阅读说明：本技术 应用于数据分组会话的服务优化 (Service optimization applied to data packet sessions ) 是由 米格尔·安杰尔·穆诺兹德拉托雷阿隆索 卡洛斯·吉梅内斯科登 维罗尼卡·桑切斯维加 于 2019-05-16 设计创作，主要内容包括：本发明涉及一种用于操作会话控制实体(100)的方法,该会话控制实体被配置为控制网络中的移动订户的数据分组会话,其中,由服务应用实体(500)将至少一个服务应用于数据分组会话,该方法包括在会话控制实体处：-从请求方接收请求至少一个服务的应用的第一请求,其中,请求向请求方通知数据分组会话的至少一个会话相关参数的当前状态；-向请求方发送通知,该通知包括至少一个会话相关参数的当前状态。(The invention relates to a method for operating a session control entity (100) configured to control a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity (500), the method comprising at the session control entity: -receiving a first request from a requestor for an application requesting at least one service, wherein the request informs the requestor of a current state of at least one session related parameter of a data packet session; -sending a notification to the requesting party, the notification comprising the current state of the at least one session related parameter.)

1. A method for operating a session control entity (100), the session control entity (100) being configured to control a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity (500), the method comprising, at the session control entity:

-receiving a first request from a requestor of an application requesting said at least one service, in which first request a notification to said requestor of a current state of at least one session related parameter of said data packet session is requested;

-sending a notification to the requesting party, the notification comprising the current state of the at least one session related parameter.

2. The method according to claim 1, further sending a session establishment request for establishing the data packet session to a user plane entity (200) configured to forward user plane data of the data packet session, the session establishment request comprising a session control entity identifier allowing identification of the session control entity.

3. The method according to claim 1 or 2, wherein the first request further requests a notification of the requesting party of any future change of the at least one session related parameter, wherein the notification is sent to the requesting party each time a change of the at least one session related parameter is detected.

4. The method of any preceding claim, wherein a service chain is applied to the data packet session, the service application entity providing the at least one service as part of the service chain.

5. The method according to any one of claims 2 to 4, wherein the method comprises:

determining a user plane rule indicating a steering policy identifier for identifying a service application entity providing the at least one service for the mobile subscriber; and

-sending the user plane rules to the user plane entity (200).

6. The method of claim 5, wherein the method comprises:

retrieving policy control rules comprising a steering policy for the mobile subscriber from a policy control entity, wherein sending the session establishment request comprises sending the user plane rules.

7. The method according to any of the preceding claims, wherein the requesting party is the service application entity (500).

8. The method according to any of claims 1-6, wherein the requesting party is a user plane entity (200) configured to forward user plane data of the data packet session.

9. The method according to any of the preceding claims, wherein receiving the first request comprises receiving a subscription to a public service provided by the session control entity (100), the subscription indicating a subscription of the requestor as a consumer of the public service to any event related to the at least one session related parameter of the data packet session.

10. The method of claim 9, wherein the subscription includes a session identifier that identifies the data packet session.

11. The method of claim 9 or 10, wherein the subscription comprises a subscriber identifier identifying an individual subscriber or group of subscribers.

12. A method according to claim 9 or 10, wherein the subscription comprises session related parameters that are matched when identifying a group of subscribers.

13. The method of any of claims 9 to 12, wherein sending the notification comprises notifying the consumer of an identification of a subscription service, the session identifier, and the at least one session-related parameter.

14. The method according to any of the preceding claims, wherein the at least one session related parameter comprises at least one of: subscriber identification, any non-subscriber related parameters of the data packet session.

15. A method for operating a user plane entity (200), the user plane entity (200) being configured to forward user plane data of a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity (500), the method comprising at the user plane entity:

-receiving a session establishment request for establishing the data packet session from a session control entity (100), the session establishment request comprising a session control entity identifier allowing to identify a session control entity (100) configured to control the data packet session;

-sending a first notification about the session control entity to the service application entity (500), the first notification allowing to identify a session control entity that is to control the data packet session.

16. The method of claim 15, wherein a service chain is applied to the data packet session and the service application entity provides the at least one service as part of the service chain, wherein each service application entity in the service chain that provides at least one service is identified and the first notification is sent to each service application entity in the service chain that provides at least one service.

17. The method of claim 15 or 16, wherein the first notification comprises an indication of: the session control entity identified by the session control entity identifier is configured to provide an open service related to the data packet session, thereby allowing the service application entity to subscribe to the open service.

18. The method of claim 16 or 17, wherein the first notification comprises the session control entity identifier.

19. The method according to any one of claims 15 to 18, wherein the method comprises:

receiving a user plane rule from the session control entity (100) indicating a steering policy identifier for identifying a service application entity providing the at least one service for the mobile subscriber.

20. A method for operating a service application entity (500), the service application entity (500) being configured to apply at least one service to a data packet session of a mobile subscriber in a network, the method comprising, at the service application entity:

-receiving a first notification from a user plane entity configured to forward user plane data of the data packet session, the first notification allowing to identify a session control entity that is to control the data packet session;

-sending a first request to the session control entity requesting to be informed of a current state of at least one session related parameter of the data packet session;

-receiving a response to the first request, the response comprising a current state of the at least one session related parameter.

21. The method of claim 20, wherein the first notification includes an indication of: the session control entity identified by the first notification is configured to provide an open service related to the data packet session, thereby allowing the service application entity to subscribe to the open service, wherein sending the first request comprises sending a subscription to the open service provided by the session control entity, the subscription indicating a subscription of the service application entity as a consumer of the open service to any event related to the at least one session related parameter of the data packet session.

