Patent Description:
The Fifth Generation, <NUM>, telecommunications core network architecture is an example of a Service Based Architecture, SBA, in which Network Functions, NF, provide one or multiple services to entities requiring telecommunications services from a particular NF. In turn, an NF may also request telecommunications services from another NF, for example. The NFs of the Core Network, CN, are self-contained functionalities that can be modified and updated in an isolated manner, i.e. without affecting other NFs.

The concept of provision of services between entities in a telecommunications system or telecommunications network is not limited to strictly service organised architectures. The service concept may be widely used in data communication, data exchange and/or data processing environments, wherein one or multiple service producers or service providers provide services for supporting data processing by one or multiple service consumers.

The provision of (logical) communication services enables a more flexible development of new services, as it becomes possible to connect to communication entities and other system components of a telecommunications system without introducing specific new interfaces, for example.

The operational communication of the SBA domain with the outside world, i.e. the communication entities of the telecommunications system, may run through existing or still to be developed communication interface protocols arranged for operational message handling. Present point-to-point communication interface protocols for operational message handling between the SBA domain and network entities in a <NUM> telecommunications system are designated N1, N2 and N4, for example. Fixed access networks and Long Term Evolution, LTE, network access, for example, operate with other specific signalling protocols.

The various communication interface protocols are implemented in some of the NFs in the SBA domain. Accordingly, the NFs that implement these network communication interface protocols contain both services and their related functionality as well as network communication interface functionality. Accordingly, the interface functionality towards communication entities in a telecommunications system, such as User Equipment, UE, Radio Access Networks, RANs, and User Plane, UP, nodes is not designed on a service-based paradigm.

This means, for example, that these communication interface protocols, such as e.g. the Stream Control Transmission Protocol, SCTP, are not following the request-response paradigm of the SBA, and are also not supported by current cloud infrastructures, which in general assume Hypertext Transfer Protocol, HTTP, based communication messaging.

Several mechanisms defined for the different NFs in the Third Generation Partnership Project, 3GPP, SBA domain are influenced by the external network interfaces and the assumption of point-to-point communication, such as load balancing, overload control and Non-Access Stratum, NAS, level congestion control.

Handling "non-service based" functionality for the NFs in the SBA domain results in difficulties to reconcile current NF functionality with SBA models based on functionality implementation.

Further, the coupling of certain external interfaces to specific NFs also implies that some NFs are involved in certain transactions even if same, from a service architecture perspective, would not have any role in that transaction otherwise. For example, in a <NUM> SBA domain, a Protocol Data Unit, PDU, session modification procedure, from a service provision perspective, would logically involve only the Session Management Function, SMF. However, since the Access and Mobility Function, AMF, implements the interfaces N1 and N2 towards the UE and RAN, respectively, the AMF is also involved in sending NAS session management messages processed by the SMF.

Implementing the external network communication interfaces at certain NFs of the SBA compromises separation of specialized NF functionality. For example, in the case when the UE has sessions in multiple network slices, the same AMF terminating the NAS security association must handle the UE control traffic in both slices, although the two slices may require different access and mobility management, or the AMF implementation may be optimized or simplified in different ways depending on the slice. Accordingly, there is a need for improving operational message handling between communication entities operatively connected to an SBA domain of a core network of a telecommunications system.

Document <CIT> discloses a method for managing registration in a wireless communication system and a device for same. Reference is also made to "<NPL>. Document <CIT> discloses a system and method for providing mobile communication. Further document <CIT> discloses interworking between a <NUM> system (5GS) and a <NUM> evolved packet system (EPS) in a mobile network. A serving gateway (SGW) on <NUM> side and an access and mobility management function (AMF) on <NUM> side interface with a session management function (SMF) plus packet data network gateway (PGW) and user plane function (UPF) plus PGW which perform the interworking.

In a first aspect of the present disclosure, there is provided a Network Gateway Service, NGS, in a Service Based Architecture, SBA, domain, deployed in a core network of a telecommunications system according to claim <NUM>.

The present disclosure provides an independent, separate, self-contained service functionality, called network gateway service, in the SBA for operational message handling between the SBA and communication entities external of the SBA in a telecommunications system.

Allocating the communication between the SBA and its external communication environment to a separate service or services in the SBA, among others, effectively solves the interdependency problem, i.e. unnecessary couplings that exist between present Network Functions, NFs, in the SBA domain for operational message handling with the communication entities and difficulties in updating and modifying NFs providing both service and operational message handling functionality.

