Patent Description:
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.

<FIG>illustrates different existing systems for handling service requests, as set out in 3GPP TS <NUM> v16. In more detail, <FIG> illustrates a system that uses direct communication, while <FIG> illustrates a system that uses indirect communication.

In the systems illustrated in <FIG>, 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 <FIG> also comprises a network repository function (NRF). Thus, in the system illustrated in <FIG>, 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 <FIG>, 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 <FIG>, 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 <FIG> also comprise an NRF.

In the system illustrated in <FIG>, 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 <FIG>, 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 <NUM>, 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 <FIG>.

<FIG>is a signalling diagram illustrating an exchange of signals in an existing system, such as the system illustrated in <FIG> but it will be understood the issue described can also apply to the system illustrated in <FIG>. The system illustrated in <FIG> comprises a first SCP node <NUM>, a first NF node <NUM> of a service consumer ("NFc"), a second NF node <NUM> of a service producer ("NFp1"), and a third NF node <NUM> of a service producer ("NFp2"). The first SCP node <NUM> is configured to operate as an SCP between the first NF node <NUM> and the second NF node <NUM>. The second NF node <NUM> can be configured to run a service <NUM> and the third NF node <NUM> can be configured to run a service <NUM>. The second NF node <NUM> and the third NF node <NUM> can be configured to run the same service or a different service. The second NF node <NUM> and the third NF node <NUM> can be part of a set <NUM> of NF nodes of a service producer. The system illustrated in <FIG> also comprises a network repository function <NUM>.

In <FIG>, steps <NUM>-<NUM> relate to a first request for a user equipment (UE)/session context. As illustrated by block <NUM> of <FIG>, the UE/session context may be stored. In more detail, as illustrated by block <NUM> of <FIG>, the first NF node <NUM> determines what discovery and selection parameters to use. The parameters can be associated with a certain service in a received request, which is not illustrated in <FIG>. As illustrated by blocks <NUM> and <NUM> of <FIG>, the first NF node <NUM> stores the UE/session context for the request received. This storage may be cached or externally stored.

As illustrated by arrow <NUM> of <FIG>, the first NF node <NUM> initiates transmission of a discovery request to the NRF <NUM> 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 <NUM> of <FIG>, the first NF node <NUM> receives a response from the NRF <NUM> comprising the NF profile(s) of one or more NF nodes of the service producer. As illustrated by blocks <NUM> and <NUM> of <FIG>, the first NF node <NUM> can store the discovered NF profile(s) in the corresponding UE/session context. As illustrated by block <NUM> of <FIG>, the first NF node <NUM> selects 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 NF node <NUM> selects the second NF node <NUM>.

As illustrated by arrow <NUM> of <FIG>, the first NF node <NUM> initiates transmission of a service request towards the first SCP node <NUM>. The first NF node <NUM> may know via which SCP to route the service request by configuration or other means. The service request can comprise information identifying the selected second NF node <NUM>, such as a hypertext transfer protocol (HTTP) header that identifies the selected second NF node <NUM> (the target application programming interface (API) root). As illustrated by block <NUM> of <FIG>, the first SCP node <NUM> replaces its own 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 block <NUM> of <FIG>, the first SCP node <NUM> may perform any extra functionality, such as monitoring/tracing.

As illustrated by arrow <NUM> of <FIG>, the first SCP node <NUM> initiates transmission of the service request towards the selected second NF node <NUM>. As illustrated by arrow <NUM> of <FIG>, the first SCP node <NUM> receives a response comprising the result. The result may comprise some business logic (BL) information, e.g. as a result of the service execution. As illustrated by arrow <NUM> of <FIG>, the first SCP node <NUM> initiates transmission of the response comprising the result towards the first NF node <NUM>. As illustrated by blocks <NUM> and <NUM> of <FIG>, the first NF node <NUM> can store the result.

In <FIG>, steps <NUM>-<NUM> relate to subsequent service requests for an existing UE/Session context. As illustrated by block <NUM> of <FIG>, another request (not illustrated) to execute a service is received by the first NF node <NUM> and this service request is identified to correspond to the same UE/session context in respect of which the earlier request was received. As illustrated by block <NUM> of <FIG>, the process is repeated from block <NUM> onwards. In <FIG>, steps <NUM>-<NUM> relate to subsequent service requests for an existing UE/Session context where reselection is required, where step <NUM> is the same as step <NUM> and steps <NUM>-<NUM> are the same as steps <NUM>-<NUM>. However, as illustrated by arrow <NUM> of <FIG>, there is a lack of response from the second NF node <NUM>.

