EP4335145A1

EP4335145A1 - Method for registering a user terminal with a network-sliced communication network

Info

Publication number: EP4335145A1
Application number: EP22726483.5A
Authority: EP
Inventors: Sandrine Lataste; Steve Tsang Kwong U
Original assignee: Orange SA
Current assignee: Orange SA
Priority date: 2021-05-03
Filing date: 2022-04-27
Publication date: 2024-03-13
Also published as: CN117597970A; WO2022234219A1; US20240236909A1; FR3122543A1

Abstract

The invention relates to a method for registering a user terminal (L/Fl) with a network-sliced communications network, by a network device (A/Fl), and comprising - a step of receiving (200) a registration request sent by the user terminal to register with the network - a step of obtaining (300), in context information associated with the user terminal, an authorisation/rejection of at least one network slice previously authorised/rejected during a previous registration of the user terminal for the same type of access and the same registration area, or - a step of autonomous determination (400) of a registration status for each of the network slices subscribed to by the user and identified by the network device in a network parameter comprising the identifiers of all the network slices subscribed to by the user, delivering a registration decision.

Description

TITLE: Method for registering a user terminal with a communications network organized in network slices

Technical area

The invention is located in communications networks, and in particular in networks in which network slices are instantiated, making it possible to dedicate communications network equipment/functions/configurations for specific services and/or specific clients and/or specific terminals.

Prior art

Some network architectures specified and deployed today are structured in network slices allowing a user terminal, depending on the customer's subscription (the terminal can be used by a user other than the customer who has taken out a subscription; the term user or customer will be used indifferently thereafter for simplification), to benefit from specific functions (routing, processing, administration, etc.) adapted to one or more criteria among the type of customer, the type of terminal, the type of application, type of access, etc. Thus, each slice makes it possible to offer a level of quality of service and security in accordance with one or more criteria cited above. It should also be noted that customers and terminals are on the one hand increasingly diversified (loT terminals (Internet of Things in English), smartphones, robots, residential gateways, variety of so-called communicating equipment, etc.) and on the other hand have quite different capacities and needs. This development is also accompanied by a capacity of at least some of these terminals to be able to access simultaneously or not a plurality of applications whose data is possibly routed on distinct network sections. It should be noted that these developments target both fixed networks and mobile networks and that the specifications of so-called fifth generation (5G) networks incorporate this structuring into network slices.

According to the specifications of the 5G networks to which particular reference will be made in the remainder of this description, a user terminal must implement a registration procedure in order to be able to access the slots subscribed by the user (for example in his 5G subscription). The subscribed S-NSSAI slice identifiers (in English Single-Network Slice Selection Assistance Information) are stored locally by the terminal (in a noted data, in English, Configured NSSAI) and in the network (in a noted data, in English, Subscribed NSSAI). The registration procedure therefore begins with a step implemented by the terminal consisting in generally requesting registration for one or more slices, for example by indicating the S-NSSAI slice identifier(s) in the Requested NSSAI parameter of its registration request. This request is implemented on the basis of information stored by the user terminal, and in particular relating to the slices configured (Configured NSSAI) and possibly authorized (Allowed NSSAI) during a previous recording.

Thus, the user terminal also stores the identifiers of slots for which the terminal is authorized to activate one or more packet data sessions, via the network and in particular via an entity denoted AMF (Access and Mobility Function), in a datum denoted , in English, Allowed NSSAI, containing all or part of the subscribed S-NSSAI. The user terminal also stores the identifiers of slices which are prohibited to it (by the network) in a datum denoted, in English, Rejected NSSAI. These authorized/rejected slice identifiers are received by the terminal in the acceptance response from the network during its registration procedure with the network.

The registration procedure then comprises a step of determination, by the network, of the slices authorized, respectively rejected, to communicate to the user terminal. The network (in particular via the AMF entity) accepts the registration request on the basis of the slices requested, for the type of access and the registration zone in use by the user terminal and an update may be made in the event of a change, for example in the subscription or the location of the user terminal. The acceptance response from the network contains information to report a recording status (authorised/rejected/in progress status) for each slice requested, for example at least one parameter from:

- Allowed NSSAI: corresponds to the identifiers of authorized S-NSSAI slices;

- Rejected NSSAI: corresponds to the identifiers of rejected S-NSSAI slices, with the reason for rejection (for example "no authorization in the public land mobile network (PLMN, in English Public Land Mobile Network) or the non-public autonomous network ( SNPN, in English Stand-alone Non-Public Network) in progress" or "no authorization in the current registration area");

- Configured NSSAI: corresponds to the particular case where the Requested NSSAI parameter of the registration request is absent or to the particular case where a change in the value of the Configured NSSAI parameter has occurred;

- Pending NSSAI: corresponds to the case where it is necessary and indicated in the subscription that the slice be authenticated before it can be considered as authorized, this authentication being in progress or to come. A response rejecting the registration request is issued in the event that no slice could be authorized or subjected to current or future authentication.

This standard registration procedure has certain drawbacks relating to the choice of slices requested by the user terminal, i.e. the S-NSSAI slice identifiers of the Requested NSSAI parameter of the registration request, this choice possibly depending on the implementation of the manufacturer of the user terminal, policies or applications defined within the user terminal, and having impacts both at the user level and at the level of the operator or the network itself.

For example, if a user wishes to access one or more slices that he did not request during recording, he must initiate another recording procedure for these slices, which lengthens his access time to the service, the time to execute the registration procedure. According to another example, if a user terminal first requests registration for the identifier ranges S-NSSAI#1, S-NSSAI#2 then wishes to use the identifier range S-NSSAI#3, it must redo a registration request for the identifier slice S-NSSAI#3. If he does not request recording for the previously recorded slices at the same time (here S-NSSAI#1 and S-NSSAI#2), he loses the previously saved slices and must redo either a recording for each slice d identifier S-NSSAI#1 then S-NSSAI#2, i.e. a record for the two “old” slices when he wants to use them. Not to mention that, in this case, if a data session was active on the user terminal for one or other of the S-NSSAI#1/S-NSSAI#2 identifier ranges, this session is interrupted at moment of acceptance of the registration of the S-NSSAI#3 identifier slice.

Another drawback lies in the fact that the current standard requires that, in the registration request of the user terminal, the Requested NSSAI parameter contain the S-NSSAI slice identifiers of the Allowed NSSAI parameter (obtained during a previous registration) for which there is one or more active data sessions. If the user terminal does not do this, for example following a bad configuration of the user terminal, then the active data sessions are interrupted since, according to the standard, a user terminal can only establish data sessions for slots authorized during of recording.

These situations are detrimental for an operator who markets 5G services, for example, because a sudden cut in current data sessions is very negative for the user experience.

For the operator, this induces additional signaling in the network for each additional recording and its interest would be to limit the number of recordings made by a user terminal while allowing better access to services for the user. Finally, the number of S-NSSAI slice identifiers of the Requested NSSAI parameter per recording request is also a concern in terms of network load, especially for the Internet of Things, and the current standard recommends reducing this number. S-NSSAI slice identifiers of the Requested NSSAI parameter per recording request.

There is therefore a need for a technique allowing an optimized procedure for the registration of network slices by a user terminal and a better determination of the authorized network slices both at the level of the user terminal and at the level of the network, while allowing applicability in 5G as well as any future generation of networks using a network slice structured architecture.

