Method for managing the connection of a terminal to a network slice

Abstract

The invention relates to a method for managing the connection of a user terminal (UE) to a network slice (TR), the method being implemented by the user terminal (UE) and comprising: - obtaining an identifier of a network slice (TR) to which the user terminal (UE) can connect after verification of the current conditions governing connection of the user terminal (UE) to the network slice (TR).

Description

Method for managing the connection of a terminal to a network slice

[0001] The technical field is that of telecommunications.

[0002] More specifically, the invention relates to a method for managing the connection of a user's terminal to a network slice. State of the art

[0003] 5G networks (short for fifth-generation mobile telecommunications networks) or 5GSA (short for 5G StandAlone) introduce the concept of a network slice. This concept relies on the virtualization of network functions. A virtual network function (VNF, or VNFs in the plural) is a computer application that implements an expected function of a computer or telecommunications network, such as a directory service, routing service, or other service. The virtualization of network functions in a 5G network enables the implementation of the network slice concept by distributing network functions across pre-selected and reserved hardware resources.A network slice is an instantiation of a set of virtual network functions, linked together and organized to provide the services of a telecommunications network. A network slice can therefore be viewed as a telecommunications network and will be perceived as such by the user terminals (mobile or otherwise) that connect to it. These terminals are called User Equipment (UE) and are often referred to by the acronym UE.

[0004] To connect to a network slice, a UE (User Equipment) needs several pieces of information. First, it needs the identifiers of the network slices it is entitled to access based on its subscription. These slice identifiers are designated by the acronym S-NSSAI, for Single Network Slice Selection Assistance Information. These identifiers are stored in a network repository. In a 5G network, the UDR (Unified Data Repository) serves as both the repository and the customer database for the network. This function includes the list of slice identifiers.

[0005] In addition to knowing the identifiers of the bandwidth slices it can access, a UE terminal must have routing rules that allow it to connect to the various platforms providing the different services within a given slice, such as voice, internet, or video streaming services. These routing rules also resolve conflicts between multiple slices providing the same service. These rules, which the UE terminal must have, are called URSPs, an acronym for UE Route Selection Policy. These URSPs are further complemented by rules for blocking traffic and counting the resources traversing the traffic, called PCCs (Policy and Charging Control).

[0006] URSP and PCC rules are established for a given UE (User Equipment) in a 5G network by the PCF (Policy Control Function), which controls network usage policies. The PCF can utilize other 5G network functions to establish URSP and PCC rules.

[0007] We provide further details on how an EU terminal obtains the information presented here according to current 5G standards.

[0008] The way in which a UE terminal is connected to a network slice, as described in current standards and carried out by the various functions of 5G networks, has at least the following two disadvantages.

[0009] One key point is that the provision of network slice identifiers to which the UE terminal has access is done by querying only a static repository stored in the UDR function. All slices accessible to the UE terminal are present in this repository, without discrimination. However, access to certain slices may be conditional upon prior payment and acceptance of these payments, which corresponds to the activation of a service, or it may be limited when a resource usage quota is reached. A UE terminal may therefore receive information to connect to a network slice that it should not have access to. The UE terminal may then attempt to use a network slice and ultimately be denied the connection. This leads to unnecessary signaling and network processing, resulting in overconsumption of hardware and energy resources.Furthermore, refusing to connect to a network slice when the UE has received a slice identifier and a URSP rule specifying how to access the slice can trigger UE instability. There is no guarantee regarding the time it will take for the UE to receive an updated URSP rule.

[0010] This current approach is chosen for reasons of simplicity and to allow more flexibility for application development within user terminals. However, it can lead to excessive resource consumption by the user endpoint (UE) or unstable operation.

[0011] A second point concerns the PCF's retrieval of URSP routing rules and PCC policies. To obtain these, the PCF reads a specific identifier from a UDR table, based on the IMSI number from the UE terminal. This identifier, accessible in a field named Subcats in the UEPolicySet table, allows the PCF to retrieve the corresponding URSP rule sets in other tables. A similar mechanism is used to retrieve the PCC rules corresponding to the IMSI. The 5G network operator's OAM (Operations and Maintenance) teams are responsible for populating the various tables with a defined Subcats identifier and with fixed sets of corresponding rules. Depending on the network equipment vendors, other tables with different names may be used, but the principle remains the same.