As illustrated by arrow <NUM> of <FIG>, if no response is received by the first SCP node <NUM>, the first SCP node <NUM> initiates transmission of a response to the first NF node <NUM>. The response comprises information (e.g. an existing HTTP error, such as a <NUM> error) indicative that there is an error situation. As illustrated by block <NUM> of <FIG>, the first NF node <NUM> needs to interpret what to do based on the error received. As illustrated by block <NUM> of <FIG>, based on a <NUM> error, a normal behaviour is for the first NF node <NUM> to perform a reselection. That is, the first NF node <NUM> selects another NF node of the service producer, since it seems that the second NF node <NUM> is not reachable. For the purpose of the illustration, it is assumed that the first NF node <NUM> selects the third NF node <NUM>. In <FIG>, steps <NUM>-<NUM> are the same as steps <NUM>-<NUM> but in relation to the third NF node <NUM>.

As illustrated by arrow <NUM> of <FIG>, there is also a lack of response from the third NF node <NUM>. This may be the case where there is a connectivity error either in general or in the connection towards the specific NF node. As illustrated by arrow <NUM> of <FIG>, if no response is received by the first SCP node <NUM>, the first SCP node <NUM> initiates transmission of a response to the first NF node <NUM>. The response comprises information (e.g. an existing HTTP error, such as a <NUM> error) indicative that there is an error situation. As illustrated by block <NUM> of <FIG>, if alternative NF nodes of the service producer are available, another selection may be performed (that, is steps <NUM> onwards may be repeated) with a similar unsuccessful result. As also illustrated by block <NUM> of <FIG>, if there are no more alternative NF nodes of the service producer available, the service request is rejected.

Thus, even though NF nodes (e.g. the second NF node <NUM> and/or third NF node <NUM>) of the service producer may be available and operational (e.g. up and running), the procedure can still fail. For example, all request via the same SCP node will fail if the SCP node has connectivity issues, which can be a large amount of requests, perhaps even all the requests from the first NF node <NUM>. A redundant SCP deployment will be common in most cases.

It is an object of the disclosure to obviate or eliminate at least some of the above-described disadvantages associated with existing techniques. The scope of protection of the present invention is defined by the appended claims. The following are presented as examples that assist in understanding the invention.

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 service communication proxy (SCP) node that is configured to operate as an SCP between a first network function (NF) node of a service consumer and a second NF node of a service producer in the network. The method comprises initiating transmission of information towards the first NF node if no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node. The first request is for the second NF node to execute a service requested by the first NF node. The information is indicative that no response is received from the second NF node to the first request.

The information is accompanied by an existing HTTP status code and the existing HTTP status code is a <NUM> Gateway Timeout.

In some embodiments, the information may be indicative of whether the second NF node is operative.

In some embodiments, the information may be indicative of whether the first SCP node failed to connect to the second NF node.

According to another aspect of the disclosure, there is provided a first SCP node comprising processing circuitry configured to operate in accordance with the method described earlier in respect of the first SPC node. In some embodiments, the first SCP node may comprise at least one memory for storing instructions which, when executed by the processing circuitry, cause the first SCP node to operate in accordance with the method described earlier in respect of the first SPC node.

According to another 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 of a service consumer. A first service communication proxy (SCP) node is configured to operate as an SCP between the first NF node and a second NF node of a service producer in the network. The method comprises initiating transmission of a second request towards the second NF node via a second SCP node in response to receiving information indicative that no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node. The first request is for the second NF node to execute a service for the first NF node. The second request is for the second NF node to execute the service for the first NF node.

The second SCP node is configured to operate as an SCP between the first NF node and the second NF node in the network. The second SCP node is a different SCP node to the first SCP node.

In some embodiments, the second SCP node may be an SCP node that is in the same SCP domain as the first SCP node and transmission of the second request towards the second NF node via the second SCP node may be initiated if the second NF node is operative.