Disclosure of Invention

The invention meets this need by proposing a method for registering a user terminal with a communications network organized into network slices, the user terminal being capable of transmitting and receiving data on the network, the user terminal comprising subscription data of a user for at least one of the slices of the network, the method being implemented at least by network equipment capable of communicating with the user terminal via the network and comprising

- A step of receiving a registration request sent by the user terminal to register with the network;

- a step of obtaining, in context information associated with the user terminal, an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration area, delivering a registration decision, or

- a step of autonomous determination of a registration status for each of the slices of the network subscribed by the user and identified by the network equipment in a network parameter comprising the identifiers of all the slices of the network subscribed by the user , issuing a registration decision.

Thus, the present technique is based on an entirely new and inventive approach to the procedure for registering a terminal with a network, consisting in taking account of one or more registrations previously carried out by the terminal under the same conditions. access and location or to determine, independently for the network (that is to say without taking into account information transmitted or not by the user terminal concerning the slots to be recorded), the recording status ( ie the authorized/rejected/pending status) of all subscribed slots identified in a network parameter listing all subscribed slots. This approach makes it possible in particular to greatly limit the number of successive recordings which may be requested by a user terminal, since a current recording takes account of a history of recordings (assuming here that the history may possibly contain the rejected slices), according to a first embodiment, or determines the status of all the tranches subscribed in a single record, according to a second embodiment.

This approach therefore also makes it possible to limit the signaling load in the network.

Moreover, this approach also makes it possible to avoid the cuts of data sessions not desired by a user, by keeping in the list of authorized slices all those having been previously authorized during previous recordings according to a first embodiment or by making additional recording unnecessary in a second embodiment.

According to a first embodiment, relating to a cumulative recording mode, the recording decision comprises at least one authorized slice parameter comprising at least one identifier of one of the slices of the network previously authorized during at least one previous recording of the user terminal for the same type of access and the same recording zone and/or at least one parameter of rejected slices comprising at least one identifier of one of the slices of the network previously rejected during at least one previous recording of the user terminal for the same type of access and the same recording area.

Thus, according to this first embodiment, any registration request received by network equipment, originating from a user terminal, is processed so as to take account of the authorized and/or rejected status, known in context information associated with the user terminal, for one or more slices previously requested during one or more previous recordings, so as to deliver a list of authorized slices and/or a list of rejected slices, for example in the form of standardized parameters such as Allowed NSSAI and Rejected NSSAI.

This makes it possible to respond to the user terminal with a list of authorized slices and/or a list of rejected slices taking account of the history of the recordings, without the user terminal having specified it, therefore without requiring modifications on the user terminal side concerning the registration request. It is the network that takes the initiative to carry out a “cumulative” registration.

In addition, this allows the user terminal not to have to include in the request, as is currently the case in the standard, the identifiers of the slots previously authorized, and on which it potentially has a packet data session in progress, otherwise this session will be terminated. According to this embodiment, any previously authorized tranche retains this status, even if the user terminal has not included it in its current registration request.

According to a particular aspect, where the registration request comprises at least one identifier of a slice subscribed by the user, the step of obtaining comprises a sub-step of determining a registration status for said at least a slice identified in the request.

Thus, according to this first embodiment, if the recording request includes one or more identifiers of one or more subscribed slots (for example via the S-NSSAI parameter in the Requested NSSAI parameter), the network equipment determines the status authorized/rejected/in progress (i.e. requiring slice authentication). This determination sub-step can be implemented before, after or simultaneously with the step for obtaining the status of the slots previously requested during one or more previous recordings. Thus, if the status of the slice or slices identified in the request is not already known from a previous recording, their status is determined during this current recording.

According to one particular characteristic, the identifier of the slice identified in the request is included, in the recording decision, in the parameter of slices authorized or the parameter of slices rejected or a parameter of slices awaiting authentication, depending of the determination sub-step.

Thus, according to this first embodiment, when the network equipment has determined the authorized/rejected status of the slot(s) identified in the request, it includes the identifier(s) of the slot(s) identified in the request in one or the other of the aforementioned parameters, listing the slices authorized respectively the slices rejected. It is also possible that the slice(s) or one of the slices identified in the request will only be authorized after successful authentication. In this case, another parameter listing the slices “pending authentication” is delivered by the network, for example in the form of the standardized parameter Pending NSSAI.

This makes it possible to respond to the user terminal with a list of authorized slices and/or a list of rejected slices taking into account the history of the recordings and the slice(s) included in the recording request, therefore also without requiring any modifications on the user terminal regarding the registration request.

According to a particular aspect, where the recording request comprises at least one slice accumulation indicator, the obtaining step comprises a sub-step of decoding said at least one received slice accumulation indicator delivering a positive accumulation indication or negative.

Thus, according to this variant of the first embodiment, provision is made for the registration request to include a specific parameter, for example denoted AdditionaIRegistration, indicating whether a "cumulative" record is required or not. This parameter must therefore be decoded by the network equipment in order to determine the rest of the procedure, depending on whether a cumulative recording is required or not. This variant therefore allows the user terminal to specifically signal to the network equipment whether or not it wishes a cumulative recording, for example in the form of a specific parameter added in the request, or in the form of a parameter modifying the NSSAI format of the current standard. This parameter corresponds for example to a boolean that can take the value 1 if a cumulative record is required and the value zero otherwise.

This approach makes it possible in particular to signal to the network equipment that a cumulative recording is desired and therefore to implement such a cumulative recording, the cumulative recording not being implemented by default (the absence of a parameter or the absence of value for the parameter not resulting in a cumulative recording).

According to a particular characteristic, if said accumulation indication is positive, the recording decision comprises at least one authorized slice parameter comprising at least one identifier of one of the slices of the network previously authorized during at least one previous recording of the terminal user for the same type of access and the same recording zone and/or at least one parameter of rejected slots comprising at least one identifier of one of the slots of the network previously rejected during at least one previous recording of the user terminal for the same type of access and the same registration area.

Furthermore, the identifier of the slice identified in the request is included, in the recording decision, in the parameter of slices authorized or the parameter of slices rejected or a parameter of slices awaiting authentication depending on the sub -determination step.

According to a particular characteristic, in the parameter of authorized slices included in the recording decision, said at least one identifier of one of the slices of the network previously authorized during at least one previous recording of the user terminal for the same type of access and the same recording area corresponds to a slot for which the user terminal has an active packet data session.

Thus, according to this other variant of the first embodiment, the network equipment performs a cumulative recording only with previously authorized slots for which the user terminal has an active data session. This makes it possible to further limit network signaling by potentially listing fewer slots in response to a recording request, while ensuring that active data sessions are not cut off even if the user terminal has omitted to request them again. According to a second embodiment, relating to a global recording mode, any recording request received by network equipment, originating from a user terminal, is processed so as to take account of each slice subscribed by the user/customer of the registration request. The autonomous determination step does not take into account one or more slice identifiers included or not in the request, ie the autonomous determination is triggered without even questioning the presence or not of slice information (s) ( ie the presence of a Requested NSSAI parameter, a fortiori the value of this parameter when it is present).

Thus, according to this second embodiment, the network equipment identifies all of the subscribed slices autonomously, that is to say without taking into account any slice identifiers present in the recording request, in order to then determine its authorized/rejected/in progress status. This autonomy allows the network not to depend on the recording request to identify the slices to be recorded, thus limiting the steps to be implemented.

According to a particular aspect, the recording decision comprises at least one authorized slices parameter comprising the identifiers of all the authorized subscribed slices and/or at least one rejected slices parameter comprising the identifiers of all the rejected subscribed slices and/or at least one tranches parameter pending/in the process of authentication comprising the identifiers of all the subscribed tranches pending/in the process of authentication.

