Network node and communication method

Abstract

A network node for handling voice media comprises: a reception unit that receives, from a first network node, a first message requesting association establishment, the first message including a network identifier; a control unit that stores context for each network identifier; and a transmission unit that transmits, to the first network node, a second message indicating that the association establishment has been executed.

Description

Network node and communication method

[0001] The present invention relates to a network node in a communication system and a communication method.

[0002] 3GPP (registered trademark) (3rd Generation Partnership Project) is currently studying a wireless communication system called 5G or NR (New Radio) (hereinafter, the wireless communication system will be referred to as "5G" or "NR") in order to achieve a larger system capacity, a higher data transmission speed, and a lower latency in wireless sections. Various wireless technologies are being studied for 5G to meet the requirements of achieving a throughput of 10 Gbps or more while keeping latency in wireless sections to 1 ms or less.

[0003] In NR, a network architecture including 5GC (5G Core Network) corresponding to EPC (Evolved Packet Core), which is the core network in the network architecture of LTE (Long Term Evolution), and NG-RAN (Next Generation - Radio Access Network) corresponding to E-UTRAN (Evolved Universal Terrestrial Radio Access Network), which is the RAN (Radio Access Network) in the network architecture of LTE, is being considered (for example, Non-Patent Document 1).

[0004] Furthermore, as an IMS (IP Multimedia Subsystem) architecture that supports the data channel capabilities of terminals, specifications for an IMS data channel network are being studied (see, for example, Non-Patent Document 2). In the IMS data channel network, a Data Channel Signalling Function (DCSF) having a signaling function, a Media Function (MF) having a media-related function, and a Data Channel Application Server (DCAS) that is an application server are arranged on both the calling and called sides.

[0005] Furthermore, in 3GPP Rel-19, in order to realize IMS voice terminal-satellite-terminal communication (UE-satellite-UE communication), reducing the impact on existing specifications when deploying 5GC network functions and IMS components on satellites is an issue (see, for example, Non-Patent Document 3). Here, terminal-satellite-terminal communication refers to terminal-to-terminal communication under routing that keeps user plane traffic within the satellite. The types of satellites handled include geostationary satellites (GEO), low Earth orbit satellites (LEO), and medium Earth orbit satellites (MEO). Furthermore, for low Earth orbit satellites and medium Earth orbit satellites, satellite constellations can be formed without using inter-satellite links (ISLs) or using inter-satellite links.

[0006] 3GPP TS 23.501 V18.4.0 (2023-12) 3GPP TS 23.228 V18.4.0 (2023-12) 3GPP TR 23.700-29 V0.4.0 (2024-03) 3GPP TS 29.176 V18.0.0 (2023-12)

[0007] In terminal-satellite-terminal communications, for example, when a satellite constellation is formed using inter-satellite links among low-earth-orbit satellites, each satellite is equipped with communication devices such as a base station, a user plane function, and an IMS access gateway. While mobile communications carriers envision sharing and using the IMS access gateways deployed on satellites by satellite communications carriers, it has been difficult to enable such use due to outdated specifications related to the IMS access gateways.

[0008] The present invention has been made in view of the above points, and has as its object to enable shared use of an IMS access gateway deployed on a satellite in a wireless communication system.

[0009] According to the disclosed technology, there is provided a network node that handles voice media, the network node having: a receiving unit that receives a first message from a first network node, the first message including a network identifier, requesting the establishment of collaboration; a control unit that stores a context for each of the network identifiers; and a transmitting unit that transmits a second message to the first network node indicating that the collaboration establishment has been performed.

[0010] According to the disclosed technology, in a wireless communication system, an IMS access gateway deployed on a satellite can be shared and made available.

