CN117014980A

CN117014980A - Session establishment method and device

Info

Publication number: CN117014980A
Application number: CN202210473226.8A
Authority: CN
Inventors: 朱迪; 梁晓鸣
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2023-11-07
Also published as: WO2023207229A1

Abstract

The application provides a session establishment method and a session establishment device, which can be applied to the field of communication, wherein the method comprises the following steps: transmitting a PDU session release request message under the condition that the first PDU session does not have a corresponding mapping evolution packet system bearer context; receiving a PDU session release command message; transmitting a PDU session establishment request message, wherein the PDU session establishment request message is used for requesting to establish a second PDU session; the first PDU session corresponds to the same service as the second PDU session. By the method, when the terminal equipment determines that the first PDU session does not have the corresponding mapping EPS bearing context, the first PDU session is actively deactivated, and a new second PDU session is re-established, so that the reliability and continuity of the service can be ensured in the process of switching the different systems of the terminal equipment, and the situations of call failure, service interruption, discontinuity and the like can be avoided.

Description

Session establishment method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for establishing a session.

Background

The wireless communication system developed by the third generation partnership project (the 3rd generation partnership project,3GPP) has evolved to the fifth generation (the 5th generation,5G), new Radio (NR) system. The protocol data unit (protocol data unit, PDU) session in the NR system and the bearer (bearer) in the 4G long term evolution (long term evolution, LTE) system function similarly, both are channels for transmitting data for traffic. However, in order to further refine the service implementation in the NR system, the basic service path is refined to use a quality of service (quality of service, qoS) flow (flow) as a basic service transmission unit, and one PDU session may include a plurality of QoS flows, where a QoS flow is a minimum granularity of distinguishing QoS by one PDU session, and different QoS flows adapt to different QoS.

At present, after the terminal equipment resides in the NR system, the terminal equipment can carry relevant mapping information carried in the LTE system to ensure the continuity of the inter-system service. In particular, when a PDU session supports interworking with an evolved packet system (evolved packet system, EPS), one QoS flow in the PDU session may correspond to one mapped EPS bearer context (mapped EPS bearer context). For a QoS flow in a PDU session, a mapping EPS bearer context corresponding to the QoS flow may be deleted for some reason, and after the terminal device performs handover between different systems, normal bearer mapping cannot be performed, which may cause problems such as service failure.

Disclosure of Invention

The application provides a session establishment method and a session establishment device, which are used for solving the problem that service failure or discontinuity occurs when terminal equipment performs switching between different systems under the condition that PDU session does not have corresponding mapping 4G bearing context.

In a first aspect, the present application provides a session establishment method, where the method may be used for a function of a terminal device side, and embodiments of the present application are not limited to a specific implementation body of the method. Taking the example that the method is applied to terminal equipment, in the method, under the condition that a first protocol data unit session does not have a corresponding mapping evolution packet system bearer context, the terminal equipment sends a protocol data unit session release request message, wherein the protocol data unit session release request message is used for requesting to release the first protocol data unit session; receiving a protocol data unit session release command message, wherein the protocol data unit session release command message is used for indicating to release the first protocol data unit session; transmitting a protocol data unit session establishment request message, wherein the protocol data unit session establishment request message is used for requesting to establish a second protocol data unit session; wherein the first protocol data unit session corresponds to the same service as the second protocol data unit session.

By the method provided by the embodiment of the application, when the terminal equipment determines that the first PDU session does not have the corresponding mapping EPS bearing context, the first PDU session can be actively deactivated, and then a new second PDU session is established for the service corresponding to the first PDU session again, so that the reliability and continuity of the service can be ensured in the process of switching different systems (such as switching from an NR system to an LTE system) of the terminal equipment, the conditions of call failure, service interruption, discontinuity and the like can be avoided, and the stability of the system is improved.

In one possible design, the terminal device is in an idle state or an inactive state before the sending of the protocol data unit session release request message.

Because the terminal equipment is in an idle state or an inactive state, the terminal equipment does not need to transmit service data through the first PDU session, so that the terminal equipment releases the first PDU session at the moment and cannot influence the service corresponding to the first PDU session.

In one possible design, before the sending the protocol data unit session release request message, the method further includes: and not transmitting the data packet of the service through the first protocol data unit session within a preset duration.

Because the terminal equipment does not transmit the service data through the first PDU session within the preset duration, the terminal equipment can be considered that the service data does not need to be transmitted at present, and the terminal equipment releases the first PDU session at the moment and does not influence the service corresponding to the first PDU session.

In one possible design, in a case where the first protocol data unit session does not have a corresponding mapping evolved packet system bearer context, the method specifically includes: receiving a protocol data unit session modification command message, wherein the protocol data unit session modification command message comprises the mapping evolution packet system bearer context; and under the condition that the bearer context of the mapping evolution packet system determines that an error exists, sending a protocol data unit session modification request message, and deleting the bearer context of the mapping evolution packet system, wherein the protocol data unit session modification request message comprises a cause value corresponding to the error.