Thus, according to this second embodiment, the network equipment systematically determines the authorised/rejected/in progress status for all the subscribed slots upon receipt of a registration request and delivers a list of authorized slots and/or a list of rejected slices, for example in the form of standardized parameters such as Allowed NSSAI and Rejected NSSAI. It is also possible that one or more of the subscribed installments will only be authorized after successful authentication. In this case, another parameter listing the slices awaiting/in the process of authentication is delivered by the network, for example in the form of the standardized parameter Pending NSSAI.

This approach makes it possible to limit the number of recordings because the user terminal receives the status of all the subscribed slots, and can therefore take it into account for any subsequent activation of a packet data session. Network signaling is therefore also severely limited.

According to a particular characteristic, the registration request comprises at least one global registration indicator triggering a decoding step of said at least one received global registration indicator delivering a positive global registration indication or negative.

Thus, according to this variant of the second embodiment, provision is made for the registration request to include a specific parameter, for example denoted alISnssaiRegistration, indicating whether or not global registration is required. This parameter transmitted by the user terminal must therefore be decoded by the network equipment in order to determine the rest of the procedure, depending on whether a global recording is required or not. This variant therefore allows the user terminal to specifically signal to the network equipment whether or not it wishes a global recording, for example in the form of a specific parameter added in the request, or in the form of a parameter modifying the NSSAI format of the current standard. This parameter corresponds for example to a Boolean which can take the value 1 if a global record is required and the value null otherwise, the global record not being implemented by default (the absence of parameter or the absence of value for the parameter not resulting in a global recording).

For example, if said global recording indication is positive, the determining step is triggered and the recording decision comprises at least one authorized slots parameter comprising the identifiers of all the authorized subscribed slots and/or at least one parameter of rejected slices comprising the identifiers of all the rejected subscribed slices and/or at least one parameter of slices awaiting authentication comprising the identifiers of all the subscribed slices awaiting authentication.

On the other hand, if said global registration indication is negative and if the registration request includes at least one identifier of a slice subscribed by the user, the determination step is triggered only for the slice or slices identified in the request and the recording decision comprises at least one parameter of authorized slices comprising at least one identifier of a slice identified in the request and authorized and/or at least one parameter of rejected slices comprising at least one identifier of an identified slice in the request and rejected and/or at least one slice parameter awaiting authentication comprising at least one identifier of a slice identified in the request and awaiting authentication.

Thus, according to an implementation of this variant of the second embodiment, if the user terminal has not requested global recording but if it has identified one or more slots in the recording request, then the network determines the authorized/rejected/pending authentication status for the slice(s) identified in the request and therefore does not perform a global registration.

Moreover, if said global registration indication is negative and if the registration request does not include an identifier of a slot subscribed by the user, the step of determining is triggered and the recording decision comprises at least one authorized slices parameter comprising the identifiers of all the authorized subscribed slices and/or at least one rejected slices parameter comprising the identifiers of all the rejected subscribed slices and/or at least one parameter of tranches awaiting authentication comprising the identifiers of all the subscribed tranches awaiting authentication.

On the other hand, according to another implementation of this variant of the second embodiment, if the user terminal has not requested global registration and has not identified slots in the registration request, then the network performs by default a global record. According to a particular aspect, the registration decision comprises a successful global registration indicator when all the subscribed slots are authorized.

Thus, according to this implementation, the network equipment also delivers a global registration indicator (for example denoted alISnssaiRegistration) when all the subscribed slices have been registered, making it possible to limit the signaling of the response, which does not include the parameters listing the authorized subscribed tranches but simply an indicator of success of the overall registration.

The present technique also relates to a method for requesting activation of a packet data session for a user terminal capable of transmitting and receiving data on a communications network organized into network slices, the method being implemented in said terminal and comprising a request for activation of a packet data session on at least one slice of the network, the activation request taking account of a recording decision, coming from at least one network equipment able to communicate with the user terminal via the network, to a registration request sent by the terminal, the registration decision comprising a successful global registration indicator indicating that all the slots subscribed by a user are authorized.

Thus, according to this implementation, the user terminal takes account, when requesting the activation of a packet data session, of a specific parameter transmitted in response to a registration request. According to a variant, on receiving the parameter indicating that all the subscribed slices have been registered (alISnssaiRegistration), the user terminal updates its local parameter Allowed NSSAI with the value of Configured NSSAI which contains all the subscribed slices.

According to a particular characteristic of the registration method, where the registration request includes a slice change indicator, the method comprises a preliminary step of checking whether at least one subscribed slice has been previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration area. Thus, according to this approach, the user terminal or the network equipment first performs a step of verifying the authorized/rejected status of one or more subscribed slots, with the aim of simplifying the registration request (when it is the user terminal which implements this check) or to directly reject this request (when it is the network equipment which implements this check and the recording status is already known for all the slots requested), when this recording request is for a change of time slot (and not when the request corresponds to a request for periodic update or of the recording duration, to a first recording, to a change of recording area or a emergency...).

For example, the preliminary verification step is implemented by the user terminal and if the verification is positive, the recording request does not contain the identifier of the slice previously authorized or rejected.

According to another example, the preliminary verification step is implemented by the network equipment for the slice identifiers included in the recording request and, if the verification is positive for all the slice identifiers included in the registration, the obtaining step is not implemented and the registration request is rejected.

Thus, according to this approach, and in the context of a cumulative recording, the network equipment checks whether all the slots identified in the request have already been the subject of a previous recording, in which case the request is rejected because it is useless: the user terminal already knows the status of the slots identified in its request.

According to a particular aspect, where the recording request includes a slice change indicator and where the method includes a preliminary verification step, implemented by the network equipment, whether all the subscribed slices have been previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration zone and, if the verification is positive, the step of obtaining or determining is not implemented and the registration request is rejected.

Thus, according to this approach, and in the context of a cumulative or global recording, the network equipment checks whether all the subscribed slots have already been the subject of a previous recording, in which case the request is rejected because it is useless: the user terminal is already aware of the status of all subscribed installments.

The invention also relates to a computer program product comprising program code instructions for implementing a method as described previously, when it is executed by a processor. The invention also relates to a recording medium readable by a computer on which is recorded a computer program comprising program code instructions for the execution of the steps of the method according to the invention as described above.

Such recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or even a magnetic recording means, for example a USB key or a hard disk.

On the other hand, such a recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means, so that the program computer it contains is executable remotely. The program according to the invention can in particular be downloaded on a network, for example the Internet network.

Alternatively, the recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the aforementioned display control method.

The invention also relates to a device for registering a user terminal with a communications network organized in network slices, said user terminal being capable of transmitting and receiving data on the network, the user terminal comprising subscription of a user for at least one of the slices of the network, the device being implemented at least by a network equipment capable of communicating with the user terminal via the network and comprising a receiver, a transmitter, a processor and a memory coupled to the processor with instructions intended to be executed by the processor for:

- receive a registration request sent by the user terminal to register with the network;

- obtain, in context information associated with the user terminal, an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration area, issuing a registration decision, or

- autonomously determine a registration status for each of the network slices subscribed by the user and identified by the network equipment in a network parameter comprising the identifiers of all the network slices subscribed by the user, delivering a registration decision.

This device, capable of implementing in all its embodiments the recording method which has just been described, is intended to be implemented in a network entity. This device and the aforementioned corresponding computer program have at least the same advantages as those conferred by the recording method according to the present technique.

The network entities described in this application may correspond to virtual entities, also called functions.