[0011] FIG. 1 is a diagram for explaining an example of a communication system. FIG. 2 is a diagram for explaining an example of a communication system in a roaming environment. FIG. 3 is a diagram for explaining an example of an IMS data channel network. FIG. 4 is a diagram showing an example of a first sequence diagram in an embodiment of the present invention. FIG. 5 is a diagram showing an example of a second sequence diagram in an embodiment of the present invention. FIG. 6 is a diagram showing an example of the functional configuration of a base station 10 and a network node 30 in an embodiment of the present invention. FIG. 7 is a diagram showing an example of the functional configuration of a terminal 20 in an embodiment of the present invention. FIG. 8 is a diagram showing an example of the hardware configuration of a base station 10, a terminal 20, and a network node 30 in an embodiment of the present invention. FIG. 9 is a diagram showing an example of the configuration of a vehicle 2001 in an embodiment of the present invention.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0013] In the operation of the wireless communication system according to the embodiment of the present invention, existing technology is used as appropriate. However, the existing technology is, for example, the existing LTE, but is not limited to the existing LTE. Furthermore, the term "LTE" used in this specification has a broad meaning including LTE-Advanced, and systems subsequent to LTE-Advanced (e.g., NR), or wireless LAN (Local Area Network), unless otherwise specified.

[0014] Furthermore, in the embodiments of the present invention, "configuring" radio parameters and the like may mean that predetermined values ​​are pre-configured, or that radio parameters notified from the network node 30 or the terminal 20 are set.

[0015] Fig. 1 is a diagram illustrating an example of a communication system. As shown in Fig. 1, the communication system is composed of a UE, which is a terminal 20, and multiple network nodes 30. Hereinafter, it is assumed that one network node 30 corresponds to each function, but multiple functions may be realized by one network node 30, or multiple network nodes 30 may realize one function. Furthermore, the "connection" described below may be a logical connection or a physical connection.

[0016] The RAN (Radio Access Network) is a network node 30 having a radio access function, which may include a base station 10, and is connected to a UE, an AMF (Access and Mobility Management Function), and a UPF (User Plane Function). The AMF is a network node 30 having functions such as terminating the RAN interface, terminating the NAS (Non-Access Stratum), registering management, connecting management, reachability management, and terminal mobility management. The UPF is a network node 30 having functions related to processing user plane data, such as a PDU (Protocol Data Unit) session point to the outside that interconnects with the DN (Data Network), packet routing and forwarding, and user plane Quality of Service (QoS) handling. The UPF and the DN constitute a network slice. In the wireless communication network according to the embodiment of the present invention, multiple network slices are constructed.

[0017] The AMF is connected to the UE, RAN, SMF (Session Management function), NSSF (Network Slice Selection Function), NEF (Network Exposure Function), NRF (Network Repository Function), UDM (Unified Data Management), AUSF (Authentication Server Function), PCF (Policy Control Function), and AF (Application Function). The AMF, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, and AF are network nodes 30 that are mutually connected via interfaces based on their respective services, Namf, Nsmf, Nnssf, Nnef, Nnrf, Nudm, Nausf, Npcf, and Naf.

[0018] The SMF is a network node 30 having functions such as session management, UE IP (Internet Protocol) address allocation and management, DHCP (Dynamic Host Configuration Protocol) function, ARP (Address Resolution Protocol) proxy, and roaming function. The NEF is a network node 30 having a function of notifying other NFs (Network Functions) of capabilities and events. The NSSF is a network node 30 having functions such as selecting a network slice to which a UE connects, determining an allowed NSSAI (Network Slice Selection Assistance Information), determining an NSSAI to be set, and determining an AMF set to which a UE connects. The PCF is a network node 30 having a function of controlling network policies. The AF is a network node 30 having a function of controlling application servers. The NRF is a network node 30 having a function of discovering NF instances that provide services. The UDM is a network node 30 that manages subscriber data and authentication data. The UDM is connected to a UDR (User Data Repository) that stores the data.

[0019] Fig. 2 is a diagram illustrating an example of a communication system in a roaming environment. As shown in Fig. 2, the network is composed of a UE, which is a terminal 20, and multiple network nodes 30. Hereinafter, it is assumed that one network node 30 corresponds to each function, but multiple functions may be realized by one network node 30, or multiple network nodes 30 may realize one function. Furthermore, the "connection" described below may be a logical connection or a physical connection.

[0020] The RAN is a network node 30 having a radio access function, and is connected to the UE, the AMF, and the UPF. The AMF is a network node 30 having functions such as RAN interface termination, NAS termination, registration management, connection management, reachability management, and mobility management. The UPF is a network node 30 having functions such as a PDU session point to the outside that interconnects with the DN, packet routing and forwarding, and user plane QoS handling. The UPF and the DN constitute a network slice. In the wireless communication network according to the embodiment of the present invention, multiple network slices are constructed.