The NGS solution according to the present disclosure enables a more flexible and independent development and improvement of new and existing services, because the operational message handling of such services with the communication entities and other system components of a telecommunications system may now completely be handled in accordance with existing SBA models for implementing service functionality.

By the decoupling of the NFs from the different network communication interfaces, all services in the SBA domain fully benefit from SBA modelling based on object/resource/data contexts that are built around a common framework that facilitates re-usability, flexibility and extensibility of services. The role and data model for the separated services remains well-defined, i.e. there are no overlaps. It also allows for separate change in data structure and control logic for the separated services. That is, it enables independent evolution paths of the external and SBA communication. The present solution supports the migration from a system with deployed NF functionality according to the current <NUM> standard.

Hence, the specific, independent, self-contained operational message handling service functionality according to the present disclosure provides increased development agility in an SBA with the ultimate benefit to boost innovation.

For operating in an SBA domain, the NGS in accordance with the present disclosure provides for service message handling with at least one of an Access and Mobility Function, AMF, and a Session Management Function, SMF, of the SBA domain. Accordingly, the independent NGS as such may be physically implemented or independently processed in any NF of an SBA domain.

However, in an example of the present disclosure, the NGS is a distinct Network Function, NF, operative in the SBA domain.

The NGS functionality in general comprises interface communication protocols, such as point-to-point communication protocols, for handling, i.e. to send and receive, operational messages to and from communication entities external to the SBA domain. This may also imply handling of security aspects, assignment of identities and mapping of identities, load (re-)balancing, overload control and congestion control, for example. The NGS functionality is further arranged for handling, i.e. exchanging, service messages in the SBA domain.

In an example of the NGS according to the present disclosure for operating in a <NUM> architecture, for example, wherein the communication entities at least comprise a Radio Access Network, RAN, and a User Equipment, UE, operatively connected to the RAN, the operational message handling with the RAN, i.e. a node or server deployed in the RAN, is provided in accordance with core network control plane interface N2 functionality and the operational message handling with the UE is provided in accordance with core network control plane interface N1 functionality.

For handling registration requests with such a GNS, i.e. wherein the GNS is arranged for operational message handling in accordance with core network control plane interface N2 functionality and core network control plane interface N1 functionality and, for example when operating as a separate distinct NF, the NGS may be arranged for providing at least one of Global Unique Temporary UE Identity, GUTI, allocation, AMF selection and SMF selection.

For AMF and SMF selection, for example, in accordance with the present disclosure, service message handling by the GNS may involve a Network Repository Function, NRF of the SBA domain.

In another example of the NGS according to the present disclosure for operating in a <NUM> architecture, for example, wherein the communication entities comprise a User Plane Function, UPF, operatively connected to a Radio Access Network, RAN, of the telecommunications system, the operational message handling with the UPF is provided in accordance with core network control plane interface N4 functionality.

The core network control plane interface N1, N2 and N4 functionality are known to the person skilled in the art and specified in the Third Generation Partnership Project, <NPL>".

Although separate or dedicated NGSs for operational message handling in accordance with core network control plane interface N1 and N2 functionality, and core network control plane interface N4 functionality, respectively, may be provided, the present disclosure also includes to integrate the N1, N2 and N4 functionality in a single NGS.

In accordance with the present disclosure, the NGS may be particularly arranged for allocating, in different service messages for the AMF and the SMF, parameters received from a communication entity, such as a UE and RAN, i.e. a node or server operating in the RAN.

In opposite direction, in accordance with the present disclosure, the NGS may be arranged for allocating, in an operational message for a communication entity, such as a UE and RAN, i.e. a node or server operating in the RAN, parameters received in different service messages from the AMF and the SMF.

In a second aspect of the present disclosure, there is provided a method of operating a Network Gateway Service, NGS, in a Service Based Architecture, SBA, domain, deployed in a core network of a telecommunications system according to claim <NUM>.

For operating in a <NUM> telecommunications system architecture, for example, wherein the communication entities at least comprise a Radio Access Network, RAN, and a User Equipment, UE, operatively connected to the RAN, the method in accordance with the present disclosure comprises operational message handling with the RAN, i.e. a node or server deployed in the RAN, in accordance with core network control plane interface N2 functionality and wherein operational messages with the UE are handled in accordance with core network control plane interface N1 functionality.