The invention also relates to a user terminal capable of transmitting and receiving data on a communications network organized into network slices with which it registers, the user terminal comprising subscription data of a user for at least one of the slices of the network, and comprising a receiver, a transmitter, a processor and a memory coupled to the processor with instructions intended to be executed by the processor for:

- check whether at least one subscribed tranche has been previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration area and, if the verification is positive, the request for The registration issued by the user terminal to register with the network does not contain the identifier of the slice previously authorized or rejected.

This user terminal is capable of implementing the registration process in all its embodiments, includes the user terminal (“user equipment” specified by the 3GPP) and can correspond for example to a loT terminal (in English Internet of Things ), a smartphone, a robot, so-called communicating equipment, a residential gateway, accessing the network via any type of fixed or mobile access specified by 3GPP or not, the network possibly corresponding to a public network called PLMN or non-public called NPN (in English Non-Public Network in particular an autonomous non-public network called SNPN, in English Stand-alone Non-Public Network).

Presentation of figures

Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of a simple illustrative example, and not limiting, in relation to the figures, among which:

[Fig 1] presents an example of a simplified architecture of a communications network in which the recording method according to one embodiment of the invention is implemented; [Fig 2] illustrates in the form of a block diagram the recording method according to one embodiment of the invention;

[Fig 3] illustrates in the form of a block diagram an example of implementation of the recording method according to a first embodiment of the invention;

[FIG 4] illustrates in the form of a block diagram an example of implementation of the recording method according to a second embodiment of the invention. Detailed Description of Embodiments of the Invention

The present technique proposes an optimized determination of the authorized/rejected slices for a user terminal, according to the slices subscribed by the user, making it possible to limit the signaling and the load of the network and to avoid undesired cuts of packet data session , while simplifying the registration process.

To do this, the present technique proposes a registration procedure based on an inventive concept based on a cumulative aspect of the determination of the authorized/rejected slices and no longer on the determination of authorization or rejection of the slices specifically identified in the request. recording as is the case according to current techniques.

According to a first embodiment, the cumulative aspect resides in the fact of taking account of one or more recordings previously made by the terminal, for the same type of access and the same recording area, and of accumulating, the where applicable, the results of this or these recordings made previously with a recording request for one or more tranches not yet authorized or rejected.

According to a second embodiment, the cumulative aspect resides in the fact of taking account of all the subscribed tranches, that is to say performing a global recording for all the subscribed tranches, without taking into account information transmitted or not by the user terminal in the recording request concerning the slices to be recorded.

Finally, according to another feature, compatible with the two aforementioned embodiments, the proposed technique makes it possible to check beforehand the authorized or rejected status of one or all of the slices likely to be the subject of a recording request. from a user terminal.

An example of network architecture, in which the proposed technique can be implemented, is first illustrated, in a simplified manner, in FIG. 1. One or more user terminals, denoted UE1, UE2, access, via a network of access AN, to one or more data networks DN1, DN2 or DN3, via one or more slices SU, SI2 and SI3.

We are then interested in a user terminal UE1 which wishes to receive data on one or more slices of a network as illustrated in figure 1.

To do this, a user Ul, for example the main user of the user terminal UE1, subscribes, with his telecommunications operator, to one or more of the slices of the network, for example according to his habits or his wishes for the consumption of content, the performance of his user terminal UE1... Following his subscription, subscription data DSub (including in particular, in a parameter denoted Subscribed NSSAI, the identifiers of the slices to which the user Ul has subscribed) are created and stored in a subscription database. In addition, an IdSub subscription identifier, for example the variable SUPI (or in English Subscription Permanent Identifier) makes it possible to access this DSub subscription data, for example when they are stored in a subscription data management network equipment. . This subscription identifier is notably stored in the SIM card of the user terminal UE1 and is representative of the subscription, containing one or more subscribed tranches, without being exclusively associated either with the user U1 or with the user terminal UE1. Indeed, another user U2 may have obtained authorization from user U1 to use his subscription, or the SIM card storing the subscription identifier may be transferred from the user terminal UE1 to another user terminal UE2 for example .

This technique relates more particularly to the procedure for registering a user terminal UE1 with the network, with a view to subsequently activating a packet data session on one or more subscribed slices of the network.

FIG. 2 illustrates the main steps of a recording method according to the present technique, implemented by equipment of the network NE1.

Thus, network equipment NE1 implements a step 200 of receiving a registration request sent by the user terminal UE1 to register with the network, and according to the first or second embodiment, described in detail below, the NE1 network equipment implements:

- a step 300 for obtaining, in context information associated with the user terminal, an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous registration of the terminal user for the same type of access and the same registration area, delivering a registration decision R, or

- a step 400 of autonomous determination of a registration status for each of the network slices subscribed by the user and identified by the network equipment in a network parameter comprising the identifiers of all the network slices subscribed by the user, issuing a registration decision R.

Description of the first embodiment

As indicated above, this first embodiment makes it possible to take account, at the time of a current recording request sent by a user terminal UE1, of one or more recordings previously made by this user terminal UE1, for the same type of access and the same registration area. The processing of the recording request by the network in this first embodiment is different from the standard because it concerns a cumulative recording instead of a supplementary recording. It should also be noted, as described below, that the request sent by the user terminal can also take additional characteristics compared to the standard, as described below in a second solution.

Whatever the solution, the network equipment, which receives a registration request from a user terminal, checks whether it has access to context information associated with the user terminal, in order to obtain in particular information relating to an authorization or rejection of at least one of the slices of the network previously authorized or rejected during at least one previous recording of the user terminal for the same type of access and the same recording zone. For example, this context information corresponds to the variable UE context, resulting from the previous recording and which can reflect an accumulation of several previous recordings according to the present technique, and notably comprises a value of Allowed NSSAI (identifiers of previously authorized slices) respectively Rejected NSSAI (previously rejected slice identifiers), which can be noted as Allowed NSSAI (UE context) respectively Rejected NSSAI (UE context). Obtaining the authorized/rejected slice(s) information resulting from the previous recording accumulation with one or more slices possibly requested in the recording request, can be implemented according to different variants, described below.

Then, depending on whether or not the recording request includes one or more slice identifiers to be recorded, the network implements different steps described below to perform a cumulative recording, that is to say to add to the result obtaining information relating to a previous registration, via the context information, the result of an authorization or rejection determination for the slice or slices identified in the registration request, when this is the case . This determination delivers, for example, a value of Allowed NSSAI (subscription), with the identifiers of slices authorized with regard to the subscription for the user terminal, among the slices identified in the registration request, and/or a value of Rejected NSSAI ( subscription) with the identifiers of slices rejected with regard to the subscription for the user terminal, among the slices identified in the registration request.

The network equipment that received the registration request therefore potentially has the following data:

- Allowed NSSAI (subscription) to describe, when the request (Requested NSSAI) includes one or more slice identifiers (S-NSSAI), the slice identifiers authorized with regard to the subscription for the user terminal;

- Rejected NSSAI (subscription) to describe, when the request (Requested NSSAI) includes one or more slice identifiers (S-NSSAI), the slice identifiers rejected with regard to the subscription for the user terminal; - Allowed NSSAI (UE context) to describe the slice identifiers (S-NSSAI) authorized already contained in the context information associated with the user terminal and accessible by the network equipment due to the previous recording;

- Rejected NSSAI (UE context) to describe the slice identifiers (S-NSSAI) rejected already contained in the context information associated with the user terminal and accessible by the network equipment due to the previous recording.

These three variants differ from each other according to the distribution of tasks between different network equipment, and in particular between an access control equipment (for example the AMF network entity, in English Access and Mobility Function) and a selection equipment. slice instance (for example the NSSF network entity in English Network Slice Selection Function) to determine the authorized/rejected slices.

