WO2021233646A1

WO2021233646A1 - Service request handling

Info

Publication number: WO2021233646A1
Application number: PCT/EP2021/060861
Authority: WO
Inventors: María Cruz Bartolomé RODRIGO
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2020-05-20
Filing date: 2021-04-26
Publication date: 2021-11-25

Abstract

There is provided a method for handling a service request in a network. The method is performed by a first network function (NF) node or a first service communication proxy (SCP) node that is configured to operate as an SCP between NF nodes of the network. In response to a request for a second NF node to execute a service requested by a service consumer, a second SCP node from which the second NF node is reachable is identifies (102) from information on one or more SCP nodes. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. Transmission of the request is initiated (104) from the identified second SCP node to the second NF node.

Description

SERVICE REQUEST HANDLING

Technical Field

The disclosure relates to a method for handling a service request in a network and a node configured to operate in accordance with that method.

Background

There exist various techniques for handling a request for a service in a network. A service request is generally from a consumer of the service (“service consumer”) to a producer of the service (“service producer”). For example, a service request may be from a network function (NF) node of a service consumer to an NF node of a service producer. The NF node of the service consumer and the NF node of the service producer can communicate directly or indirectly. This is referred to as direct communication and indirect communication respectively. In the case of indirect communication, the NF node of the service consumer and the NF node of the service producer may communicate via a service communication proxy (SCP) node.

Figure 1A-D illustrates different existing systems for handling service requests, as set out in 3GPP TS 23.501 v16.4.0. In more detail, Figure 1A and 1B illustrates a system that uses direct communication, while Figure 1C and 1D illustrates a system that uses indirect communication.

In the systems illustrated in Figure 1A and 1B, a service request is sent directly from the NF node of the service consumer to the NF node of the service producer. A response to the service request is sent directly from the NF node of the service producer to the NF node of the service consumer. Similarly, any subsequent service requests are sent directly from the NF node of the service consumer to the NF node of the service producer. The system illustrated in Figure 1B also comprises a network repository function (NRF). Thus, in the system illustrated in Figure 1B, the NF node of the consumer can query the NRF to discover suitable NF nodes of the service producer to which to send the service request. In response to such a query, the NF node of the consumer can receive an NF profile for one or more NF nodes of the service producer and, based on the received NF profile(s) can select an NF node of the service producer to which to send the service request. In the system illustrated in Figure 1A, the NRF is not used and instead the NF node of the consumer may be configured with the NF profile(s) of the NF node(s) of the service producer.

In the systems illustrated in Figure 1C and 1D, a service request is sent indirectly from the NF node of the service consumer to the NF node of the service producer via a service communication proxy (SCP) node. A response to the service request is sent indirectly from the NF node of the service producer to the NF node of the service consumer via the SCP. Similarly, any subsequent service requests are sent indirectly from the NF node of the service consumer to the NF node of the service producer via the SCP. The systems illustrated in Figure 1C and D also comprise an NRF.

In the system illustrated in Figure 1C, the NF node of the consumer can query the NRF to discover suitable NF nodes of the service producer to which to send the service request. In response to such a query, the NF node of the consumer can receive an NF profile for one or more NF nodes of the service producer and, based on the received NF profile(s) can select an NF node of the service producer to which to send the service request. In this case, the service request sent from the NF node of the service consumer to the SCP comprises the address of the selected NF node of the service producer. The NF node of the service consumer can forward the service request without performing any further discovery or selection. In case the selected NF node of the service producer is not accessible for any reason, it may be up to the NF node of the service consumer to find an alternative. In other cases, the SCP may communicate with the NRF to acquire selection parameters (e.g. location, capacity, etc.) and the SCP may select an NF node of the service producer to which to send the service request.

In the system illustrated in Figure 1D, the NF node of the consumer does not carry out the discovery or selection process. Instead, the NF node of the consumer adds any necessary discovery and selection parameters (required to find a suitable NF node of the service producer) to the service request that it sends via the SCP. The SCP uses the request address and the discovery and selection parameters in the service request to route the service request to a suitable NF node of the service producer. The SCP can perform discovery with the NRF.

For the fifth generation core (5GC), from Release 16, the SCP is included as a network element to allow indirect communication between an NF node of a service consumer and an NF node of a service producer. The indirect communication that is used can be either of the two indirect communications options described earlier with reference to Figure 1C and 1D.

Multiple SCPs may be deployed between an NF node of a service consumer and an NF node of a service producer. From Release 15, it is possible to partition networks, making use of the so called “Groupld” that identifies a group/range of users that an NF node (or NF node instance) serves. This applies to all types of NF node. It basically means that an NF node may store data for some scattered subscribers (or range of subscribers) that are identified for simplicity as a Groupld. The NF node is then able to register in the NRF with this Groupld, rather than having the need to indicate the subscriber ranges, which can be particularly problematic in the case of scattered subscribers.

Figure 2 is a signalling diagram illustrating an exchange of signals in an existing system, such as the system illustrated in Figure 1 D but it will be understood the issue described can also apply to the system illustrated in Figure 1C. The system illustrated in Figure 2 comprises a first SCP node 10a, a second SCP node 10b, a third SCP node 50a, and a fourth SCP node 50b. The system illustrated in Figure 2 also comprises first NF node 20 of a service consumer (“NFc”), a second NF node 30 of a service producer (“NFp1”), and a third NF node 70 of a service producer (“NFp2”).

The SCP nodes 10a, 10b, 50a, 50b are each configured to operate as an SCP between NF nodes in the network, e.g. between the first NF node 20 and one or more of the second NF node 30 and the third NF node 70. Any one or more of the SCP nodes 10a, 10b, 50a, 50b may be configured to operate between different NF nodes to one or more other SCP nodes. In the system illustrated in Figure 2, the first SCP node 10a is in a first SCP domain 402 and the second SCP node 10b is in a second SCP domain 404. The first SCP domain 402 and the second SCP domain 404 are different. The second SCP node 10b is a different SCP node to the first SCP node 10a. The second NF node 30 can be configured to run a service 40 and the third NF node 70 can be configured to run a service 80. The second NF node 30 and the third NF node 70 can be configured to run the same service or a different service. The second NF node 30 and the third NF node 70 can be part of a partition 400 of NF nodes of a service producer. The system illustrated in Figure 2 also comprises a network repository function 60.