Because the mapping evolution packet system bearing context has errors, deleting the mapping evolution packet system bearing context can avoid carrying out service transmission according to the error mapping evolution packet system bearing context. Further, the terminal device may cause the network device to determine the cause of the error by sending the cause value to the network device.

In one possible design, the error includes one or more of the following: the mapping evolution packet system bears the context operation semantic errors; the mapping evolution packet system carries a business flow template operation semantic error included by the context;

the mapping evolution packet system carries a business flow template operation grammar error included by the context; the mapping evolution packet system carries a packet filter semantic error included by a context; the mapping evolved packet system carries packet filter syntax errors included in the context.

In one possible design, the method further comprises: and receiving a protocol data unit session establishment acceptance message, wherein the protocol data unit session establishment acceptance message comprises a mapping evolution packet system bearing context corresponding to the second protocol data unit session.

By the method, the second protocol data unit session is established for the service again, so that the continuity of data transmission of the service is maintained.

In a second aspect, an embodiment of the present application provides a communications device, where the communications device is configured to implement the functions of the first aspect, for example, the communications device includes a module or a unit or a means for executing the steps related to the first aspect, where the functions or units or means may be implemented by software, or implemented by hardware, or implemented by executing corresponding software by hardware.

In one possible design, the communication device includes a processing unit, a communication unit, where the communication unit may be configured to receive and transmit signals to enable communication between the communication device and other devices; the processing unit may be adapted to perform some internal operations of the communication device.

In one possible design, the communication device includes a processor, and may further include a transceiver, where the transceiver is configured to receive signals, and where the processor executes program instructions to perform the method in any possible design or implementation of the first aspect. Wherein the communication device may further comprise one or more memories for coupling with the processor, which memories may hold the necessary computer programs or instructions to implement the functions referred to in the first aspect above. The processor may execute a computer program or instructions stored by the memory, which when executed, cause the communication device to implement the method in any of the possible designs or implementations of the first aspect described above.

In one possible design, the communication device includes a processor that may be used to couple with a memory. The memory may hold the necessary computer programs or instructions to implement the functions referred to in the first aspect above. The processor may execute a computer program or instructions stored by the memory, which when executed, cause the communication device to implement the method in any of the possible designs or implementations of the first aspect described above.

In one possible design, the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and perform the method of any of the possible designs or implementations of the first aspect.

It will be appreciated that in the second aspect described above, the processor may be implemented by hardware or software, and when implemented by hardware, the processor may be a logic circuit, an integrated circuit, or the like; when implemented in software, the processor may be a general purpose processor, implemented by reading software code stored in a memory. Further, the above processor may be one or more, and the memory may be one or more. The memory may be integral to the processor or separate from the processor. In a specific implementation process, the memory and the processor may be integrated on the same chip, or may be respectively disposed on different chips.

In a third aspect, there is provided a communication apparatus comprising: interface circuitry and processing circuitry. The interface circuit may include an input circuit and an output circuit. The processing circuitry is to receive signals via the input circuitry and to transmit signals via the output circuitry such that the method of the first aspect and any one of the possible implementations of the first aspect is implemented.

In a specific implementation process, the communication device may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the output signal may be output by, for example and without limitation, a transmitter and transmitted by a transmitter, and the input circuit and the output circuit may be the same circuit, which functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the application does not limit the specific implementation modes of the processor and various circuits.

In one implementation, the communication apparatus may be a wireless communication device, i.e., a computer device supporting wireless communication functionality. Specifically, the wireless communication device may be a terminal device such as a smart phone, or may be a radio access network device such as a base station. The system-on-chip may also be referred to as a system-on-chip (SoC), or simply as a SoC chip. The communication chip may include a baseband processing chip and a radio frequency processing chip. The baseband processing chip is sometimes also referred to as a modem (modem) or baseband chip. The radio frequency processing chip is sometimes also referred to as a radio frequency transceiver (transceiver) or radio frequency chip. In a physical implementation, some or all of the communication chips may be integrated inside the SoC chip. For example, the baseband processing chip is integrated in the SoC chip, and the radio frequency processing chip is not integrated with the SoC chip. The interface circuit may be a radio frequency processing chip in the wireless communication device, and the processing circuit may be a baseband processing chip in the wireless communication device.

In yet another implementation, the communication apparatus may be part of a device in a wireless communication device, such as an integrated circuit product, e.g., a system chip or a communication chip. The interface circuit may be an input/output interface, interface circuit, output circuit, input circuit, pin or related circuitry, etc. on the chip or system of chips. A processor may also be embodied as processing or logic circuitry.

In a fourth aspect, a computer-readable storage medium is provided for storing a computer program comprising instructions for performing the method of the first aspect or any one of the possible implementations of the first aspect.

In a fifth aspect, there is provided a computer program product comprising: computer program code which, when run on a computer, causes the computer to perform the method of the first aspect or any of the possible implementations of the first aspect.

In a sixth aspect, the present application provides a chip comprising a processor coupled to a memory for reading and executing a software program stored in the memory to implement the method of the first aspect or any one of the possible designs of the first aspect.

These and other aspects of the application will be more readily apparent from the following description of the embodiments.