In some embodiments, the method may comprise checking whether the second NF node is operative.

In some embodiments, checking whether the second NF node is operative may comprise checking a status of the second NF node to identify whether the second NF node is operative.

In some embodiments, the status may be checked with the second NF node or a network repository function (NRF).

In some embodiments, checking the status with the second NF node may comprise initiating transmission of a third request towards the second NF node, wherein the third request may be a request for the status of the second NF node.

In some embodiments, transmission of the second request towards the second NF node via the second SCP node may be initiated if no response to the first request is received from the second NF node due to the first SCP node failing to connect to the second NF node.

In some embodiments, the method may comprise checking whether the first SCP node failed to connect to the second NF node.

In some embodiments, the first SCP node failing to connect to the second NF node may be the first SCP node itself failing to connect to the second NF node or at least one fourth SCP node failing to connect to the second NF node, wherein the at least one fourth SCP node may be configured to operate as an SCP between the first SCP node and the second NF node.

In some embodiments, checking whether the at least one fourth SCP node failed to connect to the second NF node may comprise checking a status of the at least one fourth SCP node to identify whether the at least one fourth SCP node failed to connect to the second NF node.

In some embodiments, the status may be checked with the at least one fourth SCP node or a network repository function (NRF).

In some embodiments, checking the status with the at least one fourth SCP node may comprise initiating transmission of a fourth request towards the at least one fourth SCP node, wherein the fourth request may be a request for the status of the at least one fourth SCP node.

According to another aspect of the disclosure, there is provided a first NF node comprising processing circuitry configured to operate in accordance with the method described earlier in respect of the first NF node. In some embodiments, the first NF node may comprise at least one memory for storing instructions which, when executed by the processing circuitry, cause the first NF node to operate in accordance with the method described earlier in respect of the first NF node.

According to another aspect of the disclosure, there is provided a method performed by a system. The method may comprise the method described earlier in respect of the first SCP node and/or the method as described earlier in respect of the first NF node. According to another aspect of the disclosure, there is provided a system. The system may comprise at least one first SCP node as described earlier and/or at least one first NF node as described earlier.

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

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:.

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 (e.g. a notification service or a callback 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 or telecommunications network, e.g. cellular network. The network may be a fifth generation (<NUM>) network or any other generation network. In some embodiments, the network may be a core network or a radio access network (RAN). The techniques described herein are implemented by a first service communication proxy (SCP) node and a first network function (NF) node.

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.

<FIG> illustrates a first SCP node <NUM> in accordance with an embodiment. The first SCP node <NUM> is for handling a service request in a network. The first SCP node <NUM> is configured to operate as an SCP between a first network function, NF, node (<NUM>) of a service consumer and a second NF node (<NUM>) of a service producer in the network. In some embodiments, the first SCP node <NUM> can be, for example, be a physical machine (e.g. a server) or a virtual machine (VM).

As illustrated in <FIG>, the first SCP node <NUM> comprises processing circuitry (or logic) <NUM>. The processing circuitry <NUM> controls the operation of the first SCP node <NUM> and can implement the method described herein in respect of the first SCP node <NUM>. The processing circuitry <NUM> can be configured or programmed to control the first SCP node <NUM> in the manner described herein. The processing circuitry <NUM> 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 <NUM>. In some embodiments, the processing circuitry <NUM> can be configured to run software to perform the method described herein in respect of the first SCP node <NUM>. The software may be containerised according to some embodiments. Thus, in some embodiments, the processing circuitry <NUM> may be configured to run a container to perform the method described herein in respect of the first SCP node <NUM>.

Briefly, the processing circuitry <NUM> of the first SCP node <NUM> is configured to, if no response is received from a second NF node of a service producer to a first request, initiate transmission of information towards a first NF node of a service consumer. The first request is transmitted towards the second NF node via the first SCP node <NUM> and is for the second NF node to execute (or provide) a service requested by the first NF node. The information is indicative that no response is received from the second NF node to the first request.

