Method and apparatus for performing service subscription

Abstract

The present disclosure provides a method for a first network element in a communication network to perform service subscription of a UE, comprising: in response to receiving a request including service subscription information of the UE from a second network element serving the UE and assisting in service, cross-referencing the consistency of the service subscription information of the UE in the request with the stored service subscription information of the UE; and in response to inconsistency, initiating an update of the service subscription of the UE in the second network element according to the stored service subscription information of the UE. Corresponding devices, computer-readable storage media, carriers, etc. are also provided.

Description

Technical Field

[0001] The present disclosure relates generally to the field of communication technology, and more particularly to methods, devices, computer-readable storage devices, carriers, etc. for performing service subscription. Background Art

[0002] This section is intended to provide background for various embodiments of the technology described in this disclosure. The descriptions in this section may include concepts that may be pursued, but not necessarily concepts that have been previously conceived or pursued. Therefore, unless otherwise stated herein, what is described in this section is not prior art to the specification and / or claims of the present disclosure, and is not admitted to be prior art merely by inclusion in this section.

[0003] 3GPP TS 23.501 and 23.502 formulate the event open architecture of 5GC (fifth generation core), in which several network functions such as UDM (unified data management), AMF (access and mobility management function), SMF (session management function) and PCF (policy control function) implement interfaces for exfiltrating data sent to multiple interested parties. This is the so-called network event open technology, which is based on consumers subscribing to certain UE-related events at NF (network function) and receiving subsequent notifications related to that subscribed event.

[0004] In particular, 3GPP TS 23.502 defines in clause 4.15.3.2.3 a mechanism whereby an event-expanding subscriber, such as a NEF (Network Exposure Function), subscribes at a UDM to events related to access, mobility and sessions of a specific UE. Figure 1 The concept is shown, where problems may arise. Summary of the invention

[0005] The present disclosure is directed to solving one or more of the problems that arise in service subscriptions.

[0006] According to one embodiment of the present disclosure, a method for a first network element in a communication network to perform service subscription for a user equipment UE is provided, comprising: in response to receiving a request including a UE from a second network element that serves the UE and assists in the service, cross-referencing the consistency of the service subscription information of the UE in the request with the storage service subscription information of the UE; and in response to the inconsistency between the service subscription information of the UE in the request and the storage service subscription information of the UE, initiating an update of the service subscription of the UE in the second network element according to the storage service subscription information of the UE.

[0007] According to a second embodiment of the present disclosure, a method is provided for a network element serving a user equipment UE in a communication network to perform service subscription of the UE, comprising: sending a request including service subscription information of the UE to another network element; and in response to receiving the service subscription of the UE from the other network element, updating the service subscription of the UE in the network element according to the received service subscription of the UE.

[0008] According to a third embodiment of the present disclosure, a network element operable in a communication network to perform service subscription for a user equipment UE is provided, the network element comprising: a cross-reference component configured to, in response to receiving a request including service subscription information of the UE from a second network element serving the UE and assisting in the service, check the consistency between the service subscription information of the UE in the request and the storage service subscription information of the UE; and an initiating component configured to, in response to the service subscription information of the UE in the request being inconsistent with the storage service subscription information of the UE, initiate an update of the service subscription of the UE in the second network element according to the storage service subscription information of the UE.

[0009] According to a fourth embodiment of the present disclosure, a network element serving a user equipment UE in a communication network and for executing service reservation of the UE is provided, the network element comprising: a sending component configured to send a request including service reservation information of the UE to another network element; and an updating component configured to update the service reservation of the UE in the network element according to the received service reservation of the UE in response to receiving the service reservation of the UE from the other network element.

[0010] According to a fifth embodiment of the present disclosure, there is provided a communication device in a network, comprising: a storage device, suitable for storing instructions therein; and a processor, suitable for executing the instructions so that the communication device performs the steps of any method in the method herein.

[0011] According to a sixth embodiment of the present disclosure, one or more computer-readable storage devices having computer-executable instructions stored thereon are provided, which instructions, when executed by a computing device, cause the computing device to implement any of the methods described herein.

[0012] According to a seventh embodiment of the present disclosure, there is provided a computer program comprising instructions, which, when executed on at least one processor, causes the at least one processor to perform any one of the methods described herein.

[0013] According to an eighth embodiment of the present disclosure, a carrier containing the computer program of the eighth embodiment is provided, wherein the carrier is one of an electronic signal, an optical signal, a radio signal or a computer-readable storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing and other features of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings and the appended claims. It is to be understood that these drawings only illustrate several embodiments according to the present disclosure and are therefore not to be considered as limiting the scope thereof, and the present disclosure will be described with additional particularity and detail through the use of the accompanying drawings.

[0015] Figure 1 A subscription opened for an event at a UDM in the prior art is shown.

[0016] Figure 2 It shows that problems may arise due to UE mobility between AMFs.

[0017] Figure 3 It shows that problems may arise due to UE mobility between networks.

[0018] Figure 4a A flow chart of a method for a first network element in a communication network to perform service subscription for a UE according to an embodiment of the present disclosure is shown.

[0019] Figure 4b A flow chart of a method for a second network element serving a UE in a communication network to perform service subscription for the UE according to an embodiment of the present disclosure is shown.

[0020] Figure 5a A flow chart showing a first detailed embodiment according to an embodiment of the present disclosure is shown.

[0021] Figure 5b A flow chart showing a second detailed embodiment according to an embodiment of the present disclosure is shown.

[0022] Figure 5c A flow chart showing a third detailed embodiment according to an embodiment of the present disclosure is shown.