For operating in a <NUM> telecommunications system architecture, for example, wherein the communication entities comprise a User Plane Function, UPF, operatively connected to a Radio Access Network, RAN, of the telecommunications system, the method according to the present disclosure comprises operational messages with the UPF are handled in accordance with core network control plane interface N4 functionality.

In particular, the method according to the present disclosure comprises at least one of the steps of:.

Where appropriate, service message handling in accordance with the method of the present disclosure may involve a Network Repository Function, NRF, of the SBA domain, such as for selecting an AMF and/or an SMF.

In a third aspect of the present disclosure, a computer program product is provided, comprising a computer readable storage medium, storing instructions which, when executed on at least one processor operative in an SBA domain, cause the at least one processor to carry out processing steps for performing the services according to a respective one of the first and second aspect of the present disclosure.

It will be appreciated that the entities and modules disclosed may be implemented as separate hardware and/or software modules and entities, and controlled by or executed in a processor or the like.

The above mentioned and other features and advantages of the disclosure will be best understood from the following description referring to the attached drawings. In the drawings, like reference numerals denote identical parts or parts performing an identical or comparable function or operation.

<FIG> schematically illustrates part of the reference architecture <NUM> of a fifth generation, <NUM>, Service Based Architecture, SBA, to be deployed in a core network of a telecommunications system, in accordance with the prior art. The <NUM> system architecture <NUM> generally distinguishes the following logical Network Functions, NFs:.

The logical NFs <NUM> - <NUM> of the Core Network are built of one or more services and together form an SBA domain <NUM>. Within the SBA domain <NUM> service messages are communicated and exchanged over respective communication interfaces, indicated by a capital N followed by one of the above-mentioned abbreviations of the NFs. That is, interface Namf is the service message communication interface towards the AMF <NUM>, etcetera, such as indicated in <FIG>.

Communication entities supported by the SBA <NUM> in the core network of a telecommunications system are generally referenced as:.

Operational or signalling messages between the communication entities <NUM> - <NUM> and the SBA domain <NUM> are exchanged over respective control plane interface functionality, termed N1, N2 and N4, as shown in <FIG>. That is, interface functionality or protocol N1 pertains to UE related operational messages, interface functionality or protocol N2 relates to RAN operational messages, i.e. exchanged with a node or server in a RAN <NUM>, and interface functionality or protocol N4 pertains to UPF related operational messages. As the N1 related operational messages are exchanged through a RAN <NUM> to which a particular UE <NUM> operatively connects, the N1 interface in <FIG> is schematically indicated by a dashed line. N3 and N6 are communication interfaces between the UPF <NUM> and RAN <NUM> and DN <NUM>, respectively.

A functional description of the above-mentioned network functions, interfaces and communication protocols is available from the Third Generation Partnership Project, <NPL>".

In the reference architecture shown in <FIG>, N1, N2 and N4 are so-called point-to-point communication interface protocols for operational message handling between the SBA domain <NUM> and a respective network communication entity <NUM>, <NUM>, <NUM> external of the SBA domain <NUM>. The external communication interface protocols N1 and N2 are implemented in the AMF <NUM> and the external communication interface protocol N4 is implemented in the SMF <NUM>.

Several mechanisms defined for the different NFs <NUM> - <NUM> in the SBA domain <NUM> are influenced by the external network interfaces and the assumption of point-to-point communication, such as load balancing, overload control and Non-Access Stratum, NAS, level congestion control.

As indicated in the summary part above, among others, handling of non-service based functionality for the NFs in the SBA domain results in difficulties in associating current NF functionality with SBA models based on functionality implementation, whereas linking certain external interfaces to specific NFs, i.e. the AMF and SMF, also implies that these NFs are involved in certain transactions even if same, from a service architecture perspective, would not have any role in that transaction otherwise.

<FIG> schematically illustrates an embodiment <NUM> of part of the architecture of a <NUM> telecommunication network according to the present disclosure, showing an SBA domain <NUM>, comprising an extension or addition, to the service architecture of the SBA domain <NUM> shown in <FIG>, by one or multiple separate or distinct services <NUM>, <NUM>, generally called Network Gateway Services, NGSs.

The NGSs <NUM>, <NUM> are responsible for exchanging operational messages with communication or network entities <NUM>, <NUM>, <NUM> external to the SBA domain <NUM>, and to handle respective service interactions towards a respective NF within the SBA domain <NUM>.