As illustrated by arrow 600 of Figure 2, the first NF node 20 initiates transmission of a service request towards the first SCP node 10 in the first SCP domain 402. The first NF node 20 may know via which SCP to route the service request by configuration or other means. The service request can comprise one or more discovery parameters (e.g. in case of SCP model C with the usage of Set, or SCP model D), or a target application programming interface (API) root (e.g. that identifies the final NF node of the service producer or the final instance of the NF service producer in the case of SCP model C). If the service request does not comprise a target API root, steps 602-610 of Figure 2 may be performed. As illustrated by block 602 of Figure 2, the first SCP node 10a may store the one or more received discovery parameters.

As illustrated by arrow 604 of Figure 2, the first SCP node 10a initiates transmission of a discovery request towards the NRF 60 to obtain NF profile(s) of one or more NF nodes of the service producer for the service that needs to be executed. As illustrated by arrow 606 of Figure 2, the first SCP node 10a receives a response from the NRF 60 comprising the NF profile(s) of one or more NF nodes of the service producer, which can be used as a destination. As illustrated by block 608 of Figure 2, the first SCP node 10a can store the discovered NF profile(s). As illustrated by block 610 of Figure 2, the first SCP node 10a may select one NF node of the service producer from the one(s) discovered using, for example, functional criteria (e.g. subscription permanent identifier (SUPI), network slice selection assistance information (NSSAI), data network name (DNN), etc.) or non functional criteria (e.g. load, capacity, etc.). For the purpose of the illustration, it is assumed that the first SCP node 10a selects the second NF node 30.

As illustrated by arrow 612 of Figure 2, the first SCP node 10a initiates transmission of a discovery request towards the NRF 60 to obtain SCP profile(s) of one or more potential SCP nodes that can be used to reach the required destination, which in this case is the second NF node 30. As illustrated by arrow 614 of Figure 2, the first SCP node 10a receives a response from the NRF 60 comprising the NF profile(s) of one or more SCP nodes. As illustrated by block 616 of Figure 2, there is not enough information in the SCP profile(s) to be able to determine which SCP(s) can actually be used to reach the second NF node 30. For example, there may not be enough information to find the SCP domain for the partition 400 comprising the second NF node 30. That is, there may not be enough information related to the GroupldX of the partition 400. As such, if the partition 400 is deployed with a specific SCP domain, it is not possible to route the request to reach the second NF node 30.

Thus, even though NF nodes (e.g. the second NF node 30 and/or third NF node 70) of the service producer may be available and operational (e.g. up and running), the procedure can still fail, since the first SCP node 10a does not know how to reach the NF nodes of the service producer.

Summary

It is an object of the disclosure to obviate or eliminate at least some of the above- described disadvantages associated with existing techniques.

Therefore, according to an aspect of the disclosure, there is provided a method for handling a service request in a network. The method is performed by a first network function (NF) node or a first service communication proxy (SCP) node that is configured to operate as an SCP between NF nodes of the network. The method is performed in response to a request for a second NF node to execute a service requested by a service consumer. The method comprises identifying, from information on one or more SCP nodes, a second SCP node from which the second NF node is reachable. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. The method comprises initiating transmission of the request from the identified second SCP node to the second NF node. In some examples, the identified second SCP node may be the first SCP node. In some examples, the identified second SCP node may be a different SCP node to the first SCP node. In some examples, the first SCP node may be in a first SCP domain and the second SCP node may be in a second SCP domain, wherein the first SCP domain and the second SCP domain may be different.

In some examples, for at least one of the one or more SCP nodes, the information may be indicative of which one or more NF nodes of the network are reachable from that SCP node.

In some examples, the information may be on the second SCP node and the information is indicative that the second NF node is reachable by the second SCP node. In some examples, the information may be on a plurality of SCP nodes, wherein the plurality of SCP nodes may comprise the second SCP node and the information is indicative that the second NF node is reachable by the second SCP node. In some examples, the information may be stored at the first SCP node, at one or more other nodes, and/or at a network repository function (NRF). In some examples, the method may comprise initiating transmission of a request for the information towards the one or more other nodes and/or the NRF. In some examples, the request may comprise information indicative of the second NF node.

In some examples, the method may comprise receiving the information from the one or more other nodes and/or the NRF. In some examples, for at least one of the one or more SCP nodes, an SCP profile of that SCP node may comprise the information. In some examples, the information on each of the one or more SCP nodes may comprise one or more unique identifiers, wherein each unique identifier uniquely identifies one of the one or more NF nodes of the network that are reachable from that SCP node.

In some examples, a partition in the network may comprise the second NF node or the second NF node and one or more other NF nodes of the service producer. In some examples, the information may be indicative of at least one type of NF node comprised within the partition. In some examples, one or more NF nodes of the partition may be the same type of NF node, or one or more NF nodes of the partition may be instances of the same type of NF node. In some examples, the type of NF node may be a unified data management (UDM) node, an access and mobility management function (AMF) node, a session management function (SMF) node, an authentication server function (AUSF) node, a unified data repository (UDR) node, a policy control function (PCF) node, or a home subscriber server (HSS) node.

In some examples, multiple services and/or service instances may be executable by each type of NF node. In some examples, each NF node of the partition may be reachable from the identified second SCP node. In some examples, each NF node of the partition may be capable of executing the service requested. In some examples, data required to execute the service requested may be reachable by each NF node of the partition. In some examples, the information may comprise a unique identifier of the data. In some examples, the unique identifier of the data may comprise a subscription permanent identifier (SUPI), a generic public subscription identifier (GPSI), an internet protocol multimedia private identifier (IMPI), or an internet protocol multimedia public identifier (IMPU).

In some examples, the information may comprise a unique identifier that uniquely identifies the partition. In some examples, the method may comprise receiving a response to the request from the second NF node. In some examples, the method may be performed by the first SCP node and the method may comprise initiating transmission of the response to the first NF node. In some examples, the first SCP node and the first NF node may be deployed in independent deployment units, and/or the first SCP node and the second NF node may be deployed in independent deployment units. In some examples, the first SCP node may be deployed as a distributed network element.

In some examples, part of the first SCP node may be deployed in the same deployment unit as the first NF node. In some examples, the second SCP node and the first NF node may be deployed in independent deployment units, and/or the second SCP node and the second NF node may be deployed in independent deployment units. In some examples, the second SCP node may be deployed as a distributed network element.

