, the data description information is second data description information. The present embodiment and the embodiment shown in fig. 4b take as an example triplet information which does not constitute a limitation on the second data descriptive information.

Referring to fig. 4a, based on the subscription of the reachable event after the failure of the downlink data notification in fig. 2, in this embodiment, a process of acquiring a corresponding policy rule when updating the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein specifically, the process includes:

401a, UE accesses the network, establishes PDU conversation:

at this point the AF has completed subscription to the reachable events after failure of the downstream data notification according to the embodiment shown in fig. 2.

402a, AF sends a subscription request message to NEF:

the AF sends an nnef_eventExposure_ Subscribe Request message to the NEF requesting up to date (availability of downlink data notification failure) event subscription after failure to update the downstream data notification.

The message carries the NEF subscription association identifier and updated triplet information, and in this embodiment, the triplet information is used to replace the first data description information in the original subscription, so as to generate a policy rule corresponding to the triplet information. In this embodiment or the example implemented in fig. 4b, the triplet information is also referred to as second data description information or second description information. The NEF subscription association identifier is generated by NEF during the event subscription.

403a, NEF sends a subscription request message to the UDM:

the NEF sends a Nudm_EventExposure_ Subscribe Request message to the UDM requesting to update the reachable event subscription after the downlink data notification fails.

The message carries the UDM subscription association identity and the triplet information received in step 402 a. The UDM subscription association identity is generated by the UDM during the event subscription.

404a, UDM sends a subscription request message to the AMF registered by the UE:

the UDM sends a namf_eventExposure_ Subscribe Request message to the AMF registered by the UE requesting to update the reachable event subscription after the downlink data notification fails.

The message carries AMF subscription association identification and the triplet information. The AMF subscription association identification is generated by the AMF during the event subscription.

405a, AMF returns an acknowledgement message to UDM:

the AMF updates the subscription information for the event based on the AMF subscription association identification and the triplet information received in step 404a and returns a confirmation message to the UDM.

406a, UDM returns an acknowledgement message to NEF:

after receiving the confirmation message sent by the AMF, the UDM may update the subscription information of the event according to the UDM subscription association identifier and the triplet information received in step 403a, and return the confirmation message to the NEF.

407a, NEF returns an acknowledgement message to AF:

after receiving the acknowledgement message sent by the UDM, the NEF may update the subscription information of the event according to the NEF subscription association identifier and the triplet information received in step 402a, and return an acknowledgement message to the AF.

In the embodiment of the present application, step 406a may also be performed before step 404a or step 405a, so long as it is performed after step 403 a; step 407a may also be performed before any of steps 403a to 406a, so long as it is performed after step 402a, and is not limited herein.

408a, AMF sends a third message to V-SMF:

AMF sends Nsmf_PDUSion_ UpdateSMContext Request message to V-SMF to request to update event subscription failed in downstream data notification. In this embodiment, this message may also be referred to as a third message. In the embodiment of the application, the third message is used for requesting the subscription of the update event from the V-SMF.

The message carries the NEF notification association identifier and the triplet information. The NEF notification association identification is received during an event subscription.

409a, V-SMF returns an acknowledgement message to the AMF.

The V-SMF updates the subscription information of the event according to the NEF notification association identifier and the triplet information, and returns a confirmation message to the AMF.

There are two implementations of steps 410a to 414a, specifically as follows:

410a, V-SMF sends a fourth message to the second SMF:

the V-SMF in step 408a receives the third message, and may determine, according to the NEF notification association identifier, a downlink data notification failure event, and determine, according to the message, that the subscription of the event needs to be updated. In the embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, which is used to identify the subscription of the first event.

The V-SMF sends an nsmf_pduse_update Request message to the second SMF, the message requesting updating of the first N4 information. In this embodiment, this message may also be referred to as a fourth message. In the embodiment of the application, the fourth message is used for requesting the second SMF to update the policy rule for processing data corresponding to the subscription event.

The message carries triplet information, transaction identification and DDN_failure indication information. Ddn_failure indication information, also referred to as event subscription type indication information, is generated during event subscription and is used to indicate the type of event subscription.

In an embodiment of the present application, step 410a may also be performed before step 409a, so long as it is performed after step 408a, which is not limited herein.

411a, the second SMF sends an eighth message to the PCF:

in the event subscription process, the second SMF saves the corresponding relation between the transaction identifier and the PCC rule identifier, and at the moment, the second SMF can determine the corresponding PCC rule identifier according to the transaction identifier.

The second SMF sends an npcf_smpolicy control_update request message to the PCF, where the message is used to request updating the PCC rule corresponding to the PCC rule identifier. In this embodiment, this message may also be referred to as an eighth message. In the embodiment of the application, the eighth message is used for requesting updating of the PCC rule from the PCF.

The message carries the triplet information, the PCC rule identification and the PCRT received in the event subscription process.

Optionally, an operation indication modification may also be carried in the message, which indicates that the message is used to request an updated PCC rule.

412a, the PCF updates the PCC rules based on the triplet information and sends a fifth policy rule to the second SMF:

the PCF updates the PCC rules based on the triplet information, i.e., includes the triplet information in a filter template in the PCC rules. Optionally, the PCC rule may include DDN Failure notification control indication information. The DDN Failure notification control indication information is generated in the event subscription process, and the PCF can determine the indication information through the corresponding relation between the indication information and the PCC rule mark; the DDN Failure notification control instruction information may be generated by the PCF based on the ddn_failure instruction information, and is not limited specifically herein.

The PCF returns a confirmation message to the second SMF, wherein the message carries the updated PCC rule. In the embodiment of the present application, the PCC rule generated in the event subscription process may also be referred to as a third policy rule.

Optionally, the DDN Failure notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

413a, the second SMF updates the first N4 information (N4 information) and sends a fourth policy rule to the V-SMF:

the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first N4 information further includes DDN Failure notification control indication information, and the first PDR is determined according to the PCC rule, where the first PDR carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. Optionally, the DDN Failure notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

414a, V-SMF sends a second N4 information to UPF:

since the DDN Failure notification control indication information is included in the first N4 information or the acknowledgement message in step 413a, the V-SMF determines that the first N4 information is used to detect the downlink data Failure notification event. The V-SMF determines second N4 information from the first N4 information.

410a, V-SMF determines that an update of policy rules for processing data needs to be requested and sends a fourth message to the second SMF:

the V-SMF receives the third message in step 408a, and may determine, according to the NEF notification association identifier in the third message, a downlink data notification failure event, and determine, according to the message, that the subscription of the event needs to be updated. In the embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, which is used to identify the subscription of the first event.

The V-SMF sends an nsmf_pduse_update Request message to the second SMF, the message requesting updating of the first N4 information. In this embodiment, this message may also be referred to as a fourth message. The message carries triplet information and transaction identification. The transaction identifier is generated during event subscription, and is used to represent an event between the first SMF and the second SMF, specifically corresponds to subscription of a downlink data notification failure event in this embodiment.

411a, the second SMF sends an eighth message to the PCF:

The second SMF sends an npcf_smpolicy control_update request message to the PCF, where the message is used to request updating the PCC rule corresponding to the PCC rule identifier. In this embodiment, this message may also be referred to as an eighth message.

The message carries the triplet information and the PCC rule identification. Alternatively, the message may carry a PCRT.

the PCF updates the PCC rules based on the triplet information, i.e., includes the triplet information in a filter template in the PCC rules.

The PCF returns a confirmation message to the second SMF, wherein the message carries the updated PCC rule. In the embodiment of the present application, the PCC rule generated in the event update process may also be referred to as a fifth policy rule.

the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

In step 412a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores a correspondence between the PCC rule identifier and the transaction identifier during subscription, the second SMF may determine, according to the PCC rule identifier, the transaction identifier corresponding to the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information and the transaction identifier. In the embodiment of the present application, the first N4 information generated in the event updating process may also be referred to as a fourth policy rule.

414a, V-SMF sends a second N4 information to UPF:

the V-SMF may associate the first N4 information with the downlink data notification failure event subscription according to the transaction identifier received in step 413a, and determine that the first N4 information is used to detect the downlink data notification failure event. The V-SMF determines second N4 information according to the first N4 information and the downlink data failure notification event subscription.

415a-149a：

Steps 415a to 419a are similar to steps 215 to 219 of the example embodiment of fig. 2 and are not repeated here.

Referring to fig. 4b, based on the subscription of the reachable event after the failure of the downlink data notification in fig. 3, in this embodiment, a process of acquiring a corresponding policy rule when updating the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein specifically, the process includes:

401b, the UE accesses the network to establish PDU session:

at this point the AF has completed subscription to the reachable events after failure of the downstream data notification according to the embodiment shown in fig. 3.

