Methods for accessing a service and for providing services, and corresponding terminal, service function instance and computer programs

Abstract

The invention relates to a method for providing at least one service to a terminal (11) via a communication network (12) using network slices, the method involving: • selecting (1311) at least one network slice or one type of network slice suitable for routing the data associated with said at least one service, • transmitting (1312) at least one piece of information characteristic of the at least one selected network slice or type of network slice to the terminal.

Description

Description Title of the invention: Methods for accessing a service and providing services, terminal, service instance, and corresponding computer programs. 1. Technical field

[0001] The field of the invention is that of communications within at least one communications network, and in particular that of value-added IP services.

[0002] More specifically, the invention relates to access to at least one service using the network slice resources of a communications network.

[0003] In particular, the invention proposes a solution for selecting one or more network slices for all or part of the traffic destined for a service instance or a terminal. 2. Prior art

[0004] A network slice can be defined as a partition of the network such as a virtual private network (VPN) deployed on fixed infrastructure, mobile infrastructure, or a combination of both.

[0005] The characteristics of a network slice are mainly expressed in terms of capacity (bandwidth) and quality of service (e.g. latency, one-way transit time, etc.), or even security (e.g. preservation of the confidentiality of information transmitted within the VPN through the use of encryption techniques) and service functions (“Service Functions (SF)”).

[0006] The characteristics of a network slice are for example presented in the document “A Framework for IETF Network Slices” by A. Farrel et al., version 21 published on June 15, 2023.

[0007] An example of using network slices deployed in a 5G mobile infrastructure is presented in the document “A Realization of IETF Network Slices for 5G Networks Using Current IP / MPLS Technologies” by KG Szarkowicz et al., version 9 published on May 23, 2023.

[0008] Traditionally, traffic that can be routed within a network slice is authorized (also called access control) to use the paths established within the slice. Such authorization is typically based on the application of traffic classification rules. These rules are generally applied by a network access point within which network slices have been deployed. This access point is a node located at the edge of the network and is generally deployed in front of client access or used to connect a network to other networks. neighbors. For example, such an access point may be located at the connection interface of a gateway that provides access to the Internet network. This gateway is called a "packet gateway" for the most recent generations (4G, 5G) of mobile networks. In this case, the traffic classification function could be located at the connection interface of a "packet gateway" to the Internet network. The access point may also be located at the connection interface of a mobile terminal (or "User Equipment" or UE in English) to the radio access network (or "Radio Access Network" or RAN in English), in particular so as to optimize the use of radio resources according to the type of network slice and the profile of the traffic that it is likely to carry. A traffic profile is the set of characteristics specific to the traffic.These characteristics may reflect the sensitivity of applications to latency, transit delay or packet loss, but also usage practices, for example traffic that would only be generated over a given period (for example, management traffic related to the execution of a scheduled equipment maintenance operation during the night). Traffic classification and admission control rules are therefore applied at the edge of the network.

[0009] It should also be remembered that the 3GPP organization has defined different types of network slices, according to their characteristics: - a first type of network slices allowing the provision of an improved mobile broadband service (“Enhanced Mobile BroadBand” or EMBB in English); - a second type of network slices enabling a service to be offered as part of a (massive) deployment of the Internet of Things (massive Internet of Things or mloT in English); and - a third type of network slices allowing the provision of an ultra-reliable, low-latency communications service (“Ultra Reliable Low Latency Communications” or URLLC in English).

[0010] The choice to design and deploy one or other of these types of network slice is conditioned by the nature of the traffic characteristic of the applications or services used or subscribed to by a user. For example, a so-called "immersive" service that uses augmented or virtual reality techniques is generally very demanding in terms of latency and reliability of data exchanges: the use of URLLC type slices is therefore preferred for an immersive service of this type.

[0011] It is also noted that traffic classification rules can be complex, because the level of granularity associated with the engineering and deployment of a network slice can be macroscopic (for example, a network slice deployed to route traffic to the Internet), or microscopic (for example, a network slice deployed for application traffic exchanged between two mobile terminals).

[0012] This granularity generates an overall complexity in the engineering of network slices, for example a difficulty in optimizing the use of resources implemented by a network slice, by a set of network slices, or by all network slices, or a difficulty in strictly guaranteeing the isolation of traffic routed within a network slice, or even a difficulty in strictly guaranteeing the level of quality or security associated with a network slice, or even the level of availability and resilience of a given network slice, etc.

[0013] In particular, the complexity of configuring and applying traffic classification rules associated with the implementation of a given network slice evolves with the diversity of traffic, the richness of the organization of the structure that operates the network slice (for example, an accounting department, an R&D department, a production department) or the mode of use of the network slice (for example, management of traffic overloads during busy hours, principles of traffic load distribution). This complexity can be aggravated in particular by the evolution of traffic classification rules over time (for example, in the context of the deployment of a network slice for the retransmission of a sporting or cultural event, the traffic classification rules can evolve with the number and profile of users of the network slice).

