Network node of mobile communication network and computer program
By requesting and notifying network nodes about post-handover changes, the solution prevents analysis interruptions in NWDAF, ensuring continuous data collection during handovers in mobile communication networks.
Patent Information
- Application Number
- JP2024002746
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-11
- Publication Date
- 2025-07-24
AI Technical Summary
The occurrence of analysis interruptions in the Network Data Analytics Function (NWDAF) due to handover events in mobile communication networks, where the NWDAF loses data collection capabilities for wireless devices moving between service areas.
A network node requests information from a first network node managing a wireless device's location to notify a second network node that will manage the location post-handover, and a notification mechanism informs a third network node collecting data about the second network node, allowing pre-emptive data subscription and cancellation of unnecessary subscriptions.
This approach prevents analysis interruptions in NWDAF by ensuring continuous data collection during handovers, maintaining data integrity and service continuity.
Smart Images
Figure 2025109055000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a technique for collecting data in a mobile communication system.
Background Art
[0002] Non-Patent Document 1 discloses a configuration for data analytics services in a mobile communication network. According to Non-Patent Document 1, a Network Data Analytics Function (NWDAF) is provided in the mobile communication network. The NWDAF is one of various network functions (NFs) arranged in the mobile communication network. Other examples of NFs include an Access and Mobility Management Function (AMF) that manages the location of a Wireless Device (WD) and serves as a window for control signals transmitted and received between the WD and the NFs of the core network of the mobile communication network, a Session Management Function (SMF) that manages Protocol Data Unit (PDU) sessions for the WD, a User Plane Function (UPF) that processes user plane data transmitted and received by the WD on the PDU session, a Network Repository Function (NRF) that manages each NF, and a Network Exposure Function (NEF) that serves as a window to the outside of the mobile communication network, etc.
[0003] An NF that uses the analysis service provided by the NWDAF first subscribes to the analysis service. In the following description, an NF that subscribes to the analysis service provided by the NWDAF is referred to as a "consumer NF". The NWDAF may provide, as analysis results, for example, the load of one or more NFs, the locations of one or more WDs, the traffic of one or more WDs, etc. to the consumer NF. The NWDAF subscribes to the data provision service provided by the NF that holds the data (hereinafter referred to as analysis data) used for analysis in order to provide the analysis results to the consumer NF. In the following description, the NF that provides the analysis data to the NWDAF is referred to as a "source NF". The NWDAF collects the analysis data from one or more source NFs, performs analysis, and transmits the analysis results to the consumer NF.
Prior Art Documents
Non-Patent Documents
[0004]
Non-Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] For example, as shown in FIG. 1, it is assumed that the mobile communication network is configured such that AMF#1 and SMF#1 provide services to the WDs in area #1, and AMF#2 and SMF#2 provide services to the WDs in area #2. In FIG. 1, gNB indicates a base station. Note that in FIG. 1, the number of AMF, SMF, and gNB in area #1 is one each, but the number of AMF, SMF, and gNB in area #1 can be plural. Similarly, the number of AMF, SMF, and gNB in area #2 can also be plural. Furthermore, although not shown in FIG. 1, other NFs such as UPF may be provided in each of area #1 and area #2.
[0006] According to FIG. 1, WD#1 is located in area #1 and has established a control plane session with AMF#1 via gNB#1. Assume that SMF#1 manages the PDU session of WD#1. That is, in the configuration of FIG. 1, it is assumed that AMF#1 and SMF#1 provide services to WD#1. For example, when a consumer NF requests analysis results regarding WD#1 from NWDAF, NWDAF collects analysis data regarding WD#1 using AMF#1 and SMF#1, which provide services to WD#1, as source NFs.
