Wireless communication system, communication session establishment method, and computer program

Abstract

To simplify the communication session establishment procedure.SOLUTION: A wireless communication system includes a communication session establishment request receiving unit for receiving a communication session establishment request for establishing a communication session for communication between a terminal device and a communication partner, a communication session establishment request holding unit for holding the received communication session establishment request, a communication session adjustment request unit for requesting communication session adjustment to a communication session adjustment unit for the held communication session establishment request, and a communication session establishment control unit for performing communication session establishment control to establish the communication session using the response of the communication session adjustment from the communication session adjustment unit to the held communication session establishment request.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless communication system, a communication session establishment method, and a computer program. [Background technology]

[0002] Conventionally, a fifth generation mobile communication system (5G system) standardized by the "3rd Generation Partnership Project" has been known (see, for example, Non-Patent Documents 1 and 2). FIG. 6 is a diagram showing the architecture of the 5G system described in Non-Patent Document 1. As shown in FIG. 6, the 5G system is mainly composed of UE (User Equipment) that operates on an end device, wireless RAN (Radio Access Network) equipment, CN (Core Network) equipment, and the like.

[0003] Non-Patent Document 2 describes a communication session establishment procedure for a CN of a 5G system to dynamically establish a communication session between a UE and a server facility when an end device having a UE function communicates with an application (App) on a server facility located in an external domain via a 5G system. The server facility is, for example, a cloud host or a multi-access edge computing (MEC) host.

[0004] In the communication session establishment procedure described in Non-Patent Document 2, first, a communication session dedicated to the UE on the end device, called a "PDU session", is dynamically established between the end device and the server equipment (first communication session establishment process). In this first communication session establishment process, in communication of general services not included in emergency communication, etc., the DN (Data Network) to which the "PDU session" is connected is generally directed to the Internet.

[0005] Here, for example, due to communication requirements of the service used by the end device (e.g., low latency response, wideband communication, etc.), or for simultaneous communication with multiple hosts located in multiple DNs (Data Networks) for service redundancy, the end device may communicate with edge server equipment such as an MEC host or a host located in another DN. In this case, in the communication session establishment procedure described in Non-Patent Document 2, the CN dynamically updates the "PDU session" established by the first communication session establishment process so as to include a communication path between the UE and a specific edge server equipment (second communication session establishment process).

[0006] Dynamic updating of the communication session in the second communication session establishment process is performed, for example, by the CN's Network Exposure Function (NEF) notifying an external domain (e.g., an MEC domain) that has made an event notification subscription to the CN of the event of the first communication session establishment process, and the external domain making a Traffic Influence (TI) request to the NEF. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] 3GPP, TS 23.501, V18.2.2, 2023-07 [Non-Patent Document 2] 3GPP, TS 23.502, V18.2.0, 2023-06 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the communication session establishment procedure described in the above-mentioned non-patent document 2, the "PDU session" already established by the first communication session establishment process is updated by the second communication session establishment process, so the communication session establishment procedure as a whole is complicated.

[0009] The present invention has been made in consideration of the above circumstances, and has an object to simplify the procedure for establishing a communication session. [Means for solving the problem]

[0010] One aspect of the present invention is a wireless communication system comprising a communication session establishment request receiving unit that receives a communication session establishment request to establish a communication session for communication between a terminal device and a communication partner, a communication session establishment request holding unit that holds the received communication session establishment request, a communication session adjustment request unit that requests communication session adjustment from a communication session adjustment unit for the held communication session establishment request, and a communication session establishment control unit that performs communication session establishment control to establish the communication session using the communication session adjustment response from the communication session adjustment unit to the held communication session establishment request. One aspect of the present invention is a wireless communication system in which, in the above-mentioned wireless communication system, the communication session establishment request holding unit determines the received communication session establishment request for a terminal device that meets specific conditions, and makes the received communication session establishment request for the terminal device that meets the specific conditions the target of a request for communication session adjustment. One aspect of the present invention is a wireless communication system in which, in the above-mentioned wireless communication system, the communication session establishment request holding unit transfers the held communication session establishment request to the communication session establishment control unit after a certain period of time has elapsed, and the communication session establishment control unit performs communication session establishment control for establishing the communication session in response to the transferred communication session establishment request. One aspect of the present invention is a wireless communication system in which, in the above-mentioned wireless communication system, the communication session establishment request receiving unit is an AMF (Access and Mobility Management Function), the communication session establishment request holding unit is an NCDF (Network Coordination Determination Function), the communication session adjustment unit is an NCAF (Network Coordination Application Function), the communication session adjustment request unit is an NCEF (Network Coordination and Exposure Function), and the communication session establishment control unit is an SMF (Session Management Function).