In some examples, part of the second SCP node may be deployed in the same deployment unit as the second NF node. In some examples, at least one third SCP node may be configured to operate as an SCP between the first NF node and the first SCP node. In some examples, the information may be indicative of which one or more NF nodes of the network are directly reachable from which of the one or more SCP nodes and/or which one or more NF nodes of the network are indirectly reachable from which of the one or more SCP nodes.

In some examples, the second NF node may be directly reachable from the second SCP node. In some examples, the second NF node may be indirectly reachable from the second SCP node. In some examples, the method may comprise identifying, from the information on one or more SCP nodes, at least one third SCP node from which the identified second SCP node is reachable, wherein the information may be indicative of which one or more SCP nodes of the network are reachable from which of the one or more SCP nodes. In some examples, wherein for at least one of the one or more SCP nodes, the information may be indicative of which one or more SCP nodes of the network are reachable from that SCP node.

In some examples, the information on each of the one or more SCP nodes may comprise one or more unique identifiers, wherein each unique identifier uniquely identifies one of the one or more SCP nodes of the network that are reachable from that SCP node. In some examples, each unique identifier may be one of a routing indicator, an internal group identifier, an external group identifier, a subscription permanent identifier (SUPI), a generic public subscription identifier (GPSI), an internet protocol multimedia private identifier (IMPI), or an internet protocol multimedia public identifier (IMPU).

In some examples, an entity may comprise a network repository function NRF and one or both of the first SCP node and the second SCP node. According to an aspect of the disclosure, there is provided a first NF node or a first SCP node comprising processing circuitry configured to operate in accordance with the method described earlier.

In some examples, the first NF node or the first SCP node may comprise at least one memory for storing instructions which, when executed by the processing circuitry, cause the first NF node or the first SCP node to operate in accordance with the method described earlier. According to an aspect of the disclosure, there is provided a computer program comprising instructions which, when executed by processing circuitry, cause the processing circuitry to perform the method according to the method described earlier.

According to an aspect of the disclosure, there is provided a computer program product, embodied on a non-transitory machine-readable medium, comprising instructions which are executable by processing circuitry to cause the processing circuitry to perform the method according to the method described earlier.

In a first aspect of the present disclosure, there is provided a method for handling a request for a service in a telecommunication network, wherein the network is deployed in multiple Service Communication Proxy, SCP, domains, wherein each SCP domain is a group of one or more SCPs that can directly reach a certain group of NF producers, the method comprising the steps of:

- selecting, in response to a received request for said service, by an SCP in said first SCP domain, an NF producer instance that is able to provide said requested service;

- retrieving, by said SCP in said first SCP domain, SCP profiles of SCPs that are able to reach said NF producer instance, wherein each of said SCP profiles comprises address information of a plurality of NF producer instances that are directly reachable by said corresponding SCP;

- selecting, by said SCP in said first SCP domain, based on said received SCP profiles and based on said selected NF producer instance, an SCP in said second SCP domain that is able to directly reach said NF producer instance;

- initiating, by said SCP in said first SCP domain, transmission of said request to the selected SCP in said second SCP domain.

In an example, each of said SCP profiles comprises a group identification, wherein each group identification is associated with at least one NF producer instance that is directly reachable by said corresponding SCP.

In a further example, the step of retrieving comprises any of retrieving, by said SCP in said first SCP domain, said SCP profiles from a Network Repository Function, NRF, in said telecommunication network retrieving, by said SCP in said first SCP domain, said SCP profiles stored on said SCP in said first SCP domain.

In a further example, said group identification is any of: routing Indicator;

Unified Data Management, UDM, Group ID or range(s) of SUPIs or range(s) of Generic Public Subscription Identifiers ,GPSIs, or range(s) of internal group identifiers, or range(s) of external group identifiers for UDM;

Unified Data Repository, UDR, Group ID or range(s) of Subscription Permanent Identifiers, SUPIs, or range(s) of GPSIs, or range(s) of external group identifiers for UDR.

Authentication Server Function, AUSF, Group ID or range(s) of SUPIs for

AUSF;

- Policy Control Function, PCF, Group ID or range(s) of SUPIs for PCF. Home subscriber Server, HSS, Group ID or set(s) of IMPIs or set(s) of

IMPU for HSS.

In another example, said NF producer instance is comprised by any of: a unified data management, UDM, node; an access and mobility management function, AMF, node; a session management function, SMF, node; an authentication server function, AUSF, node; a unified data repository, UDR, node; a policy control function, PCF, node; or a home subscriber server, HSS, node.

In an example, said method further comprises the step of:

- receiving, by said SCP in said first SCP domain, said request for a service.

In a second aspect of the present disclosure, there is provided a Service Communication Proxy, SCP, in a first SCP domain that is arranged for handling a request for a service in a telecommunication network, wherein the network is deployed in multiple Service Communication Proxy, SCP, domains, wherein each SCP domain is a group of one or more SCPs that can directly reach a certain group of NF producers, the first SCP comprising:

- select equipment arranged for selecting, in response to a received request for said service, by an SCP in said first SCP domain, an NF producer instance that is able to provide said requested service;

- retrieve equipment arranged for retrieving SCP profiles of SCPs that are able to reach said NF producer instance, wherein each of said SCP profiles comprises address information of a plurality of NF producer instances that are directly reachable by said corresponding SCP;

- process equipment arranged for selecting, based on said received SCP profiles and based on said selected NF producer instance, an SCP in said second SCP domain that is able to directly reach said NF producer instance;

- initiate equipment arranged for initiating transmission of said request to the selected SCP in said second SCP domain.

In a further example, said retrieve equipment is further arranged for any of:

- retrieving said SCP profiles from a Network Repository Function, NRF, in said telecommunication network;

- retrieving said SCP profiles stored on said SCP in said first SCP domain.

In an example, said group identification is any of: routing Indicator;

Unified Data Repository, UDR, Group ID or range(s) of Subscription Permanent Identifiers, SUPIs, or range(s) of GPSIs, or range(s) of external group identifiers for UDR. Authentication Server Function, AUSF, Group ID or range(s) of SUPIs for

AUSF;

- Policy Control Function, PCF, Group ID or range(s) of SUPIs for PCF.