[0012] This situation has the drawback of being very rigid. If changes need to be made to a given slice, following a commercial operation (for example, an improvement in the quality of service for a specific traffic stream) for a subset of subscribers within that slice, this requires redefining the rule sets and assigning them a new index. This necessitates delicate coordination between the operator's teams on the one hand and the network managers on the other, even just to create the new indexSubcats. Furthermore, the number of URSP and PCC rule sets is necessarily limited to keep this rigid process feasible, while user demands would allow for maximum differentiation between each subscriber, ideally even enabling the definition of an individual service offering for each subscriber.

[0013] Here again, this choice is driven by simplicity. To achieve this, routing rules for a given network slice must be defined in advance to prevent potential resource abuse arising from knowing all possible slice identifiers. This choice of simplicity and rigidity conflicts with a mobile network operator's desire for rapid deployment of new network slice offerings. It also limits the possibilities for customizing network slices, which ideally could be tailored to individual customers.

[0014] One of the aims of the present invention is to provide improvements over the prior art.

[0015] The invention relates to a method for managing the connection of a user's terminal to a network slice, the method being implemented by the user's terminal and comprising: – obtaining an identifier of a network slice to which the user's terminal can connect after verifying the current connection conditions of the user's terminal to the slice.

[0016] Thus, information regarding the terminal's access conditions to network slices is taken into account when constructing the slice identifiers provided to the user's terminal, unlike a static list of identifiers which does not contain this information. Therefore, the possibility of a user's terminal accessing a network slice to which it is no longer entitled is eliminated or significantly reduced. Typical conditions include at least one piece of information regarding the user's subscription to the network slice.This information may include, for example, information indicating whether or not the user has used up a quota; whether or not the user has paid for their subscription; information relating to the user's presence in a given geographical area, with the user's subscription being differentiated according to the geographical area where they are located; information relating to one or more options subscribed to or not by the user; or any other information relating to the user's subscription to the network slice allowing to determine whether the user's subscription allows them to connect to the network slice.

[0017] Thanks to the invention, it is no longer possible for a user's terminal to attempt to connect to a network slice for which it has exhausted its connection quota, which presented a risk of resource abuse and terminal instability. The management method according to the invention performs checks regarding a terminal's access to a network slice before providing the terminal with all the identifiers of the network slices to which it can connect. The terminal therefore has up-to-date and relevant information on the network slices to which it can connect, taking into account the resources already consumed by the terminal in question.

[0018] In some embodiments, the process is implemented during the attachment of a user's terminal to an access network. In other embodiments, the process is implemented after this attachment, before the terminal establishes a connection to a network slice or when the user's terminal establishes its first connection to a network slice. In still other embodiments, the process is implemented before the user's terminal is attached to an access network, during a provisioning phase of the user's terminal. These different embodiments allow the user's terminal to obtain the information it needs at the most appropriate time.

[0019] According to a first embodiment, the process further includes: – obtaining a set of routing rules valid for a network slice to which the user's terminal can connect after checking the current connection conditions of the user's terminal to the network slice.

[0020] With this embodiment, the user's terminal receives routing rules that allow it to access different services in appropriate network slices. Since the user's terminal has previously only received identifiers of the network slices it can access, it is not necessary to restrict the communicated routing rules to only those of the network slice in which the user's terminal establishes its first packet exchange session, as is the case in the prior art. With this embodiment, all routing rules suitable for all network slices accessible to the user's terminal are distributed to the user's terminal at once. In this way, the transmission of information to the terminal is simplified and made more efficient.When the user's terminal establishes a data packet exchange session in a different network slice, it will already have the routing rules for that other network slice. There is no risk of resource abuse or instability in the user's terminal's operation in this other network slice, since the routing rules obtained by the terminal are those for the network slices that have been verified as accessible by the user's terminal.

[0021] According to one embodiment, which can be carried out alternatively or cumulatively with the previous embodiment, the process further comprises: – connecting to a network slice whose identifier has been obtained beforehand using routing rules of the set obtained beforehand.