22. The method according to claim 20 or 21, wherein the first request further requests to be notified of any future change of the at least one session related parameter, and the method further comprises receiving a notification each time a change of the at least one session related parameter is detected.

23. A session control entity (100) configured to control a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity (500), the session control entity comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit, the session control entity being operable to:

-receiving a first request from a requestor of an application requesting said at least one service, in which first request a notification to said requestor of a current state of at least one session related parameter of said data packet session is requested;

-sending a notification to the requesting party, the notification comprising the current state of the at least one session related parameter.

24. The session control entity of claim 23, further operable to send a session setup request for establishing the data packet session to a user plane entity (200) configured to forward user plane data of the data packet session, the session setup request comprising a session control entity identifier allowing identification of the session control entity.

25. A session control entity according to claim 23 or 24, wherein the first request further requests a notification of the requesting party of any future change of the at least one session related parameter, the session control entity being further operable to send the notification to the requesting party whenever a change of the at least one session related parameter is detected.

26. A session control entity of any of claims 23 to 25, wherein a service chain is applied to the data packet session, the service application entity providing the at least one service as part of the service chain.

27. A session control entity of any of claims 24 to 26, further operable to: determining a user plane rule indicating a steering policy identifier for identifying a service application entity providing the at least one service for the mobile subscriber, and sending the user plane rule to the user plane entity (200).

28. The session control entity of claim 27, further operable to retrieve policy control rules comprising a steering policy for the mobile subscriber from a policy control entity, and operable to send the user plane rules when sending the session establishment request.

29. A session control entity of any of claims 23 to 28, wherein the requestor is the service application entity (500) or a user plane entity (200) configured to forward user plane data of the data packet session.

30. The session control entity of any of claims 23 to 29, further operable to receive a subscription to a public service provided by the session control entity (100) upon receiving the first request, the subscription indicating a subscription of the requestor as a consumer of the public service to any event related to the at least one session-related parameter of the data packet session.

31. The session control entity of claim 30, wherein the subscription comprises a session identifier identifying the data packet session.

32. A session control entity of claim 30 or 31, wherein the subscription comprises a subscriber identifier identifying an individual subscriber or group of subscribers.

33. A session control entity of claim 31 or 32, wherein the subscription comprises session related parameters that are matched when identifying a group of subscribers.

34. The session control entity of any of claims 30 to 33, further operable to notify the consumer of an identification of a subscription service, the session identifier and the at least one session related parameter when sending the notification.

35. A user plane entity (200) configured to forward user plane data of a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity (500), the user plane entity comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit, the user plane entity being operable to:

-receiving a session establishment request for establishing the data packet session from a session control entity (100), the session establishment request comprising a session control entity identifier allowing to identify a session control entity (100) configured to control the data packet session;

-sending a first notification about the session control entity to the service application entity (500), the first notification allowing to identify a session control entity that is to control the data packet session.

36. The user plane entity of claim 35, wherein a service chain is applied to the data packet session and the service application entity provides at least one service as part of the service chain, further operable to identify each service application entity in the service chain that provides at least one service and to send the first notification to each service application entity in the service chain that provides at least one service.

37. The user plane entity of claim 35 or 36, wherein the first notification comprises an indication of: the session control entity identified by the session control entity identifier is configured to provide an open service related to the data packet session, thereby allowing the service application entity to subscribe to the open service.

38. The user plane entity of any of claims 35 to 37, further operable to receive a user plane rule from the session control entity (100) indicating a steering policy identifier for identifying a service application entity providing the at least one service for the mobile subscriber.

39. A service application entity (500) configured to apply at least one service to a data packet session of a mobile subscriber in a network, the service application entity (500) comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit, the service application entity being operable to:

-receiving a first notification from a user plane entity configured to forward user plane data of the data packet session, the first notification allowing to identify a session control entity (100) that is to control the data packet session;

-sending a first request to the session control entity requesting to be informed of a current state of at least one session related parameter of the data packet session;

-receiving a response to the first request, the response comprising a current state of the at least one session related parameter.

40. The service application entity of claim 39, wherein the first notification comprises an indication of: the session control entity identified by the first notification is configured to provide an open service related to the data packet session, thereby allowing the service application entity to subscribe to the open service, wherein the service application entity is operable to send a subscription to the open service provided by the session control entity upon sending the first request, the subscription indicating a subscription of the service application entity as a consumer of the open service to any event related to the at least one session related parameter of the data packet session.

41. The service application entity of claim 39 or 40, wherein the first request further requests to be notified of any future change of the at least one session related parameter, the service application entity being operable to receive a notification whenever a change of the at least one session related parameter is detected.

42. A system comprising at least two members from the following group of members, the group of members comprising the following members: the service application entity of any of claims 39 to 41; a session control entity of any of claims 23 to 34; and a user plane entity according to any of claims 35 to 38.

43. A computer program comprising program code to be executed by at least one processing unit (120, 220, 320) of a session control entity (100), a user plane entity (200) or a service application entity (500), wherein execution of the program code: causing the at least one processing unit of the session control entity to perform the method according to any one of claims 1 to 14; and/or cause the at least one processing unit of the user plane entity to perform the method according to any of claims 15 to 19; and/or cause the at least one processing unit of the service application entity to perform the method according to any of claims 20 to 22.

Technical Field

The present application relates to a method for operating a session control entity and to a corresponding session control entity configured to control a data packet session. Furthermore, a method for operating a user plane entity and a corresponding user plane entity are provided. Further, a method for operating a service application entity configured to apply at least one service to a data packet session and a corresponding service application entity are provided. Finally, a system comprising at least two of the above entities, a computer program and a carrier comprising the computer program are provided.

