Network node

Abstract

This network node comprises: a control unit that stores a list of Internet Protocol (IP) address ranges set for each terminal location area to be allocated to a terminal; and a reception unit that receives, from a first network node, a first message including information indicating the terminal location area and information indicating an establishment request of a Protocol Data Unit (PDU) session. The control unit includes a transmission unit that specifies an IP address range on the basis of the information indicating the terminal location area, allocates an IP address to the terminal on the basis of the IP address range, and transmits, to the first network node, a second message including information indicating that the IP address has been allocated to the terminal and information indicating the acceptance of establishment of the PDU session.

Description

Network Node

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

[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 38.300 V18.0.0 (2023-12) 3GPP TS 38.331 V18.0.0 (2023-12) 3GPP TS 38.413 V18.0.0 (2023-12) 3GPP TS 29.502 V18.5.0 (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. User data is transmitted and received between a terminal and an arbitrary server on the ground via the base station on the satellite, the user plane function on the satellite, and the NTN GW (Non-Terrestrial Network Gateway; see Non-Patent Document 4, Sections 3.2 and 16.14.1).

[0008] However, when the user plane function is switched as the satellite moves, it is not possible to properly transmit and receive user data.

[0009] The present invention has been made in view of the above-mentioned points, and has as its object to appropriately transmit and receive user data via a satellite in a wireless communication system.

[0010] According to the disclosed technology, a network node is provided that has a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal coverage area to be assigned to a terminal, and a receiving unit that receives a first message from a first network node, the first message including information indicating the terminal coverage area and information indicating a request to establish a PDU (Protocol Data Unit) session, wherein the control unit identifies an IP address range based on the information indicating the terminal coverage area, assigns an IP address to the terminal based on the IP address range, and further has a transmitting unit that transmits a second message to the first network node, the second message including information indicating that the IP address has been assigned to the terminal and information accepting the establishment of the PDU session.

[0011] According to the disclosed technology, it is possible to appropriately transmit and receive user data via a satellite in a wireless communication system.

[0012] FIG. 1 is a diagram for explaining an example of a communication system. FIG. 1 is a diagram for explaining an example of a communication system in a roaming environment. FIG. 1 is a diagram for explaining an example of an IMS data channel network. FIG. 2 is a diagram showing an example of a first sequence diagram in an embodiment of the present invention. FIG. 3 is a diagram showing an example of a second sequence diagram in an embodiment of the present invention. FIG. 4 is a diagram showing an example of a third sequence diagram in an embodiment of the present invention. FIG. 5 is a diagram showing an example of a fifth 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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:

[0026] 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.

[0027] 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.

[0028] The S-CSCF (Serving-Call Session Control Function) is a network node 30 having functions related to session control for the UE.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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).

[0033] 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.

[0034] (Example) A procedure for appropriately transmitting and receiving user data via satellites in a wireless communication system will be described. In this example, it is assumed that a plurality of low-earth orbit satellites (LEOs) equipped with base stations, UPFs, and IMS AGWs form a satellite constellation using inter-satellite links (ISLs). In addition, N2 intermediaries, N4 intermediaries, and Iq intermediaries are deployed on the ground as intermediary devices, communicating with the base stations and UPFs, respectively, deployed in the plurality of LEOs.

[0035] 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. That is, the N2 Intermediary acts as the AMF to the base station and as a base station to the AMF. The N4 Intermediary performs communication with the UPF and communication with the SMF based on the interface (N4) between the UPF and the SMF. That is, the N4 Intermediary acts as the SMF to the UPF and as a UPF to the SMF. The Iq Intermediary performs communication with the IMS AGW and communication with the P-CSCF based on the interface between the IMS AGW and the P-CSCF. That is, the Iq Intermediary acts as the P-CSCF to the IMS AGW and as the IMS AGW to the P-CSCF.

[0036] The intermediary device and the terminal connect to different LEOs depending on the time based on the satellite ephemeris, which is information indicating the relationship between the position of a satellite in its orbit and time.

[0037] Satellite communications operators mainly prepare base stations, UPFs, and IMS AGWs deployed in LEOs, as well as intermediate devices and NTN GWs (Non-Terrestrial Network Gateways; see Sections 3.2 and 16.14.1 of Non-Patent Document 4) deployed on the ground, as dedicated equipment for satellite constellation communications. On the other hand, mobile communications operators mainly prepare AMFs, SMFs, P-CSCFs, and other network nodes deployed on the ground, as satellite constellation utilization equipment.

