Method, network function node and computer readable medium for event report management

Abstract

The present disclosure provides a method for managing event reports of a user equipment served by a first NF node. The method is implemented at a first NF node and includes, when the UE moves to be served by a second NF node, in response to receiving a UE context transmission request from the second NF node, including an indication in a first UE context indicating a UE event state of a first subscription event reported last time, and transmitting the first UE context to the second NF node. The present disclosure also discloses a corresponding NF node and a corresponding computer readable medium for implementing the method.

Description

Technical Field

[0001] The present disclosure generally relates to the field of telecommunication technology, and more particularly to a method and a network function (NF) node for managing event reporting of a user equipment (UE) and a corresponding computer-readable medium. 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 explored, but not necessarily concepts that have been previously conceived or explored. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the specification and / or claims of this disclosure and is not admitted to be prior art merely by inclusion in this section.

[0003] In the fifth generation (5G) network, network slices are introduced as logical networks that provide specific network capabilities and network characteristics. An instance of a network slice (e.g., Network Slice Instance, NSI) is a set of NF instances and required resources (e.g., computing, storage, and network resources) that constitute a deployed network slice. NF is a processing function adopted or defined by 3GPP in a network, with defined functional behaviors and 3GPP-defined interfaces. NF can be implemented as a network element on dedicated hardware, a software instance running on dedicated hardware, or a virtualized function instantiated on an appropriate platform (e.g., cloud infrastructure). NF instance is an identifiable instance of NF. NF service is a function exposed by NF through a service-based interface and used by other authorized NFs. NF service instance is an identifiable instance of NF service. NF service set is a set of interchangeable NF service instances of the same service type within an NF instance. NF service instances in the same NF service set can access the same context data. NF set is a set of interchangeable NF instances of the same type that support the same service and the same network slice. NF instances in the same NF set can be geographically distributed differently, but can access the same context data.

[0004] According to 3GPP TS23.501, the 5G system supports the function of tracking and reporting UE mobility events.

[0005] Specifically, 3GPP TS23.501 specifies the following:

[0006]

[0007]

[0008] In the 5G Core Network (5GC), the Access and Mobility Management Function (AMF) provides services to the Session Management Function (SMF), other AMFs, Policy Control Function (PCF), Short Message Service Function (SMSF), Network Data Analytics Function (NWDAF), Network Exposure Function (NEF) and other NFs through an interface based on Namf services.

[0009] 3GPP TS29.518 specifies the services provided by AMF, which defines the Namf_EventExposure service. AMF can provide this service as a service producer to enable NF to subscribe to event notifications and obtain notifications about events on its own or on behalf of another NF. Known service consumers are NEF, SMF, Unified Data Management (UDM), NWDAF, Data Collection Coordination Function (DCCF), Location Management Function (LMF) and Gateway Mobile Location Centre (GMLC). The Namf_EventExposure service provides Presence-In-AOI-Report (Presence in Area of ​​Interest (AOI)) events.

[0010] Specifically, regarding the Presence-In-AOI-Report event, 3GPP TS29.518 5.3.1 stipulates:

[0011]

[0012]

[0013] As defined in 3GPP TS29.518, the AMF notifies service subscribers when a specified UE enters or leaves a specified AOI area. When the UE moves out of the old AMF and is served by a new AMF, the old AMF transfers the UE context to the new AMF, which includes the subscription to the AOI event. The new AMF notifies event subscribers of the UE's status. However, if the UE status of the AOI event has not changed during the UE's movement, the event subscriber has already received a report on the UE status from the old AMF. The UE status report from the new AMF is redundant. Summary of the invention

[0014] At least some objects of the present disclosure are to provide a technical solution so that a new AMF that receives a UE context from an old AMF during an inter-AMF mobility process can understand the UE status last reported by the old AMF, thereby avoiding the transmission of redundant event reports.

[0015] According to a first aspect of the present disclosure, a method implemented at a first NF node is provided for managing event reporting of a UE served by the first NF node. The method comprises the following steps: when the UE moves to be served by a second NF node, in response to receiving a UE context transfer request from the second NF node, including an indication in a first UE context indicating a UE event status of a last reported first subscription event, and transferring the first UE context to the second NF node.

[0016] In an exemplary embodiment, the method may further include the following steps: in response to receiving a second UE context from a third NF node, the UE context including an indication of a last reported UE event status for a second subscription event, determining whether the current event status of the UE for the second subscription event has changed from the last reported event status by checking the indication in the second UE context.

[0017] In an exemplary embodiment, the method may further include the step of transmitting an event report indicating the current event status of the UE for the second subscription event only when it is determined that the current event status of the UE for the second subscription event has changed compared to the last reported event status.

[0018] In an exemplary embodiment, the subscription event (ie, each of the first subscription event and the second subscription event) is an AOI event.

[0019] In an exemplary embodiment, the method may further comprise the step of checking whether the first subscription event is an ongoing event, and the step of including an indication in the first UE context may comprise including the indication in the first UE context if the first subscription event is an ongoing event.

[0020] In an exemplary embodiment, the first NF node, the second NF node and the third NF node are all AMF nodes. In other words, the method is applicable to the inter-AMF mobility process.

[0021] In an exemplary embodiment, before receiving the UE context transfer request, the method may further include the following steps: receiving a request for subscribing to an event for the UE from the fourth NF node. That is, the event is subscribed by the fourth NF node (NF service consumer), and then the event report needs to be correctly transmitted to the fourth NF node.

[0022] In an exemplary embodiment, the report type of the subscription event (ie, each of the first subscription event and the second subscription event) is a continuous report.

[0023] In an exemplary embodiment, each of the first subscription event and the second subscription event is subscribed per UE or per group of UEs.

[0024] In an exemplary embodiment, the event report indicates the presence status of the UE in the AOI, including IN / OUT / UNKNOWN.