[0007] Here, as shown in FIG. 2, assume that WD#1 moves to area #2, resulting in a handover (HO) involving a change in AMF. In FIG. 2, it is assumed that AMF#2 and SMF#2 provide services to WD#1. In the state of FIG. 2, AMF#1 and SMF#1 cannot collect data regarding WD#1, and thus NWDAF also cannot collect analysis data regarding WD#1. Therefore, for example, due to timeout control or the like, NWDAF recognizes that it cannot collect analysis data regarding WD#1 from AMF#1 and SMF#1, and an analysis interruption occurs until it determines the AMF and SMF currently providing services to WD#1 and requests analysis data regarding WD#1.
[0008] This disclosure provides a technique for suppressing the occurrence of analysis interruption in NWDAF.
Means for Solving the Problem
[0009] According to one aspect of the present disclosure, a network node of a mobile communication network requests a first network node that manages the location of a wireless device (WD) to notify information indicating the second network node that will manage the location of the WD after handover of the WD, in response to selecting the second network node; and notification means for notifying, in response to obtaining information indicating the second network node from the first network node, a third network node that is collecting data related to the WD of the information indicating the second network node.
Advantages of the Invention
[0010] According to the present disclosure, it is possible to suppress the occurrence of interruption of analysis in the NWDAF.
Brief Description of the Drawings
[0011]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Modes for Carrying Out the Invention
[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of the features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Also, the same or similar configurations are given the same reference numerals, and duplicate explanations are omitted.
[0013] Figure 3 is a configuration diagram of the communication system according to this embodiment. The mobile communication network is composed of a plurality of areas including Area #1 and Area #2. In Area #1, gNB#1, AMF#1, SMF#1, and UPF#1 are arranged, and in Area #2, gNB#2, AMF#2, SMF#2, and UPF#2 are arranged. Note that the number of gNBs, AMFs, SMFs, and UPFs in Area #1 and Area #2 can be plural. Furthermore, other NFs such as NEF and NRF can be provided in each of Area #1 and Area #2. In Figure 3, WD#1 is provided with services by gNB#1, AMF#1, SMF#1, and UPF#1. That is, WD#1 establishes a control session with AMF#1 via gNB#1 and establishes a PDU session with UPF#1 via gNB#1. Note that SMF#1 manages the PDU session established by WD#1.
[0014] Also, in FIG. 3, it is assumed that the consumer NF requests the NWDAF for the analysis result regarding WD#1, and the NWDAF uses AMF#1, SMF#1, and UPF#1 as source NFs to collect the analysis data regarding WD#1. The difference from FIG. 1 is that in the present disclosure, an NF denoted as "controller" is provided. The controller has an interface for communicating with the NWDAF and each NF that can be a source NF. Note that the NWDAF can also use other NFs (not shown) provided in area #1 as source NFs to collect the data regarding WD#1. In the following description, the "analysis data regarding WD#1" obtained from the source NF is simply denoted as "analysis data". Further, the "source NF of the analysis data regarding WD#1" is simply denoted as "source NF".
[0015] FIG. 4 is a sequence diagram according to the present disclosure. The state at the start of the sequence in FIG. 4 is as shown in FIG. 3, where WD#1 is in area #1 and communicating via gNB#1. WD#1 is moving towards area #2, and it is assumed that a handover (HO) from gNB#1 to gNB#2 occurs when it enters area #2. Also, it is assumed that the consumer NF instructs the NWDAF to avoid interruption of the analysis. In the sequence of FIG. 4, the steps represented by the dotted lines indicate the processes also performed in a normal HO. For the sake of simplicity of description, not all of the processes performed in a normal HO are shown, and only the parts necessary for understanding the present disclosure are shown.
[0016] Based on the instruction of interruption avoidance from the consumer NF, the NWDAF sends an avoidance request message indicating the interruption avoidance request to the controller at S10. The avoidance request message includes information indicating the source NF that is the source of the analysis data and information indicating the AMF#1 that provides services to WD#1. Note that in this example, AMF#1 is the source NF, but there may be cases where AMF#1 is not the source NF. That is, regardless of whether the AMF providing services to WD#1 is the source NF or not, the avoidance request message includes information indicating the AMF providing services to WD#1. The controller that receives the avoidance request message sends a notification request message to AMF#1 indicated as the AMF providing services to WD#1 in the avoidance request message at S11. The notification request message is a message that requests to notify other NFs or other areas when the source NF is changed to another NF due to the HO of WD#1 or when the area is changed to another area.