[0038] In the network configured as described above, IP packets of user data are transmitted and received between a terminal and an arbitrary server on the ground via a base station on the satellite, a UPF on the satellite, and an NTN GW on the ground. Here, the IP address of the terminal is always the same, but the UPF changes as the satellite moves, making it impossible to process the user data appropriately. This process is explained below.

[0039] (Transmission of user data from a terminal) When receiving an IP packet of user data from a terminal, the NTN GW determines the IP address of the UPF, which is the next router, from the IP address of the terminal, and further derives the corresponding MAC (Media Access Control) address (which may also be called a physical address) from the IP address of the UPF. Next, the NTN GW adds the derived MAC address as the destination to the IP packet and transmits an Ethernet frame. Here, when the satellite is switched, the UPF with which the NTN GW communicates switches, and the MAC address of the UPF, and usually the IP address, also switches. Therefore, with existing methods, the NTN GW cannot properly transmit the IP packet of user data to the UPF.

[0040] In this embodiment, the following process is executed to properly transmit the IP packet.

[0041] The NTN GW identifies the terminal's area of ​​coverage (TA) from the terminal IP address, and identifies the UPF that accommodates the TA at the current time by referring to information created from the satellite ephemeris.The NTN GW then creates an Ethernet frame with the MAC address of the identified UPF attached, and transmits the Ethernet frame.

[0042] (Transmission of user data from a terminal) When receiving an IP packet of user data from a terminal, the UPF determines the IP address of the next router, the NTN GW, from the IP address of the server, and then derives the corresponding MAC address from the IP address of the NTN GW. Next, the UPF appends the derived MAC address as the destination to the IP packet and transmits the Ethernet frame. Here, when the satellite is switched, the NTN GW with which the UPF communicates is switched, and the MAC address of the NTN GW, and usually the IP address, also switches. Therefore, with existing methods, the UPF cannot properly transmit the IP packet of user data to the NTN GW.

[0043] In this embodiment, the following process is executed to properly transmit the IP packet.

[0044] The UPF refers to the information created from the satellite ephemeris to identify the NTN GW that can be connected at the current time.The UPF then creates an Ethernet frame with the MAC address of the identified NTN GW attached, and transmits the Ethernet frame.

[0045] (Sending and receiving of voice media) For the same reasons as in the case of sending and receiving user data described above, when sending and receiving voice media to and from a terminal, voice media IP packets cannot be sent and received properly between the IMS AGW on the satellite and the NTN GW on the ground.

[0046] In this embodiment, in order to properly transmit IP packets of voice media, the IMS AGW and NTN GW execute the same processing as the processing for user data described above. In the case of IP packets of voice media, the IMS AGW executes processing based on the IP address of the termination point representing the terminal (terminal representative IP address). Details of this processing will be described later.

[0047] (Area Definition) In this embodiment, the orbital plane of a satellite constellation reflecting the tracking area (TA) for a ground-fixed satellite is called an orbital plane tracking area (or terminal coverage area), and is written as a TA orbit. Furthermore, a base station 10 deployed on a satellite covers (accommodates) a specific TA and a specific TA orbit at a specific time. Furthermore, a UPF onboard a satellite covers (accommodates) a UPF SA orbit, which is a specific orbital plane UPF service area (SA), at a specific time. Here, a UPF SA orbit is composed of multiple TA orbits. When covering (accommodating) a specific TA orbit, the base station 10 can connect to a UPF 30A that includes that TA orbit in its UPF SA orbit.

[0048] The details of the processing in this embodiment will be described below using sequence diagrams. Requests, responses, notifications, etc. sent and received in the procedures described below may be called messages (for example, request messages).

[0049] (Procedure for establishing an IMS PDU session) The procedure for establishing an IMS PDU session in this embodiment will be described in detail with reference to a sequence diagram. For details of existing specifications related to messages transmitted and received in this sequence diagram, see Non-Patent Document 5 and Non-Patent Document 6.

[0050] 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.

[0051] S101: The terminal 20 transmits a request message requesting PDU session establishment to the base station 10. The request message includes information indicating the PDU session establishment request and information related to the Data Network Name (DNN), and is expressed as, for example, ULInformationTransfer(dedicatedNAS-Message(UL NAS transport(Payload container type(N1 SM information), Payload container(PDU Session Establishment request), DNN=ims))).

[0052] S102: The base station 10 generates a cell identifier (ID) and a tracking area (TA) and sets them in the user location information (see Sections 16.14.1 and 16.14.5 of Non-Patent Document 4).