[0021] The AMF is connected to the UE, RAN, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, AF, and SEPP (Security Edge Protection Proxy). The AMF, SMF, NSSF, NEF, NRF, UDM, AUSF, PCF, and AF are network nodes 30 that are interconnected via respective service-based interfaces, Namf, Nsmf, Nnssf, Nnef, Nnrf, Nudm, Nausf, Npcf, and Naf.

[0022] The SMF is a network node 30 having functions such as session management, UE IP address allocation and management, DHCP function, ARP proxy, and roaming function. The NEF is a network node 30 having a function of notifying other NFs of capabilities and events. The NSSF is a network node 30 having functions such as selecting a network slice to which a UE connects, determining an allowed NSSAI, determining a configured NSSAI, and determining an AMF set to which a UE connects. The PCF is a network node 30 having a function of controlling network policies. The AF is a network node 30 having a function of controlling application servers. The NRF is a network node 30 having a function of discovering NF instances that provide services. The SEPP is a non-transparent proxy that filters control plane messages between PLMNs (Public Land Mobile Networks). The vSEPP shown in FIG. 2 is a SEPP in the visited network, and the hSEPP is a SEPP in the home network.

[0023] As shown in Figure 2, a UE is in a roaming environment connected to a RAN and an AMF in a Visited PLMN (VPLMN). The VPLMN and a Home PLMN (HPLMN) are connected via a vSEPP and an hSEPP. The UE can communicate with a UDM in the HPLMN via the AMF in the VPLMN, for example.

[0024] Fig. 3 is a diagram illustrating an example of an IMS data channel network. As shown in Fig. 3, the IMS data channel network is configured with a terminal 20 (UE) and multiple network nodes 30 in each of an originating network and a terminating network. Hereinafter, it is assumed that one network node 30 corresponds to each function, but multiple functions may be realized by one network node 30, or multiple network nodes 30 may realize one function. Furthermore, the "connection" described below may be a logical connection or a physical connection. The network node 30 has, for example, the following functions described in Non-Patent Document 2:

[0025] The IMS-AGW (Access Gateway) is a network node 30 having a gateway function between the UE and the IMS network, a function related to access processing for voice communication, and the like.

[0026] A P-CSCF (Proxy-Call Session Control Function) is a network node 30 that has a proxy function between the UE and the IMS network, an access control function for voice communication, and the like.

[0027] The S-CSCF (Serving-Call Session Control Function) is a network node 30 having functions related to session control for the UE.

[0028] The I-CSCF (Interrogate-Call Session Control Function) is a connection point on the destination network side between networks (e.g., between the source network side and the destination network side) in the IMS network, and is a network node 30 that has, for example, the function of forwarding a received SIP request to the S-CSCF of its own network.

[0029] An IMS AS (IP Multimedia Subsystem Application Server) is a network node 30 in an IMS network that has functions such as communicating with a DCSF for event notification and receiving data channel control instructions from the DCSF to communicate with an MF. The IMS AS also receives a communication termination point registration request from a DCSF (Data Channel Signalling Function), converts the received registration request into a SIP Register, and sends it to a Serving-Call Session Control Function (S-CSCF). The IMS AS also converts a data channel establishment request received from the DCSF into a SIP INVITE and sends it to the S-CSCF.

[0030] The DCSF (Data Channel Signaling Function) is a network node 30 that has functions such as receiving an event report from the IMS-AS and determining whether to allow the provision of a data channel service, managing the bootstrap data channel, and performing HTTP web server functions.

[0031] An MF (Media Function) is a network node 30 in an IMS network that has functions such as media resource management and forwarding of data channel media traffic. The MF processes media between a DCAS (Data Channel Application Server), which is a communication termination point, and a destination termination point based on configuration information received from a DCSF. The MF may also be called a DCMF (Data Channel Media Function). The MF may also be called an MRF (Multimedia Resource Function).

[0032] A DCAS (Data Channel Application Server) is a network node 30 having functions such as a communication termination point for media and signaling in the IMS network.