As illustrated in <FIG>, in some embodiments, the first SCP node <NUM> may optionally comprise a memory <NUM>. The memory <NUM> of the first SCP node <NUM> can comprise a volatile memory or a non-volatile memory. In some embodiments, the memory <NUM> of the first SCP node <NUM> may comprise a non-transitory media. Examples of the memory <NUM> of the first SCP node <NUM> 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 <NUM> of the first SCP node <NUM> can be connected to the memory <NUM> of the first SCP node <NUM>. In some embodiments, the memory <NUM> of the first SCP node <NUM> may be for storing program code or instructions which, when executed by the processing circuitry <NUM> of the first SCP node <NUM>, cause the first SCP node <NUM> to operate in the manner described herein in respect of the first SCP node <NUM>. For example, in some embodiments, the memory <NUM> of the first SCP node <NUM> may be configured to store program code or instructions that can be executed by the processing circuitry <NUM> of the first SCP node <NUM> to cause the first SCP node <NUM> to operate in accordance with the method described herein in respect of the first SCP node <NUM>. Alternatively or in addition, the memory <NUM> of the first SCP node <NUM> can be configured to store any information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. The processing circuitry <NUM> of the first SCP node <NUM> may be configured to control the memory <NUM> of the first SCP node <NUM> to store information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein.

In some embodiments, as illustrated in <FIG>, the first SCP node <NUM> may optionally comprise a communications interface <NUM>. The communications interface <NUM> of the first SCP node <NUM> can be connected to the processing circuitry <NUM> of the first SCP node <NUM> and/or the memory <NUM> of first SCP node <NUM>. The communications interface <NUM> of the first SCP node <NUM> may be operable to allow the processing circuitry <NUM> of the first SCP node <NUM> to communicate with the memory <NUM> of the first SCP node <NUM> and/or vice versa. Similarly, the communications interface <NUM> of the first SCP node <NUM> may be operable to allow the processing circuitry <NUM> of the first SCP node <NUM> to communicate with the first NF node and/or any other node. The communications interface <NUM> of the first SCP node <NUM> can be configured to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. In some embodiments, the processing circuitry <NUM> of the first SCP node <NUM> may be configured to control the communications interface <NUM> of the first SCP node <NUM> to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein.

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

<FIG> is a flowchart illustrating a method performed by a first SCP node <NUM> in accordance with an embodiment. The first SCP node <NUM> is configured to operate as an SCP between a first NF node of a service consumer and a second NF node of a service producer in the network. The method is for handling a service request in the network. The first SCP node <NUM> described earlier with referenced to <FIG> is configured to operate in accordance with the method of <FIG>. The method can be performed by or under the control of the processing circuitry <NUM> of the first SCP node <NUM>.

The method of <FIG> is performed if no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node <NUM>. The first request is for the second NF node to execute (or provide) a service requested by the first NF node. As illustrated at block <NUM> of <FIG>, transmission of information is initiated towards the first NF node. The information is indicative that no response is received from the second NF node to the first request.

Herein, the term "initiate" can mean, for example, cause or establish. Thus, the processing circuitry <NUM> of the first SCP node <NUM> can be configured to itself transmit the information (e.g. via a communications interface <NUM> of the first SCP node <NUM>) or can be configured to cause another node to transmit the information. In some embodiments, the first request can be a hypertext transfer protocol (HTTP) request.

<FIG> illustrates a first NF node <NUM> in accordance with an embodiment. The first NF node <NUM> is for handling a service request in a network. The first NF node <NUM> is configured to operate as an SCP between a first NF node of a service consumer and a second NF node of a service producer in the network. In some embodiments, the first NF node <NUM> can be, for example, be a physical machine (e.g. a server) or a virtual machine (VM). The first NF node <NUM> can be, for example, a user equipment (UE).

As illustrated in <FIG>, the first NF node <NUM> comprises processing circuitry (or logic) <NUM>. The processing circuitry <NUM> controls the operation of the first NF node <NUM> and can implement the method described herein in respect of the first NF node <NUM>. The processing circuitry <NUM> can be configured or programmed to control the first NF node <NUM> in the manner described herein. The processing circuitry <NUM> 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 NF node <NUM>. In some embodiments, the processing circuitry <NUM> can be configured to run software to perform the method described herein in respect of the first NF node <NUM>. The software may be containerised according to some embodiments. Thus, in some embodiments, the processing circuitry <NUM> may be configured to run a container to perform the method described herein in respect of the first NF node <NUM>.