Drawings

FIG. 1 is a schematic diagram of a network architecture suitable for use in embodiments of the present application;

fig. 2 is a schematic flow chart of a session establishment method according to an embodiment of the present application;

fig. 3 is a schematic diagram of session establishment according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the drawings attached to the specification.

The communication method provided by the embodiment of the application can be applied to a fourth generation (4th generation,4G) communication system, such as long term evolution (long term evolution, LTE), a fifth generation (5th generation,5G) communication system, such as a 5G New Radio (NR), or various future communication systems, such as a sixth generation (6th generation,6G) communication system.

The method and the device provided by the embodiment of the application are based on the same or similar technical conception, and because the principle of solving the problems by the method and the device is similar, the implementation of the device and the method can be mutually referred, and the repeated parts are not repeated.

The terminal device according to the embodiment of the present application may be a wireless terminal device capable of receiving the scheduling and indication information of the network device. The terminal device may be a device that provides voice and/or data connectivity to a user, or a handheld device with wireless connectivity, or other processing device connected to a wireless modem.

A terminal device, also called User Equipment (UE), mobile Station (MS), mobile Terminal (MT), etc. A terminal device is a device that includes wireless communication functionality (providing voice/data connectivity to a user). For example, a handheld device having a wireless connection function, an in-vehicle device, or the like. Currently, examples of some terminal devices are: a mobile phone, a tablet, a notebook, a palm, a mobile internet device (mobile internet device, MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in the internet of vehicles, a wireless terminal in the unmanned (self driving), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in the smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city, or a wireless terminal in smart home (smart home), and the like. For example, the wireless terminal in the internet of vehicles may be a vehicle-mounted device, a whole vehicle device, a vehicle-mounted module, a vehicle, or the like. The wireless terminal in the industrial control can be a camera, a robot and the like. The wireless terminal in the smart home can be a television, an air conditioner, a floor sweeping machine, a sound box, a set top box and the like.

The network device involved in the embodiment of the application can be a device in a wireless network. For example, the network device may be a device deployed in a radio access network to provide wireless communication functionality for terminal devices. For example, the network device may be a radio access network (radio access network, RAN) node, also referred to as access network device, that accesses the terminal device to the wireless network.

Network devices include, but are not limited to: an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (home evolved NodeB, or home Node B, HNB, for example), a baseband unit (BBU), an Access Point (AP) in a wireless fidelity (wireless fidelity, WIFI) system, a wireless relay Node, a wireless backhaul Node, a transmission point (transmission point, TP), or a transmission reception point (transmission and reception point, TRP), etc., may also be a network device in a 5G mobile communication system. For example, next generation base stations (gNB) in NR systems, transmission reception points (transmission reception point, TRP), TP; or one or a group (including a plurality of antenna panels) of base stations in a 5G mobile communication system; alternatively, the network device may also be a network node constituting a gNB or a transmission point. Such as a BBU, or a Distributed Unit (DU), etc.

In some deployments, the gNB may include a Centralized Unit (CU) and DUs. The gNB may also include an active antenna unit (active antenna unit, AAU). The CU implements part of the functionality of the gNB and the DU implements part of the functionality of the gNB. For example, the CU is responsible for handling non-real time protocols and services, implementing the functions of the radio resource control (radio resource control, RRC), packet data convergence layer protocol (packet data convergence protocol, PDCP) layer. The DU is responsible for handling physical layer protocols and real-time services, and implements functions of a radio link control (radio link control, RLC), MAC, and Physical (PHY) layers. The AAU realizes part of physical layer processing function, radio frequency processing and related functions of the active antenna. The information of the RRC layer may eventually become information of the PHY layer or may be converted from the information of the PHY layer. Under this architecture, higher layer signaling (e.g., RRC layer signaling) may also be considered to be sent by DUs, or by DUs and AAUs. It is understood that the network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may be divided into network devices in the RAN, or may be divided into network devices in a Core Network (CN), which is not limited by the present application.

To facilitate understanding of the embodiments of the present application, a communication system suitable for use in the embodiments of the present application will first be described with reference to the communication system shown in fig. 1. Fig. 1 shows a schematic diagram of a network architecture suitable for use in embodiments of the present application. As shown in fig. 1, the terminal device may support an LTE system and an NR system. In LTE and NR systems, the network transmits data in the form of internet protocol (internet protocol, IP) packets and provides IP connectivity to terminal devices.

In the NR system, the terminal equipment can initiate a PDU session establishment request to the network side, and the network side establishes a PDU session for the service of the terminal equipment according to the request of the terminal equipment. After the PDU session is established successfully, data transmission can be performed between the terminal equipment and the network side through the PDU session, wherein one PDU session comprises one or more QoS flows. In NR systems, qoS flows are the smallest granularity for QoS management, enabling more flexible QoS control, one QoS flow for each QoS flow identification.

In the LTE system, the terminal equipment can initiate an EPS bearing establishment request to the network side, and the network side establishes the EPS bearing for the service of the terminal equipment according to the request of the terminal equipment. After the EPS bearer is established successfully, data transmission can be performed between the terminal device and the network side through the EPS bearer, wherein one EPS bearer corresponds to one EPS bearer identifier (EPS bearer identity, EBI). In NR systems, one QoS flow in a PDU session may be associated with one mapped EPS bearer context.