Background

Fig. 1 shows the architecture of a 5G core network, which comprises a unified data repository UDR10, a network disclosure function NEF 20, a network data analysis function NWDAF 30, an application function AF 40, a policy control function PCF 50, a charging function CHF 60, an access and mobility management function AMF 70, a session management function SMF 80 and a user plane function UPF 90.

The different functions provided by the different modules shown in fig. 1 are known to a person skilled in the art, and therefore a detailed description of each entity is omitted for the sake of clarity. In the following, only the functional entities relevant to the present description will be discussed in more detail. The session management function SMF 80 supports different functions. It controls inter alia traffic steering towards N6 in N6 Local Area Networks (LAN) or UPF 90.

The user plane function UPF90 supports the handling of user plane traffic, packet routing, and forwarding including traffic steering.

The term service chaining refers to traffic steering across a set of network functions. The IETF (internet engineering task force) has specified a dynamic service chaining solution called service function chaining, which can be implemented by different technologies such as SDN (software defined networking).

The service functions are deployed in the N6 reference point between the UPF90 and external packet data networks. Examples of such service functions are traffic optimization devices (e.g. TCP optimizers or HTTP proxies), firewalls, traffic probes, CGNAT (carrier-level NAT) or parental control functions.

Dynamic service chaining has high value in the operator's N6 LAN (local area network). To reduce capital expenditure (CAPEX), operators need to offload these service functions from unwanted traffic using dynamic chaining policies. For example, an operator may wish to direct a given service data flow (e.g., progressive video from a particular content provider on TCP) to a given subscriber (e.g., premium user) only under certain conditions (e.g., when the user is roaming in a given radio access network type) and also in a manner that the data flow achieves load balancing across all virtual instances of the TCP optimizer.

3GPP 29.561 defines interworking with external data network AAA (authentication, authorization and accounting) servers over RADIUS, where PGW or SMF 80 typically acts as a RADIUS client. RADIUS may be used for authorization, authentication, and/or accounting, depending on the particular data network requirements. Further, depending on the topology and RADIUS server deployment, in some cases RADIUS traffic is routed through the N6 interface by the anchor point UPF90 (in-band RADIUS) acting as an AAA proxy. In other cases, RADIUS traffic is routed directly by the SMF to the AAA server (out-of-band RADIUS).

Many service functions in N6 networks themselves require some subscriber policy and subscriber context information from traffic, such as IMSI (international mobile subscriber identity), MSISDN (mobile subscriber integrated services digital network number), location, RAT type (radio access technology). For example, the TCP optimizer may apply different local optimization profiles depending on the subscriber type or RAT type. Currently, this is achieved by the service function receiving a RADIUS accounting message for each subscriber session. The service function may receive such signaling by: (1) silently listening or proxying RADIUS accounting messages from the N6 interface (in-band RADIUS integration); (2) a RADIUS client configured to broadcast a RADIUS accounting AAA server (out-of-band RADIUS integration); or (3) configured as a standalone AAA proxy (out-of-band RADIUS integration). The integration depends on the particular operator AAA deployment and can be very complex, as AAA deployment and configuration depends on DNN and authorization/accounting use cases (in some cases, RADIUS accounting is not even enabled). Furthermore, in case more dynamic enforcement policies are needed, the service function may be integrated directly with the PCF (via the N7 interface).

The service function needs to be aware of the subscriber session in order to perform its tasks (e.g., the TCP optimizer may use the RAT type in order to somehow optimize the traffic of the subscriber). Since most service functions are being virtualized and employ an architecture of control and user plane splitting, today's mechanisms for making service functions subscriber session aware (out-of-band and/or in-band RADIUS integration as described in the background section) are ineffective. According to the previous example, the TCP optimizer service functions may be deployed in N control plane service function instances in a central data center and M user plane service instances in a local data center service network. These instances can be dynamically scaled/migrated in accordance with NFV (network function virtualization) management.

In particular, the problem with the current solutions is:

out-of-band or in-band RADIUS integration becomes prohibitively expensive and complex, as depending on the implementation of the service function CUPS (control user plane split), the operator will need to integrate its AAA server with one or more control plane instances or with one or more user plane instances that may be located in hosts and data centers other than AAA. Furthermore, the operator may be limited in the number of AAA proxies or the number of broadcast clients that the AAA server can support.

Additionally, with in-band RADIUS integration, there would be additional challenges as each service function instance now manages a reduced set of subscriber sessions. Listening to Radius traffic at the N6 LAN would mean that the service function instance maintains all subscriber sessions, not just meeting the interest set which would mean sub-optimal use of processing and memory resources. This problem cannot be easily solved by existing service chaining solutions, since the subscriber session corresponding to a given Radius charging packet needs to parse the Radius charging payload and cannot be directly inferred from existing service chaining classification rules running at the 5-tuple level.

Therefore, there is a need to overcome the above problems and simplify the integration of service functions provided by service application entities.

Disclosure of Invention

This need is met by the features of the independent claims. Further aspects are described in the dependent claims.

According to a first aspect, there is provided a method for operating a session control entity configured to control a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity. The session control entity receives a first request from a requestor of an application requesting at least one service, wherein the request informs the requestor of a current state of at least one session-related parameter of a data packet session. Further, the session control entity sends a notification to the requesting party, wherein the notification comprises a current state of the at least one session related parameter.

Furthermore, a corresponding session control entity is provided, comprising a memory and at least one processing unit, wherein the memory contains instructions executable by the at least one processing unit. The session control entity is operable to operate in the manner described above or in further detail below.