[0023] Figure 5d A flow chart showing a fourth detailed embodiment according to an embodiment of the present disclosure is shown.

[0024] Figure 6 A schematic block diagram of a first network element according to an embodiment of the present disclosure is shown.

[0025] Figure 7 A schematic block diagram of a second network element according to an embodiment of the present disclosure is shown.

[0026] Figure 8 An embodiment of an arrangement of network elements that can be used for the present disclosure is schematically shown. DETAILED DESCRIPTION

[0027] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings showing the embodiments. However, the embodiments of the present invention may be implemented in many different forms and should not be construed as being limited to the embodiments presented herein. The elements of the accompanying drawings are not necessarily drawn to scale with respect to each other. Similar reference numerals represent similar elements throughout the text.

[0028] The terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting. When used herein, it is expected that the singular forms "a, an" and "the" also include plural forms, unless the context clearly states otherwise. It will be further understood that when used herein, the terms "include" and / or "comprise" represent the presence of the described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups.

[0029] Unless otherwise defined, all terms (including technical terms) used herein have the same meaning as commonly understood. It will be further understood that the terms used herein should be understood to have the same meaning as they are in the context of this specification and the relevant art, and will not be understood in an idealized or overly formal sense, unless otherwise explicitly defined herein, such as generally understanding the concepts of AMF, UDM, NEF, etc. in the context of 3GPP specifications. Although many embodiments herein are described in the context of 5G or 5G combined with 4G, other networks may also be applicable.

[0030] Even though many embodiments are described in the context of event opening subscriptions, it is noted that embodiments of the present disclosure are not limited to event opening subscriptions, but are also applicable to other service subscriptions as appropriate.

[0031] Figure 1 The subscription opened for events in UDM in the prior art is shown. In step 1, the AF (application function) subscribes to one or more events (identified by event ID) and provides the associated notification endpoint of the AF by sending an Nnef_EventExposure_Subscribe request. The event reporting information defines the type of report requested (e.g., one-time report, periodic report, or event-based report for monitoring events). If the reporting event subscription is authorized by the NEF, the NEF records the association of the event trigger and the requester identifier. The subscription may also include the maximum number of reports and / or the maximum duration of the reporting IE.

[0032] In step 2, (this step is conditional, depending on the authorization in step 1), the NEF subscribes to (one or more) received events (identified by event ID) and provides the associated notification endpoint of the NEF to the UDM by sending a Nudm_EventExposure_Subscribe request. The NEF maps the AF-Identifier to the DNN and S-NSSAI combination based on local configuration and includes the DNN and S-NSSAI in the request. If the reporting event subscription is authorized by the UDM, the UDM records the association of the event trigger and the requester identifier. Otherwise, the UDM continues to indicate failure in step 4.

[0033] In step 3a, which is also conditional, if the requested event (e.g. monitoring loss of connectivity) requires AMF assistance, the UDM sends a Namf_EventExposure_Subscribe to the AMF serving the requested user. The UDM sends a Namf_EventExposure_Subscribe request to all serving AMFs (if the subscription applies to a UE or a group of (one or more) UEs) or to all AMFs in the same PLMN as the UDM (if the subscription applies to any UE). Since the UDM itself is not an event receiving NF, it should provide its own notification endpoint in addition to that of the NEF. Each notification endpoint is associated with a (set of) related event IDs. This will ensure that the UDM is able to receive notifications of subscription change related events. If the subscription applies to a group of (one or more) UEs, the UDM should include its own identical notification endpoint, i.e. the notification target address (plus the notification correlation Id) in the subscription to the serving AMFs of all UEs.

[0034] Note that the same notification endpoint of the UDM is to help the AMF to identify whether the subscription to the requested group events is the same when a new group member UE is registered.

[0035] In conditional step 3b, AMF confirms the execution of Namf_EventExposure_Subscribe.

[0036] In conditional step 3c, if the requested event (e.g. PDU session status) requires SMF assistance, the UDM sends a Nsmf_EventExposure_Subscribe request message to each SMF in which at least one UE identified in step 2 has an established PDU session. The NEF notification endpoint received in step 2 is included in the message. Note that in the case of home routing, the UDM sends the subscription to the V-SMF via the H-SMF.

[0037] In conditional step 3d, SMF confirms the execution of Namf_EventExposure_Subscribe.

[0038] In conditional step 4, UDM confirms the execution of Nudm_EventExposure_Subscribe. If the subscription is applicable to a group (one or more) of UEs and the maximum reporting quantity in step 1 is included in the event reporting information, the number of UEs is included in the confirmation.

[0039] In step 5, NEF confirms to the requester that the request was made

[0040] Implementation of Nnef_EventExposure_Subscribe.

[0041] In steps 6a-6b (conditional, event dependent), the UDM (event dependent) detects the event occurrence and sends an event report along with a timestamp to the associated notification endpoint of the NEF by means of a Nudm_EventExposure_Notify message. The NEF may store the information along with a timestamp in the UDR using Nudr_DM_Create or Nudr_DM_Update service operations as appropriate.

[0042] In steps 6c-6d (conditional, depending on the event), the AMF detects that the event has occurred and sends an event report along with a timestamp to the associated notification endpoint of the NEF by means of a Namf_EventExposure_Notify message. The NEF may store the information in the UDR along with a timestamp using the Nudr_DM_Create or Nudr_DM_Update service operations as appropriate. If the AMF has a maximum number of reports stored for the UE or an individual member UE, the AMF shall reduce its value by one for the reported event. For steps 6a and 6b, when the maximum number of reports is reached, and if the subscription applies to the UE, the NEF unsubscribes from the UDM for the monitored event(s), and the UDM unsubscribes from the AMF serving that UE for the monitored event(s). For both steps 6a and 6b, when the maximum number of reports is reached for an individual group member UE, the NEF uses the number of UEs received in step 4 to determine whether reporting for the group is complete. If the NEF determines that the reporting of the group is complete, the NEF unsubscribes the monitoring event(s) from the UDM, and the UDM unsubscribes the monitoring event(s) from all AMF(s) serving UEs belonging to that group. When the maximum reporting duration among the NEF, UDM and AMF expires, each of these nodes shall unsubscribe the monitoring event locally.