[0033] (Example) This example describes a procedure for sharing and enabling the use of an IMS access gateway (AGW) deployed on a satellite in a wireless communication system. In this example, it is assumed that multiple low-earth orbit satellites (LEOs) equipped with base stations, UPFs, and IMS AGWs form a satellite constellation using inter-satellite links (ISLs). Furthermore, N2 intermediaries, N4 intermediaries, and Iq intermediaries are deployed on the ground as intermediary devices, communicating with the base stations and UPFs, respectively, deployed on the multiple LEOs.

[0034] The N2 intermediary performs communication with the base station and communication with the AMF based on the interface (N2) between the base station and the AMF, i.e., the N2 intermediary acts as an AMF to the base station and as a base station to the AMF.

[0035] The N4 Intermediary communicates with the UPF and the SMF based on the interface (N4) between the UPF and the SMF, i.e., the N4 Intermediary acts as an SMF to the UPF and as a UPF to the SMF.

[0036] The Iq Intermediary communicates with the IMS AGW and the P-CSCF based on the interface between the IMS AGW and the P-CSCF, i.e., the Iq Intermediary acts as a P-CSCF to the IMS AGW and as an IMS AGW to the P-CSCF.

[0037] Satellite communications operators prepare base stations, UPFs, IMS AGWs, and intermediate devices deployed on the ground as dedicated equipment for satellite constellation communications, while mobile communications operators prepare AMFs, SMFs, and other network nodes deployed on the ground as equipment for satellite constellation communications.

[0038] Here, it is assumed that mobile communication operators will share and use the IMS access gateways deployed on satellites by satellite communication operators. However, because the H.248 protocol specifications used in the Iq interface between the P-CSCF and the IMS AGW are outdated, it has been difficult to add information elements to enable such use.

[0039] In this embodiment, instead of using an Iq interface in the IMS AGW, Iq intermediary, and P-CSCF, Nmf (see section AA.2.5 of Non-Patent Document 3 and Non-Patent Document 4), which is a service-based interface (SBI) related to a media function (MF), is used. Furthermore, in the service related to Nmf, an information element that enables input of a network identifier (PLMN ID) is added, and an IMS AGW registration procedure is added to establish association between the network and the IMS AGW.

[0040] The following describes the details of the processing in this embodiment using a sequence diagram. In the sequence diagram, the processing executed by the terminal 20, the IMS AGW 30A, the Iq intermediary 300B, the PCF 30C, the P-CSCF 30D, the S-CSCF 30E, and the P-CSCF 30F, and messages such as requests, responses, and notifications transmitted and received are described. Here, the IMS AGW 30A and the Iq intermediary 300B are network nodes deployed on a satellite. The PCF 30C, the P-CSCF 30D, and the S-CSCF 30E are network nodes deployed on the ground in a network whose network identifier is PLMN ID=gg. The P-CSCF 30F is a network node deployed on the ground in a network whose network identifier is PLMN ID=hh.

[0041] (IMS AGW Registration Procedure) The IMS AGW registration procedure will be described. Fig. 4 is a diagram showing an example of a first sequence diagram according to an embodiment of the present invention. The processing of each step will be described below.

[0042] S101: The Iq intermediary 30B sends a request message (Nmf_Association Setup request) to the IMS AGW 30A to request association establishment (settings related to association). The request message includes an information element that stores a list of supported network identifiers, but the information included in the list is currently null. For example, the request message is expressed as Nmf_Association Setup request (PLMN support list(null)).

[0043] S102: In response to the request message received in S101, the IMS AGW 30A prepares settings related to the association, and transmits a response message (Nmf_Association Setup response) to the request message to the Iq intermediary 30B.

[0044] S103: The P-CSCF 30D transmits a request message (Nmf_Association Setup request) requesting (settings related to) association establishment to the Iq intermediary 30B. The request message includes PLMN=gg in a list of supported network identifiers, and is expressed as, for example, Nmf_Association Setup request (PLMN support list(PLMN ID=gg)).

[0045] S104: The Iq intermediary 30B transmits to the IMS AGW 30A a request message (Nmf_Association Update request) requesting an update of settings related to association establishment based on the request message received in S103. The request message includes PLMN=gg in a list of supported network identifiers, and is expressed as, for example, Nmf_Association Update request (PLMN support list(PLMN ID=gg)).