In the embodiment of <FIG> the N1 and N2 operational message handling with the communication entities UE <NUM> and RAN <NUM> and the N4 operational message handling with the UPF <NUM> are performed in separate or dedicated GNSs or Gateways, N1 N2 GW <NUM> and N4 GW <NUM>, respectively. If advantageous or required, a single NGS <NUM> with the functionalities of both N1 N2 GW <NUM> and N4 GW <NUM> may be implemented, indicated by dashed lines in <FIG>.

In the prior art reference architecture, as shown in <FIG>, the AMF <NUM> is responsible for N1 and N2 operational message handling with the UE <NUM> and the RAN <NUM>. The SMF <NUM> is responsible for N4 operational message handling with the UPF <NUM>. According to the present disclosure, these and other operations are now performed by the N1 N2 GW <NUM> and the N4 GW <NUM>, respectively.

In the SBA domain <NUM> service messages are communicated and exchanged with N1 N2 GW <NUM> and N4 GW <NUM> over respective communication interfaces Nn1n2 and Nn4, respectively.

In general, separating the GW services <NUM>, <NUM> from the AMF <NUM> and SMF <NUM> will also imply a functionality change for these NFs that originally implemented the interfaces towards the external world. In the embodiment of <FIG> the thus changed NFs are indicated as AMF <NUM> and SMF <NUM>.

Additional mechanisms or operations and functionality of the SBA <NUM> influenced by the N1, N2 and N4 interfaces, such as load (re-)balancing, overload control and Non-Access Stratum, NAS, level congestion control, may also be implemented in the N1 N2 GW <NUM> and the N4 GW. Such an implementation may be performed in a manner in accordance with the current <NUM> communication standard, for example.

Accordingly, the NGS functionality in accordance with the present disclosure generally comprises one or more of the following:.

In a <NUM> core network SBA, examples of the service operations handled by the N1N2 GW are:.

The above list is merely indicative and not exhaustive. Note that other SBA services may also be optionally defined for the N1 N2 GW <NUM>, for example an Nn1n2Exposure service, to expose different N1 and N2 related events. Each of these service operations require internal functionality in the N1 N2 GW <NUM>, such as N2 message processing, achieving Non-Access Stratum, NAS, transport of N1 messages over N2 interface, etc. Note that the N1 N2 GW <NUM> also controls parts of the UE context currently maintained by the AMF <NUM>:.

The modified AMF <NUM> functionality would then result in a Namf_Comunication service that lacks the above operations and related functionality. In addition, if the N1 N2 GW <NUM> is accomplished as a stand-alone NF, the Application Programming Interface, API, of the AMF <NUM> should include another service operation that can be invoked by the N1 N2 GW <NUM> in the case when requests from N1 or N2 require invocation of an AMF <NUM>.

<FIG> schematically illustrates an embodiment <NUM> for part of the architecture of a <NUM> telecommunication network according to the present disclosure. The embodiment <NUM> differs from the embodiment <NUM> in <FIG> in that the dedicated NGSs <NUM>, <NUM> are part of the network functions <NUM>, <NUM> implementing the interface functionality. It is proposed to include a physical or a logical separation between the network gateway services <NUM>, <NUM> and any other services <NUM>, <NUM> offered by the network functions in the SBA domain <NUM>.

<FIG> schematically illustrates a procedure <NUM> for registration of a UE <NUM> in a <NUM> telecommunications system according to the present disclosure. The UE <NUM> sends a registration request <NUM> for becoming registered in the telecommunications system. The (R)AN <NUM> selects <NUM> an N1 N2 GW <NUM> with which it communicates. The registration request is then subsequently forwarded <NUM> to the selected N1 N2 GW <NUM>. If required, the N1 N2 GW <NUM> allocates <NUM> a GUTI to the UE <NUM>. The N1 N2 GW <NUM> also selects an AMF <NUM> in step <NUM>.

In step <NUM>, the registration request is forwarded to the selected AMF <NUM>. It may be noted that request is forwarded <NUM> to the newly defined AMF <NUM> service operation. The AMF <NUM> does not communicate with communication entities external to the SBA domain <NUM>, <NUM>. In step <NUM>, the system involves the PCF <NUM>, SMF <NUM>, AUSF <NUM> and the UDM <NUM> service functions to complete a registration procedure as is known in the prior art.

Steps <NUM> - <NUM> are optional and are required only when additional UE identification is required. In such a scenario, The AMF <NUM> requests <NUM> additional information, which is subsequently forwarded <NUM>, by the N1 N2 GW <NUM> to the UE <NUM>. The response containing the require additional information is transmitted back to the AMF <NUM> in steps <NUM> and <NUM>. In case of successful registration, a registration accept message is sent <NUM> as a response which will be forwarded <NUM> by N1 N2 GW <NUM> towards the UE <NUM>. The UE <NUM> may reply with a registration complete message <NUM> which will be handled by the N1 N2 GW <NUM> handling the GUTI of the UE <NUM>.