[0053] S103: The base station 10 sends a request message to the N2 intermediary 30C to request establishment of a PDU session. The request message includes user location information, information indicating the PDU session establishment request, and information about the DNN, and is expressed as, for example, Uplink NAS Transport (User Location Information, NAS-PDU (UL NAS transport (Payload container type (N1 SM information), Payload container (PDU Session Establishment request), DNN = ims))).

[0054] S104: The N2 intermediary 30C transmits the request message (Uplink NAS Transport) received in S103 to the AMF 30F. The user location information includes TA information related to the area where the terminal is located (see Sections 6.1.3.2.3.1 and 6.1.6.2.2 of Non-Patent Document 7).

[0055] S105: The AMF 30F recognizes that the request is from a terminal 20 under the control of the satellite constellation (ID (identifier) ​​= aa) based on the base station identifier corresponding to the N2 intermediary 30C.

[0056] S106: The AMF 30F sends a request message requesting establishment of a PDU session to the SMF 30G. The request message includes the satellite constellation identifier (ID=aa) recognized in S105, information related to the DNN, user location information, and information indicating the PDU session establishment request, and is expressed as, for example, Nsmf_PDUSession_CreateSMContext request (SmContextCreateData (Dnn=ims, ueLocation n1SmMsg(PDU session establishment request), satellite constellation ID=aa)).

[0057] S107: SMF 30G sends a response message (Nsmf_PDUSession_CreateSMContext response) to the request message received in S106 to AMF 30F.

[0058] S108: Based on the satellite constellation identifier (ID=aa) included in the message received in S106, SMF 30G selects the N4 intermediary 30D to which the request message requesting PDU session establishment is to be sent.

[0059] S109: SMF 30G decides to transmit the identifier (PDU session ID) of the PDU session to facilitate operation within the satellite.

[0060] S110: The SMF 30G sends a request message (PFCP Session Establishment Request) to the N4 intermediary 30D to request establishment of a PDU session. The request message includes a PDU session identifier (PDU session ID). That is, the request message requests the N4 intermediary 30D to set up a user plane in the UPF 30A.

[0061] S111: The N4 intermediary 30D selects a UPF 30A to connect to using a list created based on the satellite ephemeris. For example, the N4 intermediary 30D selects a UPF 30A to connect to at the current time based on a list showing the relationship between connectable time periods (specified by, for example, start and end times) and connectable UPF 30A candidates.

[0062] S112: The N4 intermediary 30D sends the request message (PFCP Session Establishment request) received in S110 to the UPF 30A. The request message includes the PDU session identifier (PDU session ID).

[0063] S113: The UPF 30A transmits a response message (PFCP Session Establishment response) to the request message received in S112 to the N4 intermediary 30D.

[0064] S114: The N4 intermediary 30D transmits to the SMF 30G a response message (PFCP Session Establishment response) in response to the request message received in S110. That is, the response message notifies the SMF 30G that the user plane has been set up in the UPF 30A.

[0065] S115: SMF 30G sets the pre-stored IP (Internet Protocol) address (P-CSCF address=bb) of a special P-CSCF deployed on the ground that can handle the satellite IMS AGW as the P-CSCF address of ePCO (extended Protocol Configuration Options).

[0066] S116: When the SMF 30G assigns an IP address to the terminal 20 that uses a satellite, it assigns it from the IP address range used by the satellite constellation with the identifier (ID=aa) received in S106. The IP address range may be divided into TAs (=TA orbits).

[0067] S117: The SMF 30G refers to the terminal location area (TA information) received in S106, and assigns an IP address to the terminal from the corresponding IP address range.

[0068] S118: The SMF 30G decides to transmit the identifier (Node ID) of the UPF 30A to the base station 10. After transmission, the SMF 30G may delete the identifier (Node ID).

[0069] S119: The SMF 30G transmits a message including information indicating acceptance of the PDU session establishment request to the AMF 30F. The message also includes the terminal IP address assigned in S117, the IP address of the P-CSCF set in S115 (P-CSCF address=bb), and the identifier (Node ID) of the UPF 30A determined in S118, and is expressed as, for example, Namf_Communication_N1N2MessageTransfer (N1N2MessageTransferReqData(n1MessageContainer(PDU Session Establishment accept (PDU address=terminal address, Extended protocol configuration options(P-CSCF address=bb))), n2InfoContainer(PDU Session Resource Setup Request Transfer(UPF Node ID)))).