If the terminal device establishes a PDU session in the NR system and moves to the LTE system while in the connected state, a handover procedure will be triggered. If an N26 interface exists between the NR system and the LTE system, when the terminal equipment is switched from the NR system to the LTE system, the terminal equipment can switch the service transmitted through the PDU session in the NR system to the mapping EPS bearer associated with the PDU session according to the mapping EPS bearer context, thereby ensuring smooth switching of the service and ensuring continuity of the service. Wherein, the mapping EPS bearer context may include the following information: EPS bearer identity (EPS bearer identity, EBI); mapping the length of EPS bearing context; an operation code (operation code) of the EPS bearer; number of EPS parameters; EPS parameter list, etc. The application is not limited in this regard and may also include, for example, traffic flow templates (traffic flow template, TFT), one TFT may include one or more packet filters, mapping details of EPS bearer contexts.

For example, in fig. 1, the PDU session established by the NR system for the terminal device is described by taking two QoS flows (QoS flow 1 and QoS flow 2 respectively) as an example, where both QoS flow 1 and QoS flow 2 have a mapping relationship with an EPS bearer with EBI of 5, and here, only ebi=5 is taken as an example, and the value of EBI may be other values. When the terminal equipment needs to be switched from the NR system to the LTE system, a 5G-to-4G switching flow using an N26 interface is triggered. When the terminal device performs a different system change, for example, when switching from the NR system to the LTE system, both QoS flow 1 and QoS flow 2 are mapped to EPS bearers with EBI of 5.

For a QoS flow in a PDU session, if a mapping EPS bearer context associated with the QoS flow is deleted or disabled, after the terminal device performs handover between different systems, normal bearer mapping cannot be performed, which may cause problems such as failure in service data transmission. For example, in the NR system, if the terminal device only has a PDU session corresponding to an IP multimedia subsystem (IP multimedia subsystem, IMS) of a single voice call service, after deleting a mapped EPS bearer context of the PDU session corresponding to the IMS, the terminal device initiates the voice call service in the NR system, and the network side configures the terminal device to switch to the LTE system to perform an EPS Fallback (FB) call, and since the PDU session corresponding to the current IMS does not have the mapped EPS bearer context, the terminal device initiates an attach procedure, which may cause the voice call service to fail.

For another example, in the case that the terminal device has a PDU session corresponding to the IMS of the voice call service and a PDU session corresponding to the data service in the NR system, if the terminal device deletes the mapped EPS bearer context of the PDU session corresponding to the data service, the terminal device initiates the data service in the NR system, and after the terminal device switches to the LTE system, since the current data session does not have the mapped EPS bearer context, the data service of the terminal device is in a release interruption state in a period of time, which results in a longer service delay and poor user experience.

For this reason, the present application provides a method that can solve the above-described problems, which will be described in detail later.

The plural references in the embodiments of the present application refer to two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. In addition, it should be understood that in the description of the present application, the words "first," "second," and the like are used merely for distinguishing between the descriptions and not for indicating or implying any relative importance or order.

The network architecture and the service scenario described in the embodiments of the present application are for more clearly describing the technical solution of the embodiments of the present application, and do not constitute a limitation on the technical solution provided by the embodiments of the present application, and those skilled in the art can know that, with the evolution of the network architecture and the appearance of the new service scenario, the technical solution provided by the embodiments of the present application is applicable to similar technical problems.

As shown in fig. 2, a flow chart of a session establishment method according to an embodiment of the present application is illustrated by taking interaction between a terminal device and a network device as an example, where the method includes:

Optionally, S201: the network device sends a PDU session modification command (PDU session modification command) message to the terminal device; accordingly, the terminal device receives the PDU session modification command message from the network device.

The PDU session modification command message is used for modifying the first PDU session, and comprises information such as QoS flow description of QoS flow included in the first PDU session and mapping EPS bearing context. The mapped EPS bearer context may comprise one or more TFTs, and one TFT may comprise one or more packet filters.

Optionally, S202: the terminal device checks whether there is an error in mapping the EPS bearer context.

In the embodiment of the application, the terminal equipment can check whether the mapping EPS bearing context has one or more of the following errors:

mapping EPS bearer context operation semantic errors (semantic error in the mapped EPS bearer operation);

mapping a traffic flow template operation semantic error included in the EPS bearer context (semantic errors in TFT operations);

mapping a traffic flow template operation syntax error included in the EPS bearer context (syntactical errors in TFT operations);

mapping packet filter semantic errors included in the EPS bearer context (semantic errors in packet filters);

The packet filter syntax error included in the EPS bearer context is mapped (syntactical errors in packet filters).

For example, in case one or case two, there is a mapping EPS bearer context operation semantic error:

in case one, the operation code in the mapping EPS bearer context is: the existing EPS bearer is modified and there is no existing mapped EPS bearer context associated with the PDU session being modified with the same EPS bearer identity.