According to a first variant, the access control equipment AMF checks whether it has access to context information associated with the user terminal, in order to obtain in particular information relating to an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration zone. If such is the case, the access control equipment AMF therefore obtains the values denoted Allowed NSSAI (UE context) respectively Rejected NSSAI (UE context).

Then, the AMF access control equipment itself determines which slices identified in the request are authorized or rejected, with regard to the user's subscription, or interrogates the instance selection equipment of NSSF slice, by providing it with the identifier(s) included in the request (Requested NSSAI) and the identifier(s) of the subscribed slices (for example via the Subscribed NSSAI parameter), to obtain Allowed NSSAI (subscription) and/or Rejected NSSAI (subscription ). Seen from the NSSF, this corresponds to the processing as standardized with the use of a Requested NSSAI and Subscribed NSSAI parameter.

Finally, the AMF access control equipment accumulates, preferably without duplicates, the non-empty values previously obtained to deliver Allowed NSSAI and/or Rejected NSSAI such as:

- Allowed NSSAI = Allowed NSSAI (UE context) + Allowed NSSAI (subscription);

- Rejected NSSAI = Rejected NSSAI (UE context) + Rejected NSSAI (subscription).

According to this first variant, it is therefore the access control equipment AMF which combines the recording of the slots identified in the request and the slots previously authorised/rejected during one or more previous recordings.

Depending on a particular situation, a tranche identified in the registration request may, in view of the subscription data, require a prior authentication step before being allowed. In this case, it does not appear in the list of authorized tranches nor in those of rejected tenches, but in another list, denoted for example Pending NSSAI.

Furthermore, the steps of verifying access to context information associated with the user terminal (in order to obtain in particular information relating to an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during 'at least one previous registration of the user terminal for the same type of access and the same registration zone) and determination of the values Allowed NSSAI (subscription) and/or Rejected NSSAI (subscription) can be implemented in n' any order and independently, so that the accumulation step can be implemented afterwards.

According to a second variant, the access control equipment AMF checks whether it has access to context information associated with the user terminal, in order to obtain in particular information relating to an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration zone. If this is the case, the access control equipment AMF therefore obtains the values Allowed NSSAI (UE context), respectively Rejected NSSAI (UE context).

Then, the AMF access control equipment calculates a value of "Requested NSSAI cumulated", as resulting from the cumulation without duplicate:

- S-NSSAI values of the Requested NSSAI received in the registration request from the user terminal;

- values obtained Allowed NSSAI (UE context) and possibly Rejected NSSAI (UE context).

Finally, the AMF access control device interrogates the NSSF slice instance selection device by providing it with the "cumulative Requested NSSAI" (as calculated above) and the identifier(s) of the subscribed slices (for example via the Subscribed NSSAI parameter). The NSSF slice instance selection device proceeds to determine the values:

- Allowed NSSAI, comprising the identifiers of slices among the values of “Requested NSSAI cumulated” which are authorized with regard to the subscription for the type of access and the recording zone considered;

- Rejected NSSAI, comprising the identifiers of slices among the values of "Requested NSSAI cumulated" which are rejected with regard to the subscription for the type of access and the recording zone considered.

According to this second variant, it is therefore the access control equipment AMF which combines the slots identified in the request and the slots previously authorized during one or more previous records before querying the NSSF slice instance selection device.

According to a third variant, the access control equipment AMF interrogates the slice instance selection device NSSF to determine which slices identified in the request are authorized or rejected, with regard to the subscription of the user, by providing him with the identifier(s) included in the request (Requested NSSAI) and the identifier(s) of the subscribed slices (for example via the Subscribed NSSAI parameter), and also providing him with the values obtained with regard to the information of context Allowed NSSAI (UE context) and/or Rejected NSSAI (UE context).

Thus, from these values, the NSSF slice instance selection equipment determines the Allowed NSSAI (subscription) and/or Rejected NSSAI (subscription) values for the identifiers received in the request and combines them with the Allowed NSSAI (UE context) and/or Rejected NSSAI (UE context) values to deliver Allowed NSSAI and/or Rejected NSSAI such as:

- Allowed NSSAI = Allowed NSSAI (UE context) + Allowed NSSAI (subscription);

- Rejected NSSAI = Rejected NSSAI (UE context) + Rejected NSSAI (subscription).

Alternatively, the NSSF equipment can calculate a "Cumulated Requested NSSAI" value, i.e. treat the AMF request as if the Requested NSSAI value were a "Cumulative Requested NSSAI" resulting from the accumulation without duplicates:

- S-NSSAI values of the Requested NSSAI of the user terminal registration request;

- Allowed NSSAI (UE context) and possibly Rejected NSSAI (UE context) values and thus determine the values of:

According to this third variant, it is therefore the slice instance selection equipment NSSF which combines the recording of the slices identified in the request and the slices previously authorized during one or more previous recordings.

Depending on a particular situation, a tranche identified in the registration request may, in view of the subscription data, require a prior authentication step before being allowed. In this case, it does not appear in the list of authorized slices or in those of rejected slices, but in another list, noted for example Pending NSSAI.

According to these three variants, the AMF access control equipment knows the Subscribed NSSAI parameter, for example by interrogating another subscription data management equipment (for example the UDM entity according to the standard in force, in English Unified Data Management , storing this subscription data itself or able to obtain it from one or more other entities such as UDR, in English Unified Data Repository ensuring their storage).

Furthermore, according to the current standard, it is known to send information to the NSSF slice instance selection equipment, such as for example information from Requested NSSAI and from Subscribed NSSAI. On the other hand, the present technique provides for creating a new parameter to provide the NSSF slice instance selection equipment with the information of Allowed NSSAI (UE context) and/or Rejected NSSAI (UE context) for the third variant.

The second solution will now be described, in relation to FIG. 3, according to which the recording request is different with respect to the standard to allow the user terminal to indicate that a cumulative recording is required.

According to a first variant, a specific parameter, slice accumulation indicator, is added to the recording request and according to a second variant, a parameter already present in the recording request is modified, by adding a parameter or by modification of an existing parameter. For example, the format of the NSSAI parameter (Network Slice Selection Assistance Information, representing a set of slices) is augmented by an optional parameter, denoted additionaIRegistration, of Boolean type indicating:

- when it is equal to the value “1”, that the user terminal wishes to perform a cumulative recording;

- when it is equal to the value “0” (or when it is not present (second solution described below)), the user terminal does not wish to perform a cumulative recording.

The network equipment interprets or decodes, during a decoding sub-step, the slice accumulation indicator (for example the additionaIRegistration parameter described above) received in the registration request from the user terminal, from so as to deliver a positive or negative cumulative indication according to the value of the indicator.

Then, if the cumulative indication is positive, ie the user terminal requires cumulative recording, then the network equipment implements a step 300 for obtaining, in context information associated with the user terminal, an authorization or a rejection of at least one of the network slices previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same zone recording. This step 300 is described in detail below, in relation to the second solution.

On the other hand, if the accumulation indication is negative, then the network equipment implements a "conventional" recording taking into account only the identifiers of slots specified in the recording request when this is the case, or delivers a recording decision based only on previous recording(s), as described below in connection with the second solution.