[0022] Thanks to this embodiment, the user's terminal can access a network slice. Since only the identifiers of the network slices it can access, taking into account any resource monitoring of the slices, have been communicated to it, and likewise for the routing rules, the user's terminal is guaranteed to be able to access the desired slice, whereas, in the prior art, it is possible to be disconnected from a slice a posteriori, once the checks have been carried out, which can lead to significant instability of the user's terminal.Thanks to the invention, these disadvantages are avoided; the information provided to the user's terminal relates to all the slices which it can access at the time in question, and only those slices, and they are provided all at once to speed up connections to the network slices once the information has been provided according to the method of the invention.

[0023] The invention also relates to a method of providing a user terminal with information relating to a connection of the user terminal to a network slice, implemented by a network component comprising said network slice, said method comprising: – checking the current connection conditions of the user terminal to network slices included in said network; – providing the user terminal with an identifier of said network slice if the current connection conditions checked indicate that the user terminal can connect to said network slice.

[0024] This aspect of the invention enables the provision of information to the user's terminal that will allow it to connect to a network slice. Since the user's terminal's normal connection conditions are verified before a slice identifier is provided, there is a guarantee that the user's terminal can indeed connect to the network slice whose identifier is provided.

[0025] In some embodiments, the process of providing information to a user's terminal is implemented during the attachment of the terminal to an access network. In other embodiments, the process is implemented after this attachment, before the terminal establishes a connection to a network slice or when the user's terminal establishes its first connection to a network slice for which it already has the identifier. In still other embodiments, the process is implemented before the user's terminal is attached to an access network, during a provisioning phase of the user's terminal. These different embodiments allow the user's terminal to obtain the information it needs at the most appropriate time.

[0026] According to one embodiment, the method further comprises: – providing the user terminal with a set of routing rules valid for a network slice to which the user terminal can connect according to the current verified connection conditions.

[0027] In this embodiment, routing rules adapted for connecting to different network slices are provided to the user's terminal. In this way, in addition to the slice identifiers to which the user's terminal can connect, the network component to which the network slice belongs provides the user's terminal with the routing rules that will allow it to connect to that network slice. This provision is successful if the usual connection conditions are met, ensuring that routing rules are only provided to a terminal if it can connect to the network slice.

[0028] According to one embodiment, which can be implemented alternatively or cumulatively with the previous embodiment, the network slice identifier and / or the routing rule set is provided to the user terminal by a network access control function.

[0029] The network access control function is a virtual function that is adapted to provide the network slice identifiers to which a user's terminal can connect, as well as the routing rules that the terminal can use.

[0030] In one embodiment, the network comprising the network slice is a 5G network and the network access control function is the so-called AMF function.

[0031] In the case where the network to which the network slice belongs is a 5G network, the so-called AMF function (acronym for Access Management Function) is the most suitable to provide these network slice identifiers.

[0032] According to one embodiment, which can be implemented alternatively or cumulatively with the previous embodiment, the routing rule set is provided to the user terminal by a network user session management function.

[0033] The initial provisioning of slice identifiers can occur during the initial phase of attaching the user terminal to an access network. The subsequent provisioning, in certain embodiments, of routing rules valid for network slices can take place when the user terminal attempts to connect to network slices and thus opens communication sessions with the network. The network's user session management function is then appropriate for providing these routing rules.

[0034] In one embodiment, the set of routing rules provided to the user's terminal includes indications relating to routing rules, rather than the routing rules themselves. This variant has the same effect of allowing the terminal to route its various streams into different slices based on the provided indications or rules.

[0035] According to one embodiment, which can be implemented alternatively or cumulatively with the preceding embodiments, the network slice identifier provided by the access control function is obtained by said access control function by filtering slice identifiers recorded, in connection with a terminal user identifier, by a network client database, said filtering using information relating to the monitoring of slice resource usage in connection with the terminal user identifier, said information being obtained from a network usage policy control function.