[0017] In the example of Figure 4, at S12, AMF#1 has received an HO request from gNB#1 to HO WD#1 from gNB#1 to gNB#2. In response to the reception of the HO request, AMF#1 selects the AMF after HO. The AMF after HO may remain AMF#1, but in the example of Figure 4, since WD#1 has moved from area #1 in Figure 3 to area #2, AMF#1 has selected AMF#2 as the AMF after HO. Therefore, according to the notification request message at S11, AMF#1 notifies the controller at S13 that the AMF after HO is AMF#2 and the area after HO is area #2. The controller notifies the NWDAF at S14 that the area of WD#1 has been changed to area #2 and the AMF providing services to WD#1 has been changed to AMF#2.
[0018] In S15, the NWDAF sends a subscription request message to the AMF#2 that will provide services to WD#1. The subscription request message indicates a request for analysis data from the AMF#2. Also, in S16, the controller sends an SMF notification request message to the AMF#2 that will provide services to WD#1. The SMF notification request message is a message that requests notification of the selected SMF when the AMF#2 selects the SMF that manages the PDU session of WD#1. Although not shown in Figure 4, when the NWDAF uses another NF in area #1 different from the AMF, SMF, and UPF as the source NF, the NWDAF sends a subscription request message to the same type of NF in area #2.
[0019] In S17, the AMF#1 sends the information necessary to provide services to WD#1 to the AMF#2. Then, in S18, the AMF#2 selects the SMF that processes the PDU session of WD#1. In the example of Figure 4, the AMF#2 has selected the SMF#2. In S19, the AMF#2 sends the information necessary to provide services to WD#1 to the SMF#2. Note that S17 - S19 are the processes in a normal HO.
[0020] According to the message at S16, AMF#2 notifies the controller at S20 that it has selected SMF#2. At S21, the controller notifies NWDAF that the SMF providing services to WD#1 is changed to SMF#2. At S22, NWDAF sends a subscription request message to SMF#2 which will provide services to WD#1. The subscription request message indicates a request for analysis data from SMF#2. Also, at S23, the controller sends a UPF notification request message to SMF#2 which will provide services to WD#1. The UPF notification request message is a message that requests notification of the selected UPF when SMF#2 selects the UPF that processes the PDU session of WD#1, that is, the UPF that processes the user data transmitted and received by WD#1.
[0021] On the other hand, at S24, SMF#2 selects the UPF that processes the PDU session of WD#1. In the example of Figure 4, SMF#2 has selected UPF#2. At S25, SMF#2 sends the information necessary to process the PDU session of WD#1 to UPF#2. Note that S24 and S25 are the processes in a normal HO.
[0022] According to the message at S23, SMF#2 notifies the controller at S26 that it has selected UPF#2. At S27, the controller notifies NWDAF that the UPF processing the PDU session of WD#1 is changed to UPF#2. At S28, NWDAF sends a subscription request message to UPF#2. The subscription request message indicates a request for analysis data from UPF#2. Also, at S29, AMF#2 sends a HO request to gNB#2. After that, the HO of WD#1 is completed.
[0023] Also, in S30, the NWDAF cancels unnecessary subscriptions. Unnecessary subscriptions are, for example, subscriptions to AMF#1, SMF#1, and UPF#1. Further, when WD#1 uses other NFs in area #1 different from AMF, SMF, and UPF as source NFs, based on the notification in S14, the NWDAF was assumed to be able to send a subscription request message to the same type of NFs in area #2. However, among the source NFs in area #1, there may be those that do not change from area #1 to area #2 and continue to collect data regarding WD#1 even if the location area of WD#1 changes from area #1 to area #2. If such an NF exists, the subscription to the same type of NFs in area #2 becomes an unnecessary subscription.