In essence, in the example illustrated in FIG. 3, the user terminal UE1 requests to register, cumulatively, with the network for the slices identified by the identifiers S/2 and S/4, the user having previously subscribed slices SU to SI 10. For example, and as described below, the recording request includes these two identifiers S/2 and S/4. The network equipment NE1, upon receipt 200 of this cumulative registration request, and after having decoded the “additionaIRegistration” parameter present in the registration request, obtains, during a step 300, in an associated context information to the user terminal, the status of the slices previously authorized or rejected during at least one previous recording of the user terminal for the same type of access and the same recording zone, in this example, slices S/2, S/ 3, S/5, SI6 and S/7. In this case, in this example, slices S/3, S/6 and S/7 have already been authorized and slice S/5 has already been rejected. Next, the network equipment NE1 determines the status of the slots identified in the request, namely S/2, authorized, and S/4, rejected. Finally, the equipment of the network NE1 delivers a recording decision comprising the authorized slots S/2, S/3, SI6 and S/7 and the rejected slots S/4 and S/5. The user terminal UE1 therefore receives, in response to its recording request for 2 slots, more complete information than according to the techniques of the prior art.

Thus, in this example, the accumulation of registration is implemented at the explicit request of the user and is not implemented by default by the network entity.

According to another example, the network entity systematically implements cumulative recording as soon as it receives a recording request: the use of a parameter emanating from the user terminal in its recording request is then not necessary and anyway would not be scanned by the network equipment. The network entity systematically implements the cumulative recording to replace the supplementary recording provided for in the standard.

According to another example, the network entity systematically implements cumulative recording by choice according to the policy of the operator, which means that the network equipment would be able to make a supplementary recording according to the standard and a cumulative recording according to the invention, and the operator could configure it to apply one rather than the other according to his own policy (note that the configuration of the type of recording is not limiting and could cover the supplementary recording, the cumulative recording, global recording as in the second embodiment described below, see others).

According to a last example, the network entity conditionally implements the cumulative recording by choice according to the policy of the operator, which means that the network equipment would be able to make a supplementary recording according to the standard and a cumulative recording according to the invention but would implement cumulative recording when one or more conditions are met, for example only for a loT terminal and/or a terminal accessing from a fixed access.

According to a third solution, the accumulation of the recordings of the slots possibly identified in the request is implemented only with the slots previously authorized during one or more previous recordings and for which the user terminal has an active packet data session. To do this, the access control equipment AMF has access, via the context information associated with the user terminal, to information from each active packet data session (for example via the PDU Session level context parameter) allowing it in particular to know the identifiers of the slices concerned by an active session.

This first embodiment therefore makes it possible to limit the number of recordings triggered by the user terminal, because, thanks to the cumulative recording, the slices recorded during a previous recording remain recorded during the following recording. This therefore makes it possible to limit the signaling load in the network. Finally, this makes it possible to avoid an undesired cutoff of an active packet data session, even if, by mistake, the user terminal did not identify in the current recording request the slot identifier(s) for which a packet data session is in progress.

Moreover, this first embodiment offers great flexibility because the cumulative recording can be requested by the user terminal or be implemented at the initiative of the network.

In the particular case where the recording request does not include any slice identifier, the network equipment delivers a recording decision comprising only the authorized or rejected slice parameters relating to a previous recording. This notably makes it possible, for example, not to interrupt an active packet data session on a slice that the user terminal would have omitted to identify again in the recording request. Finally, according to another variant embodiment, the response of the network equipment after a cumulative recording comprises a parameter, for example of Boolean type, indicating that the cumulative recording results in the recording of all the subscribed slots. In this case, instead of returning in the cumulative registration response the exhaustive list of authorized slots corresponding to all the subscribed slots, then the network returns only one parameter, for example denoted alIRegistration, so as to lighten the signalling.

The presence of such an alIRegistration parameter in the network response to a cumulative registration request allows the user terminal to know that all the subscribed slots are authorized and that it can therefore make a packet data session activation request. for any of these subscribed tranches. To do this, the user terminal must interpret or decode this parameter received in the response. Then, according to a first implementation, a request to activate a packet data session for this user terminal takes account of this recording indicator of all the subscribed slots by using an identifier from among the identifiers of the subscribed slots. According to a second implementation, the user terminal can, after having decoded the alIRegistration parameter, modify the content of the value Allowed NSSAI, stored locally, by putting therein the identifiers of all the subscribed slices. Then, during a packet data session activation request, the user terminal uses this value to know which slot is authorized.

Description of the second embodiment

As indicated previously, the second embodiment implements a global recording for all the subscribed slots based, autonomously by the network equipment implementing this second embodiment, on information known to the network listing the slots subscribed associated with the subscription information of the user terminal at the origin of the recording request, and without taking account of information transmitted or not by the user terminal in the recording request concerning the slices to be recorded.

The processing of the registration request by the network in this second embodiment is different from the standard because it concerns a global registration instead of a supplementary registration. It should also be noted that the request sent by the user terminal may take on additional characteristics with respect to the standard. Reference will be made to a first solution below when the request is specific and therefore includes a characteristic according to the invention, a second solution otherwise.

We will now describe the first solution, in relation to FIG. 4, according to which the registration request comprises an indication of the user terminal requesting a registration overall. In this way, to request a recording of all the subscribed slices, the user terminal is not obliged to specify all the identifiers of the subscribed slices in the recording request, as is the case according to current techniques, which reduces strongly the size of the record request.

According to a first variant, this indication is in the form of a specific parameter new with respect to the standard, global registration indicator, added in the registration request. According to a second variant, this indication reuses a parameter already defined in the standard, by modifying a component parameter or by adding a new parameter to it. For example, the format of the NSSAI parameter (Network Slice Selection Assistance Information, representing a set of slices) is augmented by an optional parameter, denoted alISnssaiRegistration, of boolean type indicating:

- when it is equal to the value “1”, that the user terminal wishes to perform a global recording;

- when it is equal to the value "0", the user terminal does not wish to perform a global recording.

The network equipment interprets or decodes, during a decoding sub-step, the global registration indicator (for example the alISnssaiRegistration parameter described above) received in the registration request from the user terminal, from so as to deliver a positive or negative global recording indication according to the value of the indicator.

Then, if the global registration indication is positive, i.e. the user terminal requires a global registration, then the network equipment implements a step 400 for autonomous determination of a registration status (authorization/rejection/ current) for each of the network slices subscribed by the user identified in a network parameter comprising the identifiers of all the network slices subscribed by the user, delivering a registration decision. This autonomous determination step 400 is implemented without taking into account one or more slice identifiers included in the request.

For example, the network equipment knows the identifiers of the subscribed slices thanks to the subscription data of the user terminal obtained by interrogating another subscription data management equipment (for example the UDM entity according to the standard in force, in English Unified Data Management, storing this subscription data itself or able to obtain it from one or more other entities such as UDR, in English Unified Data Repository ensuring their storage). This step 400 is described in detail below, in relation to the second solution.

On the other hand, if the global registration indication is negative, then the network equipment implements a “forced” global registration in the event that the registration request does not includes no slice identifier. Otherwise, ie if at least one slice is identified in the recording request, the network equipment does not implement the recording according to the invention and can implement the steps of a conventional, or standard, recording based solely on the determination of a registration status of the slice or slices identified in the request.

According to this first solution, the registration response delivered by the network to the user terminal can also include a successful global registration indicator, for example the same parameter alISnssaiRegistration as that contained in the request. This response parameter is optional, of Boolean type for example, and indicates that all subscribed slices have been recorded (i.e. that all subscribed slices have been authorized) when it is equal to the value "1". It is equal to the value "0", otherwise, i.e. when at least one subscribed slot has been rejected, and the response of the network equipment is that described below in relation to the second solution, i.e. it includes the identifiers of all the subscribed tranches "distributed" according to the authorized/rejected/in progress status (i.e. awaiting authentication), determined for each subscribed tranche.