402b-407b:

Steps 402b to 407b are similar to steps 402a to 407a of the example of fig. 4a, and are not repeated here.

In the embodiment of the present application, step 406b may also be performed before step 404b or step 405b, so long as it is performed after step 403 b; step 407b may also be performed before any of steps 403b to 406b, so long as it is performed after step 402b, and is not limited herein.

408b, the AMF sends an update context request message to the V-SMF:

AMF sends Nsmf_PDUSion_ UpdateSMContext Request message to V-SMF to request to update event subscription failed in downstream data notification.

The message carries the NEF notification association identifier and the triplet information. The NEF notification association identification is received during the event subscription.

409b, V-SMF sends an update request message to the second SMF:

the V-SMF sends an nsmf_pduse_update Request message to the second SMF requesting to Update the event subscription for which the downlink data notification failed.

The message carries the NEF notification association identifier and the triplet information.

410b, the second SMF returns an acknowledgement message to the V-SMF.

411b, V-SMF returns an acknowledgement message to AMF.

Steps 412b to 415b have two implementations, specifically as follows:

412b, the second SMF determines that an update of the policy rules for processing the data needs to be requested and sends updated triplet information to the PCF:

in step 409b, the second SMF receives the update request message, and may determine, according to the NEF notification association identifier in the message, a downlink data notification failure event, and determine, according to the message, that the subscription of the event needs to be updated. In the embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, which is used to identify the subscription of the first event.

In the event subscription process, the second SMF stores the correspondence between the NEF notification association identifier and the PCC rule identifier, where the NEF notification association identifier corresponds to the subscription of the event, and at this time, the second SMF may determine the PCC rule identifier corresponding to the event subscription.

The second SMF sends an npcf_smpolicy control_update request message to the PCF, where the message is used to request updating the PCC rule corresponding to the PCC rule identifier.

The message carries the triplet information and the PCC rule identification. And DDN Failure indication information. The DDN Failure indication information, also referred to as event subscription type indication information, is generated during an event subscription for indicating the type of event subscription.

In the embodiment of the present application, the step 412b may also be performed before the step 410b or 411b, so long as it is performed after the step 409b, which is not limited herein.

413b-415b：

The a implementation of steps 413b to 415b is similar to the a implementation of steps 412a to 414a of the example embodiment of fig. 4a, and will not be repeated here.

In the event subscription process, the second SMF stores the correspondence between the transaction identifier and the PCC rule identifier, where the transaction identifier corresponds to the event subscription, and at this time, the second SMF may determine the PCC rule identifier corresponding to the event subscription.

The message carries the triplet information and the PCC rule identification.

Alternatively, the message may carry the PCRT described above.

413b-415b：

The B implementation of steps 413B to 415B is similar to the B implementation of steps 412a to 414a of the example embodiment of fig. 4a, and will not be repeated here.

416b-420b：

Steps 416b to 420b are similar to steps 415a to 419a of the example embodiment of fig. 4a, and are not repeated here.

In the embodiment shown in fig. 4a and fig. 4b, the first SMF, the second SMF and the PCF update the PCC rules, the first PDR, the second PDR, the FAR and the URR related to the subscribed event into corresponding policy rules generated according to the second data description information according to the event subscription type indication information and the notification control indication information, or the association relationship among the data description information identifier, the PCC rule identifier and the subscribed event, so as to implement updating of the policy rules of the event.

3. Reachable event after deletion of downlink data notification failure:

referring to fig. 5a, based on the subscription of the reachable event after the failure of the downlink data notification in fig. 2, in this embodiment, a process of deleting the subscription of the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

501a, UE accesses the network, establishes PDU conversation:

consistent with step 401a in the example implemented in fig. 4a, further description is omitted here.

502a, AF sends a unsubscribe request message to NEF:

AF sends Nnef_EventExposure_ Unsubscribe Request message to NEF requesting to delete subscription of reachable event after failure of downstream data transfer.

The message carries the NEF subscription association identifier received in the event subscription process.

503a, NEF sends a subscription request message to the UDM:

the NEF sends a Nudm_EventExposure_ Unsubscribe Request message to the UDM requesting deletion of subscription to reachable events after failure of downstream data delivery.

The message carries the UDM subscription association identifier received in the event subscription process.

504a, UDM sends a subscription request message to the AMF registered by the UE:

the UDM sends a namf_eventExposure_ Unsubscribe Request message to the AMF registered by the UE requesting to delete the subscription of the reachable event after the downlink data transfer failure.

The message carries the AMF subscription association identification received in the event subscription process.

505a, AMF returns an acknowledgement message to the UDM.

506a, UDM returns an acknowledgement message to the NEF.

507a, NEF returns an acknowledgement message to the AF.

508a, AMF sends a fifth message to V-SMF:

the AMF sends an Nsmf_PDUSion_ UpdateSMContext Request message to the V-SMF requesting to delete the downstream data notification failure event.

The message carries an unsubscribe indication and a NEF notification association identifier (Notification Correlation Id) received during the event subscription.

In the embodiment of the present application, step 506a may also be performed before step 504a or step 505a, so long as it is performed after step 503 a; step 507a may also be performed before any of steps 503a to 506a, as long as it is performed after step 502 a; step 508a may also be performed before any of steps 505a to 507a, so long as it is performed after step 504a, and is not limited herein.

509a, V-SMF returns an acknowledgement message to the AMF.

510a, V-SMF determines that it is required to request deletion of the first N4 information and sends a sixth message to the second SMF:

the V-SMF may determine that the downlink data transfer fails according to the NEF notification association identifier in step 508a, and determine that the subscription of the event needs to be deleted according to the unsubscribe indication, thereby determining that the deletion of the first N4 information needs to be requested. In the embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, which is used to identify the subscription of the first event.

In the subscribing process, the V-SMF stores the corresponding relation between the event subscription and the transaction identifier, and at the moment, the transaction identifier corresponding to the event subscription can be queried.

Specifically, the V-SMF sends an nsmf_pduse_update Request message to the SMF, where the message carries an indication of requesting to delete the first N4 information. In this embodiment, this message is also referred to as a sixth message, which is used to request deletion of the first N4 information.

The message carries a transaction identifier and an operation instruction delete.

In the embodiment of the present application, step 510a may also be performed before step 509a, so long as it is performed after step 508a, which is not limited herein.

511a, the second SMF sends a ninth message to the PCF:

in the event subscription process, the second SMF stores the correspondence between the transaction identifier and the PCC rule identifier, and at this time, the second SMF may determine the corresponding PCC rule identifier according to the transaction identifier.

The second SMF sends an npcf_smpolicy control_update request to the PCF requesting deletion of the PCC rule.

The message carries the PCC rule identification and the operation instruction delete.

512a, the PCF deletes the PCC rule and returns an acknowledgement message to the SMF:

the PCF may delete the PCC rule corresponding to the PCC rule identification based on the PCC rule identification received in step 511 a.

The PCF returns a confirmation message to the second SMF, where the message carries an indication of deleting the PCC rule corresponding to the PCC rule identifier, and specifically, the message may include the PCC rule identifier and the deletion indication.

513a, the second SMF deletes the first N4 information, and sends an indication to the V-SMF to delete the first N4 information:

the second SMF deletes the first N4 information stored in the local area of the second SMF according to the deleted PCC rule identification, and sends an instruction for deleting the first N4 information to the V-SMF.

514a, V-SMF and UPF interactively delete the corresponding PDR, FAR and URR.

And the V-SMF determines that the second N4 information needs to be deleted according to the received indication of deleting the first N4 information, and the V-SMF and the UPF interactively delete the PDR, the FAR and the URR corresponding to the second N4 information.

Referring to fig. 5b, based on the subscription of the reachable event after the failure of the downlink data notification in fig. 3, in this embodiment, a process of deleting the subscription of the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

501b, the UE accesses the network and establishes PDU session:

502b-507b：

Steps 502b to 507b are similar to steps 502a to 507a of the example of fig. 5a, and will not be repeated here.

508b, the AMF sends an update context request message to the V-SMF:

The message carries an unsubscribe indication and a NEF notification association identifier received in the event subscription process.

509b, V-SMF sends an update request message to the second SMF:

the V-SMF sends an nsmf_pduse_update Request message to the second SMF requesting to delete the downlink data notification failure event.

The message carries the NEF notification association identifier and the unsubscribe indication.