Alternatively, there is provided a session control entity configured to control a data packet session of a mobile subscriber in a network, wherein at least one service is applied to the data packet session by a service application entity. The session control entity comprises a first module configured to receive a first request from a requestor of an application requesting at least one service, wherein the request informs the requestor of a current state of at least one session-related parameter of a data packet session. Furthermore, the session control entity comprises a second module configured to send a notification to the requestor, wherein the notification comprises a current state of the at least one session related parameter.

Furthermore, a method for operating a user plane entity configured to forward user plane data of a data packet session of a mobile subscriber in a network is provided, wherein at least one service is applied to the data packet session by a service application entity. The user plane entity receives a session establishment request for establishing a data packet session from a session control entity, wherein the session establishment request comprises a session control entity identifier allowing to identify a session control entity configured to control the data packet session. Further, the user plane entity sends a first notification to the service application entity, wherein the first notification allows to identify a session control entity that is to control the data packet session.

Furthermore, a corresponding user plane entity is provided, comprising a memory and at least one processing unit, wherein the memory contains instructions executable by the at least one processing unit, wherein the user entity is operable to operate in the manner described above or in further detail below.

Alternatively, there is provided a user plane entity configured to forward user plane data of a data packet session of a mobile subscriber, comprising a first module configured to receive a session establishment request for establishing the data packet session from a session control entity, wherein the session establishment request comprises an identifier of the session control entity, which allows identifying the session control entity. The second module of the user plane entity is configured to send a first notification to the service application entity, wherein the notification allows to identify the session control entity.

When the user plane entity receives the identifier of the session control entity from the session control entity and forwards this information to the service application entity, the service application entity is informed which session control entity is to process the data packet session. Thus, the service application entity may then directly contact the session control entity, so that the session control entity may inform the service application entity about the session related parameters.

Furthermore, a method for operating a service application entity configured to apply at least one service to a data packet session of a mobile subscriber in a network is provided. The service application entity receives a first notification from a user plane entity configured to forward user plane data of the data packet session, wherein the first notification allows identification of a session control entity that is to control the data packet session. Furthermore, a first request is sent to the session control entity requesting to be informed of the current state of at least one session related parameter of the data packet session. Further, a response to the first request is received, the response comprising a current state of at least one session-related parameter.

When the service application entity informs the session control entity that it wants to be informed of any session related parameters, the service application entity is informed of the current state of the session related parameters so that the service application entity can then provide the required service to the data packet session.

Furthermore, a corresponding service application entity is provided, comprising a memory and at least one processing unit, wherein the memory contains instructions executable by the at least one processing unit, wherein the service application entity is operable to operate in the manner described above or in further detail below.

As an alternative, a service application entity configured to apply at least one service to a data packet session of a mobile subscriber in a network is provided, wherein the service application entity comprises a first module configured to receive a first notification from a user plane entity configured to forward user plane data of the data packet session. The first notification allows identification of a session control entity that will control the data packet session. The second module is configured to send a first request to the session control entity requesting to be informed of a current state of at least one session related parameter of the data packet session. The third module is configured to receive a response to the first request, the response including a current state of at least one session-related parameter.

Furthermore, a system comprising at least two of the above entities is provided.

Further, a computer program is provided, comprising program code to be executed by at least one processing unit of a session control entity, a user plane entity or a service application entity, wherein execution of the program code causes the at least one processing unit to perform the method as described above or in further detail below.

Further, a carrier comprising the computer program is provided, wherein the carrier is one of an electronic signal, an optical signal, a radio signal or a computer readable storage medium.

It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or alone without departing from the scope of the present application. The features of the aspects described above and of the embodiments described below may be combined with each other in other embodiments, unless explicitly stated otherwise.

Other features and advantages will become apparent to those skilled in the art upon reading the following detailed description and drawings.

Drawings

Fig. 1 shows a schematic architectural diagram of a 5G cellular network.

Figure 2 shows an example schematic architectural diagram of a cellular network including a service chain incorporating features of the present invention.

Figure 3 shows a schematic diagram of a sequence diagram representing the exchange of messages between the involved entities incorporating features of the invention.

Fig. 4 shows another schematic diagram of a sequence diagram representing the exchange of messages between the involved entities according to another embodiment.

Fig. 5 shows an example flow chart of a method performed by the session control entity in a situation as shown in fig. 3 or fig. 4.

Fig. 6 shows an example flow diagram of a method performed by a user plane entity in the situation as shown in fig. 3.

Fig. 7 shows an example flow diagram of a method performed by a service application entity applying a service to a data packet session in the situation shown in fig. 3.

Fig. 8 shows an exemplary schematic representation of a session control entity configured to control a data packet session incorporating features of the present invention.

Fig. 9 shows another example schematic representation of the session control entity of fig. 8.

Figure 10 shows an exemplary schematic representation of a user plane entity incorporating features of the present invention.

Figure 11 shows another exemplary schematic representation of a user plane entity terminating a user plane of a data packet session and incorporating features of the present invention.

Figure 12 shows an exemplary schematic representation of a service application entity applying a service to a data packet session incorporating features of the present invention.

Figure 13 shows another example schematic representation of a service application entity providing services to a data packet session incorporating features of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the following description of the embodiments should not be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described below or by the drawings, which are merely illustrative.

The figures are to be regarded as schematic representations and elements shown in the figures are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose will become apparent to those skilled in the art. Any connection or coupling between functional blocks, devices, components of physical or functional units shown in the figures and described below may also be achieved through an indirect connection or coupling. A coupling or wired or wireless connection between the components may be established. The functional blocks may be implemented in hardware, software, firmware, or a combination thereof.