[0014] There is therefore a need for a new service access technique that seeks to improve the utilization of network slice resources. 3. Statement of the invention

[0015] The invention proposes a solution which does not have all the drawbacks of the prior art in the form of a method for providing at least one service to a terminal, via a communication network implementing network slices, comprising: - the selection of at least one network slice, or a type of network slice, suitable for routing the data associated with said at least one service, - the transmission, to said terminal, of at least one piece of information characteristic of said at least one network slice, or type of network slice, selected.

[0016] Such a method may in particular be implemented by a service instance, which provides the service that the terminal wishes to access. For example, such a service instance is an application server hosted by the service provider or another infrastructure. Such a method applies regardless of whether the service is provided by a single service instance or by a group of service instances.

[0017] Thus, during a first step, the method selects at least one network slice (or at least one type of network slice (for example EMBB, mloT or URLLC if we consider a 5G network)) suitable for routing the data associated with said at least one service.

[0018] In particular, such a network slice (or type of network slice) can be selected by a service instance taking into account a context relating to the service considered (for example, depending on the nature of the service considered, the number of users wishing to simultaneously access the service considered). Indeed, the service instance has information relating to the service or the context of which the communication network is not aware. It therefore has information enabling it to select, according to at least one embodiment, one or more network slices (or type(s) of network slice) optimized for routing traffic via the communication network.

[0019] Once said at least one network slice has been selected (or said at least one type of network slice selected), at least one piece of information characteristic of said at least one network slice (or said at least one type of network slice) selected is transmitted to the terminal. For example, such characteristic information may be transmitted in a parameter hereinafter called “Slice-selector”.

[0020] Such a procedure is hereinafter called REVES, for “REflectiVE Slicing”.

[0021] For example, if a network slice type is selected, the characteristic information is the network slice type. If a network slice is selected, the characteristic information is for example a network slice identifier, for example a 3GPP NSSAI type identifier, or a network partition identifier (“Network Resource Partition”), for example a customized version of the network topology and resources (“Filtered Topology”), or even a network slice type. More generally, any information allowing the terminal to identify a network slice or a network slice type suitable for accessing the service in question can be used. In particular, such information makes it possible to identify a network slice or a network slice type optimized for accessing the service in question.

[0022] In a particular embodiment, the method implements the transmission, to said terminal, of at least one traffic classification rule associated with said at least one selected network slice, or type of network slice.

[0023] Such rules can be passed in the "Slice-selector" parameter, for example.

[0024] Thus, the terminal can configure the traffic classification rule(s) making it possible to associate the traffic with said at least one selected network slice (or type of network slice). Alternatively, the terminal can communicate to at least one intermediate router, for example a CPE (“Customer Premises Equipment”) or other equipment for connection to the communications network the traffic classification rule(s) that such intermediate equipment is intended to apply.

[0025] In a particular embodiment, the method comprises transmitting, auditing terminal, at least one piece of information relating to traffic classification.

[0026] Such information relating to the traffic classification may be transmitted in addition to said at least one characteristic information of said at least one selected network slice (or network slice type). It may also be transmitted according to the “Slice-selector” parameter. Alternatively, such information relating to the traffic classification may be deduced from said at least one characteristic information.

[0027] These include, for example:

[0028] - a port number characteristic of the traffic sent or received by the terminal, sent or received by the service instance, or sent or received by an intermediate router, or

[0029] - a marking, for example using a DSCP code contained in the DS field (“Differentiated Services”) from the header of an IP packet, or

[0030] - a TCP / UDP option, for example the MPTCP option. Such an option allows a TCP session to be established on several distinct paths, each of these paths being able to be established within the same network slice or several distinct network slices,

[0031] - etc.

[0032] In a particular embodiment, the method comprises, during a communication session, verifying that the network slice used for routing a first message from said terminal to at least one service instance, called the first network slice, is suitable for providing said at least one service.

[0033] If the verification confirms that said first network slice is suitable, said selection of said first network slice for the transmission of at least one second message between said terminal and said at least one service instance is confirmed.

[0034] If, on the other hand, the verification process determines that said first network slice is not suitable, said selection process identifies a second network slice distinct from said first network slice for the transmission of at least one second message from said terminal to said at least one service instance, during said communication session.

[0035] If a communication session is already in progress, it is thus possible to switch from a first network slice to a second network slice without interruption of service.

[0036] In other words, if the service instance detects that the network slice used by the terminal to route traffic to the service instance is not optimal for the service in question, the service instance may offer to switch to another network slice better suited for the service in question, without requiring the establishment of a new communication session.