[0025] According to a second aspect of the present disclosure, a first NF node is provided for managing UE event reports served by the first NF node, comprising: a communication interface for communication, at least one processor, and a memory comprising instructions, which, when executed by at least one processor, enables the first NF node to execute the method of the first aspect above.

[0026] According to a third aspect of the present disclosure, a computer program is provided, which includes instructions. When the instructions are executed by at least one processor, the first NF node executes the method of the first aspect.

[0027] According to a fourth aspect of the present disclosure, there is provided a carrier including the above-mentioned computer program, wherein the carrier is one of an electric signal, an optical signal, a radio signal or a computer-readable storage medium.

[0028] According to the above technical solution of the present disclosure, the source NF service provider (e.g., the first NF node) supports sending event notifications to the subscribed NF nodes, and (e.g., in the UE context) provides an indication of the last reported event status of the UE for the subscribed event to the second source NF service provider (i.e., the second NF node), and provides a subscription to the subscribed event so that the second NF node can decide whether to report the current status of the subscribed event by checking the received indication. Therefore, the second NF node will no longer report the status of the subscribed event that has been reported by the first NF node, reducing redundant and erroneous information and reducing the possibility of erroneous reduction in the number of reports. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The objects, advantages and features of the present disclosure will become more apparent from the description of the preferred embodiments in conjunction with the accompanying drawings, in which:

[0030] Figure 1 An example of a wireless communication system in which embodiments of the present disclosure may be implemented is shown;

[0031] Figure 2 A wireless communication system represented by a 5G network architecture consisting of core NFs is shown;

[0032] Figure 3 The use of service-based interfaces (rather than Figure 2 5G network architecture in 5G network architecture using point-to-point reference points / interfaces);

[0033] Figure 4 A scenario of inter-AMF mobility procedure is shown, where AOI reporting is triggered every time the UE moves from one AMF to another AMF for service;

[0034] Figure 5A A flowchart of a method for managing event reporting of a UE according to an exemplary embodiment of the present disclosure is schematically shown;

[0035] Figure 5B A flowchart schematically shows another method for managing event reporting of a UE according to an exemplary embodiment of the present disclosure;

[0036] Figure 6 An exemplary signaling diagram illustrating a scenario for applying an indication of the present disclosure according to an exemplary embodiment of the present disclosure is shown;

[0037] Figure 7 A schematic diagram exemplarily shows a structure of a first NF node according to an exemplary embodiment of the present disclosure; and

[0038] Figure 8 A structural diagram of a first NF node according to an exemplary embodiment of the present disclosure is exemplarily shown.

[0039] It should be noted that in all drawings, the same or similar reference numerals are used to indicate the same or similar elements; the various parts in the drawings are not drawn to scale but are only used for illustration purposes, and thus should not be understood as any limitation or restriction on the scope of the present disclosure. DETAILED DESCRIPTION

[0040] The principles and spirit of the present disclosure will be described below in conjunction with exemplary embodiments. Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. However, other embodiments are also included within the scope of the subject matter disclosed herein, and the disclosed subject matter should not be interpreted as being limited to 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. Further information can also be found in the following references:

[0041] 1)3GPP TS23.501V17.5.0(2022-06),

[0042] 2)3GPP TS29.122V17.5.0(2022-03),

[0043] 3)3GPP TS29.503V17.6.0(2022-03),

[0044] 4) 3GPP TS29.518V17.6.0 (2022-06), and

[0045] 5)3GPP TS29.522V17.5.0(2022-03).

[0046] The phrases "one embodiment", "an embodiment", "an exemplary embodiment", etc. mentioned in this specification indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. In addition, these phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it should be considered that those skilled in the art can implement these features, structures, or characteristics in other embodiments, whether or not explicitly described.

[0047] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that when the terms "comprise", "have", and / or "include" are used herein, the presence of the features, elements, and / or components, etc. is specified, but the presence or addition of one or more other features, elements, components, and / or combinations thereof is not excluded.

[0048] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0049] The techniques described herein can be used in various wireless communication networks, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-Frequency Division Multiple Access (SC-FDMA), Long Term Evolution (LTE), New Radio (NR), and other networks developed in the future. The terms "network" and "system" are sometimes used interchangeably. For illustration purposes only, certain aspects of these techniques are described below for a fifth generation wireless communication network. However, those skilled in the art will recognize that the techniques described herein can also be used in other wireless networks, such as the LTE and corresponding radio technologies mentioned herein, as well as wireless networks and radio technologies proposed in the future.

[0050] One type of communication device is a wireless communication device, which can be any type of wireless device capable of accessing (i.e., being served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to, user equipment (UE) in a 3GPP network, machine type communication (MTC) devices, and Internet of Things (IoT) devices.

[0051] As used herein, the term "UE" may be, for example, but not limited to: user equipment (UE), SS (Subscriber Station), portable subscriber station (PSS), mobile station (MS), mobile terminal (MT) or access terminal (AT). UE may include, but not limited to: mobile phones, cellular phones, smart phones, or personal digital assistants (PDA), portable computers, digital cameras and other image acquisition terminal devices, game terminal devices, music storage and playback devices, wearable terminal devices, vehicle-mounted wireless terminal devices, etc. In the following description, the terms "UE", "wireless communication device", "terminal device", "mobile terminal" and "user equipment" may be used interchangeably.

[0052] As used herein, a "network node" is any node belonging to the radio access network or the core network of a cellular communication network / system.

[0053] Figure 1 An example of a wireless communication system 100 in which embodiments of the present disclosure may be implemented is shown. The wireless communication system 100 may be a cellular communication system, such as a 5G New Radio (NR) network or an LTE cellular communication system. As shown, in this example, the wireless communication system 100 includes a plurality of radio access nodes 120 (e.g., an evolved Node B (eNB), a 5G base station referred to as a gNB, or other base stations or the like) and a plurality of wireless communication devices 140 (e.g., conventional UEs, machine type communication (MTC) / machine-to-machine (M2M) UEs). The wireless communication system 100 is organized into cells 160, which are connected to a core network 180 via respective radio access nodes 120. The radio access nodes 120 are capable of communicating with wireless communication devices 140 (also referred to herein as communication devices 140 or UE 140) and any additional elements suitable for supporting communication between wireless communication devices or between a wireless communication device and another communication device (e.g., a landline phone). The core network 180 includes one or more network nodes or functions 190. In some embodiments, the network nodes / functions 190 may include, for example Figures 2 to 3 Any network capabilities shown.