[0043] In steps 6e-6f (conditional, depending on the event), when the SMF detects a subscription event, the SMF sends an event report to the associated notification endpoint of the NEF provided in step 3c by means of a Nsmf_EventExposure_Notify message. The NEF may store the information in the UDR together with a timestamp using the Nudr_DM_Create or Nudr_DM_Update service operations as appropriate.

[0044] In step 7 (conditional, depending on the events in steps 6a-6f), the NEF forwards the received report event to the AF via Nudm_EventExposure_Notify and / or Namf_EventExposure_Notify. In case of a PDU Session Status event, the NEF maps it to a PDN Connectivity Status Notification when reporting to the AF.

[0045] In step 8 (conditional, event dependent), the AMF detects that a subscription change related event occurs (e.g. a subscription correlation ID change due to AMF reallocation or a new subscription correlation ID is added due to a new group of UEs being registered), it sends an event report to the associated notification endpoint of the UDM by means of a Namf_EventExposure_Notify message.

[0046] As can be understood from the previous description, if the UDM receives a subscription open for events for the UE, and the events to be monitored require assistance from the AMF, SMF or GMLC, the UDM is responsible for sending subscriptions for the required events to those relevant network elements.

[0047] When an event open booking request is received at the UDM ( Figure 1 There is no procedure in TS 23.502 for determining the action taken by that UDM when the UE is not currently attached to a 5GC. One possibility is that the subscription should remain active in the UDM as long as the expiry time of the subscription is not reached, regardless of the registration state of the UE.

[0048] When an event open booking request is received at the UDM ( Figure 1 In step 2) of , assuming that the UE is registered, the UDM checks the list of AMFs and SMFs currently serving the UE and sends a subscription to each of them if an event requires reporting by those network functions. The determination of the AMFs and SMFs serving the UE is made when the subscription is received at the UDM. If new SMFs serve the UE later (e.g. due to activation of new PDU Sessions), the UDM does not follow these new SMFs and does not feed the subscription with data in such new SMFs.

[0049] 3GPP TS 23.501 and 23.502 specify the procedure for AMF transfer, which is a mechanism by which a UE served by an initial AMF eventually becomes served by a target AMF due to UE mobility. During this AMF transfer procedure, the initial AMF sends the target AMF the UE context, including a list of currently subscribed events to be monitored. This allows the target AMF to continue reporting when these events occur.

[0050] Even in case of UE context transfer between AMFs, problems may arise when the AMF does not support reporting of one or more events, either because resources are exhausted (such as lack of internal memory) or because the limits of a given MTC (Machine Type Communication) provider are reached (the number of simultaneous events is reached), etc.

[0051] Figure 2 Shows a scenario where problems may arise due to UE mobility between AMFs. Figure 2 The process in can be divided into two stages: intra-5GC mobility from AMF-1 to AMF-2 and intra-5GC mobility from AMF-2 to AMF-3. In the stage of intra-5GC mobility from AMF-1 to AMF-2 (steps / boxes 201-208), the AMF serving the UE has changed from AMF-1 to AMF-2. In the context transfer of step 201, AMF-2 receives EE (event open) subscription information from AMF-1, but cannot create resources for all events received at box 202 due to lack of support or due to exhaustion of resources (such as lack of internal memory) or due to reaching the limit of a given MTC provider.

[0052] Other scenarios are also possible. For example, assume that AMF-1 supports event opening for events 1 and 2. UDM has received subscriptions for events 1, 2, and 3, all of which require reporting by AMF-1. UDM sends subscriptions for events 1, 2, and 3 to AMF-1, but event 3 is not accepted due to lack of support. Then, later, the UE context is transferred from AMF-1 to AMF-2, which includes subscriptions for events 1 and 2. AMF-2 lacks a subscription for event 3 even if it can support event 3, and it will not be able to provide notification for this event 3. As a result, consumers of event opening do not get notifications for event 3 because AMF-2 is unaware of this subscription.

[0053] It should be noted that UDM is generally combined with HSS (Home Subscriber Server) in 3GPP specifications, but other scenarios are not excluded.

[0054] Then in step 203, AMF-2 uses e.g.

[0055] Nudm_uecm3gppAccessRegistration message registers with UDM and is completed with Nudm_uecm3gppAccessRegistrationResponse message in step 204. In box 205, AMF-2 sends a notification request for each created resource (i.e., for each event open subscription) using, for example, a namfEventExposureNotify message as shown in step 206 to indicate to UDM that the event resources are now located in different AMFs. Multiple subscriptions may require multiple notification requests. Then in box 207, UDM stores the new event open subscription location. This is done for each notification received in 3GPP. Then, UDM confirms to AMF-2 using, for example, a namfEventExposureNotifyResponse message.

[0056] In the second phase of intra-5GC mobility from AMF-2 to AMF-3 (steps / boxes 209-216), the AMF serving the UE has changed from AMF-2 to AMF-3. The process is similar to steps / boxes 201-208. Since the EE subscription information received in the context transfer is incomplete (as described above, some events are missing in the first phase), the missing events are not monitored and the subscription is never restored.