In the context of the present application, the term user entity or user equipment UE refers to a device used by an individual for his or her personal communication. It may be a telephone type device, a cellular telephone, a mobile station, a cordless telephone or a personal digital assistant type device (e.g. laptop, notebook, notepad, tablet) equipped with a wireless data connection. The UE may also be associated with a non-human being, such as an animal, plant, or machine.

The invention will be described in connection with a 5G network solution, however it should be understood that the mechanism described below may also be applied in other networks, e.g. 4G, when the session control entity SMF is replaced by the control plane part of a packet gateway (PGW-C) or the control plane part of a TDF (traffic detection function) (TDF-C), and wherein the user plane entity handling the user plane data of the data packet session (UPF in a 5G network) is replaced by the user plane part of a gateway (PGW-U) or the user plane part of a traffic detection function (TDF-U).

As will be explained below, existing public services of the session control entity (SMF in the examples given below) may be extended to allow the subscriber session parameters of the data packet session to be disclosed.

The mechanism described below allows any service application entity (hereinafter also referred to as service function SF) to become a consumer of the above-mentioned SMF public service. The service application entity can request or subscribe to per-user and/or per-body parameters of the data packet session granularity. This means that a consumer (e.g. a service application entity or a user plane entity) may subscribe to a producer (SMF) on a per user session basis, e.g. the consumer provides the UE session ID at subscription. The consumer may also subscribe to user session parameters. Here, the subscriber subscribes to any user session parameter such as user location or RAT type, without concern for other parameters such as IMSI or MSISDN.

The UPF, which is an example of a user plane entity, sends an SMF identifier to a service application entity in order to discover SMFs, i.e. how the consumer knows which SMF handles the user of the PDU session and discloses the above-mentioned subscriber session parameters.

Fig. 2 shows a schematic architectural diagram of a 5G service network, wherein a data packet session of a mobile subscriber is sent to the UE5 via a chain of services provided by different service application entities 500, wherein the data packet session may originate from one of the packet data networks 85. In the 5G core network, in addition to the functions shown in fig. 1, a network repository function NRF 25, a unified data management UDM 35, AN authentication server function AUSF 45 and AN access network AN 55 are shown. Further, different AAA servers 65, 75 are indicated.

In the example shown, session control entity SMF 100 controls a data packet session sent to UE5 over access network 55, where user plane data forwarding is performed by user plane entity 200. In addition, AAA servers 65 and 75 are shown for outbound and inbound radius communications.

In a 4G embodiment, the session control entity 100 will be implemented by the control plane part of the packet gateway PGW-C or the traffic detection function TDF-C, and the user plane entity 200 may be implemented in the user plane part of the packet gateway PWF-U or the traffic detection function TDF-U.

In the illustrated example, a chain of service functions is applied to a data packet session, where the chain contains different service functions. However, it should be understood that the application is also applicable to the case where a single service function 500 is applied to a data packet session.

Fig. 3, discussed below, allows the service function 500 to extend SMF public services to be subscriber aware by using new subscription session data events.

The sequence diagram shown in fig. 3 illustrates a case where the video optimizer service function subscribes to the SMF public service to retrieve subscriber session information to apply video optimization to, for example, YouTube traffic of a particular user based on session data (e.g., radio access technology type, location, etc.).

In steps S11 and S12, the UE5 triggers PDU Session Establishment (PDU Session Establishment Request; Nsmf PDU Session Create) by sending a PDU Session Establishment Request to the AMF 70. The AMF selects SMF 100 to manage the PDU Session (SMF select function in AMF selects SMF instance based on available SMF instance obtained from NRF 35 or based on configured SMF information in AMF) and triggers Nsmf PDU Session creation (Nsmf PDU Session creation). The sequence diagram in fig. 3 does not include all signaling messages involved in the PDU session setup procedure. The associated signaling messages are described in subsequent steps.

In step S13, SMF 100 triggers a message to retrieve the SM policy for the user PDU session (Npcf _ SMPolicyControl _ Create request).

In step S14, the PCF triggers a message to retrieve the policy data (Nudr _ DM _ Query request) for the user PDU session.

In step S15, the UDR10 replies with a response message including subscriber policy data. The UDR10 will return a traffic steering Policy (traffic steering identifier) for the particular application (YouTube) (Nudr _ DMQuery Response; { Subscripter Policy Data (affServiceId 0Youtube, traffic steering Policy identifier }).

In step S16, PCF 50 generates a corresponding PCC rule based on the subscriber policy data.

In step S17 based on the above, PCF 50 triggers a response message that includes the PCC rule to be applied to the user PDU session. In this case, there will be a PCC rule (traffic steering policy identifier) for the YouTube application that includes a flow steering policy (Npcf _ SMPolicyControl _ Create Response; { PCC rule (applied:. YouTube, traffic steering policy identifier }).

In step S18, the SMF 100 selects the UPF 200 and triggers a PFCP (packet forwarding control protocol) session establishment request message including the corresponding PDR/FAR/QER/URR. In this case, there will be a PDR (packet detection rule) of PDI applied of type appId ═ YouTube and a FAR (PFCD Session Establishment Request) including traffic policyidentifier and SMF identifier (smfd) as Forwarding Policy { PDF with DPI (applying ═ YouTube), FAR (Forwarding Policy0traffic policyidentidentification, smfld }).

In step S19, the UPF 200 stores the PDR/FAR/QER/URR and responds to the SMF with a PFCP Session Establishment Response message (PFCP Session Establishment Response).