Briefly, the processing circuitry <NUM> of the first NF node <NUM> is configured to, in response to receiving information indicative that no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node, initiate transmission of a second request towards the second NF node via a second SCP node. The first request is for the second NF node to execute (or provide) a service requested by the first NF node. The second request is also for the second NF node to execute (or provide) the service for the first NF node. The second SCP node is configured to operate as an SCP between the first NF node and the second NF node in the network. The second SCP node is a different SCP node to the first SCP node <NUM>.

As illustrated in <FIG>, in some embodiments, the first NF node <NUM> may optionally comprise a memory <NUM>. The memory <NUM> of the first NF node <NUM> can comprise a volatile memory or a non-volatile memory. In some embodiments, the memory <NUM> of the first NF node <NUM> may comprise a non-transitory media. Examples of the memory <NUM> of the first NF node <NUM> 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 <NUM> of the first NF node <NUM> can be connected to the memory <NUM> of the first NF node <NUM>. In some embodiments, the memory <NUM> of the first NF node <NUM> may be for storing program code or instructions which, when executed by the processing circuitry <NUM> of the first NF node <NUM>, cause the first NF node <NUM> to operate in the manner described herein in respect of the first NF node <NUM>. For example, in some embodiments, the memory <NUM> of the first NF node <NUM> may be configured to store program code or instructions that can be executed by the processing circuitry <NUM> of the first NF node <NUM> to cause the first NF node <NUM> to operate in accordance with the method described herein in respect of the first NF node <NUM>. Alternatively or in addition, the memory <NUM> of the first NF node <NUM> can be configured to store any information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. The processing circuitry <NUM> of the first NF node <NUM> may be configured to control the memory <NUM> of the first NF node <NUM> to store information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein.

In some embodiments, as illustrated in <FIG>, the first NF node <NUM> may optionally comprise a communications interface <NUM>. The communications interface <NUM> of the first NF node <NUM> can be connected to the processing circuitry <NUM> of the first NF node <NUM> and/or the memory <NUM> of first NF node <NUM>. The communications interface <NUM> of the first NF node <NUM> may be operable to allow the processing circuitry <NUM> of the first NF node <NUM> to communicate with the memory <NUM> of the first NF node <NUM> and/or vice versa. Similarly, the communications interface <NUM> of the first NF node <NUM> may be operable to allow the processing circuitry <NUM> of the first NF node <NUM> to communicate with the first SCP node <NUM> and/or any other node. The communications interface <NUM> of the first NF node <NUM> can be configured to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein. In some embodiments, the processing circuitry <NUM> of the first NF node <NUM> may be configured to control the communications interface <NUM> of the first NF node <NUM> to transmit and/or receive information, data, messages, requests, responses, indications, notifications, signals, or similar, that are described herein.

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

<FIG> is a flowchart illustrating a method performed by a first NF node <NUM> in accordance with an embodiment. The method of <FIG> is for handling a service request in the network. The first NF node <NUM> described earlier with referenced to <FIG> is configured to operate in accordance with the method of <FIG>. The method can be performed by or under the control of the processing circuitry <NUM> of the first NF node <NUM>. A first SCP node <NUM> is configured to operate as an SCP between the first NF node <NUM> and a second NF node of a service producer in the network,.

The method of <FIG> is performed in response to receiving information indicative that no response is received from the second NF node to a first request. The first request is transmitted towards the second NF node via the first SCP node <NUM> and is for the second NF node to execute (or provide) a service for the first NF node <NUM>. As illustrated at block <NUM> of <FIG>, transmission of a second request is initiated towards the second NF node via a second SCP node for the second NF node to execute (or provide) the service for the first NF node. The second SCP node is configured to operate as an SCP between the first NF node <NUM> and the second NF node in the network. The second SCP node is a different SCP node to the first SCP node <NUM>.

There is also provided a system. The system can comprise at least one first SCP node <NUM> as described herein and/or at least one first NF node <NUM> as described herein. The system may also comprise any one or more of the other nodes mentioned herein.