[0024] As described above, according to the sequence in Figure 4, before HO is completed, the NWDAF can request a subscription for analysis data for the AMF, SMF, and UPF after HO in advance, and further for the NFs that may be changed by HO, so that analysis data can be obtained after HO is completed. Therefore, interruption of analysis at the NWDAF can be suppressed.
[0025] Note that not all of AMF, SMF, and UPF are changed by HO. For example, in the case of HO within the same area, AMF may not be changed. Further, in the case of HO within an area, even if AMF is changed, SMF and UPF may not be changed as a result. Below, in the sequence of Figure 4, the case where the source NFs before and after HO are the same will be described. In the following description, AMF#2, SMF#2, and UPF#2 in Figure 4 shall be read as AMF after HO, SMF after HO, and UPF after HO, respectively. AMF after HO, SMF after HO, and UPF after HO may be the same as AMF#1, SMF#1, and UPF#1 before HO, respectively.
[0026] <When AMF is the same> When AMF#1 is notified at S13, the controller can notify NWDAF of AMF#1 and Area#1 at S14. However, since NWDAF has subscribed to the analysis data from AMF#1, it is not necessary to send a subscription request message to the AMF after HO at S15. Note that since the SMF after HO and the UPF after HO can be different from SMF#1 and UPF#1, the processing from S16 is performed. Note that since the controller has obtained information about the source NF from NWDAF at S10, it can determine that the AMF has not changed before and after HO. Therefore, the processing of S14 and S15 can also be omitted.
[0027] <When the SMF is the same> When SMF#1 is notified at S20, the controller can notify NWDAF of SMF#1 at S21. However, since NWDAF has subscribed to the analysis data from SMF#1, it is not necessary to send a subscription request message to the SMF after HO at S22. Note that since the UPF after HO can be different from UPF#1, the processing from S23 is performed. Note that since the controller has obtained information about the source NF from NWDAF at S10, it can determine that the SMF has not changed before and after HO. Therefore, the processing of S21 and S22 can also be omitted.
[0028] <When the UPF is the same> When UPF#1 is notified at S26, the controller can notify NWDAF of UPF#1 at S27. However, since NWDAF has subscribed to the analysis data from UPF#1, it is not necessary to send a subscription request message to the UPF after HO at S28. Note that since the controller has obtained information about the source NF from NWDAF at S10, it can determine that the UPF has not changed before and after HO. Therefore, the processing of S27 and S28 can also be omitted.
[0029] In addition, in Fig. 4, AMF#1, SMF#1, and UPF#1 are used as source NFs. However, one or more of AMF#1, SMF#1, and UPF#1 may not be source NFs. In the following, the case where one or more of AMF#1, SMF#1, and UPF#1 are not source NFs will be described.
[0030] <When AMF#1 is not a source NF> For example, when AMF#1 is not a source NF and SMF#1 and UPF#1 are source NFs, S14 and S15 in Fig. 4 can be omitted. However, other processes are performed to determine the SMF and UPF after HO.
[0031] <When AMF#1 and SMF#1 are not source NFs> When AMF#1 and SMF#1 are not source NFs and UPF is a source NF, S14 and S15, S21 and S22 in Fig. 4 can be omitted. However, other processes are performed to determine the UPF after HO.
[0032] <When AMF#1, SMF#1, and UPF#1 are not source NFs> When AMF#1, SMF#1, and UPF#1 are not source NFs but other NFs in Area #1 are source NFs, the processes from S10 to S14 are performed to make a subscription request for other NFs that can be changed by HO. Note that in S14, only the area after HO needs to be notified to the NWDAF.