Home subscriber Server, HSS, Group ID or set(s) of IMPIs or set(s) of

IMPU for HSS.

In an example, said NF producer instance is comprised by any of: a unified data management, UDM, node; an access and mobility management function, AMF, node; a session management function, SMF, node; an authentication server function, AUSF, node; a unified data repository, UDR, node; a policy control function, PCF, node; or a home subscriber server, HSS, node.

In a further example, said SCP further comprises:

- receive equipment arranged for receiving said request for a service.

In a further aspect, there is provided a computer program comprising instructions which, when executed by processing circuitry, cause the processing circuitry to perform the method according to any of method examples as provided above.

In another aspect, there is provided a computer program product, embodied on a non- transitory machine-readable medium, comprising instructions which are executable by processing circuitry to cause the processing circuitry to perform the method according to any of the method examples as provided above.

Thus, an improved technique for handling service requests in a network is provided.

Brief description of the drawings

For a better understanding of the technique, and to show how it may be put into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1A-D is a block diagram illustrating different existing systems;

Figure 2 is a signalling diagram illustrating an exchange of signals in an existing system;

Figure 3 is a block diagram illustrating a first service communication proxy (SCP) node according to an example;

Figure 4 is a flowchart illustrating a method performed by a first SCP node according to an example;

Figure 5A-B is a signalling diagram illustrating an exchange of signals in a system according to an example; and

Figure 6 is a block diagram illustrating a first SCP node according to an example.

Detailed Description

Herein, techniques for handling a service request in a network are described. A service request can also be referred to as a request for a service. Generally, a service is software intended to be managed for users. Herein, a service can be any type of service, such as a communication service a context management (e.g. user equipment context management (UECM)) service, a data management (DM) service, or any other type of service. The techniques described herein can be used in respect of any network, such as any communications network. The network may be a fifth generation (5G) network or any other generation network. In some examples, the network may be a core network or a radio access network (RAN). The techniques are implemented by the first network (NF) node 20 of the service consumer and/or the first service communication proxy (SCP) node 10a.

Figure 3 illustrates a first SCP node 10a in accordance with an example. The first SCP node 10a is for handling a service request in a network. The first SCP node 10a is configured to operate as an SCP between NF nodes in the network. In some examples, the first SCP node 10a can be, for example, be a physical machine (e.g. a server) or a virtual machine (VM). It will be understood that the description of Figure 3 can equally apply to the first NF node 20 referred to herein and all references to “the first SCP node 10a” are thus interchangeable with “the first NF node 20”. The first NF node 20 can be, for example, a user equipment (UE).

An NF is a third generation partnership project (3GPP) adopted or 3GPP defined processing function in a network, which has defined functional behaviour and 3GPP defined interfaces. An NF can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualised function instantiated on an appropriate platform, e.g. on a cloud infrastructure. Herein, the term “node” in relation to an “NF node” will be understood to cover each of these scenarios.

As illustrated in Figure 3, the first SCP node 10a comprises processing circuitry (or logic) 12a. The processing circuitry 12a controls the operation of the first SCP node 10a and can implement the method described herein in respect of the first SCP node 10a. The processing circuitry 12a can be configured or programmed to control the first SCP node 10a in the manner described herein. The processing circuitry 12a can comprise one or more hardware components, such as one or more processors, one or more processing units, one or more multi-core processors and/or one or more modules. In particular implementations, each of the one or more hardware components can be configured to perform, or is for performing, individual or multiple steps of the method described herein in respect of the first SCP node 10a. In some examples, the processing circuitry 12a can be configured to run software to perform the method described herein in respect of the first SCP node 10a. The software may be containerised according to some examples. Thus, in some examples, the processing circuitry 12a may be configured to run a container to perform the method described herein in respect of the first SCP node 10a.

Briefly, the processing circuitry 12a of the first SCP node 10a is configured to, in response to a request for a second NF node to execute a service requested by a service consumer, identify a second SCP node from which the second NF node is reachable. More specifically, the SCP node 10a may be configured to retrieve SCP profiles of SCPs that are able to reach the second NF node, i.e. the NF producer instance, wherein each of the profiles comprises routing information of a plurality of NF producer instances that are directly reachable by the corresponding SCP. The second SCP node is identified from information on one or more SCP nodes. That is, the second SCP node is selected based on the SCP profiles and based on the selected NF producer instance. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. The processing circuitry 12a of the first SCP node 10a is configured to initiate transmission of the request from the identified second SCP node to the second NF node.

As illustrated in Figure 3, in some examples, the first SCP node 10a may optionally comprise a memory 14a. The memory 14a of the first SCP node 10a can comprise a volatile memory or a non-volatile memory. In some examples, the memory 14a of the first SCP node 10a may comprise a non-transitory media. Examples of the memory 14a of the first SCP node 10a include, but are not limited to, a random access memory (RAM), a read only memory (ROM), a mass storage media such as a hard disk, a removable storage media such as a compact disk (CD) or a digital video disk (DVD), and/or any other memory.

The processing circuitry 12a of the first SCP node 10a can be connected to the memory 14a of the first SCP node 10a. In some examples, the memory 14a of the first SCP node 10a may be for storing program code or instructions which, when executed by the processing circuitry 12a of the first SCP node 10a, cause the first SCP node 10a to operate in the manner described herein in respect of the first SCP node 10a. For example, in some examples, the memory 14a of the first SCP node 10a may be configured to store program code or instructions that can be executed by the processing circuitry 12a of the first SCP node 10a to cause the first SCP node 10a to operate in accordance with the method described herein in respect of the first SCP node 10a. Alternatively or in addition, the memory 14a of the first SCP node 10a can be configured to store any information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. The processing circuitry 12a of the first SCP node 10a may be configured to control the memory 14a of the first SCP node 10a to store information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. In some examples, as illustrated in Figure 3, the first SCP node 10a may optionally comprise a communications interface 16a. The communications interface 16a of the first SCP node 10a can be connected to the processing circuitry 12a of the first SCP node 10a and/or the memory 14a of first SCP node 10a. The communications interface 16a of the first SCP node 10a may be operable to allow the processing circuitry 12a of the first SCP node 10a to communicate with the memory 14a of the first SCP node 10a and/or vice versa. Similarly, the communications interface 16a of the first SCP node 10a may be operable to allow the processing circuitry 12a of the first SCP node 10a to communicate with the first NF node 20, the second SCP node 10b and/or any other node. The communications interface 16a of the first SCP node 10a can be configured to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. In some examples, the processing circuitry 12a of the first SCP node 10a may be configured to control the communications interface 16a of the first SCP node 10a to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein.