[0011] One aspect of the present invention is a communication session establishment method executed by a wireless communication system, the communication session establishment method including: a communication session establishment request receiving step of receiving a communication session establishment request for establishing a communication session for communication between a terminal device and a communication partner; a communication session establishment request holding step of holding the received communication session establishment request; a communication session adjustment request step of requesting communication session adjustment from a communication session adjustment unit for the held communication session establishment request; and a communication session establishment control step of performing communication session establishment control to establish the communication session using the communication session adjustment response from the communication session adjustment unit in response to the held communication session establishment request.

[0012] One aspect of the present invention is a computer program for causing a computer of a wireless communication system to execute a communication session establishment request receiving step of receiving a communication session establishment request for establishing a communication session for communication between a terminal device and a communication partner, a communication session establishment request holding step of holding the received communication session establishment request, a communication session adjustment request step of requesting communication session adjustment from a communication session adjustment unit for the held communication session establishment request, and a communication session establishment control step of performing communication session establishment control to establish the communication session using the communication session adjustment response from the communication session adjustment unit in response to the held communication session establishment request. Effect of the Invention

[0013] According to the present invention, it is possible to obtain an effect of simplifying the communication session establishment procedure. [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a schematic configuration example of a wireless communication system according to an embodiment. [Diagram 2] FIG. 2 illustrates a method for establishing a communication session according to an embodiment. [Diagram 3] A diagram showing an example of the operation of NCDF according to one embodiment. [Figure 4] A diagram showing an example of the operation of NCDF according to one embodiment. [Diagram 5] 1 is an example of a detailed procedure of a communication session establishment method according to an embodiment. [Figure 6] FIG. 1 illustrates the architecture of a conventional 5G system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a 5G system will be described as an example of a wireless communication system. In addition, as an example of dynamically establishing a communication session, a case where a communication session with a MEC host is dynamically established will be described.

[0016] 1 is a block diagram showing a schematic configuration example of a wireless communication system according to an embodiment. The wireless communication system 1 includes a CN (Core Network) (C-Plane) 100, a base station (gNB) 121, a UPF (User Plane Function) (ULCL (Uplink Classifier)) 122, and UPFs (PSAs (PDU Session Anchors)) 123 and 124.

[0017] 1, a communication session (PDU session) for communication between a UE (terminal equipment) of the device 200 and a communication partner is established by the CN 100 between the base station (gNB) 121 and UPFs (PSA) 123, 124 via a UPF (ULCL) 122. This allows the UE of the device 200 to communicate with a host of a communication partner, an application (App) in the MEC host 300, and the like via the Internet 500 in communication of an application (App) of the device 200.

[0018] CN100 is composed of NFs (Network Functions) of the control plane (C-plane), such as AMF (Access and Mobility Management Function) 101, NCDF (Network Coordination Determination Function) 102, NCEF (Network Coordination and Exposure Function) 103, SMF (Session Management Function) 104, PCF (Policy Control Function) 105, and UDR (Unified Data Repository) 106.

[0019] The AMF 101 further adds a function for the request transmission processing function unit of the AMF to set a different transmission destination for each request type to the AMF described in Non-Patent Document 1. With this additional function, the AMF 101 transmits to the NCDF 102 only "Nsmf_PDUSession_CreateSMContext Request", which is a request equivalent to a communication session establishment request among various requests transmitted from the conventional AMF to the SMF.

[0020] The NCDF 102 is a newly added NF that is not described in Non-Patent Document 1. The NCDF 102 holds a communication session establishment request received from the AMF 101. With respect to the held communication session establishment request, the NCDF 102 requests the NCEF 103 to request an external domain to perform communication session adjustment for the communication session to be newly established, and waits for a response from the NCEF 103 indicating completion of the communication session adjustment. During this time, the NCDF 102 reserves the held communication session establishment request.

[0021] The functions of NCDF102 are as follows:

[0022] (1-1) A function of receiving a communication session establishment request transmitted by the AMF 101. The NCDF 102 may receive a communication session establishment request (a request signal equivalent to "Nsmf_PDUSession_CreateSMContext Request") transmitted by a functional unit in the wireless communication system 1 equivalent to the AMF 101.