[0046] S105: The IMS AGW 30A recognizes that there is a connection to a network whose network identifier is PLMN ID=gg, based on the list of supported network identifiers included in the request message received in S104.

[0047] S106: The IMS AGW 30A transmits to the Iq intermediary 30B a response message (Nmf_Association Update response) in response to the request message received in S104.

[0048] S107: The Iq intermediary 30B sends a response message (Nmf_Association Setup response) to the request message received in S103 to the P-CSCF 30D. The response message includes the satellite constellation identifier (ID=aa).

[0049] S108: The P-CSCF 30F transmits a request message (Nmf_Association Setup request) requesting (settings related to) association establishment to the Iq intermediary 30B. The request message includes PLMN=hh in a list of supported network identifiers, and is expressed as, for example, Nmf_Association Setup request (PLMN support list(PLMN ID=hh)).

[0050] S109: The Iq intermediary 30B sends to the IMS AGW 30A a request message (Nmf_Association Update request) requesting an update of settings related to association, based on the request message (Nmf_Association Setup request) received in S103 and S108. The request message includes PLMN=gg and PLMN=hh in a list of supported network identifiers, and is expressed as, for example, Nmf_Association Update request (PLMN support list(PLMN ID=gg, PLMN ID=hh)).

[0051] S110: The IMS AGW 30A recognizes that there is a connection to a network with a network identifier PLMN ID=hh, based on the list of supported network identifiers included in the request message received in S109.

[0052] S111: The IMS AGW 30A stores information (context) for each network identifier (PLMN ID) in order to perform processing for each network identifier (PLMN ID).

[0053] S112: The IMS AGW 30A sends a response message (Nmf_Association Setup response) to the request message received in S109 to the Iq intermediary 30B. The response message may indicate that the requested association has been established, and may include information indicating that the requested association has been established.

[0054] S113: The Iq intermediary 30B sends a response message (Nmf_Association Setup response) to the request message received in S108 to the P-CSCF 30D. The response message includes the satellite constellation identifier (ID=aa).

[0055] Through the above processing, the IMS AGW 30A is registered for each terrestrial network (each PLMN ID), and access to the IMS AGW 30A becomes possible.

[0056] (IMS Voice Call Procedure) The IMS voice call procedure will now be described. Fig. 5 is a diagram showing an example of a second sequence diagram according to the embodiment of the present invention. The processing of each step will now be described.

[0057] S201: The terminal 20 sends a message (SIP INVITE) requesting an IMS voice call to the P-CSCF 30D.

[0058] S202: The P-CSCF 30D has information about the range of IP addresses used by terminals under the satellite constellation (ID=aa).

[0059] S203: The P-CSCF 30D recognizes that the terminal is using the satellite constellation (ID=aa) from the IP address of the terminal included in the message received in S201. Furthermore, the P-CSCF 30D selects the Iq intermediary 30B that belongs to the satellite constellation (ID=aa). From then on, messages processed by the Iq intermediary 30B use the Nmf interface instead of the H.248 protocol interface.

[0060] S204: The P-CSCF 30D sends a request message (Nmf_MRM_Create request) requesting voice media configuration to the Iq intermediary 30B. This message includes a network identifier (PLMN ID=gg) and is expressed as, for example, Nmf_MRM_Create request (MediaContext(PLMN ID=gg)).

[0061] S205: The Iq intermediary 30B refers to a list including the start time, end time, and destination IMS AGW, which is created with reference to the satellite ephemeris, and selects the IMS AGW 30A.

[0062] S206: The Iq intermediary 30B sends a request message (Nmf_MRM_Create request) requesting voice media configuration to the IMS AGW 30A. The message includes a network identifier (PLMN ID=gg) and is expressed as, for example, Nmf_MRM_Create request (MediaContext(PLMN ID=gg)).

[0063] S207: The IMS AGW 30A executes voice media configuration processing using a context corresponding to each network identifier (PLMN ID). Here, the IMS AGW 30A may allocate its own internal resources for each network identifier (PLMN ID).

[0064] S208: The IMS AGW 30A determines to request acquisition of resources at the termination point on the IMS AGW 30A side for data transmission with the destination side.