Although the first SCP node 10a is illustrated in Figure 3 as comprising a single memory 14a, it will be appreciated that the first SCP node 10a may comprise at least one memory (i.e. a single memory or a plurality of memories) 14a that operate in the manner described herein. Similarly, although the first SCP node 10a is illustrated in Figure 3 as comprising a single communications interface 16a, it will be appreciated that the first SCP node 10a may comprise at least one communications interface (i.e. a single communications interface or a plurality of communications interface) 16a that operate in the manner described herein. It will also be appreciated that Figure 3 only shows the components required to illustrate an example of the first SCP node 10a and, in practical implementations, the first SCP node 10a may comprise additional or alternative components to those shown.

Figure 4 is a flowchart illustrating a method performed by a first SCP node 10a in accordance with an example. The first SCP node 10a is configured to operate as an SCP between NF nodes in the network. The method of Figure 4 is for handling a service request in the network. It will be understood that the description of Figure 4 can equally apply to the first NF node 20 referred to herein and all references to “the first SCP node 10a” are thus interchangeable with “the first NF node 20”. The first SCP node 10a described earlier with referenced to Figure 3 is configured to operate in accordance with the method of Figure 4. The method can be performed by or under the control of the processing circuitry 12a of the first SCP node 10a.

The method of Figure 4 is performed in response to a request for a second NF node to execute a service requested by a service consumer. As illustrated at block 102 of Figure 4, a second SCP node from which the second NF node is reachable is identified. The second SCP node is identified from information on one or more SCP nodes. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. As illustrated at block 104 of Figure 4, transmission of the request is initiated from the identified second SCP node to the second NF node.

Herein, the term “initiate” can mean, for example, cause or establish. Thus, the processing circuitry 12a of the first SCP node 10a can be configured to itself transmit the request (e.g. via a communications interface 16a of the first SCP node 10a) or can be configured to cause another node to transmit the request.

Figure 4 may thus entail that first, in step 102, SCP profiles are retrieved which are able to reach the NF producer instance, wherein each of the SCP profiles comprises routing information of a plurality of NF producer instances that are directly reachable by the corresponding SCP. Then, an appropriate SCP is selected based on the SCP profiles and based on the selected NF producer instance. And finally, in step 104, a transmission of the request to the selected SCP in a second SCP domain is initiated.

Figure 5A-B is a signalling diagram illustrating an exchange of signals in a system according to an example. The system illustrated in Figure 5A-B comprises a first SCP node 10a, a second SCP node 10b, a third SCP node 50a, and a fourth SCP node 50b. However, it will be understood that the system may comprise any other number of SCP nodes. The system illustrated in Figure 5A-B also comprises a first NF node 20 of a service consumer (“NFc”), a second NF node 30 of a service producer (“NFp1”), and a third NF node 70 of a service producer (“NFp2”).

The SCP nodes 10a, 10b, 50a, 50b are each configured to operate as an SCP between NF nodes in the network, e.g. between the first NF node 20 and one or more of the second NF node 30 and the third NF node 70. Any one or more of the SCP nodes 10a, 10b, 50a, 50b may be configured to operate between different NF nodes to one or more other SCP nodes. In the system illustrated in Figure 5A-B, the first SCP node 10a is in a first SCP domain 402 and the second SCP node 10b is in a second SCP domain 404. The first SCP domain 402 and the second SCP domain 404 are different. The second SCP node 10b is a different SCP node to the first SCP node 10a. Generally, an SCP domain is a group of one or more SCPs that can reach certain NF nodes (or NF node instances) or SCPs directly, i.e. without passing through an intermediate SCP. SCP nodes in the same SCP domain are able to reach the same NF nodes, whereas SCP node in different SCP domains are unable to reach the same NF nodes.

The second NF node 30 can be configured to run a service 40 and the third NF node 70 can be configured to run a service 80. The second NF node 30 and the third NF node 70 can be configured to run the same service or a different service. The second NF node 30 and the third NF node 70 can be part of a partition 400 of NF nodes of a service producer. The system illustrated in Figure 5A-B also comprises a network repository function 60. In some examples, an entity may comprise the NRF 60 and one or both of the first SCP node 10a and the second SCP node 10b. That is, in some examples, the first SCP node 10a and/or the second SCP node 10b can be merged with the NRF 60 in a combined entity.

In some examples, the first SCP node 10a and the first NF node 20 may be deployed in independent deployment units, and/or the first SCP node 10a and the second NF node 30 may be deployed in independent deployment units. Thus, a first SCP node 10a based on independent deployment units is possible, as described in 3GPP TS 23.501 V16.4.0. In other examples, the first SCP node 10a may be deployed as a distributed network element. For example, in some examples, part (e.g. a service agent) of the first SCP node 10a may be deployed in the same deployment unit as the first NF node 20. Thus, a first SCP node 10a based on service mesh is possible, as described in 3GPP TS 23.501 V16.4.0.

In some examples, the second SCP node 10b and the first NF node 20 may be deployed in independent deployment units, and/or the second SCP node 10b and the second NF node 30 may be deployed in independent deployment units. Thus, a second SCP node 10b based on independent deployment units is possible, as described in 3GPP TS 23.501 V16.4.0. In other examples, the second SCP node 10b may be deployed as a distributed network element. For example, in some examples, part (e.g. a service agent) of the second SCP node 10b may be deployed in the same deployment unit as the second NF node 30. Thus, a second SCP node 10b based on service mesh is possible, as described in 3GPP TS 23.501 V16.4.0.

In some examples, at least one third SCP node may be configured to operate as an SCP between the first SCP node 10a and the first NF node 20. Thus, a multipath of SCP nodes is possible.