[0037] In a particular embodiment, the first message is an access message to said at least one service, comprising a first indicator signaling that said terminal supports the routing of data via at least one network slice.

[0038] For example, such a first indicator is subsequently denoted "slice_aware". Setting this parameter to "1" indicates, for example, that the terminal supports traffic routing via at least one network slice. In particular, such a first indicator can be transmitted for each new communication session.

[0039] Thus, the terminal sends a first message containing a first "slice_aware" indicator at the beginning of a communication session, when the terminal begins to invoke the service. To do this, it can in particular use a default network slice (first network slice).

[0040] The service instance can check whether the network slice used is optimal for the service in question, taking into account the context, and possibly inform the terminal that using another network slice would be more suitable. The terminal can then send at least one second message that can pass through this new, more suitable network slice (second network slice), during the same communication session.

[0041] In particular, said at least one piece of information characteristic of said at least one network slice, or type of network slice, selected by the service instance can be transmitted to the terminal in any message associated with said current session, for example in an HTTP request allowing access to an Internet site.

[0042] In another embodiment, the invention relates to a service instance adapted to implement the method for providing at least one service described above. Such a service instance may of course have the various characteristics relating to the method for providing at least one service according to the invention, which may be combined or considered in isolation. Thus, the characteristics and advantages of this service instance are the same as those of the method and are not detailed further.

[0043] The invention further relates to a method for accessing at least one service by a terminal, via a communication network implementing network slices, comprising: - the reception of at least one piece of information characteristic of at least one network slice, or a type of network slice, adapted to the routing of data associated with said at least one service, selected by at least one service instance capable of providing said at least one service to said terminal, - the transmission of at least one message to said at least one service instance, via a network slice identified from said at least one characteristic information, taking into account at least one classification rule- traffic information associated with said identified network slice.

[0044] Such a method can in particular be implemented by a terminal connected to the communications network.

[0045] Thus, a terminal has at least one piece of information characteristic of at least one network slice (or at least one type of network slice) selected by a service instance capable of providing the service in question. As already indicated, such a service instance may in particular take into account the context relating to the service in question to choose, according to a particular embodiment, the network slice(s) (or type(s) of network slice) optimized for routing traffic via the communication network.

[0046] In particular, the method can identify a network slice from said at least one characteristic information (recorded for example in the “Slice-selector” parameter), and connect to this network slice to send traffic to the service instance.

[0047] In one embodiment, the method comprises receiving said at least one traffic classification rule from said at least one service instance, and configuring said terminal with said at least one traffic classification rule.

[0048] Optionally, the terminal may also receive at least one piece of information relating to the traffic classification, in addition to said at least one piece of information characteristic of said at least one selected network slice (or type of network slice). Alternatively, such information relating to the traffic classification may be deduced from said at least one piece of characteristic information.

[0049] In a particular embodiment, the method comprises transmitting configuration instructions of at least one intermediate router (for example a CPE) of said communication network with said at least one traffic classification rule.

[0050] The router can then use these rules to authorize or not the routing of traffic sent by the terminal via the network slice selected from the characteristic information.

[0051] In a particular embodiment, the method comprises updating said at least one traffic classification rule following the reception of at least one new item of information characteristic of at least one network slice, and which is therefore likely to cause said update (for example, traffic congestion observed within the initially selected network slice).

[0052] In this way, it is possible to switch traffic routing from a first slice to a second network slice during the same communication session.

[0053] In a particular embodiment, the method comprises a step of validating said identified network slice, implemented prior to the transmission of at least one message via said identified network slice.

[0054] For example, such a validation step involves verifying with the terminal user that the identified network slice can be used for traffic sent by the terminal.

[0055] In a particular embodiment, the method comprises the transmission, to said at least one service instance, of a first indicator signaling that said terminal supports the routing of data via at least one network slice (“Slice-aware” for example).

[0056] For example, the first indicator is inserted into a dedicated header of an access message to at least one service, for example in an HTTP header, a QUIC frame, etc.

[0057] In another embodiment, the invention relates to a terminal adapted to implement the method of accessing at least one service described above. Such a terminal may of course have the various characteristics relating to the method of accessing at least one service according to the invention, which may be combined or considered in isolation. Thus, the characteristics and advantages of this terminal are the same as those of the method and are not detailed further.

[0058] In the various embodiments envisaged, at least one of said network slices may be composed of at least one local network slice deployed in at least one subnetwork of the communication network (for example in an access network, a collection network, a core network, a transit network).

[0059] The invention also relates to at least one computer program comprising instructions for implementing at least one of the methods described above, when this or these programs are executed by a processor, as well as at least one information medium readable by a computer comprising instructions of at least one computer program as mentioned above.