[0065] S209: The IMS AGW 30A transmits to the Iq intermediary 30B a response message (Nmf_MRM_Create response) in response to the request message received in S206.

[0066] S210: The Iq intermediary 30B sends to the P-CSCF 30D a response message (Nmf_MRM_Create response) in response to the request message received in S204.

[0067] S211: The P-CSCF 30D sends the message (SIP INVITE) received in S201 requesting the IMS voice call to the S-CSCF 30E. The request message includes setting information (SDP offer) related to the IMS voice call.

[0068] S212: The S-CSCF 30E executes processing related to the IMS voice call request to the terminating network based on the processing of the existing specifications.

[0069] S213: The S-CSCF 30E transmits a response message (SIP 183 Session Progress) from the terminating network to the P-CSCF 30D. The response message includes configuration information (SDP answer) that includes information about the terminating point of the terminating side.

[0070] S214: The P-CSCF 30D sends a request message (Nmf_MRM_Update request) to the Iq intermediary 30B to request an update of the voice media settings. The request message includes setting information including information about the termination point on the destination side.

[0071] S215: The Iq intermediary 30B sends a request message (Nmf_MRM_Update request) to the IMS AGW 30A to request an update of the voice media settings. The request message includes setting information including information about the termination point on the destination side.

[0072] S216: The IMS AGW 30A sets a termination point on the destination side for data transmission with the destination side.

[0073] S217: The IMS AGW 30A transmits to the Iq intermediary 30B a response message (Nmf_MRM_Update response) in response to the request message received in S215.

[0074] S218: The Iq intermediary 30B sends a response message (Nmf_MRM_Update response) to the request message received in S214 to the P-CSCF 30D.

[0075] S219: The P-CSCF 30D sends a request message (Nmf_MRM_Create request) to the Iq intermediary 30B requesting the setting of audio media.

[0076] S220: The Iq intermediary 30B sends a request message (Nmf_MRM_Create request) to the IMS AGW 30A, requesting the setting of voice media.

[0077] S221: The IMS AGW 30A sets a terminal-side termination point for terminal-bound data. The IMS AGW 30A also sets a termination point on its own device side.

[0078] S222: The IMS AGW 30A transmits to the Iq intermediary 30B a response message (Nmf_MRM_Create response) in response to the request message received in S220.

[0079] S223: The Iq intermediary 30B sends a response message (Nmf_MRM_Create response) to the request message received in S219 to the P-CSCF 30D.

[0080] S224: The P-CSCF 30D transmits to the terminal 20 a response message (SIP 183 Session Progress) in response to the message requesting an IMS voice call received in S201.

[0081] S225: The P-CSCF 30D sends a request message (Npcf_PolicyAuthorization_Create request) to the PCF 30C to request the setting of a QoS flow for transmitting voice media. The request message includes information indicating that a PDU session identifier (ID) is requested.

[0082] S226: The PCF 30C sends a response message (Npcf_PolicyAuthorization_Create response) to the request message received in S225 to the P-CSCF 30D. The response message includes a PDU session identifier (ID=ss). Here, the PCF 30C has already acquired the PDU session identifier (ID) when the PDU session was established.

[0083] S227: Thereafter, processing based on the existing specifications is executed.

[0084] S228: The P-CSCF 30D sends a request message (Nmf_MRM_Update request) requesting an update of the voice media settings to the Iq intermediary 30B. The request message includes a PDU session identifier (ID=ss).

[0085] S229: The Iq intermediary 30B sends a request message (Nmf_MRM_Update request) to the IMS AGW 30A to request an update of the voice media settings. The request message includes a PDU session identifier (ID=ss).

[0086] S230: The IMS AGW 30A transmits a response message (Nmf_MRM_Update response) to the request message received in S229 to the Iq intermediary 30B.

[0087] S231: The Iq intermediary 30B sends a response message (Nmf_MRM_Update response) to the request message received in S228 to the P-CSCF 30D.

[0088] Thereafter, by executing processing based on existing specifications, it is possible to make an IMS voice call using the IMS AGW 30A deployed on the satellite.

[0089] According to the above-described embodiment, it is possible to share and use IMS access gateways deployed on satellites in a wireless communication system.