In case two, the operation code in the mapping EPS bearer context is: a new EPS bearer is created or an existing EPS bearer is modified and the generated mapped EPS bearer context has an optional parameter (e.g., mapped EPS QoS parameter or traffic flow template of the proprietary EPS bearer context) that is invalid or missing.

The above is merely an example, and other situations may exist for mapping EPS bearer context operation semantic errors, which are not illustrated one by one.

For example, if the mapped EPS bearer context includes a TFT, in case three, there is a traffic flow template operation semantic error:

case three, the PDU session modification command message indicates that the TFT operates as: existing TFTs of the proprietary EPS bearer context are deleted.

The above is merely an example, and other situations may exist for the business flow template operation semantic errors, which are not illustrated one by one.

For example, if the mapped EPS bearer context includes a TFT, in case four, there is a traffic flow template operation syntax error:

in case four, the TFT indicated by the PDU session modification command message operates as: "delete TFT" or "no TFT operation" and there is a list of non-null packet filters in the TFT.

The above is merely an example, and other situations may exist for a traffic flow template operation syntax error, which are not illustrated one by one.

For example, if the mapped EPS bearer context includes TFTs, in case five, there is a packet filter semantic error:

in case five, a packet filter is composed of conflicting packet filter components, this will invalidate the packet filter.

The above is merely an example, and other cases of packet filter semantic errors may exist and are not illustrated herein one by one.

For example, if the mapped EPS bearer context includes TFTs, in case six, there is a packet filter syntax error:

in case six, the reserved value of the packet filter component identifier is used when there are other types of syntax errors in the encoding of the packet filter.

The above is merely an example, and other cases of packet filter syntax errors may exist and are not illustrated herein one by one.

In addition to the errors described above, other errors may exist in embodiments of the present application. For example, in case seven, if the opcode in the EPS bearer context mapped included in the PDU session modification command message is "create new EPS bearer", and there is neither a corresponding authorized QoS flow description nor an existing QoS flow description corresponding to the EPS bearer identity contained in the EPS bearer context in the PDU session modification command message. In this case, it may be determined that there is an error in mapping the EPS bearer context.

As another example, in case eight, if the selected PDU session type is "Unstructured", the terminal device supports inter-system switching from the N1 mode to the S1 mode, the terminal device does not support establishment of a PDN connection for a PDN type set to "non-IP" in the S1 mode, and the parameter list field of one or more authorized QoS flow descriptions received in the authorized QoS flow description resource element of the PDU session modification command message contains EBI, the terminal device should locally remove EBI from the parameter list field of the one or more authorized QoS flow descriptions. In this case, it may be determined that there is an error in mapping the EPS bearer context.

For another example, in case nine, if the selected PDU session type is "Ethernet", the terminal device supports inter-system switching from N1 mode to S1 mode, the terminal device does not support establishment of PDN connection for PDN type set to "non-IP" in S1 mode, the terminal device, the network or both do not support Ethernet PDN type in S1 mode, and the parameter list field of one or more authorized QoS flow descriptions received in the authorized QoS flow description resource element of the PDU session modification command message contains EBI, from which the terminal device should locally remove EBI. In this case, it may be determined that there is an error in mapping the EPS bearer context.

In the embodiment of the present application, when any error exists in the mapped EPS bearer context, the terminal device may further execute S203:

s203: the terminal equipment sends PDU conversation modification request information to the network equipment, deletes the mapping EPS bearing context, and the PDU conversation modification request information comprises a cause value corresponding to the error; accordingly, the network device receives the PDU session modification request message from the terminal device.

For example, if there is a mapping EPS bearer context operation semantic error, the PDU session modification request message includes a cause value of #85.

If there is a traffic flow template operation semantic error, the PDU session modification request message includes a cause value of #41.

If there is a traffic flow template operation syntax error, the PDU session modification request message includes a cause value of #42.

If there is a packet filter semantic error, the PDU session modification request message includes a cause value #44.

If there is a packet filter syntax error, the PDU session modification request message includes a cause value of #45.

If there is an error in case seven through case nine, the PDU session modification request message includes a cause value of #85.

The above is merely an example, and each error may also correspond to other cause values, which may be determined according to the evolution of the protocol.

S204: under the condition that the first protocol data unit session does not have the corresponding mapping evolution packet system bearer context, the terminal equipment sends a PDU session release request message to the network equipment; accordingly, the network device receives the PDU session release request message from the terminal device.

Wherein the PDU session release request message is for requesting release of the first PDU session.

In the embodiment of the present application, the absence of the corresponding mapped EPS bearer context for the first PDU session may refer to the absence or absence of the corresponding mapped EPS bearer context for the first PDU session. In this case, when the terminal device performs the inter-system conversion, for example, the terminal device switches from the NR system to the LTE system, the terminal device cannot determine the EPS bearer corresponding to the first PDU session in the LTE system, and the service corresponding to the first PDU session may have discontinuous or failed data transmission.

There may be various scenarios where the first PDU session does not have a corresponding mapped EPS bearer context, for example, in the case of S201 to S203, when there is an error in the mapped EPS bearer context corresponding to the first PDU session, the terminal device deletes the mapped EPS bearer context corresponding to the first PDU session, and then the terminal device may determine that the first PDU session does not have a corresponding mapped EPS bearer context. Of course, the above is merely an example, and other situations may exist where the first PDU session does not have a corresponding mapped EPS bearer context, which the present application is not limited to.