It should be noted that the unsubscribing indication in step 509b may be generated according to the unsubscribing indication in step 508b, or the unsubscribing indication in step 508b is not limited herein.

510b, the second SMF returns an acknowledgement message to the V-SMF.

511b, V-SMF returns an acknowledgement message to the AMF.

512b, the second SMF determines that a request to delete a policy rule for processing data is required, and sends a request to the PCF to delete the PCC rule:

in step 509b, the second SMF receives the update request message, and the second SMF may determine, according to the NEF notification association identifier in the request, that the downlink data transmission fails, and determine, according to the unsubscribe indication, that the subscription of the event needs to be deleted, thereby determining that the PCC rule needs to be requested to be deleted. In the embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, which is used to identify the subscription of the first event.

In the embodiment of the present application, the step 512b may be performed before the step 510b or the step 511b, so long as the step 509b is performed, which is not limited herein.

513b-515b：

Steps 513b to 515b are similar to steps 512a to 514a of the example embodiment of fig. 5a, and are not repeated here.

In the embodiment shown in fig. 5a and fig. 5b, the first SMF, the second SMF and the PCF delete the policy rules such as the PCC rule, the first PDR, the second PDR, the FAR, and the URR related to the event subscription according to the association relationship between the data description information identifier, the PCC rule identifier and the subscription event, thereby deleting the policy rules of the event.

It should be noted that, in the embodiment of the present application, the event identifier may also be an identifier of another event, for example, a downlink data transfer status event, where different event identifiers represent different subscription events, and accordingly, different PCC rules and policy rules may be generated, and the network element may correspondingly perform different operations, which is not limited herein.

The process of providing policy rules for downstream data transfer state events is illustrated next. In the embodiment of the present application, the downlink data transmission status event may also be referred to as a downlink data transmission status event or a downlink data notification status event, and in the embodiment of the present application, the event is also referred to as a first event.

2. Acquiring a policy rule of a downlink data transmission state event:

1. subscribing to a downlink data transfer status event:

referring to fig. 6, when the UE is in a roaming state, i.e., the V-SMF cannot interact directly with the PCF, the AF subscribes to a downlink data transfer state event, and the first SMF requests PCC rules from the PCF. For the scenario where there is an I-SMF for the PDU session, the V-SMF may be replaced with an I-SMF, which is not limited herein. One flow of providing policy rules in the embodiment of the application includes:

601. the UE accesses the network and establishes a PDU session:

Optionally, during PDU session establishment or modification, the PCF may send a policy control request trigger (PCRT, policy control request trigger) to the second SMF, which subscribes to a downstream data transfer state event carrying the data description (downlink data delivery status event subscribed with traffic descriptor). The PCRF is configured to instruct the second SMF to request PCC rules from the PCF when receiving a downlink data delivery status event subscription carrying a data description.

In the embodiment of the present application, the PCRT is also referred to as a downlink data notification event subscription trigger.

602. AF sends subscription request message to NEF:

AF sends a Nnef_EventExposure_ Subscribe Request message to NEF, subscribing to downstream data transfer state (downlink data delivery status) events.

The message carries an event identification (event id), an AF notification endpoint (AF notification endpoint), triplet information, an external identification of the user or an external user group identification, and a discarded delivery status.

In the embodiment of the present application, besides the discarded delivery state, the subscribed delivery state may also be a buffer or a transfer, and the discarded delivery state is taken as an example in this embodiment, and no limitation is caused to the subscribed delivery state.

In the embodiment of the application, the data description information provided during event subscription is called first data description information, and the data description information provided during event update is called second data description information. In this embodiment or the embodiment shown in fig. 7, the data description information is first data description information.

Event identification (event id) represents an event subscribed to, in this embodiment, the identification of a downstream data transfer state event.

603. The NEF sends a subscription request message to the UDM:

The NEF sends a Nudm_EventExposure_ Subscribe Request message to the UDM, subscribing to downstream data transfer status events.

The message carries the event identification, the triplet information, the discarded delivery status and the external identification of the user or the external user group identification received in step 602, and a NEF notification endpoint (NEF notification endpoint) for the NEF to receive the subscription notification.

The NEF notification endpoint is to instruct the endpoint of the NEF to receive the subscription notification, and the NEF notification endpoint may include a NEF notification target address (NEF notification target address) and a NEF notification association identification (NEF notification correlation Id). When the NEF assigns the same NEF notification target address to multiple subscription notifications, different events may be distinguished by the NEF notification association identification.

604. The UDM sends a subscription request message to a second SMF registered by the UE:

the UDM receives the external user identity in step 603 and can determine the internal user identity from the external identity.

In the embodiment of the present application, when the event subscription is specific to a plurality of users, the external identifier of the user in steps 602 and 603 may also be an external user group identifier, where the external user group identifier represents each of the users, and the internal identifier of each of the users may be determined according to the external user group identifier, which is not limited herein.

The UDM may determine, according to the local correspondence stored in the UDM and the internal identifier of the user, a second SMF registered by the UE, and send an nsmf_eventExposure_ Subscribe Request message to the second SMF registered by the UE, to subscribe to a downlink data transfer state event.

The message carries the event identifier, the triplet information, the NEF notification endpoint, the discarded delivery status, and the user internal identifier received in step 203.

If a user group identity is received in step 603, the UDM may send the above message for each UE in the user group to the second SMF registered by the UE.

605. The second SMF sends a first message to the V-SMF:

the second SMF sends an Nsmf_EventExposure_ Subscribe Request message to the V-SMF registered by the UE, and subscribes to the downlink data transfer state event. In this embodiment, the message may also be referred to as a first message;

the message carries the event identifier, the NEF notification association identifier, the triplet information, the discarded delivery status received in step 604, and the user internal identifier.

If a user group identification is received in step 604, the second SMF may send the above message for each UE in the user group to the V-SMF registered with the UE.

606. The V-SMF returns an acknowledgement message to the second SMF:

The V-SMF assigns an SMF subscription association identifier (SMF subscription correlation id) to identify a downstream data transfer state event based on the event identifier received in step 605, indicating that the event has been subscribed successfully at the V-SMF.

And the V-SMF stores the received information, and returns a confirmation message to the second SMF, wherein the message carries the SMF subscription related identification.

607. The second SMF returns an acknowledgement message to the UDM:

the second SMF assigns an SMF subscription association identifier (SMF subscription correlation id) to identify a downstream data transfer state event based on the event identifier received in step 604, indicating that the event has been subscribed successfully at the second SMF.

And the second SMF stores the received information and returns a confirmation message to the UDM, wherein the message carries the SMF subscription related identification.

Step 607 may also be performed before step 605 or 606, as long as it is performed after step 603.

608. The UDM returns an acknowledgement message to the NEF:

the UDM assigns a UDM subscription association identifier (UDM subscription correlation id) to the event subscription, the UDM subscription association identifier identifying a downstream data transfer state event indicating that the event has been subscribed successfully at the UDM.

609. The NEF returns an acknowledgement message to the AF:

the NEF assigns a NEF subscription association identifier (NEF subscription correlation id) to the event subscription, the NEF subscription association identifier identifying a downstream data transfer state event indicating that the event subscription has been successful at the NEF.

In an embodiment of the present application, step 608 may be performed before any of steps 604 to 607, as long as it is performed after step 603; step 609 may be performed before any of steps 603 to 608, so long as it is performed after step 602, and is not specifically limited herein.

There are two implementations of steps 610 through 614, specifically as follows:

610. the V-SMF determines that a policy rule for processing data needs to be requested and sends a second message to the second SMF:

in step 601, when the V-SMF receives indication information that policy charging control is applied to the UE, reports indication information that a downlink data transfer state event subscription is received, or reports indication information that data description information is received, the V-SMF may determine that PCC is applied to the PDU session, and when the V-SMF determines that data needs to be buffered in the UPF, it may also determine that the received event subscription needs to be reported to the second SMF and a policy for processing the data in the UPF is requested.

The V-SMF may assign a Transaction identifier (Transaction Id) to the event, the Transaction identifier being used to represent a Transaction between the V-SMF and the second SMF for subsequent modify and delete operations. In the embodiment of the application, the transaction identifier may also be referred to as first identification information. In an embodiment of the present application, the transaction identifier corresponds to a subscription for the first event, and the transaction identifier may also be used to identify a policy rule request for the subscription for the first event. In this embodiment, the transaction identifier corresponds to a subscription to a downstream data transfer state event.

The V-SMF may further allocate downlink data transfer status indication information according to the subscription of the event in step 605, where the downlink data transfer status indication information is used to indicate that the received event subscription type is a downlink data transfer status subscription.