In steps S20 and S21, the UPF determines which SFs 500 (in this case, video optimizer SFs) are in the chain indicated by the traffic engineering policy identifier. This is done by local UPF configuration, which includes a list of SFs that map to a particular trafficsteeringpolidentidentidentifier. In addition, the presence of an smfrid will activate some logic in the UPF (in particular, the video optimizer SF will need to be informed of the fact that the SMF instance identified by the smfrid supports services related to subscriber session data). Based on this, the UPF 200 issues an instruction to the video optimizer SF so it can subscribe to new subscriber session data events. For this purpose, the UPF triggers a Naf HTTP POST message to the video optimizer SF. The body of the HTTP POST message will include information indicating that subscriber session information (UESessionId) for the UE session is available at a particular smf (smfrid). The UESessionId should include information that allows the SF to identify the user session, such as an external user identity (externalId or gpsi) and/or the UE IP address. Alternatively, instead of using a REST interface between the UPF and the video optimizer SF, the UPD may simply add smfld as metadata over NSH (Naf HTTP Post; { Subscriber session info for UESession ID at smfld }).

In step S22, the video optimizer SF responds to the UPF 200 with a Naf 200OK success response after receiving the message in the previous step (Naf 200 OK).

In step S23, the video optimizer SF subscribes to the SMF 100 for the subscriber session data event of the PDU session of the UE. To this end, the video optimizer SF triggers an Nsmf HTTP POST message to the target SMF (determined by smfrid, which may be just the SMF IP address). The body of the HTTP POST message will include information indicating a subscription (Nsmf _ evendexposure _ subscription) to the SMF public service, specifically a subscription to a new Subscriber Session Data event (EventID) for a PDU Session (UESessionId) for a particular UE. In addition, the video optimizer SF may subscribe only to specific subscriber session parameters of interest (e.g. only RAT type and location) and/or limit notifications to a set of subscribers matching specific conditions. In this example, it is assumed that the video optimizer SF is a trusted entity from the network operator's point of view. If not, the video optimizer SF should interact with the SMF through the NEF of the network operator (Nsmf HTT POST (Subscripte); { Nsmf _ EventExposure _ Subscripte, UESessinid, EventID ═ Subscripter Session Data }).

In step S24, after receiving the message in the previous step, the SMF will respond to the video optimizer SF 500 with an Nsmf200OK successful response (Nsmf 200 OK).

In steps S25 and S26, the SMF event disclosure service notifies the consumer (video optimizer SF 500) of the subscriber session parameters of interest. To this end, the SMF 100 triggers an Nsmf HTTP POST message to the video optimizer SF. The body of the HTTP POST message will indicate a notification related to SMF public service (Nsmf _ EventExposure _ Notify), specifically a notification of a new Subscriber Session Data event (EventID _ Subscriber Session Data) for a PDU Session (UESessionId) for a particular UE, which includes relevant Subscriber Session parameters of interest (e.g., RAT Type and Location) (Nsmf HTTP POST (Notify); { Nsmf _ EventExposure _ Notify, UESessionId, EventID _ Subscriber Session Data, suscribber Session parameters (RAT-Type, Location, etc.) }).

In step S27, after receiving the message in the previous step, the video optimizer SF will respond to the SMF with an Nsmf200OK success response (Nsmf 200 OK; PDU Session Establishment (connected); Application traffic (YouTube)).

In step S28, the user opens the YouTube application. The UPF detects YouTube traffic by matching incoming packets with the PDR of the PDI of the type application, appId ═ YouTube, and forwards the traffic to the video optimizer SF (FAR according to a traffic policy identifier that includes as a forwarding action a traffic directed to the video optimizer SF). The video optimizer SF applies video optimization to YouTube traffic based on the subscriber session parameters (e.g., RAT type, location, etc.) received in step S26 above.

In addition, the UPF 200 (instead of the SF 500) may be a subject that subscribes to the SMF public service according to subscriber session information. This may be the case where the UPF needs the PDU session subscriber session information of the UE to perform certain implementations (e.g. the video optimizer SF embedded in the UPF). The UPF may use this data locally, e.g. to select traffic optimization profiles not addressed by the 3GPP PCC rules, or may disclose the subscriber context to the SF by different methods, e.g. as NSH metadata insertion, sending dummy Radius signaling from the UPF to the SF, inserting in HTTP headers.

Fig. 4 illustrates a case where UPF subscribes to SMF public services to retrieve subscriber session information and forwards this information as metadata through NSH to the video optimizer SF, allowing video optimization of YouTube traffic for a particular user based on session data (e.g., RAT type, location, etc.). The steps of fig. 4 are detailed as follows:

steps S31 to S39 correspond to steps S11 to S19 of fig. 3.

In steps S40 and S41, the UPF 200 retrieves the smfId and subscribes to the SMF for the subscriber session data events of the PDU session of the UE. To this end, the UPF triggers an Nsmf HTTP POST message to the target SMF (determined by smfrid, which may be just the SMF IP address). The body of the HTTP POST message should include information indicating a subscription (Nsmf _ evendexposure _ subscription) to the SMF public service, specifically, a subscription to a new Subscriber Session Data event (EventID) of a PDU Session (UESessionId) of a specific UE. Additionally, the UPF may Subscribe only to specific Subscriber Session parameters of interest (e.g., only RAT type and location) and/or limit notifications to a set of subscribers that match specific conditions (Nsmf HTT POST (Subscripte); { Nsmf _ EventExposure _ Subscripte, UESessinid, EventID ═ Subscripter Session } Data).

In step S42, after receiving the message in the previous step, SMF 100 responds to UPF with an Nsmf200OK success response (Nsmf 200 OK).