[0090] (Device Configuration) Next, a description will be given of an example of the functional configuration of the base station 10, network node 30, and terminal 20 that perform the processes and operations described above. The base station 10, network node 30, and terminal 20 include functions for performing the above-described embodiments. However, the base station 10, network node 30, and terminal 20 may each include only a part of the functions of the embodiments.

[0091] <Base Station 10 and Network Node 30> Fig. 6 is a diagram showing an example of the functional configuration of the base station 10 and the network node 30. As shown in Fig. 6, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 6 is merely an example. As long as the operations according to the embodiment of the present invention can be performed, the names of the functional divisions and functional units may be any. Note that the network node 30 may have the same functional configuration as the base station 10. Furthermore, a network node 30 having multiple different functions in the system architecture may be composed of multiple network nodes 30 separated by function.

[0092] The transmitter 110 includes a function of generating a signal to be transmitted to the terminal 20 or another network node 30 and transmitting the signal by wire or wirelessly. The receiver 120 includes a function of receiving various signals transmitted from the terminal 20 or another network node 30 and acquiring, for example, information of a higher layer from the received signal. A communication unit including the transmitter 110 and the receiver 120 may be configured.

[0093] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads out the information from the storage device as needed.

[0094] The control unit 140 performs the processes described in the embodiments, etc. The control unit 140 also performs processes related to communication with the terminal 20. The function unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and the function unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

[0095] <Terminal 20> Fig. 7 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 7, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 7 is merely an example. As long as the operations related to the embodiment of the present invention can be performed, the names of the functional divisions and functional units may be any. In addition, the communication device that becomes the resource holder 20 may have the same functional configuration as the terminal 20.

[0096] The transmitter 210 creates a transmission signal from transmission data and transmits the transmission signal wirelessly. The receiver 220 receives various signals wirelessly and acquires higher layer signals from the received physical layer signals. The receiver 220 also has a function of receiving control signals, reference signals, etc. transmitted from the network node 30. A communication unit including the transmitter 210 and the receiver 220 may be configured.

[0097] The setting unit 230 stores various pieces of setting information received from the network node 30 by the receiving unit 220 in a storage device, and reads them out from the storage device as needed. The setting unit 230 also stores setting information that is set in advance.

[0098] The control unit 240 performs the processes described in the embodiments. The function unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and the function unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0099] (Hardware Configuration) The block diagrams (FIGS. 6 and 7) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0100] Functions include, but are not limited to, judgment, determination, assessment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0101] For example, the base station 10, the network node 30, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 8 is a diagram illustrating an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The network node 30 may have the same hardware configuration as the base station 10. The above-described base station 10 and the terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0102] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0103] Each function in the base station 10 and the terminal 20 is realized by loading specified software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0104] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0105] Furthermore, the processor 1001 reads programs (program codes), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002 and executes various processes in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 6 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. Furthermore, for example, the control unit 240 of the terminal 20 shown in FIG. 7 may be implemented by a control program stored in the storage device 1002 and running on the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may also be transmitted from a network via a telecommunications line.

[0106] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0107] The secondary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0108] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0109] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0110] Furthermore, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0111] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0112] Fig. 9 shows an example configuration of a vehicle 2001. As shown in Fig. 9, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in the present disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example.

[0113] The drive unit 2002 is configured, for example, by an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0114] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0115] The signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0116] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing (outputting) various types of information, such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from external devices via the communication module 2013 or the like to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001. The information service unit 2012 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that output information to the outside.

[0117] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driving burden on the driver, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. In addition, the driving assistance system unit 2030 transmits and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0118] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided in the vehicle 2001.

[0119] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0120] The communication module 2013 may transmit at least one of signals from the above-mentioned various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above-mentioned input.