[0033] <When SMF#1 is not a source NF> When SMF#1 is not a source NF and AMF#1 and UPF#1 are source SFs, S21 and S22 in Fig. 4 can be omitted. However, other processes are performed to determine the UPF after HO.
[0034] <When SMF#1 and UPF#1 are not source NFs> When SMF#1 and UPF#1 are not the source NFs and AMF#1 is the source NF, the processes from S10 to S15 and the process of S30 are performed. Note that the normal HO process (indicated by the dotted line) is performed.
[0035] <When UPF#1 is not the source NF> When UPF#1 is not the source NF and AMF#1 and SMF#1 are the source SFs, the processes from S10 to S22 and the process of S30 are performed. Note that the normal HO process (indicated by the dotted line) is performed.
[0036] Also, in the sequence of FIG. 4, it is assumed that the consumer NF instructs the NWDAF to avoid interruption of analysis. Accordingly, the NWDAF has sent an avoidance request message to the controller at S10. Therefore, in the present embodiment, when the consumer NF does not instruct the NWDAF to avoid interruption of analysis, the process of FIG. 4 (excluding the normal HO process indicated by the dotted line) is not executed. However, regardless of the request from the consumer NF, the NWDAF can always be configured so that the process of FIG. 4 is executed.
[0037] FIG. 5 is a flowchart of the process executed by the controller. In FIG. 5, the NF that provides services to WD#1 before handover is denoted as "NF before HO". At S50, the controller issues a notification request to the AMF before HO. This corresponds to S11 in FIG. 4. At S51, the controller acquires the information of the AMF after HO and the area from the AMF before HO. This corresponds to S13 in FIG. 4. Note that the AMF after HO and the AMF before HO may be the same. At S52, the controller notifies the NWDAF of the information of the AMF after HO and the area. This corresponds to S14 in FIG. 4. Note that when the AMF after HO and the AMF before HO are the same, S52 may be skipped.
[0038] In S53, the controller requests the HO-post AMF to notify the HO-post SMF. This corresponds to S16 in FIG. 4. In S54, the controller obtains information on the HO-post SMF from the HO-post AMF. This corresponds to S20 in FIG. 4. Note that the HO-post SMF and the HO-pre SMF may be the same. In S55, the controller notifies the NWDAF of the information on the HO-post SMF. This corresponds to S21 in FIG. 4. Note that if the HO-post SMF and the HO-pre SMF are the same, S55 may be skipped.
[0039] In S56, the controller requests the HO-post SMF to notify the HO-post UPF. This corresponds to S23 in FIG. 4. In S57, the controller obtains information on the HO-post UPF from the HO-post SMF. This corresponds to S26 in FIG. 4. Note that the HO-post UPF and the HO-pre UPF may be the same. In S58, the controller notifies the NWDAF of the information on the HO-post UPF. This corresponds to S27 in FIG. 4. Note that if the HO-post UPF and the HO-pre UPF are the same, S58 may be skipped.
[0040] FIG. 6 is a flowchart of the process executed by the NWDAF. In S60, the NWDAF requests the controller to avoid. This corresponds to S10 in FIG. 4. In S61, the NWDAF obtains information on the HO-post AMF and the area from the controller. This corresponds to S14 in FIG. 4. Note that the HO-post AMF and the HO-pre AMF may be the same. In S62, the controller requests the HO-post AMF for analysis data. This corresponds to S15 in FIG. 4. Note that if the HO-post AMF and the HO-pre AMF are the same, S62 is skipped. Also, in S63, the NWDAF requests analysis data from an NF of the same type as the source NF other than the AMF, SMF, and UPF within the HO-pre area that is in the HO-post area. Note that if the HO-post area and the HO-pre area are the same, S63 is skipped.
[0041] In S64, the NWDAF obtains the information of the SMF after HO from the controller. This corresponds to S21 in FIG. 4. Note that the SMF after HO and the SMF before HO may be the same. In S65, the controller requests the analysis data from the SMF after HO. This corresponds to S22 in FIG. 4. Note that if the SMF after HO and the SMF before HO are the same, S65 is skipped.