[0060] The method according to the invention can be implemented in various ways, in particular in wired form or in software form. 4. List of figures

[0061] Other characteristics and advantages of the invention will appear more clearly on reading the following description of a particular embodiment, given as an illustrative and non-limiting example, and the appended drawings, among which: - [Fig.1] represents a system in which the invention can be implemented; - [Fig.2] illustrates the main steps of the methods according to at least one embodiment of the invention; - [Fig.3] illustrates the main messages exchanged during the implementation of the processes according to [Fig.2]; - [Fig.4] illustrates an example of a communication network composed of several subnetworks; - [Fig.5] illustrates an example of aggregation of several services within the same network slice; - [Fig.6] illustrates an example of deployment of several service instances; - [Fig.7] illustrates an example of implementation of the methods according to [Fig.2] when the terminal is directly connected to the network of a service provider; - [Fig.8] illustrates an example of implementation of the methods according to [Fig.2] when the terminal is connected to the network of a service provider via a CPE; - [Fig.9] presents the simplified structure of the different entities according to a particular embodiment.

[0062] 5. Description of an embodiment of the invention 5.1 General principle

[0063] The general principle of the invention is based on the selection of the paths to be used for routing traffic, in a system in which a terminal wishes to access at least one service via a communication network implementing network slices. In particular, at least one service instance capable of providing the service in question can select at least one network slice, or a type of network slice, adapted to the routing of the data associated with the service in question, i.e., taking into account the nature of the service, or the context of use of the service for example.

[0064] Thus, the proposed solution offers, according to at least one embodiment, a mechanism for automatic and secure discovery of network slices deployed (or instantiated) on a fixed and / or mobile infrastructure and reserved for a certain use, for example the retransmission of a sporting or cultural event.

[0065] [Fig.l] illustrates an example of a system in which the invention can be implemented. Such a system comprises a terminal UE 11 (“User Equipment” in English) wishing to access at least one service via a communication network SSP 12 (“Slice Service Provider” in English, or service provider based on network slices) implementing network slices, for example two network slices SI. #1 161 and SI. #2 162 (“Slice” in English).

[0066] Terminal 11 may optionally be connected to network 12 via an intermediate router, for example a CPE.

[0067] The service may be provided by at least one service instance, for example by two service instances SFI #1 131 and SFI #2 132. A service instance may be connected to the network 12 via a network border node. For example, the instance 131 is connected to the network 12 via the first border node BR 141 (“Border Router” in English), and the second instance 132 is connected to the network 12 via the second border node BR 142.

[0068] We now present, in relation to [Fig.2], the main steps implemented by the different methods according to an embodiment of the invention.

[0069] It is considered that a service instance, for example the first service instance 131, selects during a step 1311 at least one network slice, or a type of network slice, suitable for routing the data associated with said at least one service.

[0070] In one embodiment, the selection of network slices (or types) by a service instance may preempt traffic classification rules provided by another channel. In another embodiment, the service instance may indicate in an instruction communicated to the terminal the precedence / priority of said instruction relative to other instructions communicated by other channels (e.g. default configuration).

[0071] The first service instance 131 can then transmit to the terminal 11, during a step 1312, at least one piece of information characteristic of said at least one network slice, or type of network slice, selected, as well as possibly at least one traffic classification rule and / or at least one piece of information relating to the traffic classification. Such information is for example transmitted in a “Slice-selector” parameter of a configuration message MSG_C.

[0072] The terminal 11 can thus receive, during a step 111, the information transmitted by the first service instance 131 in the configuration message MSG_C (Slice-selector).

[0073] From this information, the terminal 11 can identify a network slice to be used for all or part of the traffic sent by the terminal to the first service instance 131 and connect to this identified network slice, during a step 112, directly or via a router, for example the CPE 15.

[0074] The terminal 11 can then transmit at least one message comprising data, denoted MSG_D, to the first service instance 131, via said identified network slice, taking into account at least one traffic classification rule associated with said identified network slice, during a step 113.

[0075] The first service instance 131 can receive the MSG_D message during a step 1313. It can in particular verify whether the network slice identified from said at least one characteristic information used to transmit the MSG_D message is suitable for providing the service (for example by taking into account actual conditions of use of the service or more generally of the context relating to the service considered) and possibly select a new network slice, or a new type of network slice, for the transmission of the next messages sent by the terminal 11 to the first service instance 131, in particular during the same communication session.

[0076] [Fig.3] is a flow diagram illustrating the messages exchanged according to the main steps described in [Fig.2].

[0077] It is considered according to [Fig.3] that the terminal 11 first sends a service access message, comprising a first “Slice-aware” indicator (denoted MSG_A (Slice-aware)) signaling to said at least one service instance, for example to the first service instance 131, that the terminal 11 supports the routing of data via at least one network slice.