[0054] Figure 2 A wireless communication system represented by a 5G network architecture consisting of core network functions (NFs) is shown, where the interaction between any two NFs is represented by point-to-point reference points / interfaces. Figure 2 Can be seen as Figure 1 A specific implementation of system 100.

[0055] From the access side, Figure 2 The 5G network architecture shown includes multiple UEs 140 connected to the RAN 120 or access network (AN), and an access and mobility management function (AMF) 200. Typically, the RAN 120 includes a base station, such as an eNB or gNB or the like. From the core network side, Figure 2 The 5G core NF shown includes a network slice selection function (NSSF) 202, an authentication server function (AUSF) 204, a unified data management (UDM) 206, an AMF 200, a session management function (SMF) 208, a policy control function (PCF) 210 and an application function (AF) 212.

[0056] The reference points of the 5G network architecture represent detailed call flows used in developing specification standardization. The N1 reference point is defined to transmit signaling between the UE 140 and the AMF 200. The reference points connecting the AN 120 and the AMF 200 and the AN 120 and the UPF 214 are defined as N2 and N3, respectively. There is a reference point N11 between the AMF 200 and the SMF 208, which means that the SMF 208 is at least partially controlled by the AMF 200. N4 is used by the SMF 208 and the UPF 214 so that the UPF 214 can be set using the control signal generated by the SMF 208, and the UPF 214 can report its status to the SMF 208. N9 is a reference point connecting different UPFs 214, and N14 is a reference point connecting different AMFs 200. Since the PCF 210 applies policies to the AMF 200 and the SMF 208, respectively, N15 and N7 are defined. N12 is required for AMF 200 to authenticate UE 140. Since AMF 200 and SMF 208 require subscription data of UE 140, N8 and N10 are defined.

[0057] The 5GC network is designed to separate the user plane and the control plane. The user plane transmits user traffic, while the control plane transmits signaling in the network. Figure 2In the UE, UPF 214 is located in the user plane, while all other NFs (i.e., AMF 200, SMF 208, PCF 210, AF 212, NSSF 202, AUSF 204, and UDM 206) are located in the control plane. Separating the user plane and the control plane ensures that the resources of each plane can be scaled independently. Separating the user plane and the control plane also allows the UPF to be deployed separately from the control plane functions in a distributed manner. In this architecture, the UPF can be deployed very close to the UE to shorten the round trip time (RTT) between the UE and the data network in some applications that require low latency.

[0058] The 5G core network architecture consists of modular functions. For example, AMF 200 and SMF 208 are independent functions in the control plane. Separation of AMF 200 and SMF 208 allows independent evolution and expansion. Other control plane functions (such as PCF 210 and AUSF 204) can be Figure 2 The modular functional design enables the 5GC network to flexibly support various services.

[0059] Each NF interacts directly with another NF. An intermediate function can be used to route messages from one NF to another. In the control plane, a set of interactions between two NFs is defined as a service so that it can be reused. The service can support modularity. The user plane supports interactions such as forwarding operations between different UPFs.

[0060] Figure 3 The use of service-based interfaces (rather than Figure 2 The 5G network architecture in the 5G network architecture uses point-to-point reference points / interfaces). However, the above reference Figure 2 The NF described Figure 3 The services provided by NF to other authorized NFs can be disclosed to the authorized NF through the service-based interface. Figure 3 In the specification, the service-based interface is represented by the letter "N" followed by the name of the NF. For example, Namf represents the service-based interface of AMF, Nsmf represents the service-based interface of SMF, and so on. Figure 3 The Network Exposure Function (NEF) and Network Function Repository Function (NRF) discussed above Figure 2 However, it should be clarified that although Figure 2 It is not explicitly stated, but Figure 2 All NFs shown in the table can be used with Figure 3 The NEF and NRF interact.

[0061] Figures 2 to 3 Some attributes of the NF shown in can be described as follows. AMF provides UE-based authentication, authorization, mobility management, etc. Even UEs using multiple access technologies are basically connected to a single AMF because AMF is independent of the access technology. SMF is responsible for session management and assigning IP addresses to UEs. SMF also selects and controls UPF for data transmission. If the UE has multiple sessions, a different SMF can be assigned to each session to manage it separately and may provide different functions for each session. AF provides information about packet flows to the PCF responsible for policy control to support Quality of Service (QoS). Based on this information, the PCF determines policies on mobility and session management to enable the normal operation of the AMF and SMF. AUSF supports authentication functions for UEs or the like, and therefore stores data for authentication of UEs or the like, while UDM stores subscription data for UEs. The Data Network (DN) - which does not belong to the 5G core network - provides Internet access or operator services, etc.

[0062] The Nudm_EventExposure service is used by consumer NFs (e.g. NEFs) to subscribe to notifications of event occurrences via subscription service operations. For events detectable by the AMF, the UDM subscribes on behalf of the consumer NF (e.g. NEF) using the appropriate AMF service operations.

[0063] Figure 4 Scenario 400 of the inter-AMF mobility procedure is shown, where AOI reporting is triggered every time the UE moves from one AMF to another AMF for service.

[0064] Figure 4 The illustrated scenario 400 involves AMF-1 401, AMF-2 403, NRF 405, NEF 407, and AF 409. This is just an example, and the actual scenario is not limited thereto.

[0065] In step S410, AF 409 subscribes to the AOI type monitoring event notification of UE-X. That is, if the AOI status changes, that is, UE-X enters or leaves the indicated AOI, AF 409 requests to receive notification.