In the embodiment of the present application, in order to reduce the influence of the service corresponding to the release of the first PDU session, the terminal device may release the first PDU session in the following two scenarios,

in the first scenario, when the terminal device is in an RRC idle state (idle state for short) or an RRC inactive state (inactive state for short), a PDU session release request message is sent to the network device.

In the second scenario, if the terminal device does not transmit the data packet of the service through the first PDU session within the preset duration, the terminal device may send a PDU session release request message to the network device.

The specific value of the preset duration can be determined according to practical situations, which is not limited by the application. The preset duration can be configured for the network device, can be determined by the terminal device independently, and can be agreed by a protocol.

S205: the network equipment sends PDU session release command information to the terminal equipment; accordingly, the terminal device receives a PDU session release command message from the network device, the PDU session release command message being used to indicate release of the first PDU session.

Wherein the PDU session release command message may be a response to the PDU session release request message, and the network device may send the PDU session release command message to the terminal device when releasing the first PDU session is completed.

Further, after the terminal device releases the first PDU session, in order not to affect the service corresponding to the first PDU session, the terminal device may further reestablish the PDU session for the service, that is, execute the following procedure:

S206: the terminal equipment sends PDU session establishment request information to the network equipment; accordingly, the network device receives the PDU session establishment request message from the terminal device.

The PDU session establishment request message is used for requesting to establish a second PDU session; the first PDU session corresponds to the same service as the second PDU session.

In the process of establishing the second PDU session, the network device may send information such as the mapped EPS bearer context corresponding to the second PDU session to the terminal device, which may be specifically referred to as follows.

S207: the network device sends a PDU session establishment acceptance (PDU session establishment accept) message to the terminal device; correspondingly, the terminal device receives the PDU session establishment acceptance message from the network device.

The PDU session establishment acceptance message comprises information such as a mapped EPS bearing context corresponding to the second PDU session, qoS flow description of QoS flow included in the second PDU session, and the like. That is, the established second PDU session with the corresponding mapped EPS bearer context may be used as a intersystem change.

By the method provided by the embodiment of the application, when the terminal equipment determines that the first PDU session does not have the corresponding mapping EPS bearing context, the first PDU session can be actively deactivated, and then a new second PDU session is established for the service corresponding to the first PDU session again, so that the reliability and continuity of the service can be ensured in the process of switching different systems (such as switching from an NR system to an LTE system) of the terminal equipment, and the situations of call failure, service interruption, discontinuity and the like can be avoided.

For example, in the case that the terminal device has a PDU session corresponding to an IMS service for voice call in the NR system, if the network device modifies the PDU session corresponding to the IMS service through a PDU session modification command message, the terminal device checks the mapped EPS bearer context of the PDU session corresponding to the IMS service to determine that there is an error, so as to delete the mapped EPS bearer context of the PDU session corresponding to the IMS service. When the terminal equipment initiates a voice call service in an NR system, the network side configures the terminal equipment to switch to an LTE system for EPS FB call, the occurrence of the situations of discontinuous or failure of the voice call and the like can be avoided, the reliability of the service is improved, and the user experience is improved.

For another example, under the NR system, if the terminal device has a PDU session corresponding to the IMS service and a PDU session corresponding to the non-IMS service, and if there is no mapping bearer under the NR system, by using the method provided by the embodiment of the present application, the terminal device may reestablish the PDU session corresponding to the non-IMS service, where the reestablished PDU session has a corresponding mapping EPS bearer. At this time, when the terminal equipment is switched from the NR system to the LTE system, the service data can be transmitted without interruption, so that the switching time delay is reduced, the service reliability is improved, and the user experience is improved.

The foregoing flow is described below by way of a specific embodiment. Fig. 3 is a schematic flow chart of a session establishment method according to an embodiment of the present application.

S301: the network device sends a PDU session modification command message to the terminal device.

The PDU session modification command message is used to modify the first PDU session, and the PDU session modification command message includes information such as mapping EPS bearer context.

S302: the terminal device sends a PDU session modification completion message to the network device.

The PDU session modification command complete message is a response message to the above message.

If the terminal device determines that there is at least one error described in S201 in mapping the EPS bearer context, the following procedure is performed:

s303: the terminal equipment sends PDU conversation modification request information to the network equipment, deletes the mapping EPS bearing context, and the PDU conversation modification request information comprises a cause value corresponding to the error.

When the terminal equipment is in an idle state or an inactive state or the terminal equipment does not transmit the data packet of the service through the first PDU session within a preset duration, executing the following procedures:

s304: the terminal device sends a PDU session release request message to the network device.

The PDU session release request message is for requesting release of the first PDU session.

S305: the network device sends a PDU session release command message to the terminal device.

The protocol data unit session release command message is used to indicate that the release of the first PDU session is complete, i.e. the message indicates that the network device has deleted the first PDU session related information.

S306: the terminal device sends a PDU session release completion message to the network device.