[0057] Similar problems may also arise during UE mobility between networks. Figure 3 Shows this situation. Figure 3 The process in can be divided into two stages: EPC (Evolved Packet Core)-5GC mobility from MME (Mobility Management Entity) to AMF-2 and intra-5GC mobility from AMF-1 to AMF-2. In the EPC-5GC stage from MME to AMF-1 (steps / boxes 301-304), the mobility management network element serving the UE has changed from MME to AMF-1, and the MME performs a context transfer with AMF-1 via the N26 interface (step 301). Since the MME does not transfer the open event subscription to AMF-1 (such information is not exchanged through the N26 interface), in box 302, AMF-1 does not receive the EE subscription information in the context transfer, and therefore there will be no event open subscription in AMF-1. Therefore, consumers of event openness will not receive notifications related to all events of interest to them. Then in step 303, AMF-1 registers with UDM using, for example, the Nudm_uecm3gppAccessRegistration message, and in step 304 with

[0058] Nudm_uecm3gppAccessRegistrationResponse message completes the registration.

[0059] In the second phase of intra-5GC mobility from AMF-1 to AMF-2 (steps / boxes 305-306), the AMF serving the UE has changed from AMF-1 to AMF-2. In the context transfer of step 305, since no EE subscription is available (because no EE subscription is available in the first phase as described above), these events are not monitored and the subscription is never restored.

[0060] Please note, Figure 2 and Figure 3 The process assumes Figure 1 Steps 1-5 in have been performed and are summarized in Figure 2 and Figure 3 They are no longer shown.

[0061] Figure 4a A flow chart of a method for a first network element in a communication network to perform service subscription for a UE according to an embodiment of the present disclosure is shown.

[0062] In response to receiving a request including service subscription information of the UE from a second network element serving the UE and facilitating the service as determined in step 401, the first network element cross-references the consistency of the service subscription information of the UE in the request with the stored service subscription information of the UE in step 403. The service subscription information in the request may indicate that no service subscription is available in the second network element, or may indicate an ongoing service subscription booked at the second network. In response to the service subscription information of the UE in the request being inconsistent with the stored service subscription information of the UE as determined in step 403, the first network element initiates, in step 404, an update of the service subscription of the UE in the second network element according to the stored service subscription information of the UE.

[0063] Alternatively or additionally, if it is determined in step 405 that the first network element has at least partially failed in the update, the first network element directly initiates the update in step 407 in response to receiving a further request including the service subscription information of the UE as determined in step 406. The further request may not necessarily come from the second network element. In this case, the first network element already knows that at least a part of the service is missing in the second network element, so it does not need to check the consistency in the UE mobility before initiating the update of the service subscription next time.

[0064] Optionally or additionally, the service subscription information in the request indicates that the second network element does not have a service subscription for the UE.In an example, the request is a registration request for the second network element to register with the first network element, such as a Nudm_uecm3gppAccessRegistration message.

[0065] Optionally or additionally, the service subscription information in the request indicates the service subscription of the UE in the second network element. In an example, the request is a notification request for the second network element to notify the first network element, such as a namfEventExposureNotify message. Optionally or additionally, the notification request includes all service subscriptions of the UE, each including a unique identifier of the corresponding subscription, an internal resource address, and one or more unique identifiers of the corresponding service of the corresponding subscription.

[0066] Optionally or additionally, the initiation of step 404 further includes: sending all service subscriptions of the UE contained in the stored service subscription information to the second network element for service subscription in the second network element. Accordingly, the updating includes: deleting all service subscriptions of the UE in the second network element when the service subscription of the UE exists in the second network element, and adding all service subscriptions from the stored service subscription information of the UE to the second network element, that is, subscribing services according to the stored service subscription information of the UE in the second network element. Further detailed embodiments will be described in Figure 5b and Figure 5d Shown in.

[0067] Optionally or additionally, the initiation of step 404 further includes: sending the difference between the service subscription information of the UE in the request and the storage service subscription information of the UE to the second network element for service subscription modification. Accordingly, the update includes: when there is a service subscription inconsistent with the storage service subscription information in the second network element, deleting the service subscription in the second network element that is inconsistent with the storage service subscription information, and adding a service subscription in the storage service subscription information of the UE that does not exist in the second network element to the second network element, that is, modifying the service subscription of the UE in the second network element. Other detailed embodiments will be described in detail in Figure 5a and Figure 5c Shown in.

[0068] In response to either request, both initiation methods described above are applicable. When the service subscription information in the request indicates the service subscription of the UE in the second network element, both the service subscription and the service subscription modification are applicable. When the service subscription information in the request indicates that the second network element does not have the service subscription of the UE, the service subscription modification created out of thin air is actually the same as the service subscription.

[0069] Alternatively or additionally, in response to not receiving a request within a time window (eg, a few seconds) after the second network element becomes registered with the first network element as determined in step 402, then in step 404 an update is directly initiated.

[0070] In an example, the first network element is a UDM and the second network element comprises one or more of the following: an AMF, an SMF or a GMLC (Gateway Mobile Location Centre).

[0071] In the example, the service subscription is an event open subscription and the stored service subscription information of the UE is stored in a UDR (Unified Data Repository).

[0072] In an example, the network is a 5G network or a combination of a 5G network and a 4G network or any other suitable network.

[0073] Alternatively or additionally, the service subscriptions in the UE's stored service subscription information remain active until they expire. Given that services can be active for months (as requested by NEF (Network Open Function)), it may not be unusual for events to be lost during such a period and they are never recovered in the network. In this way, as long as the service subscriptions have not expired, they remain active in the stored service subscription information to support UDM to update the service subscriptions in other network elements (such as AMF, etc.).