[0070] S120: The AMF 30F transmits a message including information indicating acceptance of the PDU session establishment request to the N2 intermediary 30C. The message also includes the terminal IP address, the P-CSCF IP address (P-CSCF address=bb), and the UPF 30A identifier (Node ID) received in S119, and is expressed as, for example, PDU Session Resource Setup Request (NAS-PDU (DL NAS transport (Payload container type (N1 SM information), Payload container (PDU Session Establishment accept (PDU address=terminal address, Extended protocol configuration options (P-CSCF address=bb))))), PDU Session Resource Setup Request List (PDU Session Resource Setup Request Transfer (UPF Node ID))).

[0071] S121: The N2 intermediary 30C transmits the message (PDU Session Resource Setup Request) received in S120 to the base station 10.

[0072] S122: The base station 10 extracts and stores the identifier (Node ID) of the UPF 30A included in the message received in S121.

[0073] S123: The base station 10 transmits a message including information indicating acceptance of the PDU session establishment request to the terminal 20. The message also includes the terminal IP address and the P-CSCF IP address (P-CSCF address=bb) received in S121, and is expressed as, for example, RRCReconfiguration(dedicatedNAS-Message(DL NAS transport(Payload container type(N1 SM information), Payload container(PDU Session Establishment accept(PDU address=terminal address, Extended protocol configuration options(P-CSCF address=dd)))))).

[0074] (IMS Voice Call Procedure) The details of the IMS voice call procedure in this embodiment will be explained using a sequence diagram. Fig. 5 is a diagram showing an example of a second sequence diagram in the embodiment of the present invention. The processing of each step will be explained below.

[0075] S201: The IMS AGW 30B stores information on TA (=TAorbit) associated with the IP address of the terminal. That is, the IMS AGW 30B stores a list of IP address ranges set for each terminal's area of ​​coverage to be assigned to the terminal.

[0076] S202: The IMS AGW 30B stores a set range of terminal representative IP addresses for each TA (=TAorbit). That is, the IMS AGW 30B stores a list of IP address ranges set for each terminal location area to be assigned to a termination point representing the terminal within the IMS AGW 30B.

[0077] S203: The terminal 20 transmits a message (SIP INVITE) requesting an IMS voice call to the P-CSCF 30K.

[0078] S204: The P-CSCF 30K checks the information stored in itself about the range of IP addresses used by terminals under the satellite constellation (ID=aa).

[0079] S205: The P-CSCF 30K recognizes that the terminal is using the satellite constellation (ID=aa) from the IP address of the terminal included in the message received in S203. Furthermore, the P-CSCF 30K selects the Iq intermediary 30H that belongs to the satellite constellation (ID=aa). From then on, messages processed by the Iq intermediary 30H use the Nmf interface instead of the H.248 protocol interface.

[0080] S206: The P-CSCF 30K determines to transmit the current terminal IP address for reference when acquiring resources (= IP address allocation) for the termination point on its own device side for data transmission with the destination side.

[0081] S207: The P-CSCF 30K sends a request message (Nmf_MRM_Create request) to the Iq intermediary 30H requesting voice media configuration. The message includes the terminal IP address and a network identifier (PLMN ID=gg), and is expressed as, for example, Nmf_MRM_Create request (MediaContext(UE IP address, PLMN ID=gg)). The request message also requests that the terminal IP address be assigned to a termination point representing the terminal within the P-CSCF 30K's own device.

[0082] S208: The Iq intermediary 30H 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 30B.

[0083] S209: The Iq intermediary 30H sends a request message (Nmf_MRM_Create request) requesting voice media configuration to the IMS AGW 30B. The message includes the terminal IP address and the network identifier (PLMN ID=gg), and is expressed as, for example, Nmf_MRM_Create request (MediaContext(UE IP address, PLMN ID=gg)).

[0084] S210: The IMS AGW 30B executes voice media configuration processing using a context corresponding to each network identifier (PLMN ID). Here, the IMS AGW 30B may allocate its own internal resources for each network identifier (PLMN ID).

[0085] S211: The IMS AGW 30B acquires resources of the termination point on its own device side related to data transmission with the destination side.

[0086] S212: The IMS AGW 30B identifies a corresponding terminal area (TA orbit) from the terminal IP address (UE IP address). The IMS AGW 30B also identifies a terminal address range based on the terminal area (TA orbit). The IMS AGW 30B also assigns a terminal representative IP address (=rr) from the terminal address range to a termination point that represents the terminal within the IMS AGW 30B.

[0087] S213: The IMS AGW 30B sends a response message (Nmf_MRM_Create response) to the request message received in S209 to the Iq intermediary 30H. The response message includes information indicating that an IP address has been assigned to the termination point that represents the terminal in the IMS AGW 30B, and is expressed as, for example, Nmf_MRM_Create response (MediaContext(terminations(medias(localMbEndpoint=rr)))).