The message is a message in response to the PDU session release command message, and the terminal device may send a PDU session release complete message after deleting the first PDU session related information locally.

Further, the terminal device may trigger to reestablish the PDU session for the service corresponding to the first PDU session, so as to ensure continuity of service data transmission corresponding to the first PDU session, and specifically may include the following steps:

s307: the terminal device sends a PDU session establishment request message to the network device.

The message is for requesting establishment of a second PDU session for a service corresponding to the first PDU session.

S308: the network device sends a PDU session establishment acceptance message to the terminal device.

The message includes information such as a mapped EPS bearer context corresponding to the second PDU session.

Through the above flow, when the terminal equipment determines that the first PDU session corresponding to the service does not have the corresponding mapping EPS bearing context, the first PDU session is released, a second PDU session corresponding to the service is established, and the established second PDU session has the corresponding mapping EPS bearing context, so that the continuity of data transmission of the service can be ensured when the terminal equipment performs different system transformation.

It will be appreciated that the examples of fig. 2-3 in the embodiments of the present application are merely for convenience of those skilled in the art to understand the embodiments of the present application, and are not intended to limit the embodiments of the present application to the specific scenarios illustrated. It will be apparent to those skilled in the art from the examples of fig. 2-3 that various equivalent modifications or variations may be made, and such modifications or variations are intended to be within the scope of the embodiments of the present application.

It will also be appreciated that the various steps of fig. 2-3 described above are merely exemplary and are not strictly limited in this regard. In addition, the sequence number of each process does not mean the sequence of execution sequence, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

It will also be appreciated that some optional features of the various embodiments of the application may, in some circumstances, be independent of other features or may, in some circumstances, be combined with other features, without limitation.

It is also to be understood that the aspects of the embodiments of the application may be used in any reasonable combination, and that the explanation or illustration of the various terms presented in the embodiments may be referred to or explained in the various embodiments without limitation.

It should be further understood that the magnitude of the various numerical numbers in the embodiments of the present application does not mean the order of execution, but merely serves to distinguish between the convenience of description and the implementation of the embodiments of the present application, and should not constitute any limitation.

It should also be understood that in the embodiments of the present application, some message names, such as a protocol data unit session release request message, are referred to, and the naming thereof does not limit the protection scope of the embodiments of the present application.

Corresponding to the methods given by the above method embodiments, the embodiments of the present application also provide corresponding apparatuses, where the apparatuses include corresponding modules for executing the above method embodiments. The module may be software, hardware, or a combination of software and hardware. It will be appreciated that the technical features described in the method embodiments described above are equally applicable to the device embodiments described below.

Fig. 4 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication device 400 comprises a communication unit 420 and a processing unit 410. The communication unit 420 may implement a corresponding communication function, and the communication unit 420 may also be a communication interface or a communication unit. The processing unit 410 may implement corresponding processing functions, such as processing instructions and/or data.

In a possible implementation manner, the communication apparatus 400 may further include a storage unit, where the storage unit may be used to store instructions and/or data, and the processing unit 410 may read the instructions and/or data in the storage unit, so that the apparatus implements the foregoing method embodiments.

The communication apparatus 400 may be configured to perform the actions performed by the terminal device in the above method embodiment, where the communication unit 420 in the communication apparatus 400 is configured to perform the operations related to the transceiving of the terminal device in the above method embodiment, and the processing unit 410 is configured to perform the operations related to the processing of the terminal device in the above method embodiment.

As a design, the communication apparatus 400 is configured to perform the actions performed by the terminal device in the above method embodiment:

a processing unit, configured to send, by a communication unit, a protocol data unit session release request message, where the protocol data unit session release request message is used to request release of a first protocol data unit session, where the first protocol data unit session does not have a corresponding mapping evolved packet system bearer context;

a communication unit, configured to receive a protocol data unit session release command message, where the protocol data unit session release command message is used to instruct to release the first protocol data unit session; transmitting a protocol data unit session establishment request message, wherein the protocol data unit session establishment request message is used for requesting to establish a second protocol data unit session; the first protocol data unit session corresponds to the same service as the second protocol data unit session.

In one possible design, the communication device is in an idle state or an inactive state before the communication unit sends a protocol data unit session release request message.

In one possible design, before the communication unit sends a protocol data unit session release request message, no data packets of the service are transmitted through the first protocol data unit session for a preset duration.

In one possible design, the communication unit is further configured to:

receiving a protocol data unit session modification command message, wherein the protocol data unit session modification command message comprises the mapping evolution packet system bearer context;

transmitting a protocol data unit session modification request message under the condition that the bearer context of the mapping evolution packet system has errors, wherein the protocol data unit session modification request message comprises a cause value corresponding to the errors;

the processing unit is further configured to: and deleting the mapping evolution packet system bearer context.

In one possible design, the error includes one or more of the following:

the mapping evolution packet system bears the context operation semantic errors;

the mapping evolution packet system carries a business flow template operation semantic error included by the context;

The mapping evolution packet system carries a business flow template operation grammar error included by the context;

the mapping evolution packet system carries a packet filter semantic error included by a context;

the mapping evolved packet system carries packet filter syntax errors included in the context.