The presence of the alISnssaiRegistration parameter in the network response to a global registration request lets the user terminal know that all subscribed slots are authorized and can therefore make a packet data session activation request for n' any of these subscribed tranches. To do this, the user terminal must also interpret or decode this parameter received in the response.

Then, according to a first implementation, a request to activate a packet data session for this user terminal takes account of this global registration indicator received following a global registration request, by using an identifier from among the identifiers of the subscribed tranches.

According to a second implementation, the user terminal can, after having decoded the alISnssaiRegistration parameter, modify the content of the Allowed NSSAI value, stored locally, by putting therein the identifiers of all the subscribed slots contained in the Configured NSSAI parameter. Then, during a packet data session activation request, the user terminal uses this value to know which slot is authorized.

In essence, in the example illustrated in FIG. 4, the user terminal UE1 requests to register globally with the network, the user having previously subscribed to the slices SU to SI10. The equipment of the network NE1, upon receipt 200 of this global registration request, and after having decoded the “alISnssaiRegistration” parameter present in the registration request, obtains, during a step 300, autonomously and from a network parameter comprising the identifiers of all subscribed network slices by the user, the recording status of all the slices of the network subscribed to by the user, ie the slices SU to SI10. In this case, in this example, the subscribed slots SU, SI2, SI3, SI6, SI7 and SI9 are authorized and the subscribed slots S/4, S/5, SI8 and SI10 are rejected. Then, the equipment of the network NE1 issues a recording decision comprising the authorized slots SU, SI2, SI3, SI6, SI7 and SI9 and the rejected slots SI4, SI5, SI8 and SI10. The user terminal UE1 therefore receives, in response to its global registration request, more complete information than according to the techniques of the prior art.

Thus, in this example as in the preceding example relating to the cumulative recording, the cumulative recording is implemented at the explicit request of the user and is not implemented by default by the network entity.

According to another example, the network entity systematically implements a global registration as soon as it receives a registration request: the use of a parameter emanating from the user terminal in its registration request is then not necessary and anyway would not be scanned by the network equipment. The network entity systematically implements global registration to replace the supplementary registration provided for in the standard.

According to another example, the network entity systematically implements global recording by choice according to the policy of the operator, which means that the network equipment would be able to make a supplementary recording according to the standard and a global recording according to the invention, and the operator could configure it to apply one rather than the other according to his own policy (note that the configuration of the type of recording is not limiting and could cover the supplementary recording, the cumulative registration, global registration, see others).

According to a last example, the network entity conditionally implements global recording by choice according to the policy of the operator, which means that the network equipment would be able to make a supplementary recording according to the standard and a global recording according to the invention but would implement cumulative recording when one or more conditions are met, for example only for a loT terminal and/or a terminal accessing from a fixed access.

We will now describe the second solution, that is to say the global recording steps implemented by the network, different from those implemented by the standard in force for example.

To do this, the AMF access control equipment determines the authorized/rejected slices for all the subscribed slices and records all the authorized subscribed slices, whether on its own initiative or on that of the user terminal via a recording indicator global, but always independently of any slices requested by the user terminal in its recording request.

This determination of the authorized/rejected slices is carried out by the network entity alone or in cooperation with another network entity (typically AMF with NSSF) for all the subscribed slices and no longer for the slices specifically identified in the registration request.

Depending on a particular situation, a subscribed tranche identified in the subscription data may require a prior authentication step before being authorized. In this case, it does not appear in the list of authorized tranches nor in those of rejected tenches, but in another list, denoted for example Pending NSSAI.

The response from the network equipment therefore includes the result of this global recording, namely an Allowed NSSAI value comprising the identifiers of the subscribed and authorized slots, and/or a Rejected NSSAI value comprising the identifiers of the subscribed and rejected slots, and /or a Pending NSSAI value comprising the identifiers of the slices awaiting authentication before authorization, each of the identifiers of the subscribed slices being in one or the other of these three parameters.

This second embodiment therefore makes it possible to limit the number of recordings triggered by the user terminal, because, thanks to a single global recording, the status authorised/rejected/pending authentication is determined in a single recording for all the slices subscribed. This therefore makes multiple registrations unnecessary. This therefore makes it possible to limit the signaling load in the network.

Moreover, when the global recording indicator is used in the request, the size of this request is greatly reduced, because it is no longer necessary to indicate one or more slice identifiers therein.

Moreover, this second embodiment also offers great flexibility because the global registration can be requested by the user terminal or be implemented at the initiative of the network. In this case (second solution of the second embodiment), recording for all the subscribed tranches is guaranteed by default, without adding any specific parameter if this is configured by the operator. It should be noted that this in no way penalizes the terminal in the use of the services but that on the contrary it gives it potential access to more recorded slices and therefore more services than with the standard.

This second embodiment makes it possible to record all the slots in a single recording procedure, while limiting the size of the request messages and as a corollary the network response in the case of the first solution. Finally, as for the first embodiment, this second embodiment makes it possible to keep packet data sessions active, even if the user terminal does not identify the slices concerned in yet another recording request, since the global recording cannot withdraw a slice that would have been previously authorized, for the same type of access and the same recording area.

Description of the prior tranche control

The proposed technique makes it possible to further limit the signaling in the network, whatever the embodiment implemented, by avoiding useless registration requests. To do this, a verification step is implemented, prior to the steps detailed above in relation to the first and second embodiments. This verification step can be implemented by the user terminal, according to a first variant, or by a network equipment, according to a second variant, and makes it possible to transmit/process a recording request only if at least one slot concerned by a future check-in has not already been authorized or rejected, for the same type of access and the same check-in area.

This verification step is only implemented when the recording to come is neither a first recording, nor a recording following a change of recording zone of the user terminal, nor a recording due to an expiration of a duration of a previous recording. In other words, the verification is implemented only for a recording request in the context of a slot change.

According to a first variant, the user terminal verifies that the slice identifier(s) that it plans to signal in its upcoming recording request are not present in the parameters stored locally listing the authorized slices (Allowed NSSAI) and listing the slices rejected (Rejected NSSAI). If this verification is negative, the recording request is transmitted to the network, otherwise it is modified so as not to contain identifiers of previously authorized or rejected slot. This implementation differs from current techniques based on the standard in force, according to which the user terminal must identify in any recording request the identifiers of the slots for which a packet data session is active, under penalty of this session being interrupted/disabled. Indeed, as described previously, a cumulative recording or a global recording makes it possible, according to all the possible variants, not to interrupt a data session in progress.

According to a second variant, it is the network equipment that implements this verification step, upon receipt of a recording request. Thus, if the network equipment receives a recording request comprising one or more slices, each of which is already known to the network as authorized slot or rejected slot, ie for example that the AMF access control equipment already has it in the context information associated with the user terminal (UE context), then it rejects the registration request . Indeed, this request is useless because the user terminal has only identified in its request slots for which it is already aware of the authorized/rejected status.

This second variant therefore assumes that the network equipment knows how to differentiate between this type of recording request for slot change and a re-recording request for mobility for example. Thus, the network equipment should not implement this verification step, when the registration request contains a registration type parameter which can be, according to the current specifications:

- an initial registration ("initial registration");

- registration after moving the user terminal ("mobility registration updating");

- periodic registration ("periodic registration updating");

- an emergency registration ("emergency registration") but that the network equipment implements this verification step for a registration request for change of slot specific to the present technique, this request being distinguished from other types of requests registration with a new value for the registration type parameter, for example "registration updating for slice(s) change".

The present technique allows, according to its different embodiments and variants, to optimize the registration procedure of a user equipment (UE) in a communications network organized in network slices, for example a 5G network and could be apply to any future generation of networks using the organization in slices. The various embodiments are based on an inventive concept based on a cumulative aspect of the determination of authorized/rejected slices and no longer on the determination of authorization or rejection of the slices specifically identified in the registration request as is the case according to current techniques.