[0078] This first access message may in particular be transmitted via a first network slice. Upon receipt of this first message, the first service instance 131 may in particular check whether the first network slice used to transmit this first message is suitable for the service in question (taking into account, for example, the nature of the service or a context relating to the service, such as a throughput, a level of quality of service, or even a desired level of security). If the first service instance 131 considers that the first network slice is suitable for routing the data associated with the service in question, information characteristic of the first network slice is transmitted from the first service instance 131 to the terminal 11, to confirm to the terminal that it can continue to send MSG_D messages relating to the service in question to the first network slice.

[0079] Conversely, if the first service instance 131 considers that the first network slice is not suitable for routing the data associated with the service in question, it selects a second network slice better suited to routing the data (for example in terms of throughput, or quality of service, or security), and transmits to the terminal 11 information characteristic of the second network slice. The terminal 11 can thus switch to the second network slice to continue its exchanges with the first service instance 131.

[0080] Optionally, as already indicated, the terminal 11 can send configuration information to an intermediate router, for example a CPE, with at least one traffic classification rule (received for example by the terminal 11 in the “Slice-selector” parameter). The intermediate router can thus apply these traffic classification rules to route or not the traffic sent by the terminal via the selected network slice.

[0081] More generally, it is considered that a slice of the communication network can be associated with other network slices to provide value-added services. For example, a service provider may rely on slices set up in different subnets to provide a service whose traffic is intended to be routed in the "global" network slice composed of slices deployed in the different subnets. This is called a "multi-domain slice" (or "stitched slices" or "hierarchical slices"). Such a network slice may indeed reflect a hierarchical structure.

[0082] For example, as illustrated in [Fig. 4], the SSP network 12 may be composed of several subnetworks 121, 122 and 123. Each subnetwork may support one or more network slices. For example, the first subnetwork 121 supports four network slices, the second subnetwork 122 supports three network slices, and the third subnetwork 123 supports four network slices. The first network slice SI. #1 161 of the communication network is for example composed of network slices SI. #3 deployed on subnetwork 121, SI. #2 deployed on subnetwork 122 and SI. #2 deployed on subnet 123. The connection interfaces between adjacent slices ("Attachment Circuits" in English) are for example managed using the mechanisms described in the document "YANG Data Models for 'Attachment Circuits'-as-a-Service (ACaaS)" by M. Boucadair et al., version 6 published on May 3, 2023.

[0083] For example, each subnetwork may be associated with a distinct domain (e.g., a communications network may be composed of an access network, a collection network, a core network, and a transit network). Each of these domains supports network slices whose engineering and operation are characteristic of the domain (e.g., a slice deployed on a 5G mobile core network may use traffic processing and operation functions characteristic of a 5G mobile core network). Thus, each domain (access, collection, core, transit, etc.) may use different technologies for the realization of the network slices.

[0084] Thus, the creation of a network slice that extends over several domains is not conditioned by the availability or activation of the same technologies used for the creation of the slices "local" to each domain.

[0085] For example, with reference to [Fig. 4], a first domain associated with the first subnet 121 sets up IPsec tunnels which are used to route traffic in the slices deployed in this domain, while a second domain associated with the second subnet 122 uses network-level virtual private network engineering (Layer 3 VPN or L3VPN) combined with traffic engineering mechanisms (“Traffic Engineering” or TE in English) to route traffic in the slices deployed in this domain, while a third domain associated with the third subnet 123 uses the resources of segment routing based on the IPv6 protocol (“Segment Routing IPv6” or SRv6 in English) to route traffic in the slices deployed in this area.

[0086] As another example, a network slice in a mobile network (e.g. 5G) may be based on the implementation of network slices in the following different sub-networks / segments: radio access network (RAN), core network (CN) and transport network (TN).

[0087] The association between a network slice, for example a 5G network slice in the case of a latest generation mobile network, and the network slices deployed in each of the segments / subnetworks composing the 5G mobile network is carried out in the control plane and at the edge of each of the RAN, CN and TN networks. The network slice deployed in the TN network is sometimes called an “IETF Network Slice”.

[0088] According to the invention, no assumption is made as to the nature of the network slices, their number, and the "mapping" between network slices of neighboring domains (for example RAN and TN, TN and CN).

[0089] For example, the mechanisms described in the previously cited document “A Realization of IETF Network Slices for 5G Networks Using Current IP / MPLS Technologies” are implemented for the realization of network slices in an IP / MPLS network (which is an example of a transport network within the meaning of 3GPP).