<FIG>is a signalling diagram illustrating an exchange of signals in a system according to an embodiment. The system illustrated in <FIG> comprises a first SCP node <NUM> and a second SCP node <NUM>. In the system illustrated in <FIG>, the second SCP node <NUM> is an SCP node that is in the same SCP domain <NUM> as the first SCP node <NUM>. The second SCP node <NUM> is a different SCP node to the first SCP node <NUM>. The first SCP node <NUM> can be as described earlier with reference to <FIG>. The second SCP node <NUM> can be as described earlier with reference to <FIG>.

The system illustrated in <FIG> comprises a first NF node <NUM> of a service consumer ("NFc"), a second NF node <NUM> of a service producer ("NFp1"), and a third NF node <NUM> of a service producer ("NFp2"). The first SCP node <NUM> is configured to operate as an SCP between the first NF node <NUM> and the second NF node <NUM>. The second SCP node <NUM> is configured to operate as an SCP between the first NF node <NUM> and the second NF node <NUM>. The second NF node <NUM> can be configured to run (or provide) a service <NUM>. The third NF node <NUM> can be configured to run (or provide) a service <NUM>. The second NF node <NUM> and the third NF node <NUM> can be configured to run (or provide) the same service or a different service. The second NF node <NUM> and the third NF node <NUM> can be part of a set (or group) <NUM> of NF nodes of a service producer. The system illustrated in <FIG> comprises a network repository function (NRF) <NUM>. In some embodiments, an entity may comprise the first SCP node <NUM> and the NRF <NUM>. That is, in some embodiments, the first SCP node <NUM> can be merged with the NRF <NUM> in a combined entity.

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

In some embodiments, at least one third SCP node may be configured to operate as an SCP between the first NF node <NUM> and the first SCP node <NUM> and/or at least one fourth SCP node may be configured to operate as an SCP between the first SCP node <NUM> and the second NF node <NUM>. Thus, a multipath of SCP nodes is possible. In some of these embodiments, the first SCP node <NUM> and one or both of the at least one third SCP node and the at least one fourth SCP node may be deployed in independent deployment units. In some embodiments, the at least one third SCP node and/or the at least one fourth SCP node may be deployed as distributed network elements.

Steps <NUM>-<NUM> and <NUM>-<NUM> of <FIG> are as described earlier with reference to <FIG>. As illustrated by arrow <NUM> of <FIG>, if no response is received from the second NF node <NUM> to the first request <NUM>, <NUM> transmitted towards the second NF node <NUM> via the first SCP node <NUM>, the first SCP node <NUM> initiates transmission of information towards the first NF node <NUM>. The information is indicative that no response is received from the second NF node <NUM> to the first request. That is, the information is indicative of a lack of response, which is a new error. In some embodiments, the information can be indicative of whether the second NF node <NUM> is operative and/or the information can be indicative of whether the first SCP node <NUM> failed to connect to the second NF node <NUM>. In some embodiments, the information can be a newly created HTTP status code or the information may be accompanied by an existing HTTP status code.

The existing HTTP status codes may already be interpreted in a particular way, e.g. <NUM> is interpreted as an SCP error, which implies that the first NF node <NUM> will consider the first SCP node to have failed completely and the first NF node <NUM> will thus always use the second SCP node instead. However, this may not be required because connections from the first SCP node to other NF nodes of the service producer may be operative (e.g. up and running) and the error may not have been identified. As such, a new 5xx may be defined, or an existing 5xx may be complemented with the new information to indicate that there is a connectivity failure, but that the second NF node <NUM> is operative (e.g. up and running). An example of an existing 5xx that may be used is <NUM> Gateway Timeout.

As illustrated by block <NUM> of <FIG>, the first NF node <NUM> can identify based on the information that there may be a connectivity failure. Thus, the information can be interpreted unambiguously as a connectivity failure. The first NF node <NUM> can identify that problem is not the second NF node <NUM> and that an SCP re-selection may solve the issue.

In some embodiments, the first NF node <NUM> may check whether the second NF node <NUM> is operative. In some embodiments, checking whether the second NF node <NUM> is operative may comprise checking a status of the second NF node <NUM> to identify whether the second NF node <NUM> is operative. For example, the status may be checked with the second NF node <NUM> or the NRF <NUM>. If the status is operative (e.g. up and running), then the first NF node <NUM> knows that the same second NF node <NUM> will be reachable if the first NF node <NUM> selects another SCP node. In the NRF, an "operative" status may be a "registered" status.