[0036] The access control function can obtain a network slice identifier to which the user's terminal can connect by performing checks with other network functions. These checks are based on a terminal user identifier, which allows retrieval of information related to the user's subscription. Information related to this identifier is stored in a network customer database. Specifically, the access control function can read, from the customer database, all slice identifiers to which the user is likely to connect. However, these identifiers must be filtered by information relating to the identified user's resource usage across the different slices.For example, access to a specific bandwidth may be subject to a resource usage quota, require a special subscription from the user, or be restricted to certain time slots or locations. This information is accessible to the access control function by requesting the network usage policy control function and providing it with the user's identifier.

[0037] In one embodiment, the network comprising the network slice is a 5G network; the terminal user identifier is the so-called IMSI identifier; the network customer database is included in the so-called UDR function; the usage policy control function is the so-called PCF function.

[0038] If the network to which the network segment belongs is a 5G network, the user identifier used to retrieve information about their subscriptions and resource usage is the IMSI (International Mobility Subscription Identifier). Customer information can be found by querying the UDR (Universal Data Repository), which includes all the segment identifiers to which the user is likely to connect if they meet the associated resource usage requirements. These requirements can be obtained from the PCF (Policy Control Function).

[0039] According to one embodiment, which can be implemented cumulatively with the previous embodiment, the usage policy control function obtains information relating to the monitoring of the use of network slice resources from a network resource counting function.

[0040] To obtain comprehensive information regarding a user's use of network bandwidth resources, the network usage policy control function can query the network resource counting function. This function can provide up-to-date information on the availability of various resources. These availability updates are based on payments made by the user for their different resource subscriptions. The network resource counting function therefore tracks the usage of various network resources by user terminals in order to perform subsequent billing operations.The network resource counting function, for example, keeps track of the usage quotas for the different resources and can tell if a resource is authorized or if its usage quota is exhausted.

[0041] In one embodiment, the network comprising the network slice is a 5G network and the network resource counting function is the so-called CHF function.

[0042] In the context of a 5G network, the network resource counting function is the CHF function (acronym for the English CHARging Function).

[0043] According to one embodiment, which can be implemented alternatively or cumulatively with the preceding embodiments, the routing rule set provided to a user's terminal is obtained after querying by a user session management function a network usage policy control function, said policy control function using recorded information and information relating to the monitoring of slice resource usage associated with a terminal user identifier.

[0044] The network user session management function is best suited to provide routing rules for network slices. However, it doesn't necessarily have direct access to the information needed to verify whether the access conditions for different network slices are met by the terminal user attempting to connect to a particular slice. The network usage policy control function can perform this verification using the terminal user's identifier.

[0045] According to one embodiment, which can be implemented cumulatively with the previous embodiment, the usage policy control function obtains information relating to the monitoring of the use of network slice resources from a network resource counting function.

[0046] It is appropriate for the network usage policy control function to query the network resource counting function to obtain certain information regarding the terminal user's resource usage. This information complements the verification performed by the network usage policy control function.

[0047] In one embodiment, the network comprising the network slice is a 5G network and the function for managing user sessions of the network is the so-called UPF function.

[0048] In the context of a 5G network, the function for managing user sessions on the network is the function called UPF (acronym for User Plane Function).

[0049] The invention also relates to a connection manager for a user's terminal to a network slice, included in the user's terminal, the connection manager comprising: – a holder of a network slice identifier to which the user's terminal can connect after verification of the current connection conditions to the network slice.

[0050] In one embodiment, the connection manager further includes: – a receptacle of a set of routing rules valid for a network slice to which the user terminal can connect after verification of the current connection conditions to the network slice.

[0051] In another embodiment, the connection manager further includes: – a connector to a network slice whose identifier has been obtained beforehand using routing rules of the set obtained beforehand.

[0052] The invention also relates to a component for providing a user terminal with information relating to a connection of the user terminal to a network slice, said provisioning component belonging to the network comprising said network slice, and comprising: – a checker of the current connection conditions of the user terminal to network slices included in said network; – a provider to the user terminal of an identifier of said network slice if the current connection conditions checked indicate that the user terminal can connect to said network slice.

[0053] In one embodiment, the delivery component further includes a provider to the user terminal of a set of routing rules valid for a network slice to which the user terminal can connect under the current verified connection conditions.

[0054] The invention also relates to a computer program capable of being implemented by a connection manager of a user terminal, the program comprising code instructions which, when executed by a processor, performs the steps of the connection management process defined above.