[0090] It is further noted that the same network slice can be used to aggregate the traffic of one or more services. Thus, as illustrated by [Fig.5], a first service SI served by one or more service instances 51 can be provided to a first client UE1 via a network slice SI. #3 of the SSP network, a second service S2 served by one or more service instances 52 can be provided to a second client UE2 via the same network slice SI. #3 of the SSP network, a third service S3 served by one or more service instances 53 can be provided to the second client UE2 via the same network slice SI. #3 of the SSP network.

[0091] Additionally, a network slice may involve one or more service functions (or "Service Functions" in English, according to the terminology used by RFC7665 - "Service Function Chaining (SFC) Architecture" by J. Halpern et al. published in October 2015, or "Network Functions" such as gNB ("gNodeB") or UPF ("User Plane Functions") according to the terminology used by 3GPP). A single service function may be provided by one or more service instances.

[0092] [Fig.6] illustrates an example of deployment of service instances. In particular, a service instance may be hosted by the SSP (e.g. service instances 63 and 64) or within another infrastructure (e.g. service instance 65).

[0093] In a particular embodiment, service chains (SFCs) may be implemented to facilitate the routing of traffic of different natures and presenting different profiles for the needs of the creation of a network slice or within a network slice (for example service instances 611, 612 and 613 of [Fig.6]). 5.2 Implementation examples

[0094] We now present some examples of implementation of the invention.

[0095] Referring to Figures 7 and 8, it is considered that the terminal 11 wishes to access at least one service Si via an SSP communication network 12 implementing network slices, for example four network slices SI. #1, SI. #2, SI. #3 and SI. #4.

[0096] The terminal 11 may optionally be connected to the network 12 via an intermediate router, for example a CPE 15 as illustrated in [Fig.8].

[0097] The service may be provided by at least one service instance, for example by the SFI 13 service instance.

[0098] Note that the procedure described here can be applied in any type of network supporting network slices, particularly in a 5G network.

[0099] Considering a 5G network as an example, the terminal 11 may use the default DNN (“Data Network Name”) to access the service “Si” provided by the SFI service instance 13. In other words, the terminal 11 sends to the SFI service instance 13 a message to access the service Si via a default path, as defined in the DNN, to access the service Si.

[0100] According to the illustrated embodiment, the terminal 11 inserts, in the access message to the SFI service instance 13, an indication that it supports the routing of traffic via at least one network slice (“network slicing”). For example, a “Slice-aware” indicator is inserted in a dedicated header of the access message (for example HTTP header, QUIC frame). Setting this parameter to “1” indicates, for example, that the terminal supports “network slicing”.

[0101] The service access message is routed from terminal 11 using the default path as declared in the terminal.

[0102] Upon receipt of the service access message, the service instance 13 checks whether the network slice used for routing the service access message, called the first network slice, is suitable for providing said at least one service, i.e. whether the resources of the first network slice are optimized.

[0103] Service instance 13 also checks whether a "Slice-aware" flag is present in the access message and / or the value of that flag.

[0104] If the “Slice-aware” indicator is set to “1”, the service instance 13 inserts into a configuration message intended for the terminal at least one piece of information characteristic of the first network slice (for example a network slice identifier, a “Network Resource Partition” identifier, a slice type).

[0105] According to the described implementation example, service instance 13 also inserts in the configuration message, or in another message, traffic classification rules to be implemented by the terminal 11. This information can be transmitted in a new object called "Slice-selector". It is noted that such rules can be configured in the terminal or in an intermediate router, such as the CPE 15, which, in the embodiment illustrated by [Fig.8], can be responsible for associating the traffic characteristic of the service accessed by the terminal with a network slice.

[0106] The service instance 13 (first service instance) may in particular transfer the configuration message comprising at least one piece of information characteristic of a network slice via which the terminal 11 communicates with the service instance 13 to at least one other service instance (second service instance), before responding to the terminal 11.

[0107] Note that no constraints are imposed on the processing logic of the access message or the configuration message.

[0108] Upon receipt of the configuration message sent by the service instance 13, the terminal 11 extracts in particular the characteristic information of the network slice (making it possible to identify the network slice or the type of the network slice for example). The terminal 11 can also extract traffic classification rules.

[0109] The terminal 11 can then negotiate with the network 12 the activation of the dedicated context (DNN for the network slice considered) according to the instructions contained in the “Slice-selector” object. In other words, the terminal seeks to connect to a network slice identified from the information carried by the configuration message.

[0110] For example, the terminal 11 may provide to a network access point, for example in the network connection request, the network slice identifier or network slice type extracted from the configuration message to facilitate the establishment of a PDU ("Packet Data Unit Session") session (or other access network-specific context, for example WLAN) with the access network.

[0111] Optionally, upon receipt of a configuration message (i.e. a message indicating the support of a specific slice for a given service), the terminal 11 can involve the user in the process of validating the implementation of the configuration specific to the network slice (for example, the terminal asks the user to confirm the connection choice).

