Methods and apparatuses for enabling provision of a service to a first wireless device

Abstract

Embodiments described herein provide methods and apparatuses for enabling provision of a service to a first wireless device whilst providing overload control for a service provider node. A method in a network node (e.g. the service provider node or a service consumer node) comprises obtaining a first indication that a service provider node is or is expected to be overloaded; and responsive to obtaining the first indication, initiating extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node, wherein the extended registration expiration timer is longer than an initial registration expiration timer and wherein, the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node.

Description

[0001] METHODS AND APPARATUSES FOR ENABLING PROVISION OF A SERVICE TO A FIRST WIRELESS DEVICE

[0002] TECHNICAL FIELD

[0003] Embodiments described herein relate to methods and apparatuses for enabling provision of a service to a first wireless device. In particular embodiments described herein enable the extension of registration expiration timers to address overload conditions in a service provider node.

[0004] BACKGROUND

[0005] The risk of overload in Mobile Networks is a well-known issue in the Telecom Industry. Depending on the severity of the outage and the downtime, a huge number of user equipments (UEs) (or wireless devices) may be in a resending mode attempting to register (or re-register) and regain services from the network.

[0006] UEs comprising smartphones constitutes the vast majority of UEs in a mobile network. Smartphones may be required to execute two consecutive registration procedures, first towards Mobile network, e.g 5G or 4G and subsequently a registration towards an Internet Protocol Multimedia Core Network Subsystem (IMS) network, in order to gather network authorization to receive services like Mobile Broadboard (MBB) from 5G or 4G and voice services from IMS Voice service engine, and to enable reachability.

[0007] When severe outage with long recovery time occurs in the network, a huge surge in the number of Registration (or re-registration) requests is a very likely scenario, and this can overload the 5GC network by exceeding the capacity of the control system on the Access and Mobility Management Function (AMF), Session Management Function (SMF), Policy Control Function PCF, Unified Data Management (UDM) network function, a Home Subscriber Server (HSS) (either in IMS or Evolved Packet Core (EPC)) or a Unified Data Repository (UDR).

[0008] However, the data layer components e.g. HSS / UDM or UDR may be the most heavily impacted by such a surge in registration requests because these are the common elements involved in all types of registration procedure, for example, 5G Registration, 4G attach, and IMS registration. These registration procedures may be considered the basic procedures that may surge in numbers upon severe network outages.

[0009] Figure 1 illustrates a network architecture showing the interfaces between the data layer components HSS / UDM / UDR and the various Radio Access Technologies (RATs).

[0010] Resources may be shared among deployed Network Function (NFs), for example: HSS in the IMS 101 , HSS in EPC 102, and the UDM / Authentication Service Function (ALISF) 103. If one of these NFs expands its resources consumption up to the maximum resources available for these NFs it will impact on the resource availability for other NFs, and they would then reach an overload status easily.

[0011] The UDR 104 is also at risk because is hosting all types of subscriber data from the various network access types (2G,3G,4G,5G and IMS).

[0012] A registration from a UE or wireless device at a NF is valid for a negotiated time upon the initial registration. To extend this time that the UE is registered with the NF a reregistration is required and the UE may initiate a re-registration before the negotiated time expires. The registration refresh interval is usually within one hour for all network access types.

[0013] 5G Registration / Re-registration:

[0014] The 5GS periodic registration update procedure is used over 3GPP access to periodically notify the availability of the UE to the network. The procedure is controlled in the UE by the periodic registration update timer, T3512. The value of timer T3512 is sent by the network to the UE in a REGISTRATION ACCEPT message. If the UE is registered over the 3GPP access, the AMF maintains an implicit de-registration timer to control when the UE is considered implicitly de-registered over the 3GPP access. The 5G Registration / Re-registration procedure is specified in section 5.3.7 of 3GPP TS 24.501 V16.4.0.

[0015] LTE Attach / Periodic TAU:

[0016] A periodic tracking area update over 3GPP access is used to periodically notify the availability of the UE to the network. The procedure is controlled in the UE by the periodic tracking area update timer (timer T3412). The value of timer T3412 is sent by the network to the UE in an ATTACH ACCEPT message and can be sent in a TRACKING AREA UPDATE ACCEPT message. The UE shall apply this value in all tracking areas of the list of tracking areas assigned to the UE, until a new value is received. The LTE Attach procedure specified in 3GPP TS 23.401. This tracking area update timer may be considered a type of registration expiration timer.

[0017] IMS Registration / Re-registration:

[0018] The UE may be required to perform a Session Initiation Protocol (SIP) re-registration prior to the expiry time of the existing registration as described in section 5.1.1.4.1 of 3GPP TS 24.229 v17.6.1. The value of the registration expiration timer is sent by the network to the UE in the SIP 200GK for SIP Register request.

[0019] There is a varied toolbox set of standardized abatement processes for 5GC network overload control for each NF to protect itself and upstream NFs peers, for example:

[0020] Throttling: the NF service consumer rejects a certain percentage of traffic to the target destination (e.g. NF service provider) without spreading to the overloaded target NF (e.g., AMF attach throttling, SMF rate limiting for PDU Session Establishment).

[0021] Reselection: the NF service consumer diverts a certain percentage of traffic to alternative peer NFs which are not overloaded.

[0022] Prioritization: prioritize the high priority (e.g., Multimedia Priority Service (MPS)) and emergency services based on message priority (Rate limiting does not affect priority services).

[0023] For example, SBI Load & Overload Control specified in 3GPP TS 29.500, ch 6.4 Overload Control specifies the following: Overload control enables an NF Service Provider, an NF Service Consumer, a Service Communication Proxy (SCP) or a Security Edge Protection Proxy (SEPP) becoming or being overloaded to gracefully reduce its incoming signalling load, by instructing the NF Service Consumers to reduce sending service requests or by instructing NF Service providers to reduce sending notification requests respectively, according to its available signalling capacity to successfully process the requests. An NF Service provider, NF Service Consumer, SCP or an SEPP may be considered overloaded when it operates over its signalling capacity.

[0024] Diameter Overload Indication Conveyance specified in the Internet Engineering Task Force (IETF) Request for comments (RFC) 7683, ch 4 Solution Overview specifies the following: The Diameter Overload Information Conveyance (DOIC) solution allows Diameter nodes to request that other Diameter nodes perform overload abatement actions (e.g. abatement processes), that is, actions to reduce the load offered to the overloaded node or realm.

[0025] SUMMARY

[0026] It will be appreciated that the current solutions described above for managing NF overload scenarios do not prevent the UEs that do manage to get registered from attempting re-register with the network upon registration refresh, during the period that the NF is still recovering from overload.

[0027] In overload situations, usually the recovery time for NF to recover from severe overload it longer than the registration expiration time (e.g. the time before the UE will need to reregister with the NF) and therefore registered users can become deregistered again due to rejection of re-registration occurring when the NF is overloaded.

[0028] Both initial registration and re-registration within the recovery time window will compete on the same resources and both will be exposed to overload abatement throttling treatments (or other abatement processes). This situation will lead to an increased blind load, and will therefore further increase the recovery time.

[0029] The same challenges described above apply in 6G. It will therefore be appreciated that there is a need to enhance the traffic abatement mechanisms beyond throttling and traffic diversion.