The downlink data transfer status indication information is also referred to as event subscription type indication information in this embodiment, and is used to indicate the type of event subscription. In the embodiment of the application, the event subscription type indication information is generated according to the subscription of the event.

Specifically, the V-SMF sends an nsmf_pduse_update Request message to the second SMF, reporting the received event subscription, requesting a policy for detecting data. The message carries triplet information, the Transaction identifier (Transaction Id) and the downlink data transmission status indication information. In this embodiment, the message may also be referred to as a second message.

611. The second SMF sends a seventh message to the PCF:

Upon receiving the transaction identifier, the second SMF needs to request the PCF for a PCC rule reachable after the downlink data transfer failure, and since the PCF has provided a PCRT carrying a downlink data transfer status event subscription of the data description before, the second SMF may send an npcf_smpolicy control_update request message to the PCF. In this embodiment, this message may also be referred to as a seventh message. In the embodiment of the application, the seventh message is used for requesting PCC rules from the PCF.

The second SMF determines, according to the downlink data transmission status indication information in the second message, that the message is used to request a PCC rule for detecting a downlink data transmission status event, and the second SMF may find the PCRT corresponding to the event received in step 601.

The message carries the triplet information and the downlink data transfer status indication information and the PCRT received in step 610.

612. The PCF formulates PCC rules and sends third policy rules to the second SMF:

The PCF formulates a PCC rule (PCC rule) according to the triplet information received in step 611, i.e. includes the triplet information in a filter template in the PCC rule, and sets a high priority, where the PCC rule includes a PCC rule identifier (PCC rule Id), and the PCC rule identifier is used to represent the PCC rule, and when the PCC rule is updated or deleted later, a corresponding PCC rule may be determined according to the PCC rule identifier, so as to make a change to the PCC rule. In the embodiment of the present application, the PCC rule identifier may also be referred to as second identification information.

The PCF may also determine downlink data transmission status notification control indication information indicating that the downlink data transmission status notification needs to be performed according to the PCRT received in step 611. The downlink data transmission state notification control indication information may be included in a PCC rule for indicating that the PCC rule is used for detecting a downlink data transmission state event.

The downlink data transfer state notification control instruction information is also referred to as notification control instruction information in the present embodiment.

Alternatively, the downlink data transmission state notification control indication information may not be included in the PCC rule, but may be carried in the acknowledgement message, which is not limited herein.

613. The second SMF receives the third policy rule, generates first N4 information (N4 information), and transmits the first policy rule to the V-SMF:

when the second SMF receives the PCC rule (third policy rule) of step 612, since the second message in step 610 includes both the triplet information and the transaction identifier, and the PCC rule is generated according to the triplet information, the second SMF may determine and store the correspondence between the transaction identifier and the PCC rule identifier according to the same. When the downlink data transmission state subscription is updated or deleted later, the PCC rule identifier corresponding to the event can be found according to the corresponding relation, so that a corresponding instruction is sent to the PCF, and the PCF updates or deletes the PCC rule corresponding to the PCC rule identifier.

The second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgement message in step 612 includes downlink data transmission status notification control indication information, so that the first N4 information may also include downlink data transmission status notification control indication information, where the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

Alternatively, the downlink data transmission status notification control indication information may be carried in the acknowledgement message, not limited herein, instead of being included in the first N4 information.

614. V-SMF sends second N4 information (second policy rule) to UPF:

since the first N4 information or the acknowledgement message in step 613 includes the downlink data transfer state notification control indication information, the V-SMF may determine that the first N4 information is used to detect a downlink data transfer state event;

When the subscribed delivery status is buffer, the FAR is used to instruct the UPF to buffer the packet matching the PDR, and the URR is used to instruct the UPF to notify the SMF when buffering the packet, which is not limited herein.

611. The second SMF sends a seventh message to the PCF:

The message carries the triplet information and PCRT received in step 610.

614. V-SMF sends second N4 information (second policy rule) to UPF:

since the V-SMF assigns a transaction identifier to the downlink data transfer state event in step 610, the V-SMF may associate the first N4 information in the message with the downlink data transfer state event subscription according to the transaction identifier in the message in step 613, and determine that the first N4 information is used to detect the downlink data transfer state event.

The V-SMF determines second N4 information according to the first N4 information and the downlink data transmission state event subscription. The method comprises the following steps:

when the V-SMF receives a UE-unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR and includes the same filter templates and priority information as the first PDR. The V-SMF may determine the associated FAR from the subscription of the downstream data transfer state event and the second PDR. The FAR is used to instruct the UPF to discard and report packets that match the second PDR.

When the V-SMF receives a notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR according to the first PDR, where the second PDR is generated according to the first PDR and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the subscription of the downstream data transfer state event and the second PDR. The FAR is used to instruct the UPF to discard buffered data matching the second PDR, and the URR is used to instruct the UPF to report when buffered data packets matching the second PDR are discarded.

615. The UPF informs the V-SMF that the matched packet is discarded:

after the UPF discards the data packet matched with the PDR according to the FAR, the UPF notifies the V-SMF that the matched data packet is discarded according to the URR.

And when the transmission state is cache, the UPF caches the data packet matched with the PDR according to the FAR, and then notifies the V-SMF that the matched data packet is cached according to the URR.

616. The V-SMF sends a notify request message to the NEF:

when the V-SMF receives a notification that the packet sent by the UPF is discarded, the V-SMF may send a notification to the NEF that the packet is discarded.

When the transmission state is the buffer, the V-SMF may send a notification to the NEF that the packet is buffered when the V-SMF receives the notification that the packet sent by the UPF is buffered.

When the transmission state is transfer, when the V-SMF detects that the PDU session is changed to ACTIVE, that is, it is confirmed that the UE is reachable, and in step 615, a notification that the data packet is buffered is received, the UPF automatically forwards the data buffered before, and at this time, the V-SMF can determine that the data packet buffered before is transferred, and send a notification that the data packet is transferred to the NEF.

Alternatively, the V-SMF may send the notification to the second SMF before the second SMF reports to the NEF, which is not limited herein.

In an embodiment of the present application, the event of discarding data or buffering data in step 615 may also be referred to as a second event, and the first SMF may determine the first event according to the second event. For example, in this embodiment, the downlink data transfer status event may be determined according to the event of discarding data or buffering data.

In the embodiment of the present application, the NEF may also be referred to as an event receiving network element, where the event receiving network element is configured to receive a report related to the first event, in this embodiment, a report of a downlink data transmission status event.

617. The NEF sends a notification request message to the AF:

the NEF sends an Nneff_EventExposure_NotifyRequest message to the AF, wherein the message carries an event identifier and an AF notification endpoint.

In the embodiment of the present application, the PCC rule may be requested not only by the first SMF but also by the second SMF, and the flow of requesting the PCC rule from the PCF by the second SMF will be described below:

1.2, the second SMF requests PCC rules from the PCF:

referring to fig. 7, when the UE is in the roaming state, the AF subscribes to a downlink data transfer state event, and the second SMF requests the PCC rule from the PCF. For the scene that the PDU session exists I-SMF, the V-SMF is replaced by the I-SMF. One flow of providing policy rules in the embodiment of the application includes:

701-705：

Steps 701 to 705 are similar to steps 601 to 605 of the embodiment shown in fig. 6, and will not be repeated here.

706. The V-SMF returns an acknowledgement message to the second SMF:

the V-SMF assigns an SMF subscription association identifier (SMF subscription correlation id) to identify a downstream data transfer state event based on the event identifier received in step 705, indicating that the event has been subscribed successfully at the V-SMF.

The V-SMF determines that the data is cached by the UPF, the V-SMF may generate an indication of the UPF to cache the data or an indication of the requesting PCC.

And the V-SMF stores the received information and returns a confirmation message to the second SMF, wherein the message carries the SMF subscription related identification and the indication of UPF cache data or the indication of requesting PCC.

707-709：

Steps 707 to 709 are similar to steps 607 to 609 of the embodiment shown in fig. 6, and are not repeated here.

Step 707 may also be performed before step 705 or 706 in embodiments of the present application, so long as it is performed after step 704; step 708 may also be performed before any of steps 704 to 707, as long as it is performed after step 703; step 709 may also be performed before any of steps 703 to 708, so long as it is performed after step 702, and is not specifically limited herein.