[0042] In S66, the NWDAF obtains the information of the UPF after HO from the controller. This corresponds to S27 in FIG. 4. Note that the UPF after HO and the UPF before HO may be the same. In S67, the controller requests the analysis data from the UPF after HO. This corresponds to S28 in FIG. 4. Note that if the UPF after HO and the UPF before HO are the same, S67 is skipped.
[0043] Note that if the source NF before and after HO is the same, S61, S64, and S66 may not occur. If S61 does not occur, S62 and S63 are skipped. Similarly, if S64 does not occur, S65 is skipped, and if S66 does not occur, S67 is skipped.
[0044] <Device Configuration> FIG. 7 is a configuration example of the above-described controller. The controller has, for example, one or more processors and one or more memory devices. The one or more memory devices may include a volatile memory device and a non-volatile memory device. By executing a computer program stored in the one or more memory devices by the one or more processors, each functional block shown in FIG. 7 can be realized. Further, the controller can be realized by a single device. Alternatively, the controller can be realized by a plurality of devices that can communicate with each other. Furthermore, the controller can be implemented in the same network node as another NF. For example, the controller can be implemented as the same network node as the NWDAF. Note that FIG. 7 shows only the functional blocks necessary for understanding the present disclosure, and the controller may have functional blocks other than those shown in FIG. 7.
[0045] The request unit 10 requests the pre - handover AMF to notify information indicating the post - handover AMF or the post - handover area in response to the pre - handover AMF that provides services to the WD selecting the post - handover AMF. Also, the request unit 10 requests the post - handover AMF to notify information indicating the post - handover SMF in response to the post - handover AMF selecting the post - handover SMF. Further, the request unit 10 requests the post - handover SMF to notify information indicating the post - handover UPF in response to the post - handover SMF selecting the post - handover UPF.
[0046] In response to obtaining information indicating each NF after handover based on the above request, the notification unit 11 notifies the NWDAF of information indicating the post - handover AMF. Note that the notification unit 11 may be configured to notify the NWDAF of information indicating the post - handover NF when the NF before and after handover is different, and not notify the NWDAF of information indicating the post - handover NF when the NF before and after handover is the same. Further, the notification unit 11 may be configured to notify the NWDAF of information indicating the post - handover NF when the NWDAF uses the pre - handover NF as the source NF, and not notify the NWDAF of information indicating the post - handover NF when the NWDAF does not use the pre - handover NF as the source NF.
[0047] Figure 8 is a configuration example of the above - described NWDAF. The NWDAF has, for example, one or more processors and one or more memory devices. The one or more memory devices may include a volatile memory device and a non - volatile memory device. By the one or more processors executing a computer program stored in the one or more memory devices, each functional block shown in Figure 8 can be realized. Also, the NWDAF can be realized by a single device. Alternatively, the NWDAF can be realized by a plurality of devices that can communicate with each other. Note that Figure 8 shows only the functional blocks necessary for understanding the present disclosure, and the NWDAF may have functional blocks other than those shown in Figure 8.
[0048] The collection unit 20 uses the NF that provides services to the WD to be analyzed as the source NF, and collects analysis data related to the WD. The request unit 21 notifies the controller of the source NF and the AMF that provides services to the WD to be analyzed, and requests to notify the controller of the changed source NF when the source NF is changed. The notification unit 22 notifies the source NF that it will collect analysis data by making a subscription request to the source NF. For example, when the notification unit 22 is notified of a change in the source NF from the controller, it makes a subscription request to the changed source NF. In addition, when another NF other than the AMF, SMF, and UPF is used as the source NF in the area before the change, in response to receiving a notification that the location area of the WD to be analyzed has changed from the NWDAF, the notification unit 22 may make a subscription request to an NF having the same function as the other NF provided in the changed area.