[0030] According to some embodiments there is provided a method performed by a network node for enabling provision of a service to a first wireless device. The method comprises obtaining a first indication that a service provider node is or is expected to be overloaded. The method further comprises responsive to obtaining the first indication, initiating extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node, wherein the extended registration expiration timer is longer than an initial registration expiration timer and wherein, the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node. According to some embodiments there is provided a method performed by a network repository function, for enabling provision of a service to a first wireless device. The method comprises receiving, from a network service provider, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers; and storing the capability indication in an entry for the network service provider.

[0031] According to some embodiments there is provided a method performed by a registration network node for enabling provision of a service to a first wireless device, wherein the registration network node is pre-configured with an initial registration expiration timer associated with a service provider node, wherein the initial registration expiration timer is for indicating to a wireless device when to perform re-registration with the service provider node. The method comprises receiving an indication that an extended registration expiration timer is to be used for a first registration request, wherein the extended registration expiration timer is longer than the initial registration expiration timer; and receiving the first registration request from a first wireless device. The method further comprises responsive to the first registration request being accepted by the service provider node, indicating the extended registration expiration timer to the first wireless device.

[0032] According to network node for enabling provision of a service to a first wireless device. The network node comprises processing and a memory, the memory containing instructions executable by the processing circuitry whereby the network node is operable to: obtain a first indication that a service provider node is or is expected to be overloaded; and responsive to obtaining the first indication, initiate extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node, wherein the extended registration expiration timer is longer than an initial registration expiration timer and wherein, the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node.

[0033] According to some embodiments there is provided a network repository function, for enabling provision of a service to a first wireless device. The network repository function comprises processing and a memory, the memory containing instructions executable by the processing circuitry whereby the network repository function is operable to: receive, from a network service provider, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers; and store the capability indication in an entry for the network service provider.

[0034] According to some embodiments there is provided a registration network node for enabling provision of a service to a first wireless device. The registration network node is adapted to be pre-configured with an initial registration expiration timer associated with a service provider node, wherein the initial registration expiration timer is for indicating to a wireless device when to perform re-registration with the service provider node. The registration network node comprises processing and a memory, the memory containing instructions executable by the processing circuitry whereby the registration network node is operable to: receive an indication that an extended registration expiration timer is to be used for a first registration request , wherein the extended registration expiration timer is longer than the initial registration expiration timer; receive the first registration request from a first wireless device; and responsive to the first registration request being accepted by the service provider node, indicate the extended registration expiration timer to the first wireless device.

[0035] According to some embodiments there is provided a computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out any of the methods described above.

[0036] According to some embodiments there is provided a carrier containing the computer program as described above, wherein the carrier comprises one of an electronic signal, optical signal, radio signal or computer readable storage medium.

[0037] According to some embodiments there is provided a computer-readable medium comprising instructions that, when executed on at least one processor, cause the at least one processor to perform any of the methods described above.

[0038] According to some embodiments there is provided a computer program product comprising non transitory computer readable media having stored thereon a computer program as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] For a better understanding of the embodiments of the present disclosure, and to show how it may be put into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0040] Figure 1 illustrates a network architecture showing the interfaces between the data layer components HSS / UDM / UDR and the various Radio Access Technologies (RATs);

[0041] Figure 2 illustrates a network system 200 comprising elements for use in implementing embodiments described herein;

[0042] Figure 3 is a flowchart illustrating a method performed by a network node for enabling provision of a service to a first wireless device;

[0043] Figure 4 illustrates a method performed by a registration network node for enabling provision of a service to a first wireless device;

[0044] Figure 5 illustrates an example implementation of the method of Figures 3 and 4;

[0045] Figure 6 is a signaling diagram illustrating an example of a network discovery procedure with a NF service consumer 203, NF service provider 204 and a NRF 600 according to some embodiments;

[0046] Figure 7 illustrates communication between a NF 700 and a service consumer node 750; Figure 8 is a signalling diagram illustrating an example implementation of the methods of Figures 3 and 4 in a diameter overload procedure in Cx domain;

[0047] Figure 9 is a signalling diagram illustrating an example implementation of the methods of Figures 3 and 4 in a diameter overload procedure in S6a domain;

[0048] Figure 10 illustrates an apparatus comprising processing circuitry (or logic);

[0049] Figure 11 is a block diagram illustrating an network node according to some embodiments; Figure 12 is a block diagram illustrating a network repository function (NRF) according to some embodiments;

[0050] Figure 13 is a block diagram illustrating a registration network node according to some embodiments.

[0051] DETAILED DESCRIPTION

[0052] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description

[0053] The following sets forth specific details, such as particular embodiments or examples for purposes of explanation and not limitation. It will be appreciated by one skilled in the art that other examples may be employed apart from these specific details. In some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g., analog and / or discrete logic gates interconnected to perform a specialized function, ASICs, PLAs, etc.) and / or using software programs and data in conjunction with one or more digital microprocessors or general purpose computers. Nodes that communicate using the air interface may have suitable radio communications circuitry. Moreover, where appropriate the technology can additionally be considered to be embodied entirely within any form of computer- readable memory, such as (ROM, EEPROM, Flash memory, a memory disc, RAM etc.) solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

[0054] Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g., digital or analogue) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and / or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

[0055] Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.

[0056] Particular embodiments are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0057] Embodiments described herein provide methods and apparatuses for enhancing, for example, existing procedures for example, the existing service based interface (SBI) load and overload control and the Diameter Overload Indication Conveyance (DOIC). In particular, embodiments described herein provide an overload traffic abatement process in which extended registration expiration timers are utilised to allow the network to dynamically extend the registration expiration timers and provide these extended timers to wireless devices upon success registration or re-registration with the network.

[0058] In overload situations, usually the network recovery time from severe overload is greater than the registration expiration timers and therefore registered users can become deregistered again due to rejection of re-registration. As a result, these users end up in a new initial registration request towards the network. Both initial registration and reregistration within the recovery time window will compete on the same available resources and both will be exposed to overload abatement throttling treatment. By extending the registration expiration timer, the incoming traffic during network recovery can be reduced. In particular, extended the registration expiration timer beyond the estimated recovery time will prevent already recovered and registered UEs from initiating re-registration during the recovery windows, which would risk the re-registration undergoing any ongoing abatement processes such as throttling and causing the wireless device to become deregistered again.

[0059] In some embodiments, the extension of the registration expiration timer may cease when the service provider node indicates that is no longer overloaded, or no longer expected to be overloaded. In this case, the original (or initial) registration expiration timer may be resumed and may be provided to UEs in the subsequent re-registration or registration requests.

[0060] It will be appreciated that embodiments described herein may be provided alongside any existing or future abatement processes such as throttling processes (e.g. loss (default) or overload rate control) or diversion of traffic.

[0061] Figure 2 illustrates a network system 200 comprising elements for use in implementing embodiments described herein. In this example, the system 200 comprises a wireless device 201 a registration network node 202, a NF service consumer 203 and a NF service provider 204.