Steps 600-614 of Figure 5A-B are as described earlier with reference to Figure 2. The subsequent method from step 700 onwards is a method that is performed in response to a request for a second NF node 30 to execute a service 40 requested by a service consumer. Where the method of Figure 5A-B is described as being performed by the first SCP node 10, it will be understood that the method can equally apply to the first NF node 20 and thus all references to “the first SCP node 10a” are interchangeable with “the first NF node 20”. In the example where the method is performed by the first SCP node 10a, the method from step 700 onwards is performed in response to receiving a request (as illustrated by arrow 600) transmitted towards the second NF node 30 via the first SCP node 10a, where the request is for the second NF node 30 to execute a service 40 requested by the first NF node 20.

As illustrated by arrow 700 of Figure 5A-B, the first SCP node 10 identifies (or selects) a second SCP node 10a, 10b from which the second NF node 30 is reachable. That is, the first SPC node 10a identifies that it can use the second SCP node 10b to reach the second NF node 30. In some examples, the identified second SCP node may be the first SCP node 10a. In other examples, the identified second SCP node may be a different SCP node 10b to the first SCP node 10a.

The present disclosure is directed to the introduction of group identifications. That is, an SCP profile may comprises a group identification, wherein each group identification is associated with at least one, pragmatically a plurality of, NF producer instance that is directly reachable by the corresponding SCP.

The above entails that a groupID or range of addresses or something like that may be defined that may be comprised by the SCP profile. The groupID may then be used for determining whether a particular SCP is able to reach the intended NF producer instance.

The second SCP node 10a, 10b is identified (or selected) from information on one or more SCP nodes. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. In some examples, for at least one of the one or more SCP nodes, the information may be indicative of which one or more NF nodes of the network are reachable from that SCP node. In some examples, the information may be on the second SCP node 10a, 10b. In these examples, the information may be indicative that the second NF node 30 is reachable by the second SCP node 10a, 10b. In some examples, the information may be on a plurality of SCP nodes, where the plurality of SCP nodes comprises the second SCP node 10a, 10b. In these examples, the information may be indicative that the second NF node 30 is reachable by the second SCP node 10a, 10b.

The information on the one or more SCP nodes may also be referred to as a routing path to one or more NF nodes of the network. A routing path can comprise one or multiple steps/hops. For example, the routing path for the second NF node 30 may comprise the first SCP node 10a and the second SCP node 10b. A routing path may be expressed in SCP domains, where each SCP domain may comprise one or more SCPs. In some examples, the information on each of the one or more SCP nodes may comprise one or more unique identifiers, where each unique identifier may uniquely identify one of the one or more NF nodes of the network that are reachable from that SCP node. In some examples, the information on the one or more SCP nodes may be indicative of which one or more NF nodes of the network are directly reachable from which of the one or more SCP nodes and/or which one or more NF nodes of the network are indirectly reachable from which of the one or more SCP nodes. An NF node of the network may be indirectly reachable from an SCP node, for example, where the NF node is reachable from the SCP node via one or more other SCP nodes. In some examples, the second NF node 30 may be directly reachable from the second SCP node 10a, 10b. In other examples, the second NF node 30 may be indirectly reachable from the second SCP node 10a, 10b.

Although not illustrated in Figure 5A-B, in same examples, the first SCP node 10a may identify, from the information on one or more SCP nodes, at least one third SCP node from which the identified second SCP node 10a, 10b is reachable. In these examples, the information can be indicative of which one or more SCP nodes of the network are reachable from which of the one or more SCP nodes. In some of these examples, for at least one of the one or more SCP nodes, the information may be indicative of which one or more SCP nodes of the network are reachable from that SCP node. In some examples, the information on each of the one or more SCP nodes may comprise one or more unique identifiers, where each unique identifier uniquely identifies one of the one or more SCP nodes of the network that are reachable from that SCP node. For example, each such unique identifier may be one of: a routing indicator, an internal group identifier, an external group identifier, a subscriber permanent identifier (SUPI), a generic public subscription identifier (GPSI), an internet protocol multimedia private identifier (IMPI), an internet protocol multimedia public identifier (IMPU), or any other unique identifier.

In some examples, the network may be partitioned. In a partitioned network, each partition can be regionalised or divided owing to a specific SCP. Generally, an expected added value of an SCP is to be able to aggregate traffic, regionalise and/or provide security features, as well as acting as a routing entity. In examples where the network is partitioned, such as that illustrated in Figure 5A-B, a partition 400 in the network may comprise the second NF node 30, or the second NF node 30 and one or more other NF nodes 70 of the service producer. In some of these examples, the information on one or more SCP nodes may be indicative of at least one type of NF node (“NFtype”) or NF node instance comprised within the partition 400. In some examples, one or more NF nodes 30, 70 of the partition 400 may be the same type of NF node. In some examples, one or more NF nodes 30, 70 of the partition 400 may be instances of the same type of NF node. Examples of the type of NF node include, but are not limited to, a unified data management (UDM) node, an access and mobility management function (AMF) node, a session management function (SMF) node, an authentication server function (AUSF) node, a unified data repository (UDR) node, a policy control function (PCF) node, a home subscriber server (HSS) node, or any other type of NF node. For each type of NF node, there may be one or more instances of that type of NF node. Thus, for example, in a group of NF nodes, there may be one or more instances of the same type of NF node and/or one or more types of NF node. In some examples, a routing indicator may identify one or more types of NF node (or NF node instance). The type may be the type that is able to manage or access a particular subscriber for which the service is requested. Thus, in some examples, the routing indicator may identify one or more types of NF node (or NF node instance) that are in the partition 400 that holds a particular SUPI.

In some examples, multiple services and/or service instances may be executable by each type of NF node. For example, each type of NF node may have (or may define) multiple services and/or service instances. For the same type of NF node, there may be different service names defined. In some examples, for each instance of NF node, there may be one or multiple service instances, even of each service type. For example, UDM instance 1, with service DM and UECM, and with n and m instances of each in the same UDM instance 1.

In some examples, each NF node 30, 70 of the partition 400 may be reachable from the identified second SCP node 10a, 10b. In some examples, each NF node of the partition 400 may be capable of executing the service 40 requested. In some examples, data required to execute the service 40 requested is reachable by each NF node of the partition 400. This data can, for example, be subscriber (or user) data and/or any other type of data. In some of these examples, the information on one or more SCP nodes may comprise a unique identifier of the data. Examples of the unique identifier of the data comprise, but are not limited to, a subscription permanent identifier (SUPI), a generic public subscription identifier (GPSI), an internet protocol multimedia private identifier (IMPI), an internet protocol multimedia public identifier (IMPU), or any other unique identifier. In some examples, the unique identifier of the data may be a subscription concealed identifier (SUCI). In these examples, the SUCI can comprise an encrypted SUPI and may also comprise a routing indicator, which may identify one or more types of NF node (or NF node instance) as mentioned earlier.