[0055] The invention also relates to a data carrier on which is recorded a computer program comprising a sequence of instructions for implementing the connection management method defined above.

[0056] The invention also relates to a computer program capable of being implemented by an information supply component to a user terminal, the program comprising code instructions which, when executed by a processor, performs the steps of the information supply process defined above.

[0057] The invention also relates to a data carrier on which is recorded a computer program comprising a sequence of instructions for implementing the information supply method defined above.

[0058] Data storage media can be any entity or device capable of storing programs. For example, media can include a storage medium, such as a ROM (e.g., a CD-ROM or a microelectronic circuit ROM), or a magnetic recording medium such as a hard drive. Alternatively, media can be transmissible, such as an electrical or optical signal, which can be transmitted via an electrical or optical cable, by radio, or by other means. Programs according to the invention can, in particular, be downloaded from a network such as the Internet. Alternatively, the information storage medium can 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 process in question.The program according to the invention can use any type of computer technology in compiled programming languages, interpreted languages, or a combination of both, as well as with regard to operating systems.

[0059] In this text, the term "component" can refer to a software component, a hardware component, or a set of hardware and software components. A software component itself corresponds to one or more computer programs or subprograms, or more generally, to any element of a program capable of implementing a function or set of functions as described. Similarly, a hardware component corresponds to any element of a hardware assembly capable of implementing a function or set of functions for the module in question (integrated circuit, smart card, memory card, etc.). A component as described in this text may comprise several interconnected functions to fulfill an expected functionality of the component. Brief description of the figures

[0060] The invention will be better understood upon reading the following description, given by way of example, and made with reference to the accompanying drawings in which:

[0061] represents an example of a connection manager for a user terminal and a network component implementing the methods of the invention.

[0062] illustrates an example of steps implemented within the framework of an embodiment of the invention. Detailed description

[0063] Lare represents a connection manager 100 within a user terminal (UE) and a provisioning component 200 within an NWK network. The connection manager 100 manages the connection of the UE to the TR network slice within the NWK network. The provisioning component 200 belongs to the NWK network and provides the UE with information regarding the connection of the user terminal to the TR network slice, which also belongs to the NWK network.

[0064] The connection manager 100 includes, in the example embodiment shown here: – a network slice identifier acquirer 101; – a set of routing rules acquirer 102; – a connector 103 to a network slice.

[0065] The provisioning component 200 includes, in the example embodiment shown here: – a checker 201 of current connection conditions; – a provider 202 of a network slice identifier; – a provider 203 of a set of routing rules.

[0066] In the embodiment described here, the registrar 101 of the connection manager 100 obtains a TR network slice identifier provided by the provider 202, which belongs to component 200. The verifier 201 has previously checked the current connection conditions of the UE terminal to the TR slice. Indeed, the connection to the TR slice may be subject to the UE terminal user subscribing to a specific option. Alternatively, this connection may be limited to the use of a resource quota, limited in time, or limited to a geographical area. The verification performed by the verifier 201 allows the UE terminal to obtain, via the registrar 101 of the connection manager 100, a TR network slice identifier only if the connection conditions of the UE terminal to the TR network slice are indeed met at that time.The provision of the identifier and the consequent obtaining are symbolized by the arrow linking the supplier 202 to the breeder 101.

[0067] In the embodiment described above, the receptacle 102 of the connection manager 100 also obtains a set of routing rules, provided by the provider 203 belonging to component 200. This set of routing rules relates to the connection of a user terminal (UE) to the network slice TR. Prior to provisioning, the verifier 201 of the provisioning component 200 checks the current connection conditions of terminals to the network slice TR. The set of routing rules will only be provided and obtained if the verification shows that the user terminal can, under the current conditions, connect to the network slice TR. The provisioning of the set of routing rules and the resulting receptacle are symbolized by the arrow connecting the provider 203 to the receptacle 102.

[0068] Continuing with the implementation example described above, connector 103 of connection manager 100 uses the obtained slice identifier and the resulting routing rule set to establish the connection between the user terminal (UE) and the network slice (TR). This connection is symbolized by the arrow linking connector 103 to the network slice (TR).