[0062] It will be appreciated that in some examples, the NF service consumer 203 and the registration network node 202 are collocated or form part of the same network node. In other examples the NF service consumer 203 and NF service provider 204 are collocated or form part of the same network node. In other examples, all of the registration network node 202, NF service consumer 203 and NF service provider 204 are collocated or form part of the same network node.

[0063] The wireless device 201 may be configured to transmits registration requests to the registration network node 202. The registration network node may then handle registration of the wireless device 201 with the NF service provider 202, either directly or via the NF service consumer 203.

[0064] When the wireless device registers with the NF service provider, under normal circumstances (e.g. when the NF service provider is not, or is not expected to become, overloaded), it is provided with an initial registration expiration timer. This initial registration expiration timer may indicate to the wireless device when to perform reregistration with the NF service provider. The registration network node 202 may be preconfigurated with the value of the initial registration expiration timer. It will be appreciated that the value of the initial registration expiration timer may be different for different NF service providers or indeed for different wireless devices or types of registration procedure.

[0065] The NF service consumer 203 may communicate with the UE to provide the service provided by the NF service provider 204.

[0066] Figure 3 is a flowchart illustrating a method performed by a network node for enabling provision of a service to a first wireless device.

[0067] The network node may comprise a service consumer node (e.g. NF service consumer 203) or a service provider node (e.g. NF service provider 204). The network node, which may comprise a physical or virtual node, may be implemented in a computing device or server apparatus and / or in a virtualized environment, for example in a cloud, edge cloud or fog deployment.

[0068] In step 301 the method comprises obtaining a first indication that a service provider node (e.g. NF service provider 204) is or is expected to be overloaded. In other words, the indication may be obtained when the service provider node determines that it is overloaded (e.g. based on some predefined condition indicating overload). In other examples, the service provider node (or a node external to the service provided node) may comprise a predictive model capable of indicating a point in time at which the service provider node is expected to be overloaded. A predictive model may for example be trained using machine learning based on training data from load level indications and patterns that happened prior overload incidents.

[0069] In examples where the network node comprises the service provider node, step 301 may comprise determining that the service provide node is, or is expected to be, overloaded.

[0070] In examples where the network node comprises the service consumer node, step 301 may comprise receiving the indication form the service provider node. In step 302, responsive to obtaining the first indication, the method comprises initiating extension of an initial registration expiration timer to an extended registration expiration timer for at least a first registration request for the service provider node. It will be appreciated that the extended registration expiration timer is longer than the initial registration expiration timer. The initial registration expiration timer and the extended registration expiration timer are timers that are used to indicate to the first wireless device, at registration (or re-registration) when to perform re-registration with the service provider node.

[0071] How much longer the extended registration expiration timer is than the initial registration expiration timer may be a design choice. It will be appreciated that the greater the difference between the initial registration expiration timer and the extended registration expiration timer, the more the overload at the service provider node will be alleviated, as fewer registration or registration requests will be received at the service provider node whilst overload is ongoing. In some examples therefore, the amount that the initial registration expiration timer is extended may depend on a measure of how overloaded the service provider node is, or is expected to be.

[0072] The at least a first registration request may comprise an initial registration request or a re-registration request. The at least a first registration request may comprise a registration request for a registration procedure comprising one of: 5G Periodic registration, or 4G Attach refresh, or IMS initial registration, 5G periodic re-registration, LTE Attach refresh and IMS re-registration.

[0073] In examples in which the network node comprises a service consumer node, step 202 may comprise transmitting an instruction that an extended registration expiration timer is to be used to a service registration node. It will be appreciated that the service consumer node may, in this example, be unaware of the actual values of the initial registration expiration timer and extended registration expiration timer.

[0074] In examples in which the network node comprises a service consumer node, and the service consumer node is responsible for handling registration of the first wireless device (e.g. the service consumer node comprises the network registration node), step 202 may comprise receiving the first registration request from a first wireless device; forwarding the first registration request to the service provider node; and responsive to the first registration request being accepted, indicating the extended registration expiration timer to the first wireless device.

[0075] In some examples, the service consumer node may perform one or more abatement processes in order to aid in alleviation of the overload condition at the service provider node. These abatement process may comprise one or more of: throttling the traffic or diverting the traffic to other service provider nodes.

[0076] In some examples, therefore, the service consumer node may only forward the first registration request to the service provider node if the first registration request is not rejected by the one or more abatement processes.

[0077] In some examples, the network node performing the method of Figure 3 comprises the service provider node. In the examples, step 302 may comprise transmitting the first indication to a service consumer node. In other words, the service provider node may indicate to the service consumer node that it is overloaded. The service consumer node may then itself perform the method of Figure 3.

[0078] In some examples, step 302 may then further comprise the service provider node transmitting an instruction to the service consumer node to use the extended registration expiration timer. For example, in some examples, the network node may specifically instruct the service consumer node to extend the registration timers. In some examples, this instruction may simultaneously indicate that the service provider node has the capability to support extension of registration expiration timers (e.g. as in the example to be described later with reference to Figure 7).

[0079] However, in other examples, the service consumer node may already be aware of whether or not the service provider node supports extension of registration expiration timers, for example from a NF discovery procedure via a network repository function (NRF) (e.g. as will be described in more detail with reference to Figure 6)

[0080] For example, step 302 may further comprise the service provider node transmitting, to a first network node, a capability indication indicating that the service provider node supports the use of extended registration timers. The first network node may comprise the service consumer node or a network repository function. Figure 4 illustrates a method performed by a registration network node (e.g. registration network node 202 illustrated in Figure 2) for enabling provision of a service to a first wireless device. The registration network node is pre-configured with an initial registration expiration timer associated with a service provider node. The initial registration expiration timer is for indicating to a wireless device when to perform reregistration with the service provider node. In some examples the value of the initial registration expiration timer may depend on the service provided by the service provider node and / or the wireless device, for example a priority associated with the wireless device. It will be appreciated that in some examples, the service consumer node comprises the registration network node. Such a node may perform both the methods of Figures 3 and 4.

[0081] In step 401 the method comprises receiving an indication that an extended registration expiration timer is to be used for a first registration request, wherein the extended registration expiration timer is longer than the initial registration expiration timer.

[0082] In step 402 the method comprises receiving the first registration request from a first wireless device.

[0083] In step 403 the method comprises responsive to the first registration request being accepted by the service provider node, indicating the extended registration expiration timer to the first wireless device.

[0084] In some examples, the method of Figure 4 may further comprise, after step 401 , receiving an indication the initial registration expiration timer is to be used for subsequent registration requests and utilizing the initial registration expiration timer after receipt of such an indication. It will be appreciated the network registration node may utilize the initial or extended registration expiration timer dynamically as requested by the service consumer node or the service provider node.

[0085] Figure 5 illustrates an example implementation of the method of Figures 3 and 4. In this example the method of Figure 3 is performed by both the NF service provider 204 and the NF service consumer 203. The service consumer 203 also performs the method of Figure 4.

[0086] In this example, service based interface (SBI) overload control is being utilised. This may be based on HTTP status codes or on an Overload Control Information (OCI) header. The embodiment described with reference to Figure 5 may be considered an enhancement to the SBI overload control specified in 3GPP TS 29.500.

[0087] In step 501 a first wireless device 500 transmits a first registration request to the NF service consumer requesting to register the first wireless device with the NF service provider. The first registration request may comprise an initial registration request (for a new registration) or a re-registration request.