Although not illustrated in <FIG>, in some embodiments, checking the status with the second NF node <NUM> comprise initiating transmission of a third request towards the second NF node <NUM>. The third request is a request for the status of the second NF node <NUM>. In these embodiments, if a response to the third request is received from the second NF node <NUM>, the second NF node <NUM> is operative. On the other hand, if no response to the third request is received from the second NF node <NUM>, the second NF node <NUM> is inoperative. The third request may, for example, be a HTTP request, such as a HTTP ping request or a HTTP head request.

In some embodiments, the first NF node <NUM> may check whether the first SCP node <NUM> failed to connect to the second NF node <NUM>. The first SCP node <NUM> failing to connect to the second NF node <NUM> may be the first SCP node <NUM> itself failing to connect to the second NF node <NUM> or at least one fourth SCP node failing to connect to the second NF node <NUM>, where the at least one fourth SCP node is configured to operate as an SCP between the first SCP node <NUM> and the second NF node <NUM>. In some embodiments, checking whether the at least one fourth SCP node failed to connect to the second NF node <NUM> may comprise checking a status of the at least one fourth SCP node to identify whether the at least one fourth SCP node failed to connect to the second NF node <NUM>. For example, the status may be checked with the at least one fourth SCP node or the NRF <NUM>.

Although not illustrated in <FIG>, in some embodiments, checking the status with the at least one fourth SCP node may comprise the first NF node <NUM> initiating transmission of a fourth request towards the at least one fourth SCP node. The fourth request is a request for the status of the at least one fourth SCP node. In these embodiments, if no response to the fourth request is received from at least one fourth SCP node, the at least one fourth SCP node failed to connect to the second NF node <NUM>. On the other hand, if a response to the fourth request is received from the at least one fourth SCP node, the at least one fourth SCP node succeeded to connect to the second NF node <NUM>. The fourth request may, for example, be a HTTP request, a HTTP ping request or a HTTP head request.

Returning back to <FIG>, as illustrated by block <NUM>, the first NF node <NUM> selects an alternative SCP node. That is, the first NF node <NUM> is able to select an alternative SCP node instead of continually trying to reach another NF node of the service producer via the same first SCP node <NUM>, which may cause a request failure or even multiple request failures, depending on the available NF nodes of the service producer. Having the ability to select an alternative SCP node prevents the first NF node <NUM> from continually selecting (in a loop) NF nodes of the service producer all with same wrong results and also prevents the first NF node <NUM> from having to abort the procedure. Thus, providing the first NF node <NUM> with the ability to select an alternative SCP node provides advantageous results in that service requests are more likely to be executed successfully.

For the purpose of this illustration, the first NF node <NUM> is assumed to select the second SCP node <NUM> as the alternative. As illustrated in <FIG>, the second SCP node <NUM> is an SCP node that is in the same SCP domain <NUM> as the first SCP node <NUM>. This means that the second SCP node <NUM> is able to reach (or is capable of reaching) the same NF nodes (e.g. the second NF node <NUM>) as the first SCP node <NUM>. 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.

As illustrated by arrow <NUM> of <FIG>, the first NF node <NUM> initiates transmission of a second request towards the second NF node <NUM> via the second SCP node <NUM> for the second NF node <NUM> to execute (or provide) the service <NUM> for the first NF node <NUM>. Thus, the first NF node <NUM> initiates transmission of the second request to the same NF node of the service producer but via an alternative SCP node. In some embodiments, transmission of the second request towards the second NF node <NUM> via the second SCP node <NUM> may (e.g. only) be initiated if the second NF node <NUM> is operative and/or if no response to the first request is received from the second NF node <NUM> due to the first SCP node <NUM> failing to connect to the second NF node <NUM>.

In <FIG>, steps <NUM>-<NUM> are the same as steps <NUM>-<NUM> except that they are performed in relation to the second request. As illustrated by arrow <NUM> of <FIG>, in some embodiments, the second NF node <NUM> may initiate transmission of a response towards the second SCP node <NUM> indicative that the second request is executed successfully. The response may comprise some business logic (BL) information, e.g. as a result of the service execution. As illustrated by arrow <NUM> of <FIG>, in some embodiments, the second SCP node <NUM> may initiate transmission of the response indicative that the second request is executed successfully to the first NF node <NUM>. As illustrated by blocks <NUM> and <NUM> of <FIG>, in some embodiments, the first NF node <NUM> may store the response.