[0066] In step S420, the NEF 407 obtains one or more Tracking Area Identities (TAIs) as a translation of the received geographic area identifying the expected AOI.

[0067] In steps S430 to S450, NEF 407 needs to identify the AMF in the TAI list that serves the TAI, that is, the AMF that serves the expected AOI. To this end, NEF 407 performs NRF discovery using the TAI as input. It should be noted that a discovery request including only one TAI in the list is required in order for the NRF to provide any AMF that serves the TAI (regardless of whether the AMF also serves other TAIs in the list).

[0068] In step S460, NEF 407 subscribes to the event to the AMF where UE-X is located, indicating the TAI corresponding to the AOI (obtained in the previous step). In this case, it is assumed that UE-X is served by AMF-1 401.

[0069] In step S470, AMF-1 401 determines that UE-X is not located in any AOI TAI. Then, in step S480, AMF-1 401 returns the current status (status = OUT since immediate reporting is requested in step S460) to NEF 407.

[0070] In step S490, as an example, UE-X enters one of the TAIs in the AOI and is still served by AMF-1 401. Since the AOI state has changed (UE-X has entered the AOI), in step S4100, AMF-1 401 notifies NEF 407 that the UE has entered the AOI (state = IN).

[0071] In step S4110, as an example, UE-X moves to a TAI served by AMF-2 403. AMF-2 403 requests a UE context from AMF-1 401. The UE context includes events that are occurring (including AOI events). AMF-1 401 returns the UE context to AMF-2 403. AMF-2 403 checks the state of UE-X and notifies NEF 407 of the state of UE-X (AOI=IN) because UE-X is in a TAI belonging to the AOI.

[0072] NEF 407 receives incorrect information that UE-X has just entered the AOI, but NEF 407 already knows this. If NEF 407 returns the received information to AF 409, AF 409 will also receive incorrect information.

[0073] Furthermore, in step S410, the number of reports to be received by the instructing AF 409. In this case, the number of remaining reports sent to the AF 409 is erroneously decremented.

[0074] The following will refer to FIG. 5A to FIG. 8A method of event report management in a network according to an exemplary embodiment of the present disclosure is described.

[0075] Figure 5A A flowchart of another method 500 for managing event reporting of a UE according to an exemplary embodiment of the present disclosure is schematically shown. In one embodiment, the method 500 may be performed at a first NF node serving the UE. The first NF node may be, for example, an AMF node.

[0076] like Figure 5A As shown, the method 500 may include steps S501 to S540.

[0077] The method 500 may start from step S510, where when the UE moves to be served by the second NF node, the first NF node receives a UE context transfer request from the second NF node. That is, initially the UE is served by the first NF node. Then, the UE moves and starts to be served by the second NF node. The second NF node sends a UE context transfer request to the first NF node for requesting the UE context.

[0078] Then the method performs step S520, wherein the first NF node includes an indication indicating the UE event status of the first subscription event last reported in the first UE context. And in step S530, the first NF node transmits the first UE context to the second NF node.

[0079] In an exemplary embodiment of the present disclosure, a first NF node (i.e., a source NF node of an inter-AMF mobility process) transmits an indication of an event status of a last reported subscription event of a UE to a second NF node (i.e., a target NF node of the inter-AMF mobility process), by, for example, including the indication in a UE context. Accordingly, when the second NF node receives the UE context including the subscription event, if the second NF node determines that the current event status has not changed from the last reported event status, it may decide not to report the current event status of the subscription event.

[0080] In an exemplary embodiment of the present disclosure, the method 500 may further include step S540, in which the first NF node checks whether the first subscription event is an ongoing event, and if the first subscription event is an ongoing event, includes an indication in the first UE context in step S520. After receiving the UE context, the target NF node should report the UE current state of the ongoing subscription event. Therefore, the first NF node may only include an indication of the ongoing event in the first UE context.

[0081] In an exemplary embodiment of the present disclosure, each of the first NF node and the second NF node mentioned in the method 500 may be an AMF node in the inter-AMF mobility process. That is, during the inter-AMF mobility process, the first NF node may be a source AMF with respect to the second NF node, and the second NF node may be a target AMF.

[0082] In an exemplary embodiment of the present disclosure, the method 500 may further include step S501, wherein before receiving the UE context transfer request, a request for UE subscription event is received from the fourth NF node. That is, the first NF node has received the subscription of the UE event status, and then during the subsequent inter-AMF mobility process, the first NF node should include the indication of the event in the UE context and transmit it to the second NF node.

[0083] The fourth NF node is the NF service consumer of the event, such as one of the SMF, PCF, NEF, UDM and AF depending on the event.

[0084] In an exemplary embodiment of the present disclosure, the subscription event is an AOI event.

[0085] In an exemplary embodiment of the present disclosure, the report type of the first subscription event is a continuous report. According to the provisions of 3GPPTS29.518 5.3.1, the report type of the AOI event can be a one-time report or a continuous report. For a one-time report event, the first NF node may have reported the status of the UE when receiving the subscription for the event, and during the inter-AMF mobility process, the second NF node does not need to report the status of the UE when receiving the UE context. Therefore, for subscription events with a report type of a one-time report, the first NF node may not need to include an indication in the context. On the contrary, for subscription events with a report type of a continuous report, during the inter-AMF mobility process, the second NF node should report the status of the UE when receiving the UE context, so the first NF node should include the indication in the UE context and transmit it to the second NF node.

[0086] In an exemplary embodiment of the present disclosure, the event is subscribed to by each UE or each group of UEs. That is, no matter whether the event is subscribed to by each UE or each group of UEs, the method 500 is applicable.

[0087] In an exemplary embodiment of the present disclosure, the event report indicates the presence status of the UE in the AOI, including IN / OUT / UNKNOWN. In the case where the first subscription event is an AOI event, the event report indicates the presence status of the UE in the AOI. The presence status may be one of IN, OUT, or UNKNOWN.