[0088] In step 502 the NF service consumer 203 forwards the first registration request to the NF service provider 204.

[0089] At step 503 the NF service provide 204 determines that it is overloaded. The criteria for determining that the NF service provider is overloaded may be, for example, when the number of incoming service requests exceeds the maximum number of messages supported by the NF service provider. The available resources at the NF service provider, such as processing power or memory, may not be sufficient to serve the number of incoming requests. It will be appreciated that how the NF service provider determines that it is overloaded may be implementation specific. Step 503 comprises an example implementation of step 301 performed by the NF service provider.

[0090] In step 504, the NF service provider 204 indicates to the NF service consumer 203 that it is overloaded. Step 504 comprises an example implementation of step 301 performed by the NF service consumer 203 and step 302 performed by the NF service provider 204.

[0091] Step 504 also comprises an example implementation of step 401 of Figure 4 (which in this example is performed by the NF service consumer). In this example, the indication that the NF service provider 204 is overloaded may be understood by the NF service consumer 203 as an indication that an extended registration expiration timer is to be used for a second registration request.

[0092] In particular, in step 504, the NF service provider 204, may reject the first registration request received in step 502. In the rejection response the NF service provider may indicate that NF_CONGESTION is the reason for the rejection.

[0093] If OCI feature is supported by NF Service Provider, the OCI header may comprise one or more of the following parameters: an indication of for how long the NF service provider should be considered overloaded, e.g. a validity timer (Period-of-Validity), an indication of a percentage of traffic towards the NF service provider 204 that the NF service consumer should reduce, e.g. a reduction percentage value (Reduction- Metric), and an indication that an extended registration expiration timer should be used, e.g. a Boolean value (Registration-Extension-Timer). When Registration-Extension-Timer is set to true this may be considered to indicate that an extended registration expiration timer should be implemented by the NF service consumer.

[0094] Alternatively, the above parameters may be communicated to the NF service consumer in some other format.

[0095] In the example of Figure 5 therefore the NF service provider 204 directly instructs the NF service consumer 203 to extend the registration expiration timer by including the Registration-Extension-Timer set to “True” in the OCI header. However, it will be appreciated that in some examples no such instruction is included, and the NF service consumer may take the indication that the NF service provider 204 is overloaded as an implicit instruction to extend the registration expiration timer.

[0096] The following gives an example of an OCI header. This is taken from TS 29.500, sections 6.4.1 , 6.4.2 and the changes by virtue of the embodiments described herein are in bold and underlined.

[0097] Header : 3gpp-Sbi-Oci

[0098] Sbi-Oci-Header = "3gpp-Sbi-Oci : " OWS oci-element * ( OWS " OWS oci-element ) OWS oci-element = timestamp RWS validityPeriod RWS olcMetric RWS olcScope timestamp = "Timestamp : " RWS DQUOTE date-time DQUOTE validityPeriod = "Period-of-Validity : " RWS 1 *DIGIT "s" olcMetric = "Overload-Reduction-Metric : " RWS ( " 100" /

[0099] %x31 -39 DIGIT / DIGIT ) "%" olcExtRegTimer = "Registration-Extension-Timer : " OWS registration-timer-value olcScope = nf Producerscope / nf ConsumerScope / s cpScope / seppScope nf Producerscope = ( ( "NF- Instance : " RWS nfinst )

[0100] / ( "NF-Set : " RWS nfset ) / ( "NF-Service-Instance : " RWS nfservinst [ RWS "NF-Inst : " RWS nfinst ] )

[0101] / ( "NF-Service-Set : " RWS nf serviceset )

[0102] ) [ RWS sNssaiList RWS dnnList ] nf ConsumerScope = ( "NFC-Instance : " RWS nfinst [ RWS "Service-Name : " RWS servname ] )

[0103] / ( "NFC-Set : " RWS nfset [ RWS "Service- Name : " RWS servname ] )

[0104] / ( "NFC-Service-Instance : " RWS nfservinst [" ; " RWS "NF-Inst : " RWS nfinst ] )

[0105] / ( "NFC-Service-Set : " RWS nf serviceset )

[0106] / ( "Callback-Uri : " RWS DQUOTE URI DQUOTE * ( RWS RWS DQUOTE URI DQUOTE ) ) servname = token scpScope = "SCP-FQDN : " RWS fqdn seppScope = "SEPP-FQDN : " RWS fqdn fqdn = token dnnList = "DNN : " RWS l *tchar * ( l*tchar ) sNssaiList = "S-NSSAI : " RWS snssai * ( RWS " &" RWS snssai ) snssai l *tchar registration- timer-value = "true" / "false"

[0107] In step 505, the NF Service Consumer 203 indicates to the first wireless device that the first registration request has been rejected. The reason of “congestion” may be included.

[0108] In step 506, the NF Service Consumer, responsive to receiving the indication that the NF service provider is overloaded in step 504, the NF service consumer determines which mechanisms to utilise in order to reduce the traffic to the NF service provider 204 as requested (e.g. as indicated by the Reduction-Metric parameter). The NF service consumer 203 may determine which of the available legacy mechanisms to utilise (e.g. throttling or dispersion of new registrations requests). In this example, as the NF service consumer 203 has been directly requested to extend the registration expiration timer (by virtue of the Registration-Extension-Timer set to “True” in the OCI header), the NF service consumer may also be configured to extend the registration expiration timer.

[0109] In some examples, however, the NF service consumer 203 may determine whether to extend the registration expiration timer. This determination may be based on an indication of whether the NF service provider is capable of supporting an extended registration expiration timer. This capability indication may be obtained by the service consumer 203 from a network repository function (NRF), as will be described later with reference to Figure 6. It will be appreciated that the NF service consumer 203 may only opt to utilise an extended registration expiration timer if the NF service provider is capable of supporting this option.

[0110] The purpose of extending the registration expiration timer is to reduce the frequency of re-registration procedures from UEs, and therefore reducing the number of messages related to re-registration from the UEs towards the NF Service consumer 203. This means there will be a reduction of the re-registration messages that would be impacted by the legacy abatement algorithms (throttling and diverse mechanisms). This may therefore improve the quality of service experienced by the UEs.

[0111] In step 507 a second wireless device 550 transmits a second registration request to the NF service consumer requesting to register the second wireless device with the NF service provider. The second registration request may comprise an initial registration request or a re-registration request. It will be appreciated that the second wireless device 550 may comprise the first wireless device 500. Step 507 comprises an example implementation of step 402 of Figure 4.

[0112] In step 508, the NF Service Consumer applying one or more abatement processes (e.g. throttling and diverse mechanisms). The one or more abatement processes may have been selected by the NF service consumer 203 or requested by the NF service provider 204. In this example, the second registration request passes through the one or more abatement processes and is transmitted to the NF service provider 204 in step 509.

[0113] Even when the NF service provider 204 is overloaded, the NF service provider 204 will be able to successfully manage some percentage of the registration requests that are received. Therefore, in this example it is assumed that the registration is managed successfully by the NF service provider 204 in step 510.

[0114] In step 511 , the NF service provider 204 indicates that the second registration request was successful to the NF service consumer 203.