[0069] The Connection Manager 100 exhibits the hardware architecture of a conventional computer. It includes a processor, RAM (Random Access Memory), and read-only memory such as Flash or ROM (not shown in the figure), as well as input / output devices, specifically connections to one or more software buses or network ports for communicating with other entities. The Connection Manager 100 is embedded in a user terminal (UE), which can be a smartphone, a conventional computer, a device such as a game console, a connected object, or a network-connected vehicle. The user terminal (UE) seeks to connect to a network slice (TR) belonging to the NWK network, and the Connection Manager 100 implements the process that facilitates the connection of the UE to the TR slice.The 100 connection manager uses hardware, software and network resources, such as antennas, which are part of the user terminal UE.

[0070] Supply component 200, on the other hand, belongs to the NWK network. It also exhibits the hardware architecture of a conventional computer and includes, in particular, a processor, at least one RAM memory unit, and at least one ROM memory unit such as Flash memory (not shown in the figure), as well as input / output devices, specifically connections to one or more software buses or network ports for communicating with other entities. Supply component 200 can be a single hardware component deployed in the NWK network or it can be formed by combining several functions present in the network, which can be deployed on separate hardware components.The supply component 200 can in particular be deployed on a cloud architecture and be made up of several virtual network functions modified to implement the information supply method according to the invention.

[0071] This, for its part, represents an example of message exchanges that can take place in an example of implementation of the processes according to the invention.

[0072] To better explain the process according to the invention, we begin by describing how information such as slice identifiers or URSP routing rules are currently provided to user terminals within the framework of 5G networks.

[0073] A network slice is defined in relation to a public land mobile network (PLMN). A public land mobile network is a mobile telecommunications network that exists in a given country and provides a user terminal with physical access to telecommunications through antennas, base stations, and other necessary equipment. Once physical access to the telecommunications network is guaranteed by the PLMN, a user terminal can access one or more network slices using the access provided by the PLMN. In mobile telecommunications, the access network is a wireless network often referred to by the acronym RAN, for Radio Access Network.

[0074] During its initial connections to a 5G network, the UE may not know all the network slice identifiers, nor have any URSP rules, or may only have one default rule. The UE obtains the slice identifiers it can access and the URSP rules as follows in the current operation of 5G networks: Upon powering on, the UE connects to the RAN access network. The RAN access network receives the identifier of the mobile network to which the UE is subscribed from the UE. This mobile network comprises several network slices that can provide different communication services to the UE. The RAN selects a virtual Access and Mobility Management Function (AMF) network for the UE, for example, based on its geographic location.The subscriber's IMSI (International Mobile Subscriber Identity) was provided by the UE (User Equipment) to the AMF (Automatic Message Function). Specifically, for confidentiality reasons, the AMF receives a SUCI (Subscription Concealed Identifier), which is an encrypted identifier derived from the IMSI. The AMF can then retrieve the IMSI by querying the AUSF (Authentication Server Function). Using the IMSI, the AMF will query the UDR (Universal Data Repository), which contains the identifiers of the data slices that the UE can access.The AMF function returns these identifiers to the UE after interacting with the NSSF (Network Slice Selection Function) and NRF (Network Repository Function), which verify whether a given network slice is indeed open at the UE's location. In fact, some network slices may not be open within a given geographic coverage area. Currently, in 5G network practice, no verification is performed regarding the IMSI-identified subscriber's subscription to the network slice or their actual use of the network slice's resources.The AMF function uses information from a static list of slices indicated as usable by the subscriber, a list present in the UDR function, without considering access control to the slices in relation to billing the user for services. The UE, which now has at least one slice identifier to access, will establish a PDU (Packet Data Unit) session with the target network using a network slice. The target network is identified by a DNN (Data Network Name) which corresponds to a traffic delivery point in the selected network slice that the UE will access. Initially, the UE does not have routing information indicating how to address the different flows of the various services in the network slice(s) it can access.When the first PDU session is created, the UE interacts with the User Plane Function (UPF). The UPF transmits the IMSI number to the Policy Control Function (PCF). The PCF then consults its profiles stored in the UDR database to retrieve URSP routing rules from the UDR. Because there has been no check to ensure the UE can access the network slice whose identifier was provided, routing rule requests may be made to slices that are ultimately not authorized, which can trigger operational instability. The PCF then transmits the created rules. The URSP rules are passed to the AMF, which then forwards them to the UE. These URSP rules may be specific to the current network slice to which the PDU session belongs, but they can also be specific to other network slices.For example, the PDU session can be specific to a particular type of traffic (business traffic to a private corporate network, or conversely, leisure traffic to a video game service). The AMF function can detect that this traffic would be better suited to another network slice and will then push the URSP rules adapted to this other network slice to the UE. The PCF function will also generate rules for potentially blocking flows and controlling the resources passing through the flows, known as PCC rules (Policy and Charging Control). These rules, which specify the quality of service and resource counting to be applied to each flow using the PDU session, are deployed in the UPF user plan function so that they are applied in future interactions between the UE and the network slice.