In some examples, the information may comprise a unique identifier that uniquely identifies the partition 400 (e.g. “Groupld”). If the unique identifier that uniquely identifies the partition 400 is not provided, it may be found with the rest of the information related to the partition 400 (e.g. the NFType and the unique identifier of the data). For example, it may be identified that for UDM, SUPI3 is in Partition 8. In some examples, the information may comprise a unique identifier (e.g. a name) of one or more services 40, 80 that are executable by the one or more NF nodes of the network. This can be useful, for example, where the partitioning of the network is per service. In the example illustrated in Figure 5A-B, the GroupX for NFp (which may be for the mentioned NFs that support partitioning, e.g. UDR, UDM, HSS, AUSF, PCF, etc.) may be accessed by the second SCP domain 404.

In some examples, the information on the one or more SCP nodes referred to herein may comprise any one or more of the following:

• Routing Indicator, for UDM and AUSF.

• UDM Group ID or range(s) of SUPIs or range(s) of GPSIs or range(s) of internal group identifiers, or range(s) of external group identifiers for UDM.

• UDR Group ID or range(s) of SUPIs or range(s) of GPSIs or range(s) of external group identifiers for UDR.

• AUSF Group ID or range(s) of SUPIs for AUSF.

• PCF Group ID or range(s) of SUPIs for PCF.

• HSS Group ID or set(s) of IMPIs or set(s) of IMPU for HSS. In some examples, the information on the one or more SCP nodes referred to herein may be stored at (or configured in) the first SCP node 10a, at the NRF 60, and/or at one or more other nodes (e.g. one or more other SCP nodes, one or more other central repositories, and/or any other one or more nodes). In some examples, the information may be distributed among multiple nodes, e.g. among multiple SCPs. In some examples, the first SCP node 10 may initiate transmission of a request for the information towards the one or more other nodes and/or the NRF 60. For example, this request may be included in the request illustrated by arrow 612 of Figure 5A-B. In some examples, request for the information may comprise information indicative of the second NF node 30 (i.e. on the destination to be reached). In some examples, the first SCP node 10 may receive the information from the one or more other nodes and/or the NRF 60. For example, the information may be received in the response illustrated by arrow 614 of Figure 5A-B.

The information on one or more SCP nodes referred to herein may be in any format. In some examples, for at least one of the one or more SCP nodes, an SCP profile of that SCP node may comprise the information. In addition to the information, an SCP profile of an SCP node may comprise one or more (e.g. a list) of attributes associated with the SCP node, such as a unique identifier of the SCP node (“SCPid”), a unique identifier of a group of NF nodes that the SCP node can reach (“Groupld”), etc. In some examples, the first SCP node 10a may process one or multiple (or even all) SCP profiles or the information in any other format to identify the next step/hop (e.g. the next SCP node or the next SCP domain) that it needs to reach. In other examples, the first SCP node 10a may be provided with the next step/hop that it needs to reach by way of the information (e.g. an address of the next SCP node may be comprised within the information), such that it can use this information directly to reach the next SCP node.

In the illustration, the next SCP node is the second SCP 10b. As illustrated by arrows 702 and 706 of Figure 5A-B, the first SCP node 10a initiates transmission of the request from the identified second SCP node 10b to the second NF node 30. For example, as illustrated by arrow 702 of Figure 5A-B, the first SCP node 10a initiates transmission of the request towards the identified second SCP node 10b and, as illustrated by arrow 706 of Figure 5A-B, the identified second SCP node 10b in the second domain initiates transmission of the request towards the second NF node 30. Thus, the identified second SCP node 10b prepares the request to reach the final destination. The first SCP node 10a is able to forward the request to the identified second SCP node 10b in the second domain and the identified second SCP node 10b can reach the second NF node 30 that can provide the service (e.g. for a corresponding partition, e.g. subscriber partition). As illustrated by block 704, in some examples, the identified second SCP node 10b may replace the SCP address in the host part of the uniform resource identifier (URI) by the one included in service request (the target API root).

As illustrated by arrow 708 of Figure 5A-B, the identified second SCP node 10b may receive a response to the request from the second NF node 30. As illustrated by arrow 710 of Figure 5A-B, the identified second SCP node 10b may initiate transmission of this response towards the first SCP node 10a. The response is thus forwarded to the first SCP node 10a in the first domain. Thus, the first SCP node 10a can receive a response to the request from the second NF node 30. As illustrated by arrow 712 of Figure 5A-B, in some examples, the first SCP node 10a may initiate transmission of the response to the first NF node 20. Thus, the response can reach the consumer. In some examples, as illustrated by block 714 of Figure 5A-B, the first NF node 20 may store the response. The response may comprise some business logic (BL) information, e.g. as a result of the service execution. The response may be stored with user equipment (UE)/session context.

Figure 6 is a block diagram illustrating a first SCP node (or a first NF node) 800 in accordance with an example. The first SCP node (or a first NF node) 800 can handle a service request in a network. The first SCP node 800 can operate as an SCP between NF nodes of the network. The first SCP node (or a first NF node) 800 operates in response to a request for a second NF node to execute a service requested by a service consumer. The first SCP node (or first NF node) 800 comprises an identifying module 802 configured to identify, from information on one or more SCP nodes, a second SCP node from which the second NF node is reachable. The information is indicative of which one or more NF nodes of the network are reachable from which of the one or more SCP nodes. The first SCP node (or first NF node) 800 comprises a transmission initiating module 804 configured to initiate transmission of the request from the identified second SCP node to the second NF node. The first SCP node (or first NF node) 800 may operate in the manner described herein in respect of the first SCP node.