Steps 710 to 713 have two implementations, specifically as follows:

710. the second SMF determines that a policy rule for processing data needs to be requested and sends an update request message to the PCF:

the second SMF may determine that a PCC rule needs to be requested from the PCF due to receiving an indication of UPF buffered data or an indication of requesting PCC in step 706. And the PCF provided a PCRT carrying a downstream data transfer state event subscription for the data description, the second SMF may send a npcf_smpolicy control_update request to the PCF requesting policy rules for processing the data.

The message carries the triplet information received in step 704 and the PCRT of the downlink data transfer status event subscription carrying the data description.

In the embodiment of the application, the PCRT may also be referred to as event subscription type indication information, where the event subscription type indication information is used to indicate the type of event subscription.

In an embodiment of the present application, step 710 may also be performed before any of steps 707 to 709, so long as it is performed after step 706, which is not limited herein.

711. The PCF formulates PCC rules and sends third policy rules to the second SMF:

the a implementation of step 711 is similar to the a implementation of step 612 of the example implemented in fig. 6, and will not be described here again.

712. The second SMF receives the third policy rule, generates first N4 information (N4 information), and transmits the first policy rule to the V-SMF:

the second SMF receives the PCC rule (third policy rule) in step 711, and since the PCC rule is generated according to the triplet information in the message in step 710, and the triplet information is associated with the subscription of the downlink data transfer state event, the second SMF assigns the SMF subscription association identifier to the subscription of the event, so that the second SMF may determine and store the correspondence between the SMF subscription association identifier and the PCC rule identifier according to the correspondence. When the subsequent updating or deleting of the failed subscription of the downlink data notification is performed, the PCC rule identifier corresponding to the event can be searched according to the corresponding relation, so that a corresponding instruction is sent to the PCF, and the PCF updates or deletes the PCC rule corresponding to the PCC rule identifier.

The second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCRT is included in the PCC rule or the confirmation message of step 711, and thus the PCRT may also be included in the first N4 information, where the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

Alternatively, the PCRT may not be included in the first N4 information, but may be carried in the acknowledgement message, which is not limited herein.

713. V-SMF sends second N4 information (second policy rule) to UPF:

the a implementation of step 713 is similar to the a implementation of step 614 of the example implemented in fig. 6, and will not be described again here.

the B implementation of step 711 is similar to the B implementation of step 612 of the example implemented in fig. 6, and will not be described here again.

the second SMF receives the PCC rule (third policy rule) in step 711, and since the PCC rule is generated according to the triplet information in the message in step 710, and the triplet information is associated with the subscription of the downlink data transmission status event, the second SMF assigns the SMF subscription association identifier to the subscription of the event, so that the second SMF may determine and store the correspondence between the SMF subscription association identifier and the PCC rule identifier according to the correspondence. When the subsequent updating or deleting of the failed subscription of the downlink data notification is performed, the PCC rule identifier corresponding to the event can be searched according to the corresponding relation, so that a corresponding instruction is sent to the PCF, and the PCF updates or deletes the PCC rule corresponding to the PCC rule identifier.

713. V-SMF sends second N4 information (second policy rule) to UPF:

the B implementation of step 713 is similar to the B implementation of step 614 of the example implemented in fig. 6 and will not be described again here.

714-716：

Steps 714 to 716 are similar to steps 615 to 617 in the embodiment shown in fig. 6, and are not described here.

2. updating the downlink data transmission status event:

referring to fig. 8a, based on the subscription of fig. 6 to the downlink data transmission status event, in this embodiment, a process of acquiring a corresponding policy rule when updating the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

801a, UE accesses to the network, establishes PDU conversation:

at this point the AF has completed subscription to the downstream data transfer state event according to the embodiment shown in fig. 6.

802a, AF sends a subscription request message to NEF:

the AF sends an nnef_eventExposure_ Subscribe Request message to the NEF requesting an update of the downstream data transfer state (downlink data delivery status) event subscription.

The message carries the NEF subscription association identifier and updated triplet information, and in this embodiment, the triplet information is used to replace the triplet information in the original subscription, so as to generate a policy rule corresponding to the triplet information. In this embodiment or the example implemented in fig. 8b, the triplet information is also referred to as second data description information or second description information. The NEF subscription association identifier is generated by NEF during the event subscription.

803a, NEF sends a subscription request message to the UDM:

the NEF sends a Nudm_EventExposure_ Subscribe Request message to the UDM requesting an update of the downstream data transfer state event subscription.

The message carries the UDM subscription association identification and the triplet information received in step 802 a. The UDM subscription association identity is generated by the UDM during the event subscription.

804a, UDM sends a subscription request message to the second SMF:

The UDM sends a namf_eventExposure_ Subscribe Request message to the second SMF requesting an update of the downstream data transmission status event.

The message carries the SMF subscription association identifier and the triplet information received in step 803. The SMF subscription association identification is the same as the second SMF assignment in step 607 in the embodiment shown in fig. 6.

805a, the second SMF sends a third message to the V-SMF registered by the UE:

the second SMF sends a namf_eventExposure_ Subscribe Request message to the UE-registered V-SMF requesting an update of the downlink data transmission status event. In this embodiment, this message may also be referred to as a third message. In the embodiment of the application, the third message is used for requesting the subscription of the update event from the V-SMF.

The message carries the SMF subscription association identifier and the triplet information received in step 804. The SMF subscription association identification is assigned by V-SMF at the time of event subscription.

806a, V-SMF returns an acknowledgement message to the second SMF:

the V-SMF determines that the subscription event is a downlink data transmission status event according to the SMF subscription association identifier received in step 805a, updates subscription information of the event according to the triplet information, and returns a confirmation message to the second SMF.

807a, the second SMF returns an acknowledgement message to the UDM:

After receiving the confirmation message sent by the V-SMF, the second SMF determines that the subscription event is a downlink data transmission status event according to the SMF subscription association identifier received in step 804a, updates subscription information of the event according to the triplet information, and returns the confirmation message to the UDM.

808a, UDM returns an acknowledgement message to NEF:

after receiving the confirmation message sent by the second SMF, the UDM determines that the subscription event is a downlink data transmission status event according to the UDM subscription association identifier received in step 803, updates subscription information of the event according to the triplet information, and returns the confirmation message to the NEF.

809a, NEF returns an acknowledgement message to AF:

after receiving the confirmation message sent by the UDM, the NEF determines that the subscription event is a downlink data transmission status event according to the NEF subscription association identifier received in step 802a, updates subscription information of the event according to the triplet information, and returns the confirmation message to the AF.

There are two implementations of steps 810a to 814a, as follows:

810a, V-SMF sends a fourth message to the second SMF:

in step 805a, when the V-SMF receives the third message, a downlink data notification status event may be determined according to the SMF subscription association identifier in the third message, and a subscription that needs to be updated according to the message is determined. In the embodiment of the application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

The message carries triplet information, transaction identification and downlink data transmission state indication information. The downlink data transmission status indication information is also referred to as event subscription type indication information, and is generated during an event subscription process, and is used to indicate a first event.

811a, the second SMF sends an eighth message to the PCF:

The message carries triplet information, PCC rule identification and downlink data transmission state indication information received in the event subscription process.

812a, the PCF updates the PCC rules based on the triplet information and sends a fifth policy rule to the second SMF:

the PCF updates the PCC rules based on the triplet information, i.e., includes the triplet information in a filter template in the PCC rules. Optionally, the PCC rule may include downlink data transmission status notification control indication information. The downlink data transmission state notification control indication information is generated in the event subscription process, and the PCF can determine the indication information through the corresponding relation between the indication information and PCC rule identification; the downstream data transmission state notification control instruction information may be generated by the PCF based on the downstream data transmission state instruction information, and is not limited herein.

Optionally, the downlink data transmission status notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

813a, the second SMF updates the first N4 information (N4 information), and sends a fourth policy rule to the V-SMF:

the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first N4 information further includes downlink data transmission status notification control indication information, and the first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. Optionally, the downlink data transmission status notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

814a, V-SMF sends a second N4 information to the UPF:

since the first N4 information or the acknowledgement message in step 813a includes the downlink data transmission status notification control indication information, the V-SMF determines that the first N4 information is used to detect a downlink data transmission status event. The V-SMF determines second N4 information from the first N4 information.

When the V-SMF receives a UE-unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR and includes the same filter templates and priority information as the first PDR. The V-SMF may determine the associated FAR from the downlink data transmission status notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard and report packets that match the second PDR.

When the V-SMF receives a notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR according to the first PDR, where the second PDR is generated according to the first PDR and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the downstream data transmission status notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard buffered data matching the second PDR, and the URR is used to instruct the UPF to report when buffered data packets matching the second PDR are discarded.