<FIG> schematically illustrates the procedure for Protocol Data Unit, PDU, session modification in a <NUM> telecommunications system according to the present disclosure. As before, the message reaches <NUM> the N1 N2 GW <NUM> first that selects <NUM> the SMF <NUM> and invokes its Nsmf_PDUSession_UpdateSMContext service. Note the difference with respect to prior art procedure in the architecture according to <FIG>, where this is performed by the AMF <NUM>. If there is a separate N1 N2 GW service <NUM> then the AMF <NUM> can be left out from this procedure, which otherwise operates with similar service operations, but involving the N1 N2 GW <NUM> instead. As a result of this, the amount of signalling will not increase for this procedure compared to the prior art. The remaining steps <NUM> - <NUM> are part of the standard procedure according to the prior art.

Part of the service handling by the NGS in accordance with the present disclosure may comprise allocation, in different service messages for an AMF <NUM> and an SMF <NUM>, parameters received in an operational message from a respective communication entity <NUM>, <NUM>, <NUM>, and allocating, by the NGS, in an operational message for a respective communication entity <NUM>, <NUM>, <NUM>, parameters received in different service messages from an AMF <NUM> and an SMF <NUM>.

<FIG> schematically illustrates a Network Gateway Service, NGS, according to the present disclosure, implemented as a separate, distinct network function NGS device or gateway <NUM>. The control message module <NUM> is a part of the gateway <NUM> that is arranged for communicating with communication entities external to the SBA domain. Such a module may be implemented as a logical entity or a physical entity. Similarly, the service message module <NUM> is responsible for communicating with the other NFs within the SBA domain. Such a communication is in the form of service messages and hence the service message module <NUM> is accordingly named. As with the control message module <NUM>, the service message module <NUM> may be implemented as a logical entity or a physical entity.

The NGS <NUM> further comprises a receiver <NUM>, <NUM> in order to receive messages from other communication entities and Network Functions part of the telecommunications system. The NGS <NUM> also comprises transmitting means <NUM>, <NUM> in order to transmit messages to other communication entities and Network Functions that are part of the telecommunications system. It may be noted that the NGS <NUM> illustrated in <FIG> may either be the N1 N2 GW <NUM> or the N4 GW <NUM>.

The storage or memory <NUM> may further store context data or state information pertaining to a particular service instance, for example, and other intermediate data values and/or a computer program product which when executed by a processor <NUM> causes the device <NUM> to perform a method according to an aspect of the present disclosure. All the internal components of the device <NUM> communicate with one another using an internal data bus <NUM>.

Other variations to the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. A computer program may be stored/distributed on a suitable medium, such as optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not construed as limiting scope thereof. Similar reference signs denote similar or equivalent functionality.

Claim 1:
A Network Gateway Service, NGS, (<NUM>, <NUM>, <NUM>) in a Service Based Architecture, SBA, domain (<NUM>, <NUM>), deployed in a core network of a telecommunications system (<NUM>, <NUM>), wherein said NGS (<NUM>, <NUM>, <NUM>) is arranged for operational message handling with communication entities (<NUM>, <NUM>, <NUM>) of said telecommunications system external of said SBA domain (<NUM>, <NUM>) in accordance with communication interface protocols of said telecommunications system (<NUM>, <NUM>), and wherein said NGS (<NUM>, <NUM>, <NUM>) is further arranged for service message handling in said SBA domain (<NUM>, <NUM>) with at least one of an Access and Mobility Function, AMF, (<NUM>) and a Session Management Function, SMF, (<NUM>) of said SBA domain (<NUM>, <NUM>) wherein said communication entities at least comprise a Radio Access Network, RAN, (<NUM>) and a User Equipment, UE, (<NUM>) operatively connected to said RAN (<NUM>), characterized in that said operational message handling with said RAN (<NUM>) is provided in accordance with core network control plane interface N2 functionality between said RAN (<NUM>) and said NGS (<NUM>, <NUM>, <NUM>) and wherein said operational message handling with said UE (<NUM>) is provided in accordance with core network control plane interface N1 functionality between said UE (<NUM>) and said NGS (<NUM>, <NUM>, <NUM>).