[0115] In step 512, the NF service consumer 203, responsive to receiving the response from the NF service provider 204 in step 511 , indicates the extended registration expiration timer to the second wireless device. In particular, the NF service consumer 203 indicates to the second wireless device in step 512 that the second registration request has been accepted by the NF service provider 204. Step 512 comprises an example implementation of step 302 when performed by the NF service consumer 203.

[0116] In some examples, it will be appreciated that the length of the extended registration expiration timer may be determined by the NF service provider 204. In some examples, the NF service provider 204 may set the extended registration expiration timer to a value that will expire after the Period-of-Validity provided by the NF service provider in the OCI header in step 504.

[0117] In step 513 the overload status of the NF service provider 204 comes to an end. This may occur due to either the validity timer Period-of-Validity expiring, or due to the NF service provider 204 indicating to the NF service consumer 203 that it is no longer overloaded. For example, the NF service provider 204 may provided to the NF service consumer 203 a Reduction-Metric value of 0. At this point, the NF service consumer 203 may return the value of the registration expiration timer to the initial registration expiration timer configured prior to step 504. In some examples therefore step 513 may comprise the NF service consumer, obtaining a second indication that the NF service provider 204 is no longer or is no longer expected to be overloaded. In other examples, step 513 may comprise the validity timer expiring.

[0118] The NF service consumer 203 may then initiate use of the initial registration timer for any registration requests received after step 513, but prior to any further indication of an overload status at the NF service provider 204.

[0119] In step 514 a third registration request is received at the NF service consumer 203 from a third wireless device 560. In step 515 the NF service consumer 203 passes the third registration request to the NF service provider 204. In step 516 the NF service consumer 203 receives a response from the NF service provider 204 indicating that the third registration request has been successful.

[0120] Then, responsive to obtaining the second indication or the validity timer expiring, the NF service consumer 203 initiates use of the initial registration timer for the third registration request, for example, by transmitting the initial registration expiration timer to the third wireless device in the response to the third registration request in step 517.

[0121] In some examples, step 302 of Figure 3 may be performed by the NF service consumer node responsive to obtaining a capability indication that the service provider node supports the use of an extended registration expiration timer. In some examples, this capability indication may be received directly from the NF service provider 204 (e.g. as will be described with reference to Figure 7), however in other examples this capability indication may be obtained from a Network Repository Function (NRF), for example, during a network discovery procedure.

[0122] Figure 6 is a signaling diagram illustrating an example of a network discovery procedure with a NF service consumer 203, NF service provider 204 and a NRF 600 according to some embodiments.

[0123] In step 601 the NRF 600 receives, from the network service provider 204, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers. The capability indication may comprise a Boolean value. The capability indication may be received as part of a update or initial registration of the NF service provider 204 with the NRF. In particular the NRF may receive in step 601 an NFProfile from the network service provider 204. The NFProfile may comprise an olcHSupportlnd attribute indicating support of an Overload protection mechanism. The attribute olcHExtRegTimer may be utilised to indicate the support of extended registration expiration timers.

[0124] In step 602, the NRF stores the capability indication in an entry for the NF service provider 204. It will be appreciated that the entry for the NF service provider may further comprise a type of service that the NF service provider 204 can provide.

[0125] In step 603, the NRF may acknowledge the update or registration of step 601.

[0126] In step 604, the NRF receives a request, from a NF service consumer, for a network function capable of providing the type of service.

[0127] In step 605, responsive to receiving the request in step 604, the NRF 600 transmits an indication to the NF service consumer 203 of the NF service provider 204. In step 605 the NRF may also transmit the capability indication to the NF service consumer.

[0128] Figures 5 and 6 illustrate implementations of embodiments described herein in a SBI context. However, it will be appreciated that the embodiments of the invention may be provided in other contexts, e.g. for other forms of communication such as Diameter Overload Information Conveyance (DOIC) between Diameter nodes. In this context, the network service consumer may comprise a CSCF (e.g. as illustrated in Figure 8) ora MME / SGSN (e.g. as illustrated in Figure 9). The network service provider 204 may comprise a network function such as HSS or UDR (e.g. as illustrated in either of Figure 8 or 9.

[0129] In the example of Diameter nodes, the capability indication of whether the 5GC network function supports the use of an extended registration expiration timer may be provided by the 5GC network function to the service consumer node in every diameter communication between the two nodes. It will appreciated that the concepts presented in Figure 5 may be applicable in the context of communication between diameter nodes as well.

[0130] Figure 7 illustrates communication between a NF 700 (e.g. HSS / UDR) and a service consumer node 750 (e.g. a diameter reacting node) /

[0131] In step 701 the diameter reacting node transmits a diameter request to the NF. The diameter request comprises the overload control (OC) -Supported-Feature Attribute Value Pair (AVP).

[0132] In step 702, the NF transmits a diameter answer to the diameter request of step 701. The diameter answer comprises the OC-Supported-Feature AVP.

[0133] For example, the grouped OC-Supported-Feature AVP may comprise the OC-Feature- Vector AVP. This OC-Feature-Vector AVP may comprise a flag value which, when set indicates that the NF supports the use of extended registration expiration timer. It will be appreciated that the OC-Feature Vector AVP may comprise other flag values that indicate support of one or more other abatement processes.

[0134] Similarly, the OC-Supported-Feature AVP may also comprise the OC-Peer-Algo AVP. The OC-Peer-Algo AVP may comprise a flag of value which, when set, indicates that the extended of the registration expiration timer is instructed by the NF. It will be appreciated that the OC-Peer-Algo AVP may comprise other flag values that indicate that one or more other abatement processes are to be used, or combinations of abatement processes are to be used. Figure 8 is a signalling diagram illustrating an example implementation of the methods of Figures 3 and 4 in a diameter overload procedure in Cx domain.

[0135] In step 801 , a first wireless device (UE A) transmits a first registration request to the CSCF 750 requesting to register the first wireless device with the HSS 700. In this example, an SIP registration procedure is used. It will be appreciated that the first registration request may comprise an initial registration request or a re-registration request.

[0136] At step 802, the CSCF 750 forwards the first registration request to the HSS 700, for example by transmitting a corresponding Cx message (UAR / MAR or SAR) to the HSS. As mentioned in the description of Figure 7, the communication between the CSCF 750 and HSS 700 may include the OC-Supported-Features AVP.

[0137] In step 803, the HSS 700 determines that it is overloaded. The criteria for determining that the HSS 700 is overloaded may be, for example, when the number of incoming service requests exceeds the maximum number of messages supported by the HSS 700. The available resources at the HSS, such as processing power or memory, may not be sufficient to serve the number of incoming requests. It will be appreciated that how the HSS determines that it is overloaded may be implementation specific. Step 803 comprises an example implementation of step 301 performed by the HSS.

[0138] In step 804, the HSS 700 indicates to the CSCF 750 that it is overloaded. For example, the HSS may answer the Cx request with an error response message, for example, DIAMETER_TOO_BUSY or UNABLE_TO_COMPLY (e.g. depending on the potential redirection of the first registration request). The error response message may comprise the OC-Supported-Feature AVP and OC-OLR AVP conveying the overload report. Step 804 comprises an example implementation of step 301 performed by the CSCF 750 and step 302 performed by the HSS 700.