[0074] Figure 4b A flow chart of a method for a second network element serving a UE in a communication network to perform service subscription for the UE according to an embodiment of the present disclosure is shown.

[0075] The method starts at step 401', where a request including service subscription information of the UE is sent to a first network element; and then at step 402', in response to receiving the service subscription of the UE from the first network element, the service subscription of the UE in the second network element is updated according to the received service subscription of the UE.

[0076] In an example, updating includes modifying a service subscription of the UE in the second network element according to the received service subscription or subscribing a service of the UE in the second network element according to the received service subscription.

[0077] In an example, the request is a notification request for the second network element to notify the first network element, or the request is a registration request for the second network element to register with the first network element.

[0078] In an example, the first network element is a UDM.In an example, the second network element comprises one or more of: an AMF, an SMF or a GMLC.

[0079] In the example, the service booking is an incident opening booking.

[0080] In an example, the network is a 5G network or a combination of a 5G network and a 4G network or any other suitable network.

[0081] based on Figure 4a and Figure 4b In an embodiment, UDM is not only responsible for distributing these service subscription requests to the applicable service network functions (such as AMF, SMF) currently registered in UDM when receiving subscription requests from consumers according to the prior art, but UDM is also responsible for making the service subscription permanent on the network and different service NFs.

[0082] In one scenario, when a new NF registers in UDM for a given UE indicating that it does not have any service subscription, UDM checks if there is a stored event subscription for this UE, for which the registering NF (AMF, SMF) should assist. In this case, UDM sends the required service subscription request or requests for the relevant service(s) to that NF.

[0083] In another scenario, if a NF is already registered in the UDM, but the consumer is in a purged state, the UDM will still send subscription requests for related service(s) to that NF.

[0084] The following will refer to Figure 5a-5d In any case, the UDM may delete all services and re-subscribe to the NF again, or may add / remove services or subscriptions that are inconsistent with the stored service subscription information.

[0085] Figure 5a A flowchart is shown in the case of intra-5GC mobility from AMF-1 to AMF-2 according to the first detailed embodiment of the present disclosure.

[0086] In step 501, AMF-2 requests context transfer of AMF-1, for example due to UE mobility, and the subscribed ongoing events (see Figure 1 3a-3b) is transferred from AMF-1 to AMF-2 as part of the context transfer. In block 502, AMF-2 receives event open subscription information from AMF-1. The received event open subscription information is incomplete due to, for example, a failure in the subscription (one or more) of the previous event (one or more) in AMF-1.

[0087] In steps 503-504, AMF-2 performs registration in the UDM as described above with respect to steps 203-204.

[0088] In box 505 and step 506, AMF-2 notifies the UDM of the internal location of the event open resource in AMF-2 and all event open subscription information in a single notification request - namfEventExposureNotify message. The notification request can include multiple subscriptions, and each subscription includes a unique identifier, an internal resource address and (one or more) unique identifiers of (one or more) events. In this way, in box 507, the UDM can compare the event open information received from AMF-2 with the event open information previously stored for the same UE. If the UDM detects that one or more event subscriptions are missing or one or more events in the existing subscriptions are missing in the event open subscription information received from AMF-2, then in step 508, the UDM sends, for example,

[0089] Nudm_EventExposureSubscribe message to initiate the update of event exposure subscription in AMF-2. Figure 4a In step 404 of the embodiment, the initiation may include sending all event open subscriptions of the UE contained in the stored event open subscription information to AMF-2 for event open subscription, or the initiation may include sending the difference between the received event open subscription information and the stored event open subscription information of the UE to AMF-2 for event open subscription modification. In step 509, AMF-2 sends, for example,

[0090] Nudm_EventExposureSubscribeResponse message to confirm the update.

[0091] In this way, event open subscription information is consistent across the network between, for example, NEF, UDM, AMF-2, etc.

[0092] Figure 5b A flowchart is shown in the case of intra-5GC mobility from AMF-1 to AMF-2 according to the second detailed embodiment of an embodiment of the present disclosure.

[0093] At step 510, AMF-2 requests a context transfer of AMF-1, e.g. due to UE mobility. However, due to, e.g., data loss by AMF-1 during restart, no event open subscription is passed on from AMF-1 to AMF-2 as part of the context transfer, and at block 502, AMF-2 does not receive any event open subscription information from AMF-1 and performs a registration with the UDM. As part of the registration request (such as a Nudm_uecm3gppAccessRegistration message at step 512), AMF-2 indicates that there is no ongoing event open subscription for the UE in AMF-2, and the UDM confirms the registration request by sending, e.g., a Nudm_uecm3gppAccessRegistrationResponse message.

[0094] At block 514, upon receiving an indication that there is no ongoing event open subscription for the UE in AMF-2, the UDM checks in the UDR whether the event subscription for the UE should be active, and if so, the UDM resumes the event open subscription at steps 515-516. The details of the process can be found in Figure 1 Description of steps 3a-3b in .

[0095] In this way, event open subscription information is consistent across the network between, for example, NEF, UDM, AMF-2, etc.

[0096] Figure 5c A flowchart is shown in the scenario of EPC-5GC mobility from AMF-1 to MME and from MME to AMF-1 according to a third detailed embodiment of an embodiment of the present disclosure.

[0097] Prior to step 517, the UE is registered and served by AMF-1. In AMF-1, one or more event open subscriptions for this UE are active.

[0098] At step 517, due to UE mobility, the UE becomes served by the MME in the EPC. The MME requests a context transfer of the AMF-1. No event open subscription is passed on from the AMF-1 to the MME as part of the context transfer because the interface between the MME and AMF-1 (such as the N26 interface) does not support such information.