[0112] The provision, by the terminal 11, of such information extracted from the configuration message makes it possible, for example, to validate the tariff conditions which may be associated with the activation of a connection of the terminal 11 to a network slice.

[0113] If the establishment of the connection of the terminal 11 to the network slice thus identified is successful, the terminal can configure and apply the traffic classification rules to be able to route the traffic relating to the service to service instance 13 via the identified network slice.

[0114] Once the connection has been established with the identified network slice, the terminal 11 can switch a current service connection, so that it can connect to the newly identified network slice, and transmit data to the service instance 13 via the identified slice. Since the identified network slice has been selected to be adapted to the service in question, the traffic via this network slice benefits from guarantees (in terms of quality or isolation, in particular), for example.

[0115] In a particular embodiment, the terminal 11 may in particular use at least one piece of information relating to the traffic classification to identify the network slice to be connected to the terminal. Such information may be useful for traffic classification purposes (for example marking, specific port number, TCP / UDP option). This information may be communicated by the service instance 13, for example in the configuration message or in another message. It may therefore be communicated specifically. Alternatively, such information may be deduced by the terminal from the characteristic information and conveyed in the configuration message.

[0116] For future connections, particularly during the same communication session, the terminal 11 may repeat the steps as described above for the first connection to a network slice.

[0117] It is also noted that if, during a communication session, the service instance 13 returns information different from that maintained locally by the terminal 11 (for example characteristic information, traffic classification rules and / or information relating to the traffic classification), the latter can update the local traffic classification and / or marking rules according to this new information.

[0118] This allows the methods according to one embodiment of the invention to adapt to the service.

[0119] Alternatively, the terminal 11 may combine the information received from the service instance 13 (e.g. characteristic information, traffic classification rules and / or information relating to traffic classification), with locally available information (including that received from the network) to optimize access to the service.

[0120] Optionally, the terminal 11 may decide to use another network slice to communicate with the service instance 13. In this case, the steps described previously may be implemented by sending a new message transmitted from the terminal to the service instance.

[0121] In particular, if said message is received by the service instance 13 via a network slice not optimized for the needs of the service, the service instance 13 may se- select a new network slice, or a new type of network slice, adapted to the needs of the service, and transmit the characteristic information of this new network slice, or a new type of network slice, to terminal 11.

[0122] More generally, the service instance is responsible for informing the terminal of any changes relating to the association of traffic with a network slice. The traffic classification rules configured within the terminal (or possibly the CPE) can be adjusted accordingly. This new information can be processed by the terminal by following the same steps as those described previously.

[0123] In a particular embodiment, the terminal may list services that are not associated with a network slice, for example by maintaining a table stored in a memory of the terminal.

[0124] We will now present in more detail, in relation to [Fig. 8], the variant according to which the terminal 11 can contact an intermediate router or other edge node of the network, such as the CPE 15, to communicate to it the information relating to the network slice identified by the terminal 11 (characteristic information). In this example, the terminal 11 can communicate to the CPE 15, in addition to the characteristic information relating to the network slice identified by the terminal 11, the traffic classification rules. For example, the terminal 11 transmits to the CPE 15 the instructions for activating the identified network slice as well as the traffic classification rules using new options which can be supported by different protocols such as PCP (Port Control Protocol), DHCP (Dynamic Host Configuration Protocol), or an RA message (“Router Advertisement” in an IPv6 environment), etc.

[0125] Upon receipt of this information, the CPE 15 can negotiate with the network the activation of the identified network slice, and possibly confirm to the terminal 11 the effective activation of the identified network slice.

[0126] According to this embodiment, the CPE 15 can thus negotiate with the terminal 11 the activation of the procedure.

[0127] Alternatively, if the terminal 11 is not directly connected to the network, then the connection equipment (CPE 15 for example) can implement the procedure described as if the terminal were directly connected to the network.

[0128] Various examples of implementation of the invention have been described above. Of course, these examples are purely illustrative and non-limiting. In particular, as already indicated, no assumption is made according to the invention as to the nature of the network slices, their number, and the possible “mapping” between network slices of neighboring domains (e.g. RAN and TN, TN and CN). In particular, a network slice can be deployed on a fixed infrastructure, mobile infrastructure, or a combination of both.

[0129] 5.3 Simplified structure of the corresponding entities

[0130] Finally, in relation to [Fig.9], we present the simplified structures of a entity, for example a service instance or a terminal according to at least one embodiment described above.

[0131] As illustrated by [Fig.9], such an entity comprises at least one memory 91 comprising a buffer memory, at least one processing unit 92, equipped for example with a programmable computing machine or a dedicated computing machine, for example a processor P, and controlled by the computer program 93, implementing steps of at least one method according to at least one embodiment of the invention.