B: the message does not carry the indication mark of the event subscription, and the corresponding policy rule is generated according to the event subscription, and the specific implementation mode is as follows:

810a, V-SMF determines that an update of policy rules for processing data needs to be requested and sends a fourth message to the second SMF:

in step 805a, when the V-SMF receives the third message, a downlink data transfer status event may be determined according to the SMF subscription association identifier in the third message, and a subscription for the event may be determined according to the message. In the embodiment of the application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

The V-SMF sends an nsmf_pduse_update Request message to the second SMF, the message requesting updating of the first N4 information. In this embodiment, this message may also be referred to as a fourth message. The message carries triplet information and transaction identification. The transaction identifier is generated at the time of event subscription, and is used to represent an event between the first SMF and the second SMF, specifically corresponds to a subscription of a downlink data transfer state event in this embodiment.

811a, the second SMF sends an eighth message to the PCF:

The message carries the triplet information and the PCC rule identification.

In step 812a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores a correspondence between the PCC rule identifier and the transaction identifier during subscription, the second SMF may determine, according to the PCC rule identifier, the transaction identifier corresponding to the PCC rule.

814a, V-SMF sends a second N4 information to the UPF:

the V-SMF may associate the first N4 information with the subscription of the downlink data notification status event according to the transaction identifier received in step 813a, and determine that the first N4 information is used to detect the downlink data notification status event. The V-SMF determines the second N4 information according to the first N4 information and the subscription of the downlink data notification status event.

815a-817a：

Steps 815a to 817a are similar to steps 615 to 617 of the embodiment shown in fig. 6 and are not repeated here.

Referring to fig. 8b, based on the subscription of fig. 7 to the downlink data transmission status event, in this embodiment, a process of acquiring a corresponding policy rule when updating the event is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

801b, accessing a network by the UE, and establishing PDU session:

at this point the AF has completed subscription to the downstream data transfer state event according to the embodiment shown in fig. 7.

802b-809b:

Steps 802b to 809b are similar to steps 802a to 809a of the example embodiment of fig. 8a, and are not described here.

In an embodiment of the present application, step 807b may also be performed before step 805b or step 806b, as long as it is performed after step 804 b; step 808b may also be performed before any of steps 804b to 807b, as long as it is performed after step 803 b; step 809b may also be performed before any of steps 803b through 808b, so long as it is performed after step 802b, and is not limited herein.

Steps 810b through 813b have two implementations, specifically as follows:

810b, the second SMF determines that an update of the policy rules for processing the data needs to be requested, and sends an update request message to the PCF:

in step 804b or 806b, the message received by the second SMF carries an SMF subscription association identifier, and the second SMF may determine, according to the identifier, a downlink data transfer state event, and determine, according to the message, a subscription that needs to be updated for the event. In the embodiment of the application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

In the event subscription process, the second SMF stores the correspondence between the SMF subscription association identifier and the PCC rule identifier, and at this time, the second SMF may determine the corresponding PCC rule identifier according to the SMF subscription association identifier.

In the embodiment of the present application, step 810b may be performed before any one of steps 805b to 809b, so long as it is performed after step 804b or 806b, which is not limited herein.

If step 810b is performed after step 806b, step 806b the second SMF may determine that the V-SMF has completed the update of the event, at which point it is more conservative to request the update from the PCF.

811b, the PCF updates the PCC rules according to the triplet information and sends a fifth policy rule to the second SMF:

the a implementation of step 811b is similar to the a implementation of step 812a of the example implemented in fig. 8a, and will not be repeated here.

812b, the second SMF updates the first N4 information (N4 information) and sends a fourth policy rule to the V-SMF:

In step 812a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores the correspondence between the PCC rule identifier and the SMF subscription association identifier during subscription, the second SMF may determine, according to the PCC rule identifier, the SMF subscription association identifier corresponding to the PCC rule.

And the second SMF returns a confirmation message to the V-SMF, wherein the message carries the first N4 information and the SMF subscription association identifier. In the embodiment of the present application, the first N4 information generated in the event updating process may also be referred to as a fourth policy rule.

811b-813b：

The a implementation of steps 811b to 813b is similar to the a implementation of steps 812a to 814a of the example of fig. 8a, and will not be repeated here.

The message carries the triplet information and the PCC rule identification.

811b-813b：

The B implementation of steps 811B to 813B is similar to the B implementation of steps 812a to 814a of the example of fig. 8a, and will not be repeated here.

814b-816b：

Steps 814b to 816b are similar to steps 714 to 716 of the embodiment shown in fig. 7 and will not be repeated here.

3. Deleting the downlink data transmission state event:

referring to fig. 9a, based on the subscription of fig. 6 to the downlink data transmission status event, in this embodiment, a process of deleting the event subscription is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

901a, UE accesses to a network, establishes PDU session:

Consistent with step 801a in the example implemented in fig. 8a, further description is omitted here.

902a, AF sends a unsubscribe request message to NEF:

the AF sends an nnef_eventExposure_ Unsubscribe Request message to the NEF requesting deletion of the event subscription.

903a, NEF sends a unsubscribe request message to the UDM:

the NEF sends a Nudm_EventExposure_ Unsubscribe Request message to the UDM requesting deletion of the event subscription.

904a, the UDM sends a unsubscribe request message to a second SMF registered by the UE:

the UDM sends an nsmf_eventExposure_ Unsubscribe Request message to the second SMF registered by the UE requesting deletion of the event subscription.

905a, the second SMF sends a unsubscribe request message to the V-SMF:

the second SMF sends an nsmf_eventExposure_ Unsubscribe Request message to the V-SMF registered by the UE requesting deletion of the event subscription.

906a, V-SMF returns an acknowledgement message to the second SMF.

907a, the second SMF returns an acknowledgement message to the UDM.

908a, UDM returns an acknowledgement message to NEF:

909a, NEF returns an acknowledgement message to the AF.

910a, V-SMF determines that it is required to request deletion of the first N4 information and sends a sixth message to the second SMF:

the V-SMF may determine, according to the SMF subscription association identifier in the unsubscribe request in step 905a, a downlink data transfer state event, and determine, according to the request, that the subscription of the event needs to be deleted, thereby determining that the deletion of the first N4 information needs to be requested. In the embodiment of the application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

911a-914a：

Steps 911 to 914 are similar to steps 511 to 514 in the embodiment shown in fig. 5, and will not be repeated here.

Referring to fig. 9b, based on the subscription of fig. 7 to the downlink data transmission status event, in this embodiment, a process of deleting the event subscription is provided, and for a scenario in which an I-SMF exists in a PDU session, the V-SMF is replaced with the I-SMF, which is not limited herein, and the process includes:

901b, accessing a network by UE, and establishing PDU session:

902b-909b:

Steps 902b to 909b are similar to steps 902a to 909a of the example embodiment of fig. 9a, and are not repeated here.

910b, the second SMF sends an update request message to the PCF:

the second SMF sends an Nsmf_PDUSion_Update Request message to the PCF requesting to delete the downlink data notification failure event.

The message carries an SMF subscription association identifier and an unsubscribe indication, and the SMF subscription association identifier is generated by a second SMF when the event is subscribed.

911b-913b：

Steps 911b to 913b are similar to steps 513b to 515b of the example embodiment of fig. 5a, and will not be repeated here.

In the following, a description will be given of a session management network element in an embodiment of the present application, referring to fig. 10, in an embodiment of the present application, a structure of the session management network element includes:

a first receiving unit 1001, configured to receive a first message, where the first message is used to request to create a subscription of a first event, where the subscription of the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is received by the UE;

A first sending unit 1002, configured to send, according to request policy indication information, a second message to a second session management network element SMF, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

a second receiving unit 1003, configured to receive the first policy rule sent by the second SMF;

a first determining unit 1004, configured to determine a second policy rule according to the first policy rule;

a second sending unit 1005 is configured to send the second policy rule to a user plane function network element UPF, so that the UPF processes the data.

Referring to fig. 11, in an embodiment of the present application, another structure of a session management network element includes:

a first receiving unit 1101, configured to receive a first message, where the first message is used to request to create a subscription of a first event, where the subscription of the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is received by the UE;

a first sending unit 1102, configured to send a second message to a second session management network element SMF according to request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

A second receiving unit 1103, configured to receive the first policy rule sent by the second SMF;

a first determining unit 1104, configured to determine a second policy rule according to the first policy rule;

a second sending unit 1105, configured to send the second policy rule to a user plane function network element UPF, so that the UPF processes the data.