[0099] After the MME is registered in the HSS, the UDM sends a deregistration request (e.g., UECM_deregisterRequest) to AMF-1 in step 518, and marks the UE as cleared in AMF in block 519. In block 521, AMF-1 may optionally save the UE context (including event open subscription) for a period of time so that the UE context can be reused if the UE moves back to AMF-1 within a short period of time. In step 520, AMF-1 confirms the deregistration request by sending a deregistration response (e.g., UECM_deregisterResponse) to the UDM.

[0100] Then, new event opening booking occurs, which is done by 5G Core External ( Figure 5c The NEF receives a request to open a subscription for an event. The NEF requests the UDM to subscribe to the received event, for example, via a Nudm_EventExposureSubscribe message in step 522. Since the UE is marked as clear in AMF-1, the UDM does not subscribe to AMF-1.

[0101] Then at block 524, the UE becomes served by AMF-1 again, for example due to UE mobility. Similarly, no event open subscription is passed on from the MME to AMF-1 as part of the UE context transfer.

[0102] Then, in steps 526-527, AMF-1 transmits the signal to the AMF-1 through, for example,

[0103] Nudm_uecm3gppAccessRegistration message and

[0104] Nudm_uecm3gppAccessRegistrationResponse message is used to perform registration with UDM.

[0105] Even if there is a valid context with event open subscription information as a result of step 521, AMF-1 treats the mobility situation as an intra-5GC mobility situation for event open, i.e., in box 528, AMF-1 notifies the UDM of the internal location of the event open resources (even if there is no change) and all event open subscription information in a single notification request.

[0106] At step 529, AMF-1 sends a single notification request (e.g.

[0107] The UDM is notified of the internal location of the EE resource in AMF-1 and all event open subscription information in a Nudm_EventExposureNotify message). The notification request can include multiple subscriptions, and each subscription includes a unique identifier, an internal resource address, and (one or more) unique identifiers of (one or more) events. In this way, in box 530, the UDM is able to compare the event open subscription information received from AMF-1 with the previously stored event open subscription information. There is a discrepancy because AMF-1 may be missing events subscribed by the NEF while the UE was served by the MME in the past. If the UDM detects one or more missing event subscriptions or one or more missing events in an existing subscription in the event open subscription information received from AMF-1, then in step 531, the UDM initiates an update of the event open subscription information in AMF-1 by sending, for example, a Nudm_EventExposureSubscribe message. Reference Figure 4a In step 404 of the embodiment, the initiation may include sending all event open subscriptions of the UE contained in the stored event open subscription information to AMF-2 for event open subscription, or the initiation may include sending the difference between the received event open subscription information and the stored event open subscription information of the UE to AMF-2 for event open subscription modification. In step 532, AMF-1 sends, for example,

[0108] Nudm_EventExposureSubscribeResponse message to confirm the update.

[0109] In this way, event open subscription information is consistent across the network between, for example, NEF, UDM, AMF-2, etc.

[0110] Figure 5d A flowchart is shown in the case of EPC-5GC mobility from MME to AMF-2 according to a fourth detailed embodiment of an embodiment of the present disclosure.

[0111] Initially, and in Figure 5d Prior to block 532 in , the UE is served by the MME of the EPC. The MME has created a UE context. For this UE, one or more event open subscriptions are active.

[0112] and Figure 5cSimilarly, the UE moves from the EPC back to the 5GC. When the 5GC selects an AMF to serve the UE due to location, mobility, or other aspects, the 5GC selects an AMF that is different from the initial AMF. In this example, the 5GC selects AMF-2 to serve the UE (when it moves away from the MME) in box 533. In step 534, AMF-1 requests a UE context transfer from the MME. However, due to the lack of this capability in the N26 interface, no event open subscription is passed on from the MME to AMF-2 as part of the UE context transfer.

[0113] At block 535, since there is no valid 5G mobility management context, but AMF-2 knows that the UE is moving away from the EPC, AMF-2 indicates to the UDM via a registration request (such as a Nudm_uecm3gppAccessRegistration message) at block 536 that the UE context does not contain any event open subscription information. This triggers the UDM to check in the UDR at block 538 whether there is an existing event open subscription stored. The registration request is confirmed at step 537 via, for example, a Nudm_uecm3gppAccessRegistrationResponse message. If existing event open subscription information is found, the UDM triggers a subscription request for all stored events (on behalf of the NEF) at steps 539-540. The details of the process can be found at Figure 1 Description of steps 3a-3b in .

[0114] In this way, event open subscription information is consistent across the network between, for example, NEF, UDM, AMF-2, etc.

[0115] Figure 6 A schematic block diagram of a first network element according to an embodiment of the present disclosure is shown. The first network element is configured to perform service subscription of a UE. The network here may be a 5G network, a 5G network combined with a 4G network, or any other suitable network.

[0116] The portion of the first network element 600 that is most affected by the adaptation of the methods described herein (e.g., a portion of the method 400) is shown as an arrangement 601 surrounded by a dashed line. The first network element and the arrangement 601 may further be configured to communicate with other entities via a communication component 602, which may be considered as a part of the arrangement 601 (not shown). The communication component 602 comprises means for communication. The arrangement 601 or the first network element may further comprise additional functionality 604, such as functional components providing conventional UE functionality, and may further comprise one or more storage devices 603. External storage devices, such as UDRs, are also possible, in which case communication towards them is performed via the communication component 602.