[0088] Figure 5BA flowchart of another method 500' for managing event reporting of a UE according to an exemplary embodiment of the present disclosure is schematically shown. In one embodiment, the method 500' may be performed at a first NF node serving the UE. The first NF node may be, for example, an AMF node.

[0089] like Figure 5B As shown, the method 500' may include steps S550-S570.

[0090] In some cases, the first NF node may also be a target NF node of an inter-AMF mobility procedure, which receives a UE context from another NF node. In this case, the method 500' may include step S550, in which a second UE context is received from a third NF node (i.e., a source NF node of the inter-AMF mobility procedure). The UE context includes an indication of the UE event status of the second subscription event reported last.

[0091] In step S560, in response to receiving the UE context, the first NF node determines whether the current event state of the UE subscribed to the second event has changed from the last reported event state by checking the indication in the second UE context.

[0092] In an exemplary embodiment of the present disclosure, method 500' may further include step S570, wherein the first NF node transmits an event report indicating the current event status of the UE for the second subscription event only when it is determined that the current event status of the UE for the second subscription event has changed from the last reported event status.

[0093] In an exemplary embodiment of the present disclosure, the second subscription event is an AOI event. For the AOI event, the serving NF node should provide the current event status of the UE when receiving the UE context. According to the present disclosure, when the serving NF node receives the UE context (i.e., the serving NF node is the target NF node of the inter-AMF mobility process), it can check whether the current status of the UE has changed from the last reported status, and only report the current status of the UE when the status has changed.

[0094] In an exemplary embodiment of the present disclosure, each of the first NF node and the third NF node mentioned in the method 500' may be an AMF node during the inter-AMF mobility procedure. That is, the third NF node may be a source AMF, and the first NF node may be a target AMF with respect to the third NF node.

[0095] In an exemplary embodiment of the present disclosure, a first NF node (e.g., a source AMF of an inter-AMF mobility process) supports sending event notifications to subscribed NF nodes, and (e.g., in a UE context) provides an indication of the last reported event status of the UE for a subscribed event to a second NF node (e.g., a target AMF of an inter-AMF mobility process), while providing a subscription to the subscribed event, so that the second NF node can decide whether to report the current status of the subscribed event by checking the indication. For example, when the second NF node receives a UE context including a subscribed event, if the second NF node determines that the current event status has not changed from the last reported event status, it can decide not to report the current event status of the subscribed event. Therefore, the transmission of redundant reports to the subscribed NF nodes can be avoided, and the number of remaining reports will not be erroneously decremented.

[0096] The terms "first" and "second" used in "first UE context" and "second UE context" are intended to distinguish between the UE context transmitted from the first NF node and the UE context received by the first NF node, without imposing any substantial limitation on the meaning of "UE context". Similarly, the terms "first" and "second" used in "first subscription event" and "second subscription event" are intended to distinguish between the subscription event transmitted with the first UE context and the subscription event transmitted with the second UE context, without imposing any substantial limitation on the meaning of "subscription event".

[0097] Figure 6 An example signaling diagram illustrating a scenario 600 to which the indications of the present disclosure are applied is shown.

[0098] Figure 6 The illustrated scenario 600 involves AMF-1 601, AMF-2 602, AMF-3 603, NRF 605, NEF 607, and AF 609. This is just an example, and the actual scenario is not limited thereto.

[0099] Steps S610 to S6100 and Figure 4410 to 4100 described in . Specifically, in step S610, AF609 subscribes to the AOI type monitoring event notification of UE-X. That is, if the AOI state changes, that is, UE-X enters or leaves the indicated AOI, AF 409 requests to receive notification. In step S620, NEF 607 obtains one or more TAIs as the received conversion of the geographical area identifying the expected AOI. In steps S630 to S650, NEF 607 needs to identify the AMF that serves the TAI in the TAI list, that is, the AMF that serves the expected AOI. To this end, NEF 607 performs NRF discovery using TAI as input. It should be noted that a discovery request that includes only one TAI in the list is required so that the NRF provides any AMF that serves the TAI (regardless of whether the AMF also serves other TAIs in the list). In step S660, NEF 607 subscribes to the event to AMF-1601, indicating the TAI corresponding to the AOI (obtained in the previous step). In step S670, AMF-1 601 determines that UE-X is not located in any AOI TAI. Then, in step S680, AMF-1 601 returns the current status (status = OUT since immediate reporting was requested in step S660) to NEF 607. In step S690, as an example, UE-X enters one of the TAIs in the AOI and is still served by AMF-1 601. Since the AOI status has changed (UE-X has entered the AOI), in step S6100, AMF-1 601 notifies NEF 607 that the UE has entered the AOI (status = IN). Step S660 is Figure 5A An example of step S501 in FIG.

[0100] In step S6110, as an example, UE-X moves to a TAI served by AMF-2 602. AMF-2 602 requests a UE context from AMF-1 601. The UE context includes events that are occurring (including AOI events). AMF-1 601 includes in the UE context an indication of the last reported status of UE-X in the AOI and transmits the UE context to AMF-2 602. Step S6110 is Figure 5A An example of step S520 and step S530 in FIG.

[0101] In step S6120, AMF-2 602 checks the status of UE-X and additionally checks the last reported status of UE-X in the UE context. In this case, AMF-2 602 determines that UE-X is still in AOI (AOI=IN), which is the same as the last reported status, and does not notify NEF 407 of the status of UE-X. Step S6120 is Figure 5BAn example of step S560 in FIG.

[0102] In step S6130, as an example, UE-X moves to a TAI served by AMF-3 603. AMF-3 603 requests a UE context from AMF-2 602. The UE context includes events that are occurring (including AOI events). AMF-2 602 includes in the UE context an indication of the last reported status of UE-X in the AOI and transmits the UE context to AMF-3 603. In this case, AMF-2 602 does not report the status of UE-X, so the last reported status of UE-X is the status reported by AMF-1 601 in step S6100 and transmitted to AMF-2 602 in step S6110. Step S6130 is Figure 5B An example of step S550 is shown.