[0139] Step 804 also comprises an example implementation of step 401 of Figure 4 (which in this example is performed by the CSCF). In this example, the OC-Supported-Feature AVP may comprise the indication that an extended registration expiration timer is to be used for a second registration request.

[0140] The embodiments described herein propose an enhancement to DOIC which allows the HSS to one or more other abatement process (e.g. legacy abatement processes) in addition to requesting that an extended registration expiration timer is used. For example, table 1 below may be utilised to provide AVPs indicating which one or more abatement processes are to be used by the CSCF.

[0141] In step 805, the CSCF 750 indicates to the first wireless device that the first registration request has been rejected. The reason of the overload at the HSS may be included.

[0142] In step 806, a second wireless device (UE B) transmits a second registration request to the CSCF to register the second wireless device with the HSS. The second registration request may comprise an initial registration request or a re-registration request. It will be appreciated that the second wireless device may comprise the first wireless device. Step 806 comprises an example implementation of step 402 of Figure 4.

[0143] If the loss or rate abatement processes have been selected in addition to “Extend- registration-expiration-timer" by the HSS reporting node (and indicated in to the CSCF in step 804), the CSCF may apply in step 807 the requested abatement processes to any new registration request received from a UE. This means that not all registration requests received from UEs will be sent to HSS due to throttling and diverse mechanisms applied according to the selected processes. In this example, the second registration request passes through the one or more abatement processes and is transmitted to the HSS in step 808.

[0144] Even when the HSS is overloaded, the HSS will be able to successfully manage some percentage of the registration requests that are received. Therefore, in this example it is assumed that the registration is managed successfully by the HSS in step 809.

[0145] In step 810, the HSS indicates that the second registration request was successful to the CSCF.

[0146] In step 811 the CSCF 750, responsive to receiving the response from the HSS in step 810, indicates the extended registration expiration timer to the second wireless device. In particular, the CSCF 750 indicates to the second wireless device in step 811 that the second registration request has been accepted by the HSS. Step 811 comprises an example implementation of step 302 when performed by the CSCF.

[0147] In some examples, it will be appreciated that the length of the extended registration expiration timer may be determined by the HSS. In some examples, the HSS may set the extended registration expiration timer to a value that will expire after a validity timer (e.g. OC-validity-Duration) provided by the HSS in the OC-OLR AVP in step 804.

[0148] In step 812 the overload status of the HSS comes to an end. This may occur due to either the validity timer OC-validity-Duration expiring, or due to the HSS indicating to the CSCF that it is no longer overloaded. For example, the HSS may provide to the CSCF an OC-Reduction-Percentage AVP (e.g. within the OC-OLR AVP) equal to 0. At this point, the CSCF may return the value of the registration expiration timer to the initial registration expiration timer configured prior to step 804. In some examples therefore step 812 may comprise the CSCF, obtaining a second indication that the HSS is no longer or is no longer expected to be overloaded. In other examples, step 812 may comprise the validity timer expiring.

[0149] The CSCF may then initiate use of the initial registration timer for any registration requests received after step 812, but prior to any further indication of an overload status at the HSS.

[0150] In step 813 a third registration request is received at the CSCF from a third wireless device (UE C). In step 814 the CSCF passes the third registration request to the HSS. In step 815 the CSCF receives a response from the HSS indicating that the third registration request has been successful.

[0151] Then, responsive to obtaining the second indication or the validity timer expiring (in step 812), the CSCF initiates use of the initial registration timer for the third registration request, for example, by transmitting the initial registration expiration timer to the third wireless device in the response to the third registration request in step 816.

[0152] Figure 9 is a signalling diagram illustrating an example implementation of the methods of Figures 3 and 4 in a diameter overload procedure in S6a domain.

[0153] In step 901, a first wireless device (UE A) transmits a first registration request to the Mobility Management Entity (MME) / Serving GPRS Support Node (SGSN) 900 requesting to register the first wireless device with the HSS 700. It will be appreciated that the first registration request may comprise an initial registration request or a re- registration request. The first registration request may be referred to as an Initial Attach or Re-Attach procedure.

[0154] At step 902, the MME / SGSN 900 forwards the first registration request to the HSS 700, for example by transmitting a corresponding S6a message (Authentication Information Request (AIR) or Update Location Request (ULR)) to the HSS. As mentioned in the description of Figure 7, the communication between the MME / SGSN 900 and HSS 700 may include the OC-Supported-Features AVP.

[0155] In step 903, the HSS 700 determines that it is overloaded. The criteria for determining that the HSS 700 is overloaded may be, for example, when the number of incoming service requests exceeds the maximum number of messages supported by the HSS 700. The available resources at the HSS, such as processing power or memory, may not be sufficient to serve the number of incoming requests. It will be appreciated that how the HSS determines that it is overloaded may be implementation specific. Step 903 comprises an example implementation of step 301 performed by the HSS.

[0156] In step 904, the HSS 700 indicates to the MME / SGSN 900 that it is overloaded. For example, the HSS may answer the S6a request with an error response message, for example, DIAMETER_TOO_BUSY or UNABLE_TO_COMPLY (e.g. depending on the potential redirection of the first registration request). The error response message may comprise the OC-Supported-Feature AVP and OC-OLR AVP conveying the overload report. Step 904 comprises an example implementation of step 301 performed by the MME / SGSN 900 and step 302 performed by the HSS 700.

[0157] Step 904 also comprises an example implementation of step 401 of Figure 4 (which in this example is performed by the MME / SGSN). In this example, the OC-Supported- Feature AVP may comprise the indication that an extended registration expiration timer is to be used for a second registration request.

[0158] The embodiments described herein propose an enhancement to DOIC which allows the HSS to one or more other abatement process (e.g. legacy abatement processes) in addition to requesting that an extended registration expiration timer is used.

[0159] For example, table 1 below may be utilised to provide AVPs indicating which one or more abatement processes are to be used by the MME / SGSN 900.

[0160] In step 905, the MME / SGSN 900 indicates to the first wireless device that the first registration request has been rejected. The reason of the overload at the HSS may be included.

[0161] In step 906, a second wireless device (UE B) transmits a second registration request to the MME / SGSN 900 to register the second wireless device with the HSS. The second registration request may comprise an initial registration request or a re-registration request. It will be appreciated that the second wireless device may comprise the first wireless device. Step 906 comprises an example implementation of step 402 of Figure 4.

[0162] If the loss or rate abatement processes have been selected in addition to “Extend- registration-expiration-timer" by the HSS reporting node (and indicated in to the MME / SGSN 900 in step 904), the MME / SGSN 900 may apply in step 907 the requested abatement processes to any new registration request received from a UE. This means that not all registration requests received from UEs will be sent to HSS due to throttling and diverse mechanisms applied according to the selected processes. In this example, the second registration request passes through the one or more abatement processes and is transmitted to the HSS in step 908.

[0163] Even when the HSS is overloaded, the HSS will be able to successfully manage some percentage of the registration requests that are received. Therefore, in this example it is assumed that the registration is managed successfully by the HSS in step 909.

[0164] In step 910, the HSS indicates that the second registration request was successful to the MME / SGSN 900.