[0023] (1-2) A function to identify various parameters (identifiers such as SUPI (Subscription Permanent Identifier), location information such as Location, session-related information such as DNN (Data Network Name), etc.) included in the communication session establishment request received by the function of (1-1).

[0024] (1-3) A function to determine the type of request (establishment of a new session, update of an existing session, etc.) from the parameters identified in (1-2).

[0025] (1-4) A function for holding a communication session establishment request received by the function (1-1).

[0026] (1-5) A function of processing the request of the type determined in (1-3) in a predetermined manner. In this embodiment, for "establishing a new session", a communication session adjustment request is sent to the NCEF 103. For "updating an existing session", the communication session establishment request received by the function of (1-1) is transferred to the SMF 104 as is.

[0027] (1-6) A function for sending a communication session adjustment request to NCEF103.

[0028] (1-7) A function of including the predetermined parameters identified by the function of (1-2) in the communication session adjustment request sent to the NCEF 103 by the function of (1-6). The predetermined parameters include at least the parameters necessary for the external domain to adjust the communication session among the various parameters included in the communication session establishment request. The predetermined parameters may be a part or all of the various parameters included in the communication session establishment request.

[0029] (1-8) Function to receive a response from NCEF103 indicating completion of communication session adjustment.

[0030] (1-9) A function that transfers the communication session establishment request held by the function (1-4) to the SMF 104 when a response of completion of communication session adjustment is received from the NCEF 103 by the function (1-8).

[0031] NCEF103 further adds to the NEF described in non-patent document 1 a function of requesting an external domain to perform communication session coordination for a newly established communication session, receiving a communication session coordination response to the communication session coordination request from the external domain, and performing pre-configuration so that session configuration-related information included in the received communication session coordination response is reflected when the new communication session is established.

[0032] The functions of NCEF103 are shown below.

[0033] (2-1) A function of storing in advance a reference table that can refer to a list of external domains (NCAF 401) that are candidates for destinations of a communication session adjustment request, and a list of subscriber information associated with NCAF 401. Note that NCEF 103 may access an external database to refer to a similar list.

[0034] (2-2) A function for receiving a communication session adjustment request from the NCDF 102.

[0035] (2-3) A function for identifying various parameters (such as identifiers such as SUPI, location information such as Location, session-related information such as DNN, etc.) included in the communication session adjustment request received by the function of (2-2).

[0036] (2-4) A function for transferring a communication session adjustment request received by the function (2-2) to NCAF401.

[0037] (2-5) A function for identifying NCAF 401 associated with UE (subscriber information) related to the communication session adjustment request from the reference table stored by the function (2-1) when the communication session adjustment request is transferred to NCAF 401 by the function (2-4), and setting the identified NCAF 401 as the destination of the communication session adjustment request. The function (2-5) may be activated as required.

[0038] (2-6) A function for converting or abstracting parameters included in a communication session adjustment request when the communication session adjustment request is transferred to the NCAF 401 by the function (2-4). The NCEF 103 may be provided with a parameter conversion table for converting or abstracting the parameters, or may access an external database to refer to similar parameter conversion information. The function (2-6) may be activated as needed.

[0039] (2-7) A function of selecting, converting, or abstracting parameters included in a communication session adjustment request based on parameter selection conditions such as a policy of the wireless communication system 1 when the communication session adjustment request is transferred to the NCAF 401 by the function of (2-4). The NCEF 103 may internally hold parameter selection conditions such as a policy of the wireless communication system 1, or may access an external database to refer to similar parameter selection conditions. The function of (2-7) may be activated as needed.

[0040] (2-8) A function of receiving from NCAF 401 a communication session adjustment response to the communication session adjustment request transferred to NCAF 401 by the function of (2-4).

[0041] (2-9) A function for identifying various parameters (identifiers such as SUPI, UPF configuration information such as DNAI (Data Network Access Identifer), etc.) included in the session configuration related information included in the communication session adjustment response received from NCAF401 by the function of (2-8).

[0042] (2-10) A function for storing the parameters identified by the function (2-9) in the corresponding location in the UDR 106.

[0043] (2-11) A function of transmitting a communication session adjustment completion response to the NCDF 102 when a communication session adjustment response is received from the NCAF 401 by the function of (2-8).