[0121] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0122] <Supplementary Notes> (Supplementary Item 1) A network node handling voice media, comprising: a receiver that receives, from a first network node, a first message requesting association establishment, the message including a network identifier; a controller that stores context for each of the network identifiers; and a transmitter that transmits, to the first network node, a second message indicating that the association establishment has been executed. (Supplementary Item 2) The network node according to Supplementary Item 1, wherein the controller is capable of performing processing related to a service-based interface for handling messages transmitted and received to the first network node. (Supplementary Item 3) A network node comprising: a receiver that receives, from a terminal, a first message requesting voice call setup, and a transmitter that transmits, to a second network node representing the first network node handling voice media, a second message requesting voice media setup, the second message including the network identifier. (Supplementary Item 4) The network node according to Supplementary Item 3, wherein the second message is a message on a service-based interface. (Supplementary clause 5) A network node comprising: a receiver that receives, from a first network node, a first message requesting association establishment, the first message including a network identifier; and a transmitter that transmits, to a second network node, a second message requesting association establishment, the first message including the network identifier, wherein the receiver receives, from the second network node, a third message in response to the second message, and the transmitter transmits, to the first network node, a fourth message in response to the first message, the fourth message including a satellite constellation identifier. (Supplementary clause 6) A communication method executed by a network node that handles voice media, the method comprising: receiving, from a first network node, a first message requesting association establishment, the first message including a network identifier; storing a context for each of the network identifiers; and transmitting, to the first network node, a second message indicating that the association establishment has been completed.

[0123] Any of Supplementary Items 1 to 6 allows a plurality of satellites to share one user plane function for communication in a wireless communication system.

[0124] (Supplementary Notes on the Embodiments) Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (as long as there is no contradiction). Boundaries between functional units or processing units in functional block diagrams do not necessarily correspond to boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor of the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor of the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

[0125] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0126] Each aspect / embodiment described in the present disclosure may be implemented using any of the following standards: LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal number)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802.34 ( The present invention may be applied to at least one of systems using 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), or other suitable systems, and next-generation systems that are extended, modified, created, or defined based on these systems. The present invention may also be applied to a combination of multiple systems (e.g., a combination of LTE and / or LTE-A with 5G).

[0127] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be rearranged unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0128] In this specification, a specific operation described as being performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and another network node other than the base station 10 (such as, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (such as an MME and an S-GW).

[0129] The information, signals, etc. described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0130] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be transmitted to another device.

[0131] In the present disclosure, the determination may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0132] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0133] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0134] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0135] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0136] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0137] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0138] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0139] In the present disclosure, terms such as "base station (BS)," "radio base station," "base station device," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. A base station may also be referred to by terms such as a macrocell, a small cell, a femtocell, and a picocell.

[0140] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage.

[0141] In the present disclosure, the base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control or operate based on the information.

[0142] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," and the like may be used interchangeably.

[0143] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0144] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object refers to a movable object, and may move at any speed. Naturally, this also includes cases where the mobile object is stationary. Examples of the mobile object include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and objects mounted thereon. The mobile object may also be a mobile object that moves autonomously based on an operational command. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0145] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0146] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station may be configured to have the functions of the user terminal described above.

[0147] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0148] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0149] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0150] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0151] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0152] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0153] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0154] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0155] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0156] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0157] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0158] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 30 Network node 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheels 2008 Rear wheels 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 RPM sensor 2023 Tire pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving assistance system unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port (IO port)

Claims

1. A network node that handles voice media, comprising: a receiving unit that receives a first message from a first network node, the first message including a network identifier, requesting establishment of association; a control unit that stores a context for each of the network identifiers; and a transmitting unit that transmits a second message to the first network node indicating that the establishment of association has been performed.

2. The network node according to claim 1, wherein the control unit is capable of executing processing related to a service-based interface for handling messages transmitted to and received from the first network node.

3. A network node having: a receiving unit that receives a first message requesting voice call setup from a terminal; and a transmitting unit that transmits a second message requesting voice media setup, including a network identifier, to a second network node that represents the first network node that handles voice media.

4. The network node according to claim 3, wherein the second message is a message on a service-based interface.

5. A network node comprising: a receiver that receives a first message requesting establishment of association from a first network node, the first message including a network identifier; and a transmitter that transmits a second message requesting establishment of association to a second network node, the second message including the network identifier, wherein the receiver receives a third message from the second network node in response to the second message; and the transmitter transmits a fourth message to the first network node in response to the first message, the fourth message including a satellite constellation identifier.

6. A communication method executed by a network node handling voice media, comprising: receiving a first message from a first network node requesting association establishment, the message including a network identifier; storing a context for each of the network identifiers; and sending a second message to the first network node indicating that the association establishment has been performed.

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