[0165] In step 911 the MME / SGSN 900, responsive to receiving the response from the cHSS in step 910, indicates the extended registration expiration timer (e.g. extended TAU timer) to the second wireless device. In particular, the MME / SGSN 900 indicates to the second wireless device in step 911 that the second registration request has been accepted by the HSS. Step 911 comprises an example implementation of step 302 when performed by the MME / SGSN 900.

[0166] In some examples, it will be appreciated that the length of the extended registration expiration timer may be determined by the HSS. In some examples, the HSS may set the extended registration expiration timer to a value that will expire after a validity timer (e.g. OC-validity-Duration) provided by the HSS in the OC-OLR AVP in step 904.

[0167] In step 912 the overload status of the HSS comes to an end. This may occur due to either the validity timer OC-validity-Duration expiring, or due to the HSS indicating to the MME / SGSN 900 that it is no longer overloaded. For example, the HSS may provide to the MME / SGSN 900 an OC-Reduction-Percentage AVP (e.g. within the OCOLR AVP) equal to 0. At this point, the MME / SGSN 900 may return the value of the registration expiration timer to the initial registration expiration timer configured prior to step 904. In some examples therefore step 912 may comprise the MME / SGSN 900, obtaining a second indication that the HSS is no longer or is no longer expected to be overloaded. In other examples, step 912 may comprise the validity timer expiring.

[0168] The MME / SGSN 900 may then initiate use of the initial registration timer for any registration requests received after step 912, but prior to any further indication of an overload status at the HSS.

[0169] In step 913 a third registration request is received at the MME / SGSN 900 from a third wireless device (UE C). In step 914 the MME / SGSN 900 passes the third registration request to the HSS. In step 915 the MME / SGSN 900 receives a response from the HSS indicating that the third registration request has been successful.

[0170] Then, responsive to obtaining the second indication or the validity timer expiring (in step 912), the MME / SGSN 900 initiates use of the initial registration timer for the third registration request, for example, by transmitting the initial registration expiration timer to the third wireless device in the response to the third registration request in step 916.

[0171] Re-registration during network recovery is one example of procedures that contributes to worsen the overload situation. The increase of the registration refresh timer is one reactive action taken by the operator when network overload arises. This action is done manually by human intervention.

[0172] Embodiments described herein allow the network to automatically and dynamically react upon overload by enforcing the registration expiration timer’s extension, for example, beyond the expected recovery time and hence prevent the registered UEs to re-enter the network.

[0173] Embodiments described herein reduce the frequency of re-registration procedures from end users, reducing in this way the number of messages related to re-registration impacted by the other abatement processes (e.g. throttling). Additionally, the reduction of the amount of re-registration procedures due to the extension of the registration expiration timer will provide room for other procedures to be completed successfully, increasing the traffic success rate despite the other abatement processes.

[0174] The extension of the registration expiration timer is an alternative that will increase the probability of successful initial registration and other procedures by offloading network for re-registration related requests during the network recovery windows. This approach will speed up the overload recovery time and a faster regain of the services.

[0175] As described above, other abatement processes may be used in tangent with the extension to the registration expiration timer, for example throttling and traffic redirection. Indeed, combining one or more other abatement processes with the extension to the registration expiration timer may lead to more effective and faster network recovery leading to a faster regain of end user services.

[0176] Figure 10 illustrates an apparatus 1000 comprising processing circuitry (or logic) 1001. The processing circuitry 1001 controls the operation of the apparatus 1000 and can implement the method described herein in relation to an apparatus 1000. The processing circuitry 1001 can comprise one or more processors, processing units, multicore processors or modules that are configured or programmed to control the apparatus 1000 in the manner described herein. In particular implementations, the processing circuitry 1001 can comprise a plurality of software and / or hardware modules that are each configured to perform, or are for performing, individual or multiple steps of the method described herein in relation to the apparatus 1000. It will be appreciated that the apparatus 1000 may comprise one or more virtual machines running different software and / or processes. The apparatus 1000 may therefore comprise, or be implemented in or as one or more servers, switches and / or storage devices and / or may comprise cloud computing infrastructure that runs the software and / or processes.

[0177] Optionally, the apparatus 1000 may comprise a memory 1003. In some embodiments, the memory 1003 of the apparatus 1000 can be configured to store instructions (e.g. program code) executable by the processing circuitry 1001 of the apparatus 1000 whereby the apparatus is operable to perform the method as described with reference to Figures 3 or 4, or the method of the registration network node in Figure 7.

[0178] Alternatively or in addition, the memory 1003 of the apparatus 1000, can be configured to store any requests, resources, information, data, signals, or similar that are described herein. The processing circuitry 1001 of the apparatus 1000 may be configured to control the memory 1003 of the apparatus 1000 to store any requests, resources, information, data, signals, or similar that are described herein

[0179] In some embodiments, the apparatus 1000 may optionally comprise a communications interface 1002. The communications interface 1002 of the apparatus 1000 can be for use in communicating with other nodes, such as other virtual nodes. For example, the communications interface 1002 of the apparatus 1000 can be configured to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The processing circuitry 1001 of apparatus 1000 may be configured to control the communications interface 1002 of the apparatus 1000 to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The communications interface 1002 can use any suitable communication technology.

[0180] The apparatus 1000 may be configured operate in the manner described herein in respect of a network function (e.g. a NF service consumer, and NF service provider or a network repository function) or a registration network node.

[0181] Figure 11 is a block diagram illustrating an network node 1100 according to some embodiments. The network node 1100 is for enabling provision of a service to a first wireless device. The network node 1100 comprises an obtaining module 1102 configured to obtain a first indication that a service provider node is or is expected to be overloaded. The network node 1100 further comprises an initiating module 1104 configured to responsive to obtaining the first indication, initiate extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node. The extended registration expiration timer is longer than an initial registration expiration timer and the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node. The network node 1100 may operate in the manner described herein in respect of a network node, for example, a service consumer node (e.g. NF service consumer) or a service provider node (e.g. NF service provider).

[0182] Figure 12 is a block diagram illustrating a network repository function (NRF) 1200 according to some embodiments. The NRF 1200 may be for enabling provision of a service to a first wireless device. The NRF 1200 comprises a receiving module 1202 configured to receive, from a network service provider, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers. The NRF further comprises a storing module 1204 configured to store the capability indication in an entry for the network service provider. The NRF 1200 may operate in the manner described herein in respect of an NRF.

[0183] Figure 13 is a block diagram illustrating a registration network node 1300 according to some embodiments. The registration network node 1300 may be for enabling provision of a service to a first wireless device. The registration network node may be adapted to be pre-configured with an initial registration expiration timer associated with a service provider node, wherein the initial registration expiration timer is for indicating to a wireless device when to perform re-registration with the service provider node.

[0184] The registration network node 1300 comprises a first receiving module 1302 configured to receive an indication that an extended registration expiration timer is to be used for a first registration request, wherein the extended registration expiration timer is longer than the initial registration expiration timer. The registration network node 1300 comprises a second receiving module 1304 configured to receive the first registration request from a first wireless device. The registration network node 1300 further comprises an indicating module 1306 configured to, responsive to the first registration request being accepted by the service provider node, indicate the extended registration expiration timer to the first wireless device. The registration network node 1300 may operate in the manner described herein in respect of a registration network node, which in some examples is implemented as part of a service consumer node (e.g. NF service consumer).