[0044] SMF 104, PCF 105 and UDR 106 are similar to those described in Non-Patent Document 1.

[0045] The MEC domain 400, which is an external domain, is made up of a Network Coordination Application Function (NCAF) 401, a control unit 402, a statistical information collection unit 403, and the like.

[0046] NCAF 401 further adds a function to the AF (Application Function) described in Non-Patent Document 1, of receiving a communication session adjustment request from NCEF 103 and transmitting a communication session adjustment response to NCEF 103 in response to the received communication session adjustment request. The communication session adjustment response has session configuration related information. The session configuration related information is information including a request for a communication session configuration from an external domain for a newly established communication session related to the communication session adjustment request.

[0047] The functions of NCAF401 are as follows:

[0048] (3-1) A function of receiving a communication session adjustment request from the NCEF 103. The NCAF 401 may register with the NCEF 103 the execution of the communication session adjustment.

[0049] (3-2) A function for identifying various parameters (such as identifiers such as SUPI, location information such as Location, session-related information such as DNN, etc.) included in the communication session adjustment request received by the function of (3-1).

[0050] (3-3) A function for confirming a request for configuration of a communication session from an external domain for a newly established communication session based on the parameter identification result by the function of (3-2). NCAF 401 may confirm the request for configuration of the communication session by the control unit 402 and the statistical information collection unit 403 in the MEC domain 400, or NCAF 401 itself may confirm the request for configuration of the communication session. There are no particular limitations on the method for confirming the request for configuration of the communication session. Information indicating the request for configuration of the communication session is included in session configuration related information. The information indicating the request for configuration of the communication session includes various parameters (identifiers such as SUPI, UPF configuration information such as DNAI, etc.).

[0051] (3-4) A function of transmitting a communication session adjustment response to the NCEF 103 based on the result of confirmation of the request for communication session configuration by the function of (3-3). The communication session adjustment response has session configuration related information. Note that, if the result of confirmation of the request for communication session configuration by the function of (3-3) shows that there is no request for communication session configuration, the communication session adjustment response includes a parameter indicating that communication session adjustment is not required.

[0052] In this embodiment, we aim to simplify the procedure for establishing a communication session (PDU session) between the base station (gNB) 121 and the UPF (PSA) 123, 124.

[0053] The procedure of the communication session establishment process according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing the communication session establishment method according to this embodiment. As an example here, NCAF 401 in MEC domain 400, which is an external domain, is registered in advance in NCEF 103 as a destination of the communication session adjustment request.

[0054] (Step S1) In response to a communication request by an application (App) of the device 200, the UE of the device 200 transmits a communication session establishment request (PDU Session Establishment Request) to the base station (gNB) 121. The AMF 101 receives the communication session establishment request from the UE of the device 200 via the base station (gNB) 121. The AMF 101 corresponds to a communication session establishment request receiving unit.

[0055] (Step S2) Upon receiving a communication session establishment request from the UE of the device 200, the AMF 101 transmits a request "Nsmf_PDUSession_CreateSMContext Request" (referred to as a target communication session establishment request) corresponding to the received communication session establishment request to the NCDF 102. The NCDF 102 holds the target communication session establishment request received from the AMF 101. The NCDF 102 corresponds to a communication session establishment request holding unit.

[0056] (Step S3) NCDF 102 transmits to NCEF 103 a communication session adjustment request related to the held target communication session establishment request.

[0057] (Step S4) In response to the communication session coordination request received from the NCDF 102, the NCEF 103 transmits the communication session coordination request to the NCAF 401 in the MEC domain 400, which is an external domain. The NCEF 103 corresponds to a communication session coordination request unit. The NCAF 401 corresponds to a communication session coordination unit.

[0058] (Step S5) In response to the communication session adjustment request received from the NCEF 103, the NCAF 401 checks a request for a communication session configuration from the MEC domain 400 for a communication session to be newly established by the target communication session establishment request. As an example here, the control unit 402 and the statistical information collection unit 403 determine the MEC host 300, which is a server facility on which a communication partner (server application (App)) of the application (App) of the device 200 is placed, and obtain information (session configuration related information) for establishing a communication session when the determined MEC host 300 is the communication partner. The NCAF 401 acquires the session configuration related information. The session configuration related information corresponds to TI (Traffic Influence).