There is also provided a computer program comprising instructions which, when executed by processing circuitry (such as the processing circuitry 12a of the first SCP node 10a or first NF node 20 described earlier), cause the processing circuitry to perform at least part of the method described herein. There is provided a computer program product, embodied on a non-transitory machine-readable medium, comprising instructions which are executable by processing circuitry (such as the processing circuitry 12a of the first SCP node 10a or first NF node 20 described earlier) to cause the processing circuitry to perform at least part of the method described herein. There is provided a computer program product comprising a carrier containing instructions for causing processing circuitry (such as the processing circuitry 12a of the first SCP node 10a or first NF node 20 described earlier) to perform at least part of the method described herein. In some examples, the carrier can be any one of an electronic signal, an optical signal, an electromagnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable storage medium.

In some examples, the first SCP node functionality and/or the first NF node functionality described herein can be performed by hardware. Thus, in some examples, any one or more of the first SCP node 10a and the first NF node 20 described herein can be a hardware node. However, it will also be understood that optionally at least part or all of the first SCP node functionality and/or the first NF node functionality described herein can be virtualized. For example, the functions performed by any one or more of the first SCP node 10a and the first NF node 20 described herein can be implemented in software running on generic hardware that is configured to orchestrate the node functionality. Thus, in some examples, any one or more of the first SCP node 10a and the first NF node 20 described herein can be a virtual node. In some examples, at least part or all of the first SCP node functionality and/or the first NF node functionality described herein may be performed in a network enabled cloud. The first SCP node functionality and/or the first NF node functionality described herein may all be at the same location or at least some of the node functionality may be distributed. It will be understood that at least some or all of the method steps described herein can be automated in some examples. That is, in some examples, at least some or all of the method steps described herein can be performed automatically.

Thus, in the manner described herein, there is advantageously provided an improved technique for handling service requests in a network. Based on the information on the one or more SCP nodes, the first NF node 20 and/or the first SCP node can find one or more SCPs that can reach a particular NF of the service producer (e.g. in a certain GroupX). Moreover, the correct SCP domain can be found in order to reach the particular NF of the service producer. The technique described herein provides the means to allow a first SCP domain 402 (or a first SCP node 10a of the first SCP domain 402), or even the first NF node 20 (e.g. in the case of a direct connection from the first NF node 20 to the second SCP domain 404, or the second SCP node 10b of the second SCP domain 404), to determine which is the domain (or which is the SCP node in the domain) that can reach the desired NF of the service producer (e.g. in a certain GroupX).

It should be noted that the above-mentioned examples illustrate rather than limit the idea, and that those skilled in the art will be able to design many alternative examples without departing from the scope of the appended claims. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim, “a” or “an” does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims. Any reference signs in the claims shall not be construed so as to limit their scope.

Claims

1. A method for handling a request for a service in a telecommunication network, wherein the network is deployed in multiple Service Communication Proxy, SCP, domains, wherein each SCP domain is a group of one or more SCPs that can directly reach a certain group of NF producers, the method comprising the steps of:

2. A method in accordance with claim 1, wherein each of said SCP profiles comprises a group identification, wherein each group identification is associated with at least one NF producer instance that is directly reachable by said corresponding SCP.

3. A method in accordance with any of the previous claims, wherein said step of retrieving comprises any of:

- retrieving, by said SCP in said first SCP domain, said SCP profiles from a Network Repository Function, NRF, in said telecommunication network;

- retrieving, by said SCP in said first SCP domain, said SCP profiles stored on said SCP in said first SCP domain.

4. A method in accordance with claim 2, wherein said group identification is any of: routing Indicator;

Unified Data Management, UDM, Group ID or range(s) of SUPIs or range(s) of Generic Public Subscription Identifiers ,GPSIs, or range(s) of internal group identifiers, or range(s) of external group identifiers for UDM; Unified Data Repository, UDR, Group ID or range(s) of Subscription Permanent Identifiers, SUPIs, or range(s) of GPSIs, or range(s) of external group identifiers for UDR.

Authentication Server Function, AUSF, Group ID or range(s) of SUPIs for

AUSF;

IMPU for HSS.

5. A method in accordance with any of the previous claims, wherein said NF producer instance is comprised by any of: a unified data management, UDM, node; an access and mobility management function, AMF, node; a session management function, SMF, node; an authentication server function, AUSF, node; a unified data repository, UDR, node; a policy control function, PCF, node; or a home subscriber server, HSS, node.

6. A method in accordance with any of the previous claims, wherein said method further comprises the step of:

- receiving, by said SCP in said first SCP domain, said request for a service.

7. A Service Communication Proxy, SCP, in a first SCP domain that is arranged for handling a request for a service in a telecommunication network, wherein the network is deployed in multiple Service Communication Proxy, SCP, domains, wherein each SCP domain is a group of one or more SCPs that can directly reach a certain group of NF producers, the first SCP comprising:

- retrieve equipment arranged for retrieving SCP profiles of SCPs that are able to reach said NF producer instance, wherein each of said SCP profiles comprises address information of a plurality of NF producer instances that are directly reachable by said corresponding SCP; - process equipment arranged for selecting, based on said received SCP profiles and based on said selected NF producer instance, an SCP in said second SCP domain that is able to directly reach said NF producer instance;

8. An SCP in accordance with claim 7, wherein each of said SCP profiles comprises a group identification, wherein each group identification is associated with at least one NF producer instance that is directly reachable by said corresponding SCP.

9. An SCP in accordance with any of the claims 7 - 8, wherein said retrieve equipment is further arranged for any of:

- retrieving said SCP profiles stored on said SCP in said first SCP domain.

10. An SCP in accordance with any of the claim 8, wherein said group identification is any of: routing Indicator;

Authentication Server Function, AUSF, Group ID or range(s) of SUPIs for

AUSF;

IMPU for HSS.

11. An SCP in accordance with any of the claims 7 - 10, wherein said NF producer instance is comprised by any of: a unified data management, UDM, node; an access and mobility management function, AMF, node; a session management function, SMF, node; an authentication server function, AUSF, node; a unified data repository, UDR, node; a policy control function, PCF, node; or a home subscriber server, HSS, node.

12. An SCP in accordance with any of the claims 7 - 11, wherein said SCP further comprises:

- receive equipment arranged for receiving said request for a service.

13. A computer program comprising instructions which, when executed by processing circuitry, cause the processing circuitry to perform the method according to any of claims 1 - 6.

14. A computer program product, embodied on a non-transitory machine- readable medium, comprising instructions which are executable by processing circuitry to cause the processing circuitry to perform the method according to any of claims 1 to 6.