In steps S43 and S44, the SMF event disclosure service notifies the consumer (UPF) of the subscriber session parameters of interest. To this end, the SMF triggers an Nsmf HTTP POST message to the UPF. The body of the HTTP POST message will indicate a notification related to SMF public service (Nsmf _ EventExposure _ Notify), specifically a notification of a new Subscriber Session Data event (EventID _ Subscriber Session Data) for a PDU Session (UESessionId) for a particular UE, including relevant Subscriber Session parameters of interest (e.g., RAT Type and Location) (Nsmf HTTP POST (Notify); { Nsmf _ EventExposure _ Notify, UESessionId, EventID _ Subscriber Session Data, suscribber Session parameters (RAT-Type, Location, etc.) }).

In step S45, UPF 200 responds to SMF 100 with an Nsmf200OK successful response after receiving the message in the previous step (Nsmf 200OK PDU Session Establishment (continuous); Application transaction (YouTube)).

In steps S46, S47, and S48, the user opens the YouTube application. The UPF 200 detects YouTube traffic by matching incoming packets with PDRs of PDIs of type applications with appId ═ YouTube, and forwards the traffic to the video optimizer SF (FAR according to a traffic policy identifier that includes as a forwarding action a traffic directed to the video optimizer SF). The UPF adds the Subscriber Session parameters (YouTube traffic) retrieved in the above-described S44 as metadata (YouTube traffic) through NSH (e.g., only in the first packet of the flow) { NSH metadata inclusion Subscriber Session parameters (RAT-Type, Location, etc.) }.

In step S49, the video optimizer SF applies video optimization to YouTube traffic based on the received subscriber session parameters (e.g., RAT type, location, etc.).

Fig. 5 shows in a generalized manner the steps performed by the session control entity or SMF 100 in the embodiments of fig. 3 and 4. In step S61, SMF 100 receives a request for information about session-related parameters. In the example given above, it is the subscription request of step S23 in fig. 3 or step S41 in fig. 4. Further, in response to the subscription, in step S62, SMF 100 sends a notification including the requested session-related parameters. This corresponds to step S26 in fig. 3, and to step S44 in fig. 4.

The received request may be one that requests the requestor (whether the service application entity 500 or the UPF 200) to be informed of any future changes of the session related parameters. Each time a change of session related parameters is detected, the requesting party is notified accordingly. In the above example, this is achieved through a subscription.

Fig. 6 summarizes the steps performed at the user plane entity 200. In step S71, the user plane entity 200 receives a session establishment request with an identifier of the session control entity. This corresponds to step S18 described in connection with fig. 3. The user plane entity then sends a notification with the session control entity identifier to the serving application entity 500 in step S72, so that the serving application entity is aware of the session control entity handling the data packet session. With the provided information, the service application entity may then subscribe to the requested service provided by the session control entity. Step S72 is implemented in fig. 3 by step S21.

As far as the service application entity 500 is concerned, some main steps are summarized in fig. 7. In step S81, the service application entity 500 receives a notification from the user plane entity 200 with an identifier of the session control entity as described above in connection with step S72. Then, in step S82, the service application entity sends a request to the session control entity 100 requesting information about the session related parameters. Step S81 is implemented by step S21, and step S82 is implemented in step S23 in fig. 3. Finally, in step S83, the service application entity receives a response with the current state of the session related parameters, as implemented in step S26 in fig. 3.

Fig. 8 shows a schematic architectural diagram of an SMF 100 that may perform the steps described above in relation to SMF 100. SMF 100 includes an input/output or interface 110 configured to send user data or control messages to other entities and configured to receive user data or control messages from other entities. As an example, the interface 110 is configured to receive a subscription request of the service application entity 500 and to inform the service application entity of the subscriber session parameters accordingly. Furthermore, the interface is configured to inform the user plane entity 200 of its identifier, as described above in connection with step S18. The SMF 100 also includes a processing unit 120 that is responsible for the operation of the SMF 100. Processing unit 120 includes one or more processors and may execute instructions stored by memory 130, which may include read-only memory, random access memory, mass storage, a hard disk, and the like. Memory 130 also includes suitable program code to be executed by processing unit 120 to implement the functions described above in relation to SMF 100.

Fig. 9 shows another example schematic representation of an SMF 300 comprising a first module 310, the first module 310 being configured to receive a request for information on session related parameters. Furthermore, a second module 320 is provided, which is configured to send a notification with the status of session related parameters to a requesting entity, which may be a serving application entity directly or a UPF as shown in fig. 4.

Fig. 10 shows a schematic architectural diagram of a user plane entity 200 that can perform the steps described above in relation to the UPF 200 shown in fig. 3 and 4. The user plane entity comprises an input/output or interface 210 configured to send user data or control messages and configured to receive user data or control messages. The interface 210 is configured to receive an identifier of the SMF 100 as described in step S18 above and to send information about the identified SMF to the service application entity as described in step S21 above.

The UPF 200 also includes a processing unit 220 that is responsible for the operation of the UPF 200. Processing unit 220 includes one or more processors and may execute instructions stored on memory 230, which may include read-only memory, random access memory, mass storage, a hard disk, and the like. The memory also includes suitable program code to be executed by the processing unit to carry out the functions described above in relation to the UPF 200.

Fig. 11 shows another example schematic representation of a user plane entity 400 comprising a first module 410, the first module 410 being configured to receive a session establishment request with an identifier of the session control entity 100, as described above in connection with fig. 3 and 4. The user plane entity 400 further comprises a second module 420 for sending a notification with the session control entity identifier to the service application entity 500.