[0059] (Step S6) The NCAF 401 transmits to the NCEF 103 a communication session adjustment response including the acquired session configuration related information.

[0060] (Step S7) NCEF 103 stores the session configuration related information included in the communication session negotiation response received from NCAF 401 in UDR 106.

[0061] (Step S8) Having received the communication session adjustment response from the NCAF 401, the NCEF 103 transmits a communication session adjustment completion response to the NCDF 102.

[0062] (Step S9) Having received the response of completion of the communication session adjustment from the NCEF 103, the NCDF 102 transfers the target communication session establishment request held in step S2 to the SMF 104.

[0063] (Step S10) The SMF 104 acquires information (information necessary to establish a new communication session) related to the target communication session establishment request stored in the UDR 106 via the PCF 105. This information related to the target communication session establishment request includes the session configuration related information stored in the UDR 106 in step S7.

[0064] (Step S11) Based on the information acquired from the UDR 106, the SMF 104 performs communication session establishment control for establishing a new communication session between the UE of the device 200 and a DN (Data Network) in which a communication partner host is located. By this communication session establishment control, in the embodiment here, a session is established between the base station (gNB) 121 and the UPFs (PSA) 123, 124 via the UPF (ULCL) 122. This allows the UE of the device 200 to communicate with a communication partner host, an application (App) in the MEC host 300, and the like via the Internet 500 in communication of an application (App) of the device 200. The SMF 104 corresponds to a communication session establishment control unit.

[0065] According to this embodiment, regarding a communication session newly established by a communication session establishment request from the UE of the device 200, the establishment of the new communication session is suspended until a response to the communication session adjustment by the foreign domain is received. The new communication session is established by reflecting session configuration related information (corresponding to TI (Traffic Influence)) obtained by the response to the communication session adjustment by the foreign domain. Since the result of the communication session adjustment by the foreign domain (corresponding to TI) is already reflected in the established new communication session, there is no need to update the communication session as in the conventional case. This can simplify the communication session establishment procedure.

[0066] Next, another example of this embodiment will be described.

[0067] Fig. 3 is a diagram showing an example of the operation of the NCDF according to this embodiment. In the embodiment of Fig. 3, only UEs that satisfy a specific condition are selected as targets for a request for communication session adjustment by an external domain. For example, only UEs that subscribe to the service of an operator that has registered for dynamic adjustment of a communication session configuration are selected as targets for a request for communication session adjustment. For example, only UEs that subscribe to a specific option among UEs that subscribe to the service of an operator that has registered for dynamic adjustment of a communication session configuration are selected as targets for a request for communication session adjustment. This improves the processing efficiency of the NCDF 102.

[0068] Specifically, the NCDF 102 includes a UE selection condition table 102T. The UE selection condition table 102T is a table for selecting a UE to be requested for communication session adjustment by an external domain. In the UE selection condition table 102T, NCEF access destination information is stored in association with a specific identifier value for each UE identifier type. The UE selection condition table 102T indicates, for each UE identifier type, access destination information (NCEF access destination information) for accessing the NCEF 103 that is the transmission destination of the target communication session establishment request for the UE with the specific identifier value. This UE selection condition table 102T selects only UEs for which NCEF access destination information can be acquired as targets for the communication session adjustment request. The UE selection condition table 102T is registered in advance from the NCEF 103 to the NCDF 102.

[0069] The NCEF access destination information is provided, for example, for each application (App).The NCEF access destination information is provided, for example, for each service of a business operator that has registered for dynamic adjustment of a communication session configuration.

[0070] (Step S100) The NCEF 103 writes a UE selection condition table 102T to the NCDF 102 in advance.

[0071] (Step S101) When the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is not "Initial request", or when the UE of the target communication session establishment request does not meet the conditions in the UE selection condition table 102T, the NCDF 102 transfers the target communication session establishment request to the SMF 104. In this case, no request for communication session adjustment by an external domain is made for the target communication session establishment request.

[0072] On the other hand, when the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is "Initial request" and the UE of the target communication session establishment request meets the conditions in the UE selection condition table 102T, the NCDF 102 holds the target communication session establishment request and transmits a communication session adjustment request for the held target communication session establishment request to the NCEF 103. This causes a request for communication session adjustment by an external domain to be made for the target communication session establishment request. In this case, the NCDF 102 transfers the held target communication session establishment request to the SMF 104 by receiving a response from the NCEF 103 indicating completion of the communication session adjustment by the external domain.