[0103] In step S6140, AMF-3 603 checks the state of UE-X and additionally checks the last reported state of UE-X in the UE context. In this case, AMF-3 603 determines that the state of UE-X has changed from the last reported state (IN->OUT). Then, in step S6150, AMF-3 603 notifies NEF 607 of the state of UE-X (AOI=OUT) because UE-X has left the OAI. NEF 407 returns the received information to AF 409. Step S6140 is Figure 5B In the example of step S560 shown, step S6150 is Figure 5B An example of step S570 is shown.

[0104] In the exemplary signaling diagram, the NEF 407 is not notified of incorrect information because the AMF-2 602 receiving the UE context may decide not to notify the NEF of the current state associated with the mobility event subscription if the AMF-2 602 determines that the state has not changed from the last reported state. If the number of reports to be received by the AF 409 is indicated, the number of remaining reports to be sent to the AF 409 may be correctly decremented.

[0105] Figure 6 The flowchart shown is only one example of a scenario in which the teachings of the present disclosure may be applied. Figure 6The NF service consumers shown include NEF 607 and AP 609. It is known that there may be different NF services and the NF service consumers may also be different, resulting in different flow charts. For example, the services provided by AMF include Namf_EventExposure service, and the known service consumers are NEF, SMF, UDM, NWDAF, DCCF, LMF and GMLC. Depending on the service, the flow chart of the subscription service may be different. Accordingly, Figure 6 The steps S610 to S660 shown may vary for different services.

[0106] The following section includes a copy of the proposed changes in 3GPP TS 29.518 V17.6.0. This also describes an example of the proposed invention. Newly added text is underlined and deleted text is struck-through.

[0107] 6.1.6.2.66 Type: AmfEventSubscriptionAddInfo

[0108] Table 6.1.6.2.66-1: Definition of AmfEventSubscriptionAddInfo type

[0109]

[0110]

[0111]

[0112] 6.1.6.2.xx Type: AreaOfInterestEventState

[0113] Table 6.1.6.2.xx-1: Definition of AreaOfInterestEventState type

[0114]

[0115] The above is only one example implementation of the proposed invention. For example, the terminology of "aoiStateOldAmf" may be different in actual implementation. Alternatively, the "presence state" may be modified by adding an IE to indicate the last reported state. The invention may also be implemented by making other modifications to the specification.

[0116] Reference below Figure 7 Describe the structure of the first NF node. Figure 7 The first NF node 700 (for example, as shown in FIG. Figure 5A and 5B The first NF node mentioned in Figure 6 The schematic structure diagram of AMF-1 to AMF-3 shown in FIG. Figure 7 The first NF node 700 in the Figure 5A The method 500 for managing event reporting of a UE described herein and the previously described ... of FIG. Figure 5B Therefore, some detailed descriptions about the first NF node 700 can refer to the corresponding descriptions of the method 500 and the method 500'.

[0117] like Figure 7 As shown, the first NF node 700 may include a receiving module 702, a transmission module 704, a context preparation module 706 and a determination module 708. Those skilled in the art should understand that in order not to obscure the concept of the present disclosure, Figure 7 The common components in the first NF node 700 are omitted. In addition, some modules may be distributed in more modules or integrated into fewer modules. For example, the receiving module 702 and the transmitting module 704 may be integrated into a transceiver module.

[0118] The first NF node 700 is included in a first NF node set consisting of a plurality of first NF nodes.

[0119] In an exemplary embodiment of the present disclosure, the receiving module 702 of the first NF node 700 may be configured to receive a request to subscribe to an event of a UE served by the first NF node 700 from a fourth NF node (ie, an NF service consumer).

[0120] In an exemplary embodiment of the present disclosure, the receiving module 702 of the first NF node 700 may be configured to receive a UE context transfer request from the second NF node when the UE moves to be served by the second NF. The context preparation module 706 of the first NF node 700 may be configured to prepare the first UE context by including an indication indicating the UE event status of the first subscription event last reported in the UE context. And, the transmission module 704 of the first NF node 700 may be configured to transmit the first prepared UE context to the second NF node.

[0121] In an exemplary embodiment of the present disclosure, the first NF node 700 (i.e., the source NF node of the inter-AMF mobility process) transmits an indication of the event status of the last reported subscription event of the UE to the second NF node (i.e., the target NF node of the inter-AMF mobility process), which is by, for example, including the indication in the UE context. Accordingly, when the second NF node receives the UE context including the subscription event, if the second NF node determines that the current event status has not changed from the last reported event status, it can decide not to report the current event status of the subscription event.

[0122] In an exemplary embodiment of the present disclosure, the determination module 708 of the first NF node 700 may be configured to determine whether the first subscription event is an ongoing event, and the context preparation module 706 of the first NF node 700 may be configured to include the indication in the first UE context if the determination module 708 determines that the first subscription event is an ongoing event.

[0123] In an exemplary embodiment of the present disclosure, the first subscription event is an AOI event.

[0124] In an exemplary embodiment of the present disclosure, the report type of the first subscription event is a continuous report. According to the provisions of 3GPPTS29.518 5.3.1, the report type of the AOI event can be a one-time report or a continuous report. For a one-time report event, the first NF node 700 may have reported the status of the UE when receiving the subscription for the event, and during the inter-AMF mobility process, the second NF node does not need to report the status of the UE when receiving the UE context. Therefore, for subscription events with a report type of a one-time report, the first NF node 700 may not need to include an indication in the context. On the contrary, for subscription events with a report type of a continuous report, during the inter-AMF mobility process, the second NF node should report the status of the UE when receiving the UE context, so the first NF node 700 should include the indication in the UE context and transmit it to the second NF node.

[0125] In an exemplary embodiment of the present disclosure, the event report indicates the presence status of the UE in the AOI, including IN / OUT / UNKNOWN. In the case where the first subscription event is an AOI event, the event report indicates the presence status of the UE in the AOI. The presence status may be one of IN, OUT, or UNKNOWN.