Fig. 12 shows a schematic architectural diagram of a service application entity 500 that may perform the steps described above in relation to the SF 500 as shown in fig. 3 or fig. 4. The service application entity 500 comprises an input/output or interface 510 configured to receive control messages or user data and configured to transmit control messages or user data. The interface 510 is configured to receive, among other things, information about an identifier that identifies the SMF. Interface 510 is also configured to send a subscription request to SMF 100 and to receive a response to the subscription.

The service application entity 500 further comprises a processing unit 520 responsible for the operation of the service application entity 500. Processing unit 520 includes one or more processors and may execute instructions stored on memory 530, which may include read-only memory, random access memory, mass storage, a hard disk, and the like. The memory also includes suitable program code to be executed by the processing unit 520 in order to implement the functions described above in relation to the SF 500.

Fig. 13 shows another example schematic representation of a service application entity 600. The entity 600 comprises a first module 610 configured for receiving a notification from the user plane entity 200 with an identifier of a session control entity 100, the session control entity 100 controlling a data packet session for which the service application entity 600 should provide a service.

A second module 620 is provided which is configured to send a request to the session control entity 100, wherein information on session related parameters is requested. As described above, the request may be a subscription request. A third module 630 is provided which receives a response from the session control entity with the current status of the session related parameters.

Some general conclusions of the different entities can be drawn from the above. As far as the session control entity or SMF 100 is concerned, a first request is received from the SF 500 or the user plane entity 200 requesting to inform the requesting party of the current state of session related parameters of the data packet session, as described above. The request is based on the fact that the service application entity is informed of which session control entity is handling the identifier of the data packet session. Preferably, prior to receiving the first request, a session establishment request may be sent to the user plane entity to establish the data packet session. The session establishment request may comprise a session control entity identifier allowing to identify the session control entity. In the above embodiment, this is achieved by step S18 in fig. 3 or as step S38 in fig. 4.

The user plane entity 200 uses this information on the session control entity identifier to send this identifier to the service application entity 500, which service application entity 500 may then address the correct SMF in order to apply the requested service to the data packet session.

The received first request requesting the current state of the session related parameters may also request that the requesting party be informed of any future changes of the at least one session related parameter and that the notification is sent to the requesting party whenever a change of the at least one session related parameter is detected.

This may be achieved by subscription, however any other implementation is possible.

Further, as shown in fig. 2, a service chain may be applied to the data packet session, and the service application entity 500 providing at least one service to the data packet session may be part of the service chain.

Further, a user plane rule may be determined indicating a steering policy identifier for identifying a service application entity providing at least one service for the mobile subscriber. The user plane rule may then be sent to the user plane entity 200.

Furthermore, the policy control rules may be retrieved by the session control entity 100 from a policy control entity comprising a steering policy for the mobile subscriber. The sending of the user plane rule may be part of the sending of the session establishment request.

The requesting party may be the service application entity 500 or the user plane entity 200.

In a 5G implementation, the reception of the first request may mean that a subscription to a public service provided by the session control entity 100 is received, the subscription indicating a subscription of the requesting party as a consumer of the public service to any event related to at least one session related parameter of the data packet session.

The subscription may include a session identifier that identifies the data packet session. The subscription may also include a subscriber identifier identifying an individual subscriber or group of subscribers, and the subscription may also include session-related parameters matching the identification of the group of subscribers.

The sending of the notification may comprise the step of notifying the consumer of the identity of the subscription service, the session identifier and the at least one session related parameter. This is detailed above in connection with step S23 of fig. 3.

When a notification is sent to the requestor, the subscribing consumer is notified of the identification of the subscription service, the session identifier, and the at least one session-related parameter.

The session related parameters may comprise a subscriber identity or any other non-subscriber related parameter, such as any other session related parameter, e.g. RAT type.

In the case of the user plane entity 200, a service chain may be applied to the data packet session, and the service application entity 500 provides at least one service as part of the service chain. Each service application entity provides at least one service in a chain of services, and a first notification comprising an identifier of the session control entity may be sent to each service application entity provided in the chain.

The first notification may comprise an indication that the session control entity 100 identified by the session control entity identifier is configured to provide a public service associated with the data packet session, thereby allowing the service application entity to subscribe to the public service.

The first notification may include a session control entity identifier.

Further, the user plane entity 500 may receive a user plane rule from the session control entity 100 indicating a steering policy identifier for identifying a service application entity providing at least one service for the mobile subscriber.

In respect of the service application entity 500, the first notification may comprise an indication that the session control entity 100 identified by the first notification is configured to provide a public service related to the data packet session, thereby allowing the service application entity to subscribe to the public service. The sending of the first request may comprise the step of sending a subscription to the public service provided by the session control entity 100, wherein the subscription indicates a subscription of the service application entity as a consumer of the public service to any event related to at least one session related parameter of the data packet session.

The first request sent to the session control entity 100 may also request that the serving application entity be informed of any future changes of the at least one session related parameter. A notification may be received whenever a change in at least one session related parameter is detected.

The above application has the advantage that it separates the deployment of service functions from the deployment of radius, which aims at solving use cases different from the service function subscriber awareness. This results in considerable cost savings, since the integration of service functions can be significantly simplified. Furthermore, providing an alternative solution to RADIUS ensures that any service function is able to perceive the service, since in some cases RADIUS integration is not feasible or RADIUS accounting is not enabled.

The above mechanism also optimizes resources by saving unnecessary CPU and memory resources so that the service application entity receives only relevant information. This allows for the deployment of nodes with lower processing power, which may reduce the amount of capital and resources invested.