[0073] In addition, the UE selection condition table 102T shown in Figure 3 is a case in which multiple NCEFs 103 are installed, and stores multiple NCEF access destination information, but when there is only one NCEF 103, the NCEF access destination information is fixed, so this does not have to be the case.

[0074] 3, UE selection condition table 102T is provided in NCDF 102, but the present invention is not limited to this. For example, records including information equivalent to that in UE selection condition table 102T may be added or deleted as appropriate to a database accessible from both NCDF 102 and NCEF 103, such as a UDR, and this record set may be referenced from NCDF 102.

[0075] Fig. 4 is a diagram showing an example of the operation of the NCDF according to this embodiment. In the embodiment of Fig. 4, when a response of the completion of the communication session adjustment from the external domain is not obtained or the response is delayed significantly, a new communication session is prevented from not being established or the establishment of the new communication session is prevented from being significantly delayed. Specifically, the NCDF 102 includes a timer (holding time timer) for limiting the time for which the target communication session establishment request is held to within a certain period of time.

[0076] (Step S201) When the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is not "Initial request", the NCDF 102 transfers the target communication session establishment request to the SMF 104. In this case, no request for communication session adjustment by an external domain is made for the target communication session establishment request.

[0077] On the other hand, the NCDF 102 holds the target communication session establishment request when the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is "Initial request." After that, the process proceeds to step S202.

[0078] (Step S202) The NCDF 102 starts a holding time timer, and transmits a communication session adjustment request related to the held target communication session establishment request to the NCEF 103. As a result, a request for communication session adjustment by an external domain is made for the target communication session establishment request.

[0079] (Step S203) The NCDF 102 checks whether the hold time timer has expired. If the hold time timer has expired, the NCDF 102 transfers the held target communication session establishment request to the SMF 104.

[0080] (Step S204) When NCDF 102 receives a response from NCEF 103 notifying completion of communication session adjustment by the external domain, NCDF 102 checks whether the hold time timer has expired. If the hold time timer has expired, step S203 transfers the held target communication session establishment request to SMF 104, and the process ends. On the other hand, if the hold time timer has not expired, the process proceeds to step S205.

[0081] (Step S205) The NCDF 102 stops the hold time timer and transfers the held target communication session establishment request to the SMF 104.

[0082] According to the embodiment of Figure 4, when a request for communication session adjustment is made by an external domain in relation to a target communication session establishment request, when there is no response or the response is significantly delayed, it is possible to suppress increased delays in establishing a new communication session.

[0083] The above-mentioned embodiments of Fig. 3 and Fig. 4 may be combined. In this case, the determination content of step S201 of Fig. 4 may be changed to the determination content of step S101 of Fig. 3. Specifically, in step S201 of Fig. 4, when the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is not "Initial request" or when the UE of the target communication session establishment request does not meet the conditions of the UE selection condition table 102T, the NCDF 102 transfers the target communication session establishment request to the SMF 104. On the other hand, when the "request type" included in the "Nsmf_PDUSession_CreateSMContext Request" (target communication session establishment request) received from the AMF 101 is "Initial request" and when the UE of the target communication session establishment request meets the conditions of the UE selection condition table 102T, the NCDF 102 holds the target communication session establishment request. After this, the process proceeds to step S202.

[0084] FIG. 5 is an example of a detailed procedure of the communication session establishment method according to the present embodiment. In FIG. 5, before the SMF 104 executes the communication session establishment procedure 2000 for actually establishing a new communication session, the communication session adjustment request procedure 1000 is executed. In the communication session adjustment request procedure 1000, a request for communication session adjustment is made to an external domain (NCAF 401), and the session configuration related information included in the response to the communication session adjustment is stored in the UDR 106. Next, in the communication session establishment procedure 2000, the session configuration related information stored in the UDR 106 is used to establish a new communication session. As a result, the new communication session established by the communication session establishment procedure 2000 already reflects the result of the communication session adjustment by the external domain (corresponding to TI), so there is no need to update the communication session as in the past. This can simplify the communication session establishment procedure. In the example of FIG. 5, it is possible to realize a processing flow for a certain UE to use a "PDU session" including an "Uplink Classifier (UL-CL)" with fewer steps than the processing flow described in Non-Patent Document 2.