According to the first embodiment relating to a cumulative recording, an accumulation of the recording statuses of slices is implemented with respect to any previous recording, limiting the number of recordings triggered by the user terminal, and therefore the load of signaling in the network, and avoiding an undesired termination of an active packet data session, even if, by mistake, the user terminal has not identified in the current recording request the slot identifier(s) for which a packet data session is in progress. According to the second embodiment relating to a global registration, all the subscribed slots can be registered with a single procedure, thus giving access to the user terminal to all the subscribed services/all the subscribed slots while limiting the signaling in the network (not need for several registration procedures for the same type of access and the same location of the user terminal).

Claims

1. Method for registering a user terminal (UE1) with a communications network organized in network slices, said user terminal being capable of transmitting and receiving data on the network, the user terminal comprising subscription data of a user for at least one of the slices of the network, the method being implemented at least by a network device (NE1) able to communicate with the user terminal (UE1) via the network and comprising

- A reception step (200) of a registration request sent by the user terminal to register with the network;

- a step of obtaining (300), in context information associated with the user terminal, an authorization or a rejection of at least one of the slices of the network previously authorized or rejected during at least one previous recording of the user terminal for the same type of access and the same registration zone, issuing a registration decision, or

- a step of autonomous determination (400) of a registration status for each of the network slices subscribed by the user and identified by the network equipment in a network parameter comprising the identifiers of all the network slices subscribed by the user, issuing a registration decision.

2. A method of registering a user terminal with a communications network according to claim 1, wherein the registration decision comprises at least one parameter of authorized slices comprising at least one identifier of one of the slices of the network previously authorized during at least one previous recording of the user terminal for the same type of access and the same recording area and/or at least one parameter of rejected slots comprising at least one identifier of one of the previously rejected slots of the network during at least one previous registration of the user terminal for the same type of access and the same registration zone.

3. A method of registering a user terminal with a communications network according to claim 2, where the registration request comprises at least one identifier of a slot subscribed by the user and the step of obtaining comprises a sub-step of determining a recording status for said at least one slice identified in the request.

4. A method of registering a user terminal with a communications network according to claim 3, where the identifier of the slice identified in the request is included, in the recording decision, in the parameter of slices authorized or the parameter of slices rejected or a parameter of slices awaiting authentication, depending on the determination sub-step.

5. Method for registering a user terminal with a communications network according to claim 1, where the registration request comprises at least one slice accumulation indicator and the step of obtaining comprises a sub-step decoding said at least one slice accumulation indicator received delivering a positive or negative accumulation indication.

6. A method of registering a user terminal with a communications network according to claim 5, wherein, if said accumulation indication is positive, the registration decision comprises at least one parameter of authorized slices comprising at least one identifier of one of the slices of the network previously authorized during at least one previous registration of the user terminal for the same type of access and the same recording zone and/or at least one parameter of slices rejected comprising at least one identifier one of the slices of the network previously rejected during at least one previous recording of the user terminal for the same type of access and the same recording zone.

7. A method of registering a user terminal with a communications network according to claim 6 and claim 3, where, in the registration decision, the identifier of the slice identified in the request is included in the parameter of slices authorized or the parameter of slices rejected or a parameter of slices awaiting authentication depending on the determination sub-step.

8. A method of registering a user terminal with a communications network according to claim 1, wherein the autonomous determination step (400) does not take account of one or more slot identifiers included in the request.

9. A method of registering a user terminal with a communications network according to claim 1 or claim 8, wherein the registration decision comprises at least one parameter of authorized slots comprising the identifiers of all the authorized subscribed slots and/or at least one rejected tranches parameter comprising the identifiers of all the rejected subscribed tranches and/or at least one tranches awaiting authentication comprising the identifiers of all subscribed tranches awaiting authentication.

10. A method of registering a user terminal with a communications network according to claim 1 or claim 8, wherein the registration request comprises at least one global registration indicator triggering a step of decoding said at least a received global registration indicator delivering a positive or negative global registration indication.

11. A method of registering a user terminal with a communications network according to claim 10, wherein, if said global registration indication is positive, the determination step is triggered and the registration decision comprises at at least one authorized slices parameter comprising the identifiers of all the authorized subscribed slices and/or at least one rejected slices parameter comprising the identifiers of all the rejected subscribed slices and/or at least one slices parameter awaiting authentication comprising the identifiers of all subscribed tranches awaiting authentication.

12. A method of registering a user terminal with a communications network according to claim 10, wherein, if said global registration indication is negative and if the registration request comprises at least one identifier of a slot subscribed by the user, the determination step is triggered only for the slice or slices identified in the request and the recording decision comprises at least one parameter of authorized slices comprising at least one identifier of a slice identified in the request and authorized and/or at least one parameter of slices rejected comprising at least one identifier of a slice identified in the request and rejected and/or at least one parameter of slices awaiting authentication comprising at least one identifier of a slice identified in the request and awaiting authentication.

13. A method of registering a user terminal with a communications network according to claim 10, where, if said global registration indication is negative and if the registration request does not include an identifier of a slice subscribed by the user, the determination step is triggered and the recording decision comprises at least one parameter of authorized slices comprising the identifiers of all the authorized subscribed slices and/or at least one parameter of rejected slices comprising the identifiers of all rejected subscribed tranches and/or at least one parameter of tranches awaiting authentication comprising the identifiers of all subscribed tranches awaiting authentication.

14. A method of registering a user terminal with a communications network according to claim 1 or claim 8, wherein the registration decision includes a successful global registration indicator when all subscribed slots are authorized.

15. A method of registering a user terminal with a communications network according to claim 1, where the registration request includes a slot change indicator and where the method includes a prior step of verifying whether at least one subscribed tranche has been previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration zone.

16. A method of registering a user terminal with a communications network according to claim 15, wherein the preliminary verification step is implemented by the user terminal and if the verification is positive, the registration request does not contain the identifier of the slice previously authorized or rejected.

17. A method of registering a user terminal with a communications network according to claim 15, wherein the preliminary verification step is implemented by the network equipment for the slot identifiers included in the request for recording and where, if the verification is positive for all the slice identifiers included in the recording request, the step of obtaining is not implemented and the recording request is rejected.

18. A method of registering a user terminal with a communications network according to claim 1, where the registration request includes a slot change indicator and where the method includes a prior step of verification, implementation by the network equipment, if all the subscribed slots have been previously authorized or rejected during at least one previous registration of the user terminal for the same type of access and the same registration zone and where, if the verification is positive , the step of obtaining or determining is not implemented and the registration request is rejected.

19. Device for registering a user terminal (UE1) with a communications network organized in network slices, said user terminal being capable of transmitting and receiving data on the network, the user terminal comprising subscription data of a user for at least one of the slices of the network, the device being implemented at least by a network device (NE1) able to communicate with the user terminal (UE1) via the network and comprising a receiver, a transmitter, a processor and a memory coupled to the processor with instructions intended to be executed by the processor for:

20. User terminal (UE1) capable of transmitting and receiving data on a communications network organized into network slices with which it registers, the user terminal comprising subscription data of a user for at least one of the slices of the network, and comprising a receiver, a transmitter, a processor and a memory coupled to the processor with instructions to be executed by the processor for:

21. Computer program comprising instructions which, when these instructions are executed by a processor, lead the latter to implement the steps of the recording method, according to claim 1.

22. Information medium readable by network equipment, and comprising instructions of a computer program according to claim 21.