[0117] Arrangement 601 may be implemented, for example, by one or more of the following: a processor or microprocessor and sufficient software and memory for storing the software, a programmable logic device (PLD), or a processor configured to perform the above and, for example, in Figure 4a and / or Figure 4b (one or more) other electronic components or processing circuits that perform the actions shown in . The arrangement 601 of the first network element may be implemented and / or described as follows.

[0118] Reference Figure 6 , the first network element may include a cross-referencing component 610 and an initiating component 620 .

[0119] The cross-referencing component 610 is configured to, in response to receiving a request including service subscription information of the UE from a second network element serving the UE and facilitating service, check consistency of the service subscription information of the UE in the request with stored service subscription information of the UE.

[0120] The initiating component is configured to initiate updating of the service subscription of the UE in the second network element according to the stored storage service subscription information of the UE in response to the service subscription information of the UE in the request being inconsistent with the stored storage service subscription information of the UE.

[0121] Details on how to execute a service booking are given in Figure 4a and Figure 4b description, and will not be repeated here.

[0122] It should be noted that two or more different units in the present disclosure may be combined logically or physically. For example, the cross-reference component 610 and the initiation component 620 may be combined into a single unit.

[0123] Figure 7 1 is a schematic block diagram of a second network element serving a UE in a communication network according to an embodiment of the present disclosure. The second network element is configured to perform service subscription of the UE. The network here can be a 5G network, a 5G network combined with a 4G network, or any other suitable network.

[0124] The part of the second network element 700 that is most affected by the adaptation of the method described herein (e.g., part of the method 400') is shown as an arrangement 701 surrounded by a dashed line. The second network element and the arrangement 701 are further configured to communicate with other entities (such as the first network element) via a communication component 702, which can be considered as part of the arrangement 701. The communication component 702 includes components for communication and may also include components for, for example, wired communication. The arrangement 701 or the second network element may further include additional functionality 704 (such as functional components providing conventional base station functionality), and may further include one or more storage devices (3) 703.

[0125] Arrangement 701 may be implemented, for example, by one or more of the following: a processor or microprocessor and sufficient software and memory for storing the software, a programmable logic device (PLD), or a processor configured to perform the above and, for example, in Figure 4b (one or more) other electronic components or processing circuit modules for the actions shown in. The arrangement portion of the second network element may be implemented and / or described as follows.

[0126] Reference Figure 7 , the second network element may include a sending component 710 and an updating component 720.

[0127] The sending component 710 is configured to send a request including the service subscription information of the UE to the first network element.

[0128] Update component 720 is configured to, in response to receiving a service subscription of a UE from a first network element, update a service subscription of the UE in the network element according to the received service subscription of the UE.

[0129] It should be noted that two or more different units in the present disclosure may be combined logically or physically. For example, the sending component 710 and the updating component 720 may be combined into a single unit.

[0130] Figure 8 An embodiment of an arrangement 800 that can be used in a first network element and a second network element is schematically shown. Here, included in the arrangement 800 is a processor 806, for example having a digital signal processor (DSP). The processor 806 can be a single unit or a plurality of units to perform different actions of the processes described herein. The arrangement 800 may also include an input unit 802 for receiving signals from other entities and an output unit 804 for providing (one or more) signals to other entities. The input unit and the output unit may be provided as an integrated network element or as Figure 6 or Figure 7 Set it up as shown in the example.

[0131] Furthermore, the arrangement 800 comprises at least one computer program product 808 in the form of a non-volatile or volatile memory, such as an electrically erasable programmable read-only memory (EEPROM), a flash memory or a hard drive. The computer program product 808 comprises a computer program 810 comprising code / computer-readable instructions which, when executed by the processor 806 in the arrangement 800, cause the arrangement 800 and / or the first network element or the second network element in which it is comprised to perform, for example, the operations previously described in connection with Figure 4a , Figure 4b or Figure 5a , Figure 5b , Figure 5c , Figure 5d The actions of the process described.

[0132] The computer program 810 may be configured as computer program code structured in a computer program module. Thus, in an exemplary embodiment, when the arrangement 800 is used in the first network element, the code in the computer program of the arrangement 800, when executed, will cause the processor 806 to perform as described with reference to Figure 4a The steps described.

[0133] In another exemplary embodiment, when the arrangement 800 is used in the second network element, the code in the computer program of the arrangement 800, when executed, will cause the processor 806 to perform as described with reference to Figure 4b The steps described.

[0134] Processor 806 may be a single central processing unit (CPU), but may also include two or more processing units. For example, processor 806 may include a general-purpose microprocessor, an instruction set processor and / or a related chipset and / or a special-purpose microprocessor such as an application-specific integrated circuit (ASIC). Processor 806 may also include a board memory for caching purposes. Computer program 810 may be carried by a computer program product 808, which is connected to processor 806. The computer program product may include a computer-readable medium on which the computer program is stored. For example, the computer program product may be a flash memory, a random access memory (RAM), a read-only memory (ROM) or an EEPROM, and the computer program modules described above may be distributed on different computer program products in the form of memory in an alternative embodiment.

[0135] Overall or depending on the situation, the service subscription information is stored in the UDM and the UDM becomes responsible for the service subscription information update at the NF, always ensuring that the service subscription is consistent across the network including for example AMF and MME, regardless of the mobility situation. Flexibility is achieved by allowing the UDM to directly initiate an update of the service subscription at the NF after an update failure, and also allowing the AMF to send a request including the service subscription information (indicating no service subscription or indicating an active service subscription). The update of the service subscription can be triggered by the UDM or the AMF. Efficiency is achieved by allowing multiple subscriptions in one request (notification request or registration request)

[0136] Although embodiments have been shown and described herein, those skilled in the art will appreciate that various changes and modifications may be made, and equivalents may be substituted for elements thereof, without departing from the true scope of the present technology. In addition, many modifications may be made to suit the particular circumstances and teachings herein without departing from the central scope thereof. Therefore, it is contemplated that the embodiments described are not limited to the particular embodiments disclosed as the best mode contemplated for carrying out the present technology, but rather that embodiments of the present invention include all embodiments falling within the scope of the appended claims.