[0085] In the above-described embodiment, a case where a communication session with a MEC host is dynamically established is given as an example of dynamic establishment of a communication session, but the present invention is not limited thereto. For example, in a handover process associated with the mobility of a UE communicating in "Session and Service Continuity (SSC) mode 2 or mode 3", a new communication session is established each time a handover is performed. The present invention can be similarly applied to the establishment of a new communication session in this handover. As a result, when a large number of IoT devices having high mobility such as connected cars but requiring low communication latency, wideband, and highly reliable communication use the wireless communication system 1, the processing load for establishing a new communication session increases, but the effect of suppressing the increase in the processing load can be obtained.

[0086] This will, for example, make it possible to improve the overall service quality in wireless networks, thereby contributing to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), which is to "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0087] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not deviate from the gist of the present invention are also included.

[0088] In addition, a computer program for implementing the functions of the wireless communication system 1 described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Note that the "computer system" referred to here may include hardware such as an OS and peripheral devices. In addition, the term "computer-readable recording medium" refers to writable non-volatile memory such as a flexible disk, an optical magnetic disk, a ROM, or a flash memory, a portable medium such as a DVD (Digital Versatile Disc), or a storage device such as a hard disk built into a computer system.

[0089] Furthermore, the term "computer-readable recording medium" includes devices that retain a program for a certain period of time, such as volatile memory (e.g., DRAM (Dynamic Random Access Memory)) within a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. The program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium, or by a transmission wave in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded in the computer system. [Explanation of symbols]

[0090] 1...wireless communication system, 100...CN (Core Network) (C-Plane), 121...base station (gNB), 122, 123, 124...UPF, 101...AMF, 102...NCDF, 103...NCEF, 104...SMF, 105...PCF, 106...UDR, 200...device (UE), 300...MEC host, 400...MEC domain, 401...NCAF

Claims

1. a communication session establishment request receiving unit for receiving a communication session establishment request for establishing a communication session for communication between the terminal device and a communication partner; a communication session establishment request holding unit for holding the received communication session establishment request; a communication session adjustment request unit that requests communication session adjustment to a communication session adjustment unit regarding the held communication session establishment request; a communication session establishment control unit that performs communication session establishment control for establishing the communication session by using a response of the communication session adjustment from the communication session adjustment unit to the held communication session establishment request; A wireless communication system comprising:

2. The communication session establishment request storage unit determining the received communication session establishment request related to a terminal device that satisfies a specific condition, and setting the received communication session establishment request related to the terminal device that satisfies the specific condition as a request target for communication session adjustment; 2. The wireless communication system according to claim 1.

3. The communication session establishment request storage unit transferring the held communication session establishment request to the communication session establishment control unit after a certain period of time has elapsed; the communication session establishment control unit performs communication session establishment control for establishing the communication session in response to the transferred communication session establishment request.

2. The wireless communication system according to claim 1.

4. The communication session establishment request receiving unit is an Access and Mobility Management Function (AMF), the communication session establishment request holding unit is a Network Coordination Determination Function (NCDF), The communication session adjustment unit is a Network Coordination Application Function (NCAF), The communication session adjustment request unit is a Network Coordination and Exposure Function (NCEF), The communication session establishment control unit is a Session Management Function (SMF).

4. A wireless communication system according to claim 1.

5. 1. A method for establishing a communication session executed by a wireless communication system, comprising: a communication session establishment request receiving step of receiving a communication session establishment request for establishing a communication session for communication between the terminal device and a communication partner; a communication session establishment request holding step of holding the received communication session establishment request; a communication session adjustment request step of requesting a communication session adjustment to a communication session adjustment unit regarding the held communication session establishment request; a communication session establishment control step of performing communication session establishment control for establishing the communication session by using a response of the communication session adjustment from the communication session adjustment unit to the held communication session establishment request; A method for establishing a communication session comprising:

6. A computer in a wireless communication system includes: a communication session establishment request receiving step of receiving a communication session establishment request for establishing a communication session for communication between the terminal device and a communication partner; a communication session establishment request holding step of holding the received communication session establishment request; a communication session adjustment request step of requesting a communication session adjustment to a communication session adjustment unit regarding the held communication session establishment request; a communication session establishment control step of performing communication session establishment control for establishing the communication session by using a response of the communication session adjustment from the communication session adjustment unit to the held communication session establishment request; A computer program for executing the above.

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