[0132] Upon initialization, the code instructions of the computer program 93 are for example loaded into a RAM memory before being executed by the processor of the processing unit 92.

[0133] If the entity is a service instance, the processor of the processing unit 92 implements steps of the method for providing at least one service described previously, according to the instructions of the computer program 93, to: - select at least one network slice, or one type of network slice, suitable for routing the data associated with said at least one service, - transmit, to said terminal, at least one piece of information characteristic of said at least one network slice, or type of network slice, selected.

[0134] If the entity is a terminal, the processor of the processing unit 92 implements steps of the method of accessing at least one service described previously, according to the instructions of the computer program 93, to: - receive at least one piece of information characteristic of at least one network slice, or a type of network slice, adapted to the routing of data associated with said at least one service, selected by at least one service instance capable of providing said at least one service to said terminal, - transmitting at least one message to said at least one service instance, via a network slice identified from said at least one characteristic information, taking into account at least one traffic classification rule associated with said identified network slice.

Claims

Claims

1. Method for providing at least one service to a terminal (11), via a communication network (12) implementing network slices, comprising: • the selection (1311) of at least one network slice, or a type of network slice, suitable for routing the data associated with said at least one service, • the transmission (1312), to said terminal, of at least one piece of information characteristic of said at least one network slice, or type of network slice, selected.

2. Method according to claim 1, characterized in that it comprises the transmission, to said terminal, of at least one traffic classification rule associated with said at least one network slice, or type of network slice, selected.

3. Method according to any one of claims 1 and 2, characterized in that said information characteristic of said at least one selected network slice belongs to the group comprising: • a network slice identifier, • a network partition identifier, • a network slice type.

4. Method according to any one of the preceding claims, characterized in that it comprises the transmission, to said terminal, of at least one item of information relating to the traffic classification.

5. Method according to any one of the preceding claims, characterized in that during a communication session, it comprises verifying that the network slice used for routing a first message from said terminal to at least one service instance, called the first network slice, is suitable for providing said at least one service, and in that: • if the suitability of said first network slice is proven, said selection confirms the selection of said first network slice for the transmission of at least one second message from said terminal to said at least one service instance, during said communication session, • if the suitability of said first network slice is not proven, said selection chooses a second network slice distinct from said first network slice for the transmission of at least one second message from said terminal to said at least one service instance, during said communication session.

6. Method according to claim 5, characterized in that said first message is an access message to said at least one service, comprising a first indicator signaling that said terminal supports the routing of data via at least one network slice.

7. Method according to any one of claims 5 and 6, characterized in that said at least one characteristic information is transmitted to said terminal by said at least one service instance in any message associated with said current session.

8. Method for accessing at least one service by a terminal (11), via a communication network (12) implementing network slices, comprising: • the reception (111) of at least one piece of information characteristic of at least one network slice, or a type of network slice, adapted to the routing of data associated with said at least one service, selected by at least one service instance capable of providing said at least one service to said terminal, • the transmission (113) of at least one message to said at least one service instance, via a network slice identified from said at least one characteristic information, taking into account at least one traffic classification rule associated with said identified network slice.

9. Method according to claim 8, characterized in that it comprises receiving said at least one traffic classification rule from said at least one service instance, and configuring said terminal with said at least one traffic classification rule.

10. A method according to claim 8 or claim 9, characterized in that it comprises transmitting configuration instructions from at least at least one intermediate router of said communication network with said at least one traffic classification rule.

11. Method according to any one of claims 8 and 9, characterized in that it comprises updating said at least one traffic classification rule following the reception of at least one new information characteristic of at least one network slice.

12. Method according to any one of claims 8 to 11, characterized in that it comprises the transmission, to said at least one service instance, of a first indicator signaling that said terminal supports the routing of data via at least one network slice.

13. Method according to any one of the preceding claims, characterized in that at least one of said network slices is composed of at least one local network slice deployed in at least one subnetwork of said communication network.

14. Service instance capable of providing at least one service to a terminal, via a communication network implementing network slices, comprising at least one processor configured to: • select at least one network slice, or one type of network slice, suitable for routing data associated with said at least one service, • transmit, to said terminal, at least one piece of information characteristic of said at least one network slice, or type of network slice, selected.

15. Terminal capable of accessing at least one service, via a communication network implementing network slices, comprising at least one processor configured to: • receive at least one piece of information characteristic of at least one network slice, or one type of network slice, suitable for routing data associated with said at least one service, selected by at least one service instance capable of providing said at least one service to said terminal, • transmit at least one message to said at least one service instance, via a network slice identified from said at least one characteristic information, taking into account at least one traffic classification rule associated with said identified network slice.

16. Computer program comprising instructions for implementing a method according to any one of claims 1 to 13 when this program is executed by a processor.

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