Claims

1. A method for a first network element in a communication network to perform service subscription of a user equipment UE, the method comprising: - in response to receiving a request including service subscription information of the UE from a second network element serving the UE and facilitating the service, cross-referencing the service subscription information of the UE in the request with the service subscription information of the UE for consistency; as well as - in response to the service subscription information of the UE in the request being inconsistent with the stored service subscription information of the UE, initiating an update of the service subscription of the UE in the second network element according to the stored service subscription information of the UE, The request includes all service subscriptions of the UE in the second network element, each of the service subscriptions includes a unique identifier of the corresponding subscription, an internal resource address, and one or more unique identifiers of corresponding one or more services in the corresponding subscription.

2. The method of claim 1, further comprising: In case the updating has at least partially failed, the updating is directly initiated in response to receiving a further request comprising service subscription information of the UE.

3. The method of claim 1, wherein: The initiating further includes sending all service subscriptions of the UE contained in the stored service subscription information to the second network element for service subscription in the second network element.

4. The method of claim 1, wherein: The initiating further includes sending a difference between the service subscription information of the UE and the stored service subscription information of the UE in the request to the second network element for service subscription modification in the second network element.

5. The method of claim 1, wherein the updating comprises: deleting all service subscriptions of the UE in the second network element if there are service subscriptions of the UE in the second network element, and All service subscriptions of the stored service subscription information from the UE are added to the second network element.

6. The method of claim 1, wherein the updating comprises: If a service subscription inconsistent with the stored service subscription information exists in the second network element, deleting the service subscription inconsistent with the stored service subscription information in the second network element, and A service subscription in the stored service subscription information of the UE that is not present in the second network element is added to the second network element.

7. The method of claim 1, wherein: The request is a notification request for the second network element to notify the first network element.

8. The method of claim 7, further comprising: In response to not receiving the request within a period of time after the second network element becomes registered with the first network element, directly initiating the updating.

9. The method of claim 1, wherein: The service subscription is an event opening subscription.

10. The method of claim 1, wherein: The first network element is a unified data management (UDM) network element.

11. The method of claim 1, wherein: The stored service subscription information of the UE is stored in a unified data repository UDR network element.

12. The method of claim 1, wherein: The service subscriptions in the stored service subscription information of the UE remain active until they expire.

13. The method of claim 1, wherein: The second network element includes one or more of the following: an access and mobility management function AMF network element, a session management function SMF network element or a gateway mobile location center GMLC network element.

14. A method for a network element serving a user equipment (UE) in a communication network to perform service subscription of the UE, the method comprising: - sending a request including service subscription information of the UE to another network element; as well as - in response to receiving a service subscription for the UE from the other network element, updating the service subscription for the UE in the network element in accordance with the received service subscription for the UE, The request includes all service subscriptions of the UE in the network element, each of the service subscriptions includes a unique identifier of the corresponding subscription, an internal resource address, and one or more unique identifiers of corresponding one or more services in the corresponding subscription.

15. The method of claim 14, wherein the updating comprises one of the following: modifying a service subscription of the UE in the network element in accordance with the received service subscription, or The UE is subscribed to a service in the network element in accordance with the received service subscription.

16. The method of claim 14, wherein: The request includes one of: a notification request for the network element to notify the other network element or a registration request for the network element to register with the other network element.

17. The method of claim 14, wherein: The other network element is a unified data management (UDM) network element.

18. The method of claim 14, wherein: The network elements include: access and mobility management function AMF network element, session management function SMF network element or gateway mobile location center GMLC network element.

19. A network element operable in a communication network to perform service subscription of a user equipment (UE), the network element comprising: - a cross-referencing component configured to, in response to receiving a request including service subscription information of the UE from a second network element serving the UE and facilitating the service, check consistency of the service subscription information of the UE in the request with stored service subscription information of the UE; as well as - an initiating component configured to, in response to the service subscription information of the UE in the request being inconsistent with the stored service subscription information of the UE, initiate an update of the service subscription of the UE in the second network element according to the stored service subscription information of the UE, The request includes all service subscriptions of the UE in the second network element, each of the service subscriptions includes a unique identifier of the corresponding subscription, an internal resource address, and one or more unique identifiers of corresponding one or more services in the corresponding subscription.

20. A network element serving a user equipment UE in a communication network for performing a service subscription of the UE, the network element comprising: - a sending component configured to send a request including service subscription information of the UE to another network element; as well as - an updating component configured to, in response to receiving a service subscription of the UE from the other network element, update a service subscription of the UE in the network element according to the received service subscription of the UE, The request includes all service subscriptions of the UE in the network element, each of the service subscriptions includes a unique identifier of the corresponding subscription, an internal resource address, and one or more unique identifiers of corresponding one or more services in the corresponding subscription.

21. A communication device in a communication network, the communication device comprising: - a storage device (808) suitable for storing instructions therein; - a processor (806) adapted to execute said instructions so as to cause said communication device to perform the steps as claimed in any one of claims 1-18.

22. One or more computer-readable storage devices (808) having stored thereon computer-executable instructions which, when executed by a computing device, cause the computing device to implement the method of any one of claims 1-18.

23. A computer readable storage device storing a computer program (810) comprising instructions which, when executed on at least one processor, cause the at least one processor to perform the method of any one of claims 1-18.

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