<FIG> is a block diagram illustrating a first SCP node <NUM> in accordance with an embodiment. The first SCP node <NUM> can handle a service request in a network. The first SCP node <NUM> can operate as an SCP between a first NF node of a service consumer and a second NF node of a service producer in the network. The first SCP node <NUM> comprises a transmission initiating module <NUM> configured to, if no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node <NUM> (where the first request is for the second NF node to execute a service requested by the first NF node), initiate transmission of information towards the first NF node. The information is indicative that no response is received from the second NF node to the first request. The first SCP node <NUM> may operate in the manner described herein in respect of the first SCP node.

<FIG> is a block diagram illustrating a first NF node <NUM> of a service consumer in accordance with an embodiment. The first NF node <NUM> can handle a service request in a network. A first NF node <NUM> can operate as an SCP between the first NF node and a second NF node of a service producer in the network. The first NF node <NUM> comprises a first transmission initiating module <NUM> configured to, in response to receiving information indicative that no response is received from the second NF node to a first request transmitted towards the second NF node via the first SCP node <NUM> (where the first request is for the second NF node to execute a service for the first NF node <NUM>), initiate transmission of a second request towards the second NF node via a second SCP node for the second NF node to execute the service for the first NF node <NUM>. The second SCP node is configured to operate as an SCP between the first NF node <NUM> and the second NF node in the network. The second SCP node is a different SCP node to the first SCP node <NUM>. The first NF node <NUM> may operate in the manner described herein in respect of the first NF node.

There is also provided a computer program comprising instructions which, when executed by processing circuitry (such as the processing circuitry <NUM> of the first SCP node <NUM> described earlier and/or the processing circuitry <NUM> of the first NF node <NUM> 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 <NUM> of the first SCP node <NUM> described earlier and/or the processing circuitry <NUM> of the first NF node <NUM> 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 <NUM> of the first SCP node <NUM> described earlier and/or the processing circuitry <NUM> of the first NF node <NUM> described earlier) to perform at least part of the method described herein. In some embodiments, 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 embodiments, the first SCP node functionality and/or the first NF node functionality described herein can be performed by hardware. Thus, in some embodiments, any one or more of the first SCP node <NUM> and the first NF node <NUM> 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 <NUM> and the first NF node <NUM> described herein can be implemented in software running on generic hardware that is configured to orchestrate the node functionality. Thus, in some embodiments, any one or more of the first SCP node <NUM> and the first NF node <NUM> described herein can be a virtual node. In some embodiments, 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 embodiments. That is, in some embodiments, at least some or all of the method steps described herein can be performed automatically. The method described herein can be a computer-implemented method.

Thus, in the manner described herein, there is advantageously provided an improved technique for handling service requests in a network. The first NF node <NUM> can be provided with the right information to allow a re-selection of an alternative SCP to route via the same NF of a service producer, e.g. when the failure seems to be due to a connectivity issue from the SCP to the NF of the service producer, rather than to a failure of an NF service producer.

Claim 1:
A method for handling a service request in a network, wherein the method is performed by a first service communication proxy, SCP, node (<NUM>) that is configured to operate as an SCP between a first network function, NF, node (<NUM>) of a service consumer and a second NF node (<NUM>) of a service producer in the network, the method comprising:
transmitting (<NUM>, <NUM>) information towards the first NF node (<NUM>) if no response is received from the second NF node (<NUM>) to a first request (<NUM>, <NUM>) transmitted towards the second NF node (<NUM>) via the first SCP node (<NUM>),
wherein the first request is for the second NF node (<NUM>) to execute a service (<NUM>) requested by the first NF node (<NUM>), and
wherein the information is indicative that no response is received from the second NF node (<NUM>) to the first request (<NUM>, <NUM>), and
wherein the information is accompanied by an existing hypertext transfer protocol, HTTP, status code and the existing HTTP status code is a <NUM> Gateway Timeout.