[0185] There is also provided a computer program comprising instructions which, when executed on a least one processor (such as the processing circuitry 1001 of the apparatus 1000 described earlier), cause the processor to carry out at least part of the method(s) described herein. According to some embodiments there is provided a carrier containing the computer program. 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 medium. There is also provided a (for example, tangible and / or non-transient) computer-readable medium comprising instructions which, when executed by at least one processor, cause the at least one processor to perform at least part of the method(s) described herein.

[0186] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments 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

CLAIMS1. A method performed by a network node for enabling provision of a service to a first wireless device, the method comprising: obtaining a first indication that a service provider node is or is expected to be overloaded; and responsive to obtaining the first indication, initiating extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node, wherein the extended registration expiration timer is longer than an initial registration expiration timer and wherein, the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node.

2. The method as claimed in claim 1 wherein the registration request comprises a registration request for a registration procedure comprising one of:Initial 5G registration, Initial LTE attach, initial IMS registration, 5G Periodic registration, or 4G Attach refresh, or IMS re-registration.

3. The method of claims 1 or 2 further comprising: obtaining a second indication that the service provider node is no longer [or is no longer expected to be] overloaded; and responsive to obtaining the second indication, initiating use of the initial registration timer for at least a second registration request.

4. The method as claimed in any one of claims 1 to 3 wherein the network node comprises a service consumer node.

5. The method of claim 4 wherein initiating extension of the initial registration expiration timer comprises: receiving the first registration request from a first wireless device; forwarding the first registration request to the service provider node; and responsive to the first registration request being accepted, indicating the extended registration expiration timer to the first wireless device.

6. The method of claim 5 further comprising: forwarding the first registration request to the service provider node responsive to the first registration request not being rejected by one or more abatement processes.

7. The method of claim 4 wherein initiating extension of the initial registration expiration timer comprises, transmitting an instruction that an extended registration expiration timer is to be used to a service registration node.

8. The method of claim 4 to 7 further comprising: responsive to a validity timer expiring, wherein the validity timer is associated with the extended registration expiration timer, initiating use of the initial registration expiration timer for at least a second registration request.

9. The method of any one of claims 4 to 8, further comprising: initiating use of the extended registration expiration timer responsive to obtaining a capability indication that the service provider node supports the use of an extended registration expiration timer.

10. The method of claim 9 further comprising receiving the capability indication in a message from the service provider node.

11. The method of claim 9 further comprising receiving the capability indication in a message from a network repository function, NRF.

12. The method of claim 9 further comprising receiving the capability indication during a network function discovery procedure.

13. The method of any one of claims 4 to 12 wherein obtaining the first indication comprises receiving the first indication from the service provider node.

14. The method of any one of claims 4 to 13 further comprising receiving an instruction from the service provider node that the extended registration expiration timer should be used for the first registration request.

15. The method of any one of claims 1 to 3, wherein the network node comprises the service provider node, and wherein initiating extension of the initial registration expiration timer comprises: transmitting the first indication to a service consumer node.

16. The method as claimed in claim 15 wherein initiating extension of the initial registration expiration timer may further comprise: transmitting an instruction to the service consumer node to use the extended registration expiration timer.

17. The method of claim 15 or 16, wherein initiating extension of the initial registration expiration timer may further comprise: transmitting, to a first network node, a capability indication indicating that the service provider node supports the use of extended registration timers.

18. The method as claimed in claim 17 wherein the first network node comprises the service consumer node.

19. The method as claimed in claim 18 wherein the first network node comprises a network repository function, NRF.

20. The method as claimed in any one of claims 16 to 19 further comprising: transmitting, to the service consumer node, an indication of one or more abatement processes to be applied by the service consumer node alongside the extended registration expiration timer.

21. A method performed by a network repository function, for enabling provision of a service to a first wireless device, wherein the method comprises: receiving, from a network service provider, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers; and storing the capability indication in an entry for the network service provider.

22. The method of claim 21 wherein the entry further comprises a type of service that the network service provider can provide.

23. The method as claimed in claim 22 further comprising:responsive to receiving a request, from a network service consumer, for a network function capable of providing the type of service, transmitting an indication to the network service consumer of the network service provider; and transmitting the capability indication to the network service consumer.

24. A method performed by a registration network node for enabling provision of a service to a first wireless device, wherein the registration network node is preconfigured with an initial registration expiration timer associated with a service provider node, wherein the initial registration expiration timer is for indicating to a wireless device when to perform re-registration with the service provider node, the method comprising: receiving an indication that an extended registration expiration timer is to be used for a first registration request, wherein the extended registration expiration timer is longer than the initial registration expiration timer; receiving the first registration request from a first wireless device; and responsive to the first registration request being accepted by the service provider node, indicating the extended registration expiration timer to the first wireless device.

25. A network node for enabling provision of a service to a first wireless device, the network node comprising processing and a memory, the memory containing instructions executable by the processing circuitry whereby the network node is operable to: obtain a first indication that a service provider node is or is expected to be overloaded; and responsive to obtaining the first indication, initiate extension of an initial registration expiration timer to an extended registration expiration for at least a first registration request to the service provider node, wherein the extended registration expiration timer is longer than an initial registration expiration timer and wherein, the initial registration expiration timer and the extended registration expiration timer are for indicating to a wireless device when to perform re-registration with the service provider node.

26. The network node as claimed in claim 25 wherein the memory further contains instructions executable by the processing circuitry whereby the network node is operable to perform the method as claimed in any one of claims 2 to 20.

27. A network repository function, for enabling provision of a service to a first wireless device, the network repository function comprising processing and a memory, the memory containing instructions executable by the processing circuitry whereby the network repository function is operable to: receive, from a network service provider, a capability indication of whether the network service provider is capable of supporting extended registration expiration timers; and store the capability indication in an entry for the network service provider.

28. The network repository function as claimed in claim 27 wherein the memory further contains instructions executable by the processing circuitry whereby the network node is operable to perform the method as claimed in any one of claims 22 to 23.

29. A registration network node for enabling provision of a service to a first wireless device, wherein the registration network node is adapted to be pre-configured with an initial registration expiration timer associated with a service provider node, wherein the initial registration expiration timer is for indicating to a wireless device when to perform re-registration with the service provider node, the registration network node comprising processing and a memory, the memory containing instructions executable by the processing circuitry whereby the registration network node is operable to: receive an indication that an extended registration expiration timer is to be used for a first registration request, wherein the extended registration expiration timer is longer than the initial registration expiration timer; receive the first registration request from a first wireless device; and responsive to the first registration request being accepted by the service provider node, indicate the extended registration expiration timer to the first wireless device.

30. A computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out a method according to any of claims 1 to 23.

31. A carrier containing the computer program according to claim 30, wherein the carrier comprises one of an electronic signal, optical signal, radio signal or computer readable storage medium.

32. A computer-readable medium comprising instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to any of claims 1 to 2333. A computer program product comprising non transitory computer readable media having stored thereon a computer program according to claim 30.

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