[0126] In an exemplary embodiment of the present disclosure, the receiving module 702 of the first NF node 700 may be configured to receive a second UE context from a third NF node. The second UE context includes an indication of a UE event state indicating a second subscription event reported last.

[0127] In response to receiving the UE context, the determination module 708 of the first NF node 700 can be configured to determine whether the current event state of the UE subscribed to the second event has changed from the last reported event state by checking the indication in the second UE context.

[0128] In an exemplary embodiment of the present disclosure, the transmission module 704 of the first NF node 700 can be configured to transmit an event report indicating the current event status of the UE for the second subscription event only when the determination module 708 determines that the current event status of the UE for the second subscription event has changed from the last reported event status.

[0129] In an exemplary embodiment of the present disclosure, the second subscription event is an AOI event. For the AOI event, the serving NF node should provide the current event status of the UE when receiving the UE context. According to the present disclosure, when the first NF node 700 that becomes the serving NF node receives the UE context (i.e., the serving NF node is the target NF node of the inter-AMF mobility process), it can check whether the current status of the UE has changed from the last reported status, and only report the current status of the UE when the status has changed.

[0130] In an exemplary embodiment of the present disclosure, the first NF node 700 (e.g., the source AMF of the inter-AMF mobility process) supports sending event notifications to subscribed NF nodes, and provides an indication of the last reported event status of the UE for the subscription event to the second NF node (e.g., the target AMF of the inter-AMF mobility process), so that the second NF node can decide whether to report the current status of the subscription event by checking the indication. For example, when the second NF node receives the UE context including the subscription event, if the second NF node determines that the current event status has not changed from the last reported event status, it can decide not to report the current event status of the subscription event. Therefore, it is possible to avoid transmitting redundant reports to the subscribed NF nodes, and the number of remaining reports will not be erroneously decremented.

[0131] Reference below Figure 8 Another structure of the first NF node 800 is described. Figure 8 The first NF node 800 (for example, as shown in FIG. Figure 5A and 5B The first NF node mentioned in Figure 6 The schematic structure diagram of AMF-1 to AMF-3 shown in FIG. Figure 8 The first NF node 800 in the Figure 5A The method 500 for managing event reporting of a UE described herein and previously referred to in Figure 5B Therefore, some detailed descriptions about the first NF node 800 can refer to the corresponding descriptions of the method 500 and the method 500'.

[0132] like Figure 8As shown, the first NF node 800 may include at least one controller or processor 803, which includes, for example, any suitable central processing unit (CPU), microcontroller, digital signal processor (DSP), etc., capable of executing computer program instructions. The computer program instructions may be stored in a memory 805. The memory 805 may be any combination of RAM (Random Access Memory) and ROM (Read Only Memory). The memory may also include a persistent memory, such as any one or combination of a magnetic memory, an optical memory, or a solid-state memory or even a remotely mounted memory. The exemplary first NF node 800 also includes a communication interface 801 for communication.

[0133] When the instruction is loaded from the memory 805 and executed by the at least one processor 803, the first NF node 800 may execute the previously referenced Figure 5A The method 500 for managing event reporting of a UE described herein and previously referred to in Figure 5B The method 500' for managing event reporting of a UE is described. The first NF node 800 is included in a first NF node set consisting of a plurality of first NF nodes.

[0134] Specifically, in an exemplary embodiment of the present disclosure, when instructions are loaded from a memory 805 and executed by at least one processor 803, the first NF node 800 can receive a request to subscribe to events of a UE served by the first NF node 800 from a fourth NF node (i.e., an NF service consumer) via the communication interface 801.

[0135] In an exemplary embodiment of the present disclosure, when instructions are loaded from a memory 805 and executed by at least one processor 803, the instructions may enable the first NF node 800 to receive a UE context transfer request from a second NF node via a communication interface 801 when the UE moves to be served by a second NF, prepare a first UE context by including an indication, wherein the indication indicates the UE event status of a first subscription event last reported in the first UE context, and transfer the first prepared UE context to the second NF node.

[0136] In an exemplary embodiment of the present disclosure, the first NF node 800 (i.e., the source NF node of the inter-AMF mobility process) transmits an indication of the event status of the last reported subscription event of the UE to the second NF node (i.e., the target NF node of the inter-AMF mobility process), which is by, for example, including the indication in the UE context. Accordingly, when the second NF node receives the UE context including the subscription event, if the second NF node determines that the current event status has not changed from the last reported event status, it may decide not to report the current event status of the subscription event.

[0137] In an exemplary embodiment of the present disclosure, when instructions are loaded from the memory 805 and executed by at least one processor 803, the first NF node 800 can determine whether the first subscription event is an ongoing event, and if it is determined that the first subscription event is an ongoing event, an indication is included in the UE context.

[0138] In an exemplary embodiment of the present disclosure, the first subscription event is an AOI event.

[0139] In an exemplary embodiment of the present disclosure, the report type of the first subscription event is a continuous report. According to the provisions of 3GPPTS29.518 5.3.1, the report type of the AOI event can be a one-time report or a continuous report. For a one-time report event, the first NF node 800 may have reported the status of the UE when receiving the subscription for the event, and during the inter-AMF mobility process, the second NF node does not need to report the status of the UE when receiving the UE context. Therefore, for subscription events with a report type of a one-time report, the first NF node 800 may not need to include an indication in the context. On the contrary, for subscription events with a report type of a continuous report, during the inter-AMF mobility process, the second NF node should report the status of the UE when receiving the UE context, so the first NF node 800 should include the indication in the UE context and transmit it to the second NF node.

[0140] In an exemplary embodiment of the present disclosure, the event report indicates the presence status of the UE in the AOI, including IN / OUT / UNKNOWN. In the case where the first subscription event is an AOI event, the event report indicates the presence status of the UE in the AOI. The presence status may be one of IN, OUT, or UNKNOWN.