In one possible design, the communication unit is further configured to:

and receiving a protocol data unit session establishment acceptance message, wherein the protocol data unit session establishment acceptance message comprises a mapping evolution packet system bearing context corresponding to the second protocol data unit session.

The foregoing is merely an example, and the processing unit 410 and the communication unit 420 may perform other functions, and a more detailed description may refer to the related descriptions in the method embodiments shown in fig. 2 to 3, which are not repeated herein.

Fig. 5 illustrates a communication device according to an embodiment of the present application, where the communication device illustrated in fig. 5 may be an implementation of a hardware circuit of the communication device illustrated in fig. 4. The communication device may be adapted to perform the functions of the terminal device in the above-described method embodiments in the flowcharts shown above. For ease of illustration, fig. 5 shows only the main components of the communication device.

As shown in fig. 5, the communication device 500 includes a processor 510 and an interface circuit 520. The processor 510 and the interface circuit 520 are coupled to each other. It is understood that interface circuit 520 may be a transceiver, pin, or input-output interface. Optionally, the communication device 500 may further comprise a memory 530 for storing instructions to be executed by the processor 510 or for storing input data required by the processor 510 to execute instructions or for storing data generated after the processor 510 executes instructions. Alternatively, some or all of memory 530 may be located in processor 510.

When the communication device 500 is used to implement the methods shown in fig. 2 to 3, the processor 510 is used to implement the functions of the processing unit 410, and the interface circuit 520 is used to implement the functions of the communication unit 420.

It is to be appreciated that the processor in embodiments of the application may be a central processing unit, as well as other general purpose processors, digital signal processors, application specific integrated circuits or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general purpose processor may be a microprocessor, but in the alternative, it may be any conventional processor.

The memory in embodiments of the present application may be random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, removable disk, or any other form of storage medium known in the art.

It should be noted that when the processor is a general purpose processor or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (storage module) may be integrated into the processor.

It should also be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A session establishment method, wherein the method is applied to a terminal device, and comprises:

transmitting a protocol data unit session release request message under the condition that a first protocol data unit session does not have a corresponding mapping evolution packet system bearer context, wherein the protocol data unit session release request message is used for requesting to release the first protocol data unit session;

receiving a protocol data unit session release command message, wherein the protocol data unit session release command message is used for indicating to release the first protocol data unit session;

Transmitting a protocol data unit session establishment request message, wherein the protocol data unit session establishment request message is used for requesting to establish a second protocol data unit session;

wherein the first protocol data unit session corresponds to the same service as the second protocol data unit session.

2. The method of claim 1, wherein the terminal device is in an idle state or an inactive state prior to the sending of the protocol data unit session release request message.

3. The method of claim 1, wherein prior to sending the protocol data unit session release request message, the method further comprises:

and not transmitting the data packet of the service through the first protocol data unit session within a preset duration.

4. A method according to any one of claims 1 to 3, wherein, in the case that the first protocol data unit session has no corresponding mapping evolved packet system bearer context, specifically comprising:

And under the condition that the mapping evolution packet system bearing context has errors, transmitting a protocol data unit session modification request message, and deleting the mapping evolution packet system bearing context, wherein the protocol data unit session modification request message comprises a cause value corresponding to the errors.

5. The method of claim 4, wherein the error comprises one or more of:

6. The method according to any one of claims 1 to 5, further comprising:

7. A communication device, comprising:

a communication unit, configured to receive a protocol data unit session release command message, where the protocol data unit session release command message is used to indicate that the first protocol data unit session is released; transmitting a protocol data unit session establishment request message, wherein the protocol data unit session establishment request message is used for requesting to establish a second protocol data unit session; the first protocol data unit session corresponds to the same service as the second protocol data unit session.

8. The apparatus of claim 7, wherein the communication device is in an idle state or an inactive state prior to the communication unit sending a protocol data unit session release request message.

9. The apparatus of claim 7, wherein no packets of the service are transmitted over the first pdu session for a predetermined period of time before the pdu session release request message is sent by the communication unit.

10. The apparatus according to any one of claims 7 to 9, wherein the communication unit is further configured to:

11. The apparatus of claim 10, wherein the error comprises one or more of:

12. The apparatus according to any one of claims 7 to 11, wherein the communication unit is further configured to:

13. A communications apparatus comprising a processor coupled to a memory, the memory having a computer program stored therein; the processor is configured to invoke a computer program in the memory to cause the communication device to perform the method of any of claims 1 to 6.

14. A wireless communications apparatus, comprising:

a processing circuit and an interface circuit; wherein,

the interface circuit is configured to couple with a memory external to the wireless communication device and provide a communication interface for the processing circuit to access the memory;

the processing circuitry is configured to execute program instructions in the memory to implement the method of any of claims 1 to 6.

15. A computer readable storage medium, characterized in that the storage medium has stored therein a computer program or instructions which, when executed by a computer, implement the method of any of claims 1 to 6.

16. A computer program product, characterized by:

the computer program product comprising program code for implementing the method of any of claims 1 to 6 when executed by a processor.