A third receiving unit 1106, configured to receive a third message, where the third message is used to request updating of the subscription of the first event, and the third message includes second description information of the data;

a third sending unit 1107, configured to send a fourth message to the second SMF, where the fourth message is used to request updating of the first policy rule, and the fourth message includes the first identifier and the second description information;

a fourth receiving unit 1108, configured to receive a fourth policy rule sent by the second SMF, where the fourth policy rule is a policy rule obtained after updating the first policy rule;

a first updating unit 1109, configured to update the second policy rule according to the fourth policy rule.

A fifth receiving unit 1110, configured to receive a fifth message, where the fifth message is used to request deletion of the subscription of the first event;

A fourth sending unit 1111, configured to send a sixth message to the second SMF, where the sixth message is used to request deletion of the first policy rule, and the sixth message includes the first identifier and a deletion indication.

A sixth receiving unit 1112, configured to receive the request policy indication information sent by the second SMF.

In this embodiment, the second receiving unit 1103 may include a first receiving subunit 11031;

a first receiving subunit 11031, configured to receive the first policy rule and notification control indication information sent by the second SMF, where the notification control indication information is determined according to the event subscription type indication information;

in the present embodiment, the first determination unit 1104 may include a first determination subunit 11041 or a second determination subunit 11042;

a first determining subunit 11041, configured to determine the second policy rule according to the first policy rule and the notification control indication information.

A second determining subunit 11042 is configured to determine the second policy rule according to the first policy rule and the subscription of the first event.

In the following, a session management network element in an embodiment of the present application will be described, referring to fig. 12, in an embodiment of the present application, a structure of the session management network element includes:

A seventh receiving unit 1201, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, where the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

a fifth sending unit 1202, configured to send a seventh message to a policy control network element PCF, where the seventh message is used to request a third policy rule corresponding to the first description information, and the seventh message includes the first description information and the event subscription type indication information;

an eighth receiving unit 1203, configured to receive the third policy rule sent by the PCF;

a second determining unit 1204, configured to determine a first policy rule according to the third policy rule;

a sixth sending unit 1205 is configured to send the first policy rule to the first SMF.

Referring to fig. 13, in an embodiment of the present application, another structure of a session management network element includes:

a seventh receiving unit 1301, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, where the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

A fifth sending unit 1302, configured to send a seventh message to a policy control network element PCF, where the seventh message is configured to request a third policy rule corresponding to the first description information, and the seventh message includes the first description information and a downlink data notification event subscription trigger, where the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

an eighth receiving unit 1303, configured to receive the third policy rule sent by the PCF;

a second determining unit 1304, configured to determine a first policy rule according to the third policy rule;

a sixth sending unit 1305 is configured to send the first policy rule to the first SMF.

A ninth receiving unit 1306, configured to receive first request policy indication information sent by the PCF, where the first request policy indication information includes indication information that reports receiving a downlink data notification event subscription;

a seventh sending unit 1307, configured to send second request policy indication information to the first SMF, where the second request policy indication information includes at least one of indication information that policy charging control is applied to the UE, indication information that the report receives a downlink data notification event subscription, or indication information that the report receives data description information.

A tenth receiving unit 1308, configured to receive a fourth message sent by the first SMF, where the fourth message includes the first identifier and second description information of the data;

an eighth sending unit 1309, configured to send an eighth message to the PCF, where the eighth message includes a second identifier and the second description information, where the eighth message is used to request updating the third policy rule, the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier;

an eleventh receiving unit 1310, configured to receive a fifth policy rule sent by the PCF, where the fifth policy rule is a policy rule obtained after updating the third policy rule;

a second updating unit 1311, configured to update the first policy rule according to the fifth policy rule to obtain a fourth policy rule;

a ninth sending unit 1312 is configured to send the fourth policy rule to the first SMF.

A twelfth receiving unit 1313, configured to receive a sixth message sent by the first SMF, where the sixth message includes the first identifier and a deletion indication;

a tenth sending unit 1314, configured to send a ninth message to the PCF, where the ninth message is used to request deletion of the third policy rule, and the ninth message includes the second identifier, where the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier.

In this embodiment, the eighth receiving unit 1303 may include a second receiving subunit 13031;

a second receiving subunit 13031, configured to receive the third policy rule and notification control instruction information sent by the PCF, where the notification control instruction information is determined according to the downlink data notification event subscription trigger;

in the present embodiment, the sixth transmitting unit 1305 may include a first transmitting subunit 13051;

a first sending subunit 13051 configured to send the first policy rule and the notification control instruction information to the first SMF.

Fig. 14 is a schematic structural diagram of a session management network element according to an embodiment of the present application, where the session management network element 1400 may include one or more central processing units (central processing units, CPU) 1401 and a memory 1405, and one or more application programs or data are stored in the memory 1405.

Wherein the memory 1405 may be volatile storage or persistent storage. The program stored in the memory 1405 may include one or more modules, each of which may include a series of instruction operations in the traffic control unit. Still further, the central processor 1401 may be arranged to communicate with the memory 1405 and to execute a series of instruction operations in the memory 1405 on the traffic control unit 1400.

The traffic control unit 1400 may also include one or more power supplies 1402, one or more wired or wireless network interfaces 1403, one or more input/output interfaces 1404, and/or one or more operating systems, such as Windows ServerTM, mac OS XTM, unixTM, linuxTM, freeBSDTM, etc.

The service control unit 1400 may perform the operations performed by the session management network element in the embodiments shown in fig. 2 to 9b, which are not described herein.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. With such understanding, all or part of the technical solution of the present application may be embodied in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM, random access memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Claims

1. A method for providing policy rules, wherein the method is applied to a first session management network element SMF, the first SMF not having the capability to interact directly with a policy control network element PCF, the method comprising:

sending a second message to a second session management network element SMF according to the request policy indication information, wherein the second message comprises the first description information, and the second message is used for requesting a first policy rule corresponding to the first description information; the request policy indication information is used for indicating the first SMF to acquire policy rules corresponding to subscription events from the PCF, and the second SMF has the capability of directly interacting with the PCF;

receiving the first policy rule sent by the second SMF;

determining a second policy rule according to the first policy rule;

2. The method of claim 1, wherein the second message further includes a first identifier, the first identifier being used to identify a transaction between the first SMF and the second SMF, and wherein after the second message is sent to the second session management network element SMF, the method further includes:

receiving a third message, wherein the third message is used for requesting to update the subscription of the first event, and the third message comprises second description information of the data;

sending a fourth message to the second SMF, where the fourth message is used to request updating of the first policy rule, and the fourth message includes the first identifier and the second description information;

receiving a fourth policy rule sent by the second SMF, wherein the fourth policy rule is a policy rule obtained after updating the first policy rule according to the second description information;

and updating the second policy rule according to the fourth policy rule.

3. The method of claim 1, further comprising a first identification in the second message, the first identification identifying a transaction between the first SMF and the second SMF, the method further comprising, after sending the second message to a second session management network element SMF:

Receiving a fifth message, wherein the fifth message is used for requesting to delete the subscription of the first event;

and sending a sixth message to the second SMF, wherein the sixth message is used for requesting to delete the first policy rule, and the sixth message comprises the first identification and the deletion indication.

4. A method according to any of claims 1 to 3, characterized in that before said sending a second message to the second session management network element SMF according to the request policy indication information, the method further comprises:

and receiving the request strategy indication information sent by the second SMF.

5. A method according to any one of claims 1 to 3, characterized in that:

the request policy indication information includes at least one of indication information of policy charging control applied to the UE, indication information reporting reception of a downlink data notification event subscription, or indication information reporting reception of data description information.

6. A method according to any one of claims 1 to 3, characterized in that:

the second message further comprises event subscription type indication information, wherein the event subscription type indication information is used for indicating the subscription type of the first event.

7. The method of claim 6, wherein the receiving the first policy rule sent by the second SMF comprises:

receiving the first policy rule and notification control indication information sent by the second SMF, wherein the notification control indication information is determined according to the event subscription type indication information and is used for indicating actions corresponding to the event subscription;

the determining a second policy rule according to the first policy rule includes:

and determining the second policy rule according to the first policy rule and the notification control indication information.

8. A method according to any one of claims 1 to 3, wherein said determining a second policy rule from said first policy rule comprises:

and determining the second policy rule according to the first policy rule and the subscription of the first event.