[0141] In an exemplary embodiment of the present disclosure, when instructions are loaded from the memory 805 and executed by at least one processor 803, the instructions may cause the first NF node 800 to receive a second UE context from a third NF node via the communication interface 801. The second UE context includes an indication of a UE event status indicating a second subscription event that was last reported.

[0142] In an exemplary embodiment of the present disclosure, when instructions are loaded from the memory 805 and executed by at least one processor 803, the first NF node 800 can determine whether the current event state of the UE subscribing to the second event has changed from the last reported event state by checking the indication in the second UE context.

[0143] In an exemplary embodiment of the present disclosure, when instructions are loaded from the memory 805 and executed by at least one processor 803, the first NF node 800 can transmit an event report indicating the current event status of the UE for the second subscription event via the communication interface 801 only when it is determined that the current event status of the UE for the second subscription event has changed from the last reported event status.

[0144] In an exemplary embodiment of the present disclosure, the second subscription event is an AOI event. For the AOI event, the serving NF node should provide the current event status of the UE when receiving the UE context. According to the present disclosure, when the first NF node 800 that becomes the serving NF node receives the UE context (i.e., the serving NF node is the target NF node of the inter-AMF mobility process), it can check whether the current status of the UE has changed from the last reported status, and only report the current status of the UE when the status has changed.

[0145] In an exemplary embodiment of the present disclosure, the first NF node 800 (e.g., the source AMF of the inter-AMF mobility process) supports sending event notifications to subscribed NF nodes, and provides an indication of the last reported event status of the UE for the subscribed event to the second NF node (e.g., the target AMF of the inter-AMF mobility process), so that the second NF node can decide whether to report the current status of the subscribed event by checking the indication. For example, when the second NF node receives a UE context including a subscribed event, if the second NF node determines that the current event status has not changed from the last reported event status, it can decide not to report the current event status of the subscribed event. Therefore, it is possible to avoid transmitting redundant reports to the subscribed NF nodes, and the number of remaining reports will not be erroneously decremented.

[0146] Aspects of the present disclosure may also be embodied as methods and / or computer program products. Therefore, the present disclosure may be embodied in hardware and / or hardware / software (including firmware, resident software, microcode, etc.). In addition, the embodiment may take the form of a computer program product on a computer-usable or computer-readable storage medium, in which a computer-usable or computer-readable program code is embodied for use by an instruction execution system or used in combination with an instruction execution system. Such an instruction execution system may be implemented in an independent manner or in a distributed manner. The actual software code or dedicated control hardware used to implement the embodiments described herein does not limit the present disclosure. Therefore, although the operations and behaviors of various aspects are described without reference to specific software codes, it should be understood that those skilled in the art can design software and control hardware based on the description herein to implement various aspects.

[0147] Furthermore, some parts of the present disclosure may be implemented as “logic” that performs one or more functions. The logic may include hardware, such as an application specific integrated circuit or a field programmable gate array, or a combination of hardware and software.

[0148] It should be emphasized that the term “comprising” used in this specification is used to specify the presence of stated features, integers, steps, components or groups, but does not exclude the presence or addition of one or more other features, integers, steps, components or groups.

[0149] Unless explicitly described, any element, action or instruction used in this disclosure should not be interpreted as essential or indispensable to this disclosure. In addition, as used herein, the article "a" is intended to include one or more items. When only one item is referred to, the term "one" or similar language is used. In addition, unless otherwise explicitly stated, the phrase "based on" is intended to mean "based at least in part on".

[0150] The above description only provides the embodiments of the present disclosure and is not intended to limit the present disclosure in any way. Therefore, any modification, replacement, improvement or similar content within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. A method implemented at a first network function NF node, for managing event reporting of a user equipment UE served by the first NF node, the method comprising: when the UE moves to be served by a second NF node, in response to receiving (S510) a UE context transfer request from the second NF node, including (S520) in the first UE context an indication of a last reported UE event state for a first subscription event, and The first UE context is transmitted (S530) to the second NF node.

2. The method according to claim 1, further comprising: In response to receiving (S550) a second UE context from a third NF node, the second UE context including an indication of a last reported UE event status for a second subscription event, determining (S560) whether a current event status of the UE for the second subscription event has changed from the last reported event status by checking the indication in the second UE context.

3. The method according to claim 2, further comprising: Only when it is determined that the current event status of the UE for the second subscribed event has changed from the last reported event status, an event report indicating the current event status of the UE for the second subscribed event is transmitted (S570). 4 . The method according to claim 1 , wherein each of the first subscription event and the second subscription event is an Area of ​​Interest (AOI) event.

5. The method according to any one of claims 1 to 3, further comprising checking (S540) whether the first subscription event is an ongoing event, and Including (S520) an indication in the first UE context comprises: if the first subscription event is an ongoing event, including the indication in the first UE context.

6. The method according to any one of claims 1 to 3, wherein each of the first NF node, the second NF node and the third NF node is an access and mobility management function AMF node.

7. The method according to any one of claims 1 to 3, wherein: Before receiving (S510) the UE context transfer request, the method further includes: Receive (S501) a request from the fourth NF node to subscribe to an event for the UE.

8. A method according to claim 4 and as appended to claim 3, wherein the reporting type of the first subscription event and the second subscription event is continuous reporting.

9. The method according to claim 4 and as dependent on claim 3, wherein each of the first subscription event and the second subscription event is subscribed on a per-UE or per-group-UE basis.

10. The method according to claim 4 and as dependent on claim 3, wherein the event report indicates the presence status of the UE in the AOI, including inside / outside / unknown.

11. A first network function NF node (800), which is used to manage event reports of a user equipment UE served by the first NF node, the first NF node comprising: a communication interface (801) for communication, at least one processor (803), and A memory (805) comprising instructions which, when executed by at least one of the processors (803), causes the first NF node (800) to perform a method according to any one of claims 1 to 10.

12. A computer program comprising instructions which, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 10.

13. A carrier comprising the computer program according to claim 12, wherein the carrier is one of an electric signal, an optical signal, a radio signal or a computer-readable storage medium.

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