[0075] We have schematically described here the interactions that occur during the initial power-up and connection to a network slice of a UE terminal, that is, during the establishment of the first PDU session, in current 5G network practice. During subsequent connections, the UE terminal can establish a PDU session within a different network slice. It will then receive the URSP rules limited to that slice.

[0076] Furthermore, when the UE terminal connects to the AMF function, the connection is initially determined by geographical considerations. It is possible that the UE terminal may need to communicate with a different AMF function instance, and in this case, the first AMF function contacted directs the UE terminal to the correct one. For the sake of simplicity, we disregard this possibility and assume that the UE terminal always contacts the appropriate AMF function instance from the outset.

[0077] Within the scope of the invention, one possible embodiment is the application of the methods according to the invention to 5G networks. In this case, the connection manager 100 is included in a user terminal (not shown in the figure) and the delivery component 200 is formed from several virtual network functions modified to implement the method of providing connection information to the connection manager 100. The virtual network functions that form the component 200 in this example are the AMF, UPF, UDR, PCF and CHF functions, which are known virtual network functions in 5G networks.

[0078] In the example shown, the first exchange described is the transmission of the user's IMSI identifier by the connection manager 100 to the AMF function. The AMF function is a network access control function. This exchange is a simplification of the exchanges that actually occur in 5G telephony, because the identifier actually addressed is an encrypted identifier called SUCI from the user's terminal, which then allows the AMF function to obtain the IMSI identifier in an interaction not shown in the example. It is also possible that the identifier addressed is a 5G-GUTI structure (acronym for Globally Unique Temporary Identifier), which also allows the IMSI identifier to be retrieved after an initial interaction between the terminal and the AMF function.

[0079] Prior to this exchange, the UDR function, which serves as a repository for various customer information or a customer database, was provisioned with relevant information about the terminal user and their various subscriptions, and therefore their access to different network segments. This is represented by the PROV arrow pointing to the UDR function.

[0080] The AMF function having obtained the IMSI identifier will request the UDR function to obtain a set of TRi slices to which the user of the terminal whose connection is managed by manager 100 can connect.

[0081] The AMF function then queries the PCF function, which is a policy control function, using the IMSI identifier. The PCF function can itself query the CHF function, which is a network resource counting function. This query verifies the current connection conditions of the user's terminal to the different TRi slices. If a resource usage condition is not met, the slice will not ultimately be offered to the connection manager by the AMF function. In the example above, the AMF function transmits a TR slice identifier to the UE terminal after verification.

[0082] Upon subsequent connection to a network slice, the 100 connection manager will send an identifier to the UPF function, which manages user sessions on the network. This identifier will allow the UPF function to obtain an IMSI identifier in a manner similar to that described previously.

[0083] The UPF function will query the PCF function, which may in turn query the CHF function. This verification of the current connection conditions of the user identified by the IMSI precedes the construction by the PCF function of routing rules specific to the user and the bandwidth ranges to which they can access.

[0084] The PCF function then transmits these routing rules in two sets. The PCC rules are passed to the UPF function, which stores them. The URSP rules are passed to the AMF function, which then forwards them to the 100 connection manager.

[0085] The implementation of the invention's method thus enabled the connection manager 100 to obtain information useful for connecting the terminal to network slices after a check of the current connection conditions had taken place. The connection manager 100 will therefore prevent attempts by the user's terminal to connect to slices to which the user cannot connect under the current conditions. This will improve the operational stability of the network and user terminals by preventing connection attempts to network slices that are ultimately inaccessible.