9. A method for providing policy rules, wherein the method is applied to a second session management network element SMF, the second SMF having a capability of directly interacting with a policy control network element PCF, the method comprising:

receiving a second message sent by a first session management network element (SMF), wherein the second message comprises first description information and event subscription type indication information, the event subscription type indication information is used for indicating the type of event subscription, the event subscription is for User Equipment (UE), the first description information is used for identifying data received by the UE, and the first SMF does not have the capability of directly interacting with the PCF;

A seventh message is sent to a policy control network element PCF, the seventh message is used for requesting a third policy rule corresponding to the first description information, the seventh message includes the first description information and a downlink data notification event subscription trigger, a PCRT is from the PCF, and the PCRT is used for indicating the second SMF to request a PCC rule from the PCF when receiving an event subscription;

receiving the third policy rule sent by the PCF;

determining a first policy rule according to the third policy rule;

and sending the first policy rule to the first SMF.

10. The method of claim 9, wherein prior to the receiving the second message sent by the first session management network element SMF, the method further comprises:

receiving first request strategy indication information sent by the PCF, wherein the first request strategy indication information comprises indication information for reporting that a downlink data notification event subscription is received;

and sending second request policy indication information to the first SMF, where the second request policy indication information includes at least one of indication information that policy charging control is applied to the UE, indication information that the report receives a downlink data notification event subscription, or indication information that the report receives data description information.

11. The method of claim 9 or 10, wherein if the receiving the third policy rule sent by the PCF comprises:

receiving the third policy rule and notification control instruction information sent by the PCF, wherein the notification control instruction information is determined according to the downlink data notification event subscription trigger, and the notification control instruction information is used for representing actions corresponding to the event subscription;

the sending the first policy rule to the first SMF includes:

and sending the first policy rule and the notification control indication information to the first SMF.

12. The method of claim 9 or 10, wherein the second message includes a first identification identifying a transaction between the second SMF and the first SMF, the method further comprising, after the sending of the seventh message to the PCF:

receiving a fourth message sent by the first SMF, wherein the fourth message comprises the first identifier and second description information of the data;

an eighth message is sent to the PCF, wherein the eighth message comprises a second identifier and the second description information, the eighth message is used for requesting to update the third policy rule, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the first identifier;

Receiving a fifth policy rule sent by the PCF, wherein the fifth policy rule is a policy rule obtained after updating the third policy rule according to the second description information;

updating the first policy rule according to the fifth policy rule to obtain a fourth policy rule;

and sending the fourth policy rule to the first SMF.

13. The method of claim 9 or 10, wherein the second message includes a first identification identifying a transaction between the second SMF and the first SMF, the method further comprising, after the sending of the seventh message to the PCF:

receiving a sixth message sent by the first SMF, wherein the sixth message comprises the first identifier and a deletion instruction;

and sending a ninth message to the PCF, wherein the ninth message is used for requesting to delete the third policy rule, the ninth message comprises a second identifier, the second identifier is the identification information of the third policy rule, and the second identifier is determined according to the first identifier.

14. A session management network element, SMF, the SMF being a first SMF, the first SMF not having the capability to interact directly with a policy control network element, PCF, the first SMF comprising:

a first sending unit, configured to send a second message to a second session management network element SMF according to request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information, where the request policy indication information is used to instruct the first SMF to obtain, from the PCF, a policy rule corresponding to a subscription event, and the second SMF has a capability of directly interacting with the PCF;

15. The SMF of claim 14, wherein said second message further comprises a first identifier, said first identifier being used to identify a transaction between said first SMF and said second SMF, said SMF further comprising, after said second message is sent to a second session management network element SMF:

A third receiving unit, configured to receive a third message, where the third message is used to request updating of the subscription of the first event, and the third message includes second description information of the data;

a third sending unit, configured to send a fourth message to the second SMF, where the fourth message is used to request updating of the first policy rule, and the fourth message includes the first identifier and the second description information;

a fourth receiving unit, configured to receive a fourth policy rule sent by the second SMF, where the fourth policy rule is a policy rule obtained by updating the first policy rule according to the second description information;

and the first updating unit is used for updating the second policy rule according to the fourth policy rule.

16. The SMF of claim 14, further comprising a first identification in the second message, the first identification identifying a transaction between the first SMF and the second SMF, the SMF further comprising, after sending the second message to a second session management network element SMF:

a fifth receiving unit, configured to receive a fifth message, where the fifth message is used to request deletion of a subscription of the first event;

And a fourth sending unit, configured to send a sixth message to the second SMF, where the sixth message is used to request deletion of the first policy rule, and the sixth message includes the first identifier and a deletion indication.

17. The SMF according to any of the claims 14 to 16, characterized in that said SMF further comprises, before said sending a second message to a second session management network element SMF according to request policy indication information:

and a sixth receiving unit, configured to receive the request policy indication information sent by the second SMF.

18. The SMF according to any of claims 14 to 16, characterized in that:

19. The SMF according to any of claims 14 to 16, characterized in that:

20. The SMF of claim 19, wherein said second receiving unit comprises:

A first receiving subunit, configured to receive the first policy rule and notification control indication information sent by the second SMF, where the notification control indication information is determined according to the event subscription type indication information, and the notification control indication information is used to indicate an action corresponding to the event subscription;

the first determination unit includes:

and the first determining subunit is used for determining the second policy rule according to the first policy rule and the notification control instruction information.

21. The SMF according to any of claims 14 to 16, wherein said first determining unit comprises:

and the second determining subunit is used for determining the second policy rule according to the first policy rule and the subscription of the first event.

22. A session management network element, SMF, the SMF being a second SMF, the second SMF having the capability of directly interacting with a policy control network element, PCF, the second SMF comprising:

a seventh receiving unit, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, where the event subscription type indication information is used to indicate a type of event subscription, where the event subscription is an event subscription for a user equipment UE, the first description information is used to identify data received by the UE, and the first SMF does not have a capability of directly interacting with the PCF;

A fifth sending unit, configured to send a seventh message to a policy control network element PCF, where the seventh message is configured to request a third policy rule corresponding to the first description information, where the seventh message includes the first description information and a downlink data notification event subscription trigger, where a downlink data notification event subscription trigger PCRT is from the PCF, and where the PCRT is configured to instruct the second SMF to request, when an event subscription is received, a PCC rule to the PCF;

23. The SMF of claim 22, wherein prior to said receiving a second message sent by a first session management network element SMF, said SMF further comprises:

a ninth receiving unit, configured to receive first request policy indication information sent by the PCF, where the first request policy indication information includes indication information that reports that a downlink data notification event is received and subscribes;

a seventh sending unit, configured to send second request policy indication information to the first SMF, where the second request policy indication information includes at least one of indication information that policy charging control is applied to the UE, indication information that the report receives a downlink data notification event subscription, or indication information that the report receives data description information.

24. The SMF according to claim 22 or 23, wherein if said eighth receiving unit comprises:

the second receiving subunit is configured to receive the third policy rule and notification control indication information sent by the PCF, where the notification control indication information is determined according to the downlink data notification event subscription trigger, and the notification control indication information is used to indicate an action corresponding to the event subscription;

the sixth transmitting unit includes:

and the first sending subunit is used for sending the first policy rule and the notification control indication information to the first SMF.

25. The SMF of claim 22 or 23, wherein said second message comprises a first identification identifying a transaction between said second SMF and said first SMF, said SMF further comprising, after said sending a seventh message to said PCF:

a tenth receiving unit, configured to receive a fourth message sent by the first SMF, where the fourth message includes the first identifier and second description information of the data;

an eighth sending unit, configured to send an eighth message to the PCF, where the eighth message includes a second identifier and the second description information, where the eighth message is used to request updating the third policy rule, the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier;

An eleventh receiving unit, configured to receive a fifth policy rule sent by the PCF, where the fifth policy rule is a policy rule obtained by updating the third policy rule according to the second description information;

the second updating unit is used for updating the first policy rule according to the fifth policy rule to obtain a fourth policy rule;

and a ninth sending unit, configured to send the fourth policy rule to the first SMF.

26. The SMF of claim 22 or 23, wherein said second message comprises a first identification identifying a transaction between said second SMF and said first SMF, said SMF further comprising, after said sending a seventh message to said PCF:

a twelfth receiving unit, configured to receive a sixth message sent by the first SMF, where the sixth message includes the first identifier and a deletion indication;

a tenth sending unit, configured to send a ninth message to the PCF, where the ninth message is used to request deletion of the third policy rule, and the ninth message includes a second identifier, where the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier.

27. A session management network element, SMF, comprising:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the method of any one of claims 1 to 8.

28. A session management network element, SMF, comprising:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the method of any one of claims 9 to 13.

29. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a program which, when executed by the computer, performs the method of any one of claims 1 to 13.