[0049] According to the present disclosure, when executed by the one or more processors of a device having one or more processors, a computer program that causes the device to function as the above-described controller or NWDAF, and a computer-readable storage medium storing the computer program are provided. Further, according to the present disclosure, a method executed by the controller or NWDAF regarding the processes shown in FIGS. 4 to 6, a computer program that causes a device having one or more processors to execute the method, and a computer-readable storage medium storing the computer program are provided.
[0050] As described above, it is possible to suppress the occurrence of interruption of analysis in the NWDAF. Therefore, it is possible to contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, "Build resilient infrastructure, promote sustainable industrialization, and foster innovation."
[0051] The invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the invention.
Description of Reference Numerals
[0052] 10: Requirement section, 11: Notification section
Claims
1. A network node of a mobile communication network, requesting means for requesting the first network node, which manages the location of a wireless device (WD), to notify information indicating the second network node in response to selecting a second network node that will manage the location of the WD after handover of the WD; notification means for notifying, in response to obtaining information indicating the second network node from the first network node, the third network node that is collecting data related to the WD of the information indicating the second network node; A network node comprising:
2. The network node according to claim 1, wherein the notification means notifies the third network node of the information indicating the second network node when the first network node and the second network node are different.
3. The network node according to claim 1, wherein the notification means notifies the third network node of the information indicating the second network node when the third network node is collecting data related to the WD from the first network node.
4. The network node according to claim 1, wherein the requesting means requests the second network node to notify information indicating the fourth network node in response to the second network node selecting a fourth network node that will manage a session with respect to the WD after the handover.
5. The network node according to claim 4, wherein the notification means notifies the third network node of the information indicating the fourth network node when the network node that manages the session with respect to the WD before the handover is different from the fourth network node.
6. The network node according to claim 4, wherein the notification means notifies the third network node of the information indicating the fourth network node when the third network node is collecting data related to the WD from the network node that manages the session with respect to the WD before the handover.
7. The requesting means requests the fourth network node to notify information indicating the fifth network node in response to the fourth network node selecting a fifth network node that will process user data transmitted and received by the WD after the handover, according to the network node of claim 4.
8. The notifying means notifies the third network node of information indicating the fifth network node when a network node that processes user data transmitted and received by the WD before the handover is different from the fifth network node, according to the network node of claim 7.
9. The notifying means notifies the third network node of information indicating the fifth network node when the third network node has collected data regarding the WD from a network node that processes user data transmitted and received by the WD before the handover, according to the network node of claim 7.
10. The third network node and the network node are the same node, according to the network node of claim 1.
11. The first network node and the second network node are nodes that implement an access and mobility management function (AMF), The third network node is a node that implements a network data analysis function (NWDAF), The fourth network node is a node that implements a session management function (SMF), The fifth network node is a node that implements a user plane function (UPF), according to the network node of claim 7.
12. A network node of a mobile communication network, A collecting means for collecting data regarding the WD from a first network node that provides services to the wireless device (WD); A requesting means for requesting a second network node to notify the other network node when the network node providing services to the WD is changed from the first network node to another network node; A notifying means for notifying the other network node to obtain data regarding the WD in response to being notified by the second network node that the other network node has been notified; A network node comprising the above.
13. The first network node is a node implementing an access and mobility management function (AMF), a node implementing a session management function (SMF), or a node implementing a user plane function (UPF), the network node according to claim 12.
14. The second network node notifies the network node that the WD moves from a first area to a second area based on a request from the network node, When the notification means collects data regarding the WD from a third network node different from the AMF, SMF, and UPF, in response to being notified that the WD has moved to the second area from the second network node, it notifies a network node having the same function as the third network node arranged in the second area to acquire data regarding the WD. The network node according to claim 13.
15. A computer program that, when executed by the one or more processors of a device having one or more processors, causes the device to function as the network node according to any one of claims 1 to 14.