Claims

Method for managing the connection of a user terminal (UE) to a network slice (TR), the method being implemented by the user terminal (UE) and comprising: – obtaining an identifier of a network slice (TR) to which the user terminal (UE) can connect after verification of the current connection conditions of the user terminal (UE) to the network slice (TR). Management method according to claim 1 characterized in that the method further comprises: – obtaining a set of routing rules valid for a network slice (TR) to which the user terminal (UE) can connect after verification of the current connection conditions of the user terminal (UE) to the network slice (TR). Management method according to claim 2 characterized in that the method further comprises: – connecting to a network slice (TR) whose identifier has been obtained beforehand using routing rules of the set obtained beforehand. Method of providing a user terminal (UE) with information relating to a connection of the user terminal (UE) to a network slice (TR), implemented by a component (200) of the network (NWK) comprising said network slice (TR), said method comprising: – checking the current connection conditions of the user terminal (UE) to network slices included in said network (NWK); – providing the user terminal (UE) with an identifier of said network slice (TR) if the current connection conditions checked indicate that the user terminal (UE) can connect to said network slice (TR). Supply method according to claim 4 further comprising: – providing the user terminal (UE) with a set of routing rules valid for a network slice to which the user terminal (UE) can connect according to the current verified connection conditions. A supply method according to any one of claims 4 to 5 characterized in that the network slice identifier (TR) and / or the routing rule set is supplied to the user terminal (UE) by a network access control function (AMF) (NWK). A supply method according to claim 6 characterized in that the network slice identifier (TR) supplied by the access control function (AMF) is obtained by said access control function (AMF) by filtering slice identifiers registered, in connection with a terminal user identifier (IMSI), by a network user (NWK) customer database (UDR), said filtering using information relating to the monitoring of slice resource usage in connection with the terminal user identifier (UE) (IMSI), said information being obtained from a network usage policy control (PCF) function (NWK). Supply method according to claim 7 characterized in that the policy control function (PCF) obtains information relating to the monitoring of the use of resources of the tranches from a network resource metering function (CHF). A supply method according to claim 6 characterized in that the routing rule set provided by the access control function (AMF) is obtained after querying by a network user (NWK) session management function (UPF) of a network usage policy control function (PCF), said policy control function (PCF) using recorded information and information relating to monitoring the use of resources in slices in connection with an identifier (IMSI) of the terminal user (UE). Supply method according to claim 9 characterized in that the policy control function (PCF) obtains information relating to the monitoring of the use of resources of the tranches from a network resource metering function (CHF). Connection manager (100) of a user terminal (UE) to a network slice (TR), included in the user terminal (UE), the connection manager (100) comprising: – an acquirer (101) of a network slice identifier to which the user terminal (UE) can connect after verification of the current connection conditions to the network slice (TR). A supply component (200) to a user terminal (UE) of information relating to a connection of the user terminal (UE) to a network slice (TR), said supply component (200) belonging to the network (NWK) comprising said network slice (TR), and comprising: – a checker (201) of the current connection conditions of the user terminal (UE) to network slices included in said network (NWK); – a provider (202) to the user terminal of an identifier of said network slice (TR) if the checked current connection conditions indicate that the user terminal (UE) can connect to said network slice (TR). Computer program capable of being implemented by a connection manager (100), the program comprising code instructions which, when executed by a processor, performs the steps of the method of managing the connection of a user terminal (UE) to a network slice (TR) according to claim 1. Data carrier on which is recorded a computer program comprising sequences of instructions for implementing the method of managing the connection of a user terminal (UE) to a network slice (TR) according to claim 1. Computer program capable of being implemented by a supply component (200), the program comprising code instructions which, when executed by a processor, performs the steps of the method of supplying a user terminal (UE) with information relating to a connection of the user terminal (UE) to a network slice (TR) according to claim 4. Data carrier on which is recorded a computer program comprising sequences of instructions for the implementation of the method of providing to a user terminal (UE) information relating to a connection of the user terminal (UE) to a network slice (TR) according to claim 4.

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