[0088] S214: The Iq intermediary 30H sends to the P-CSCF 30K a response message (Nmf_MRM_Create response) in response to the request message received in S207. The response message includes information indicating that the IP address has been assigned to the termination point that represents the terminal in the Iq intermediary 30H, and is expressed as, for example, Nmf_MRM_Create response (MediaContext(terminations(medias(localMbEndpoint=rr)))).

[0089] S215: The P-CSCF 30K sends a message (SIP INVITE) requesting an IMS voice call to the S-CSCF 30L. The request message includes configuration information (SDP offer) that includes information about the calling termination point.

[0090] S216: The S-CSCF 30L executes processing related to the IMS voice call request to the terminating network based on the processing of the existing specifications.

[0091] The process following S216 will now be described. Fig. 6 is a diagram showing an example of a third sequence diagram according to an embodiment of the present invention. The process of each step will now be described.

[0092] S221: The S-CSCF 30L transmits a response message (SIP 183 Session Progress) from the terminating network to the P-CSCF 30K. The response message includes configuration information (SDP answer) that includes information about the terminating point of the terminating side.

[0093] S222: The P-CSCF 30K sends a request message (Nmf_MRM_Update request) to the Iq intermediary 30H to request an update of the voice media settings. The request message includes setting information including information about the destination termination point.

[0094] S223: The Iq intermediary 30H sends a request message (Nmf_MRM_Update request) to the IMS AGW 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.

[0095] S224: The IMS AGW 30B sets a termination point on the destination side for data transmission with the destination side.

[0096] S225: The IMS AGW 30B transmits a response message (Nmf_MRM_Update response) to the request message received in S223 to the Iq intermediary 30H.

[0097] S226: The Iq intermediary 30H transmits to the P-CSCF 30K a response message (Nmf_MRM_Update response) in response to the request message received in S222.

[0098] S227: The P-CSCF 30K transmits a request message (Nmf_MRM_Create request) to the Iq intermediary 30H, requesting the setting of audio media.

[0099] S228: The Iq intermediary 30H sends a request message (Nmf_MRM_Create request) to the IMS AGW 30B, requesting the setting of voice media.

[0100] S229: The IMS AGW 30B sets a terminal-side termination point for the data destined for the terminal. The IMS AGW 30B also sets a termination point on its own device side.

[0101] S230: The IMS AGW 30B transmits a response message (Nmf_MRM_Create response) to the request message received in S228 to the Iq intermediary 30H.

[0102] S231: The Iq intermediary 30H transmits to the P-CSCF 30K a response message (Nmf_MRM_Create response) in response to the request message received in S227.

[0103] S232: The P-CSCF 30K transmits to the terminal 20 a response message (SIP 183 Session Progress) in response to the message requesting an IMS voice call received in S203 of FIG.

[0104] S233: The P-CSCF 30K transmits a request message (Npcf_PolicyAuthorization_Create request) to the PCF 30J 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.

[0105] S234: The PCF 30J sends to the P-CSCF 30K a response message (Npcf_PolicyAuthorization_Create response) in response to the request message received in S233. The response message includes a PDU session identifier (ID=ss). Here, the PCF 30J has already acquired the PDU session identifier (ID) when the PDU session was established.

[0106] S235: Thereafter, processing based on the existing specifications is executed.

[0107] S236: The P-CSCF 30K sends a request message (Nmf_MRM_Update request) to the Iq intermediary 30H, requesting an update of the voice media settings. The request message includes a PDU session identifier (ID=ss).

[0108] S237: The Iq intermediary 30H sends a request message (Nmf_MRM_Update request) requesting an update of the voice media settings to the IMS AGW 30B. The request message includes a PDU session identifier (ID=ss).

[0109] S238: The IMS AGW 30B transmits a response message (Nmf_MRM_Update response) to the request message received in S237 to the Iq intermediary 30H.

[0110] S239: The Iq intermediary 30H transmits to the P-CSCF 30K a response message (Nmf_MRM_Update response) in response to the request message received in S236.

[0111] Thereafter, by executing processing based on existing specifications, it becomes possible to make an IMS voice call using the IMS AGW30B deployed on the satellite.

[0112] (Downlink Data Arrival) The process relating to downlink data arrival in this embodiment will be described in detail using a sequence diagram. Fig. 7 is a diagram showing an example of a third sequence diagram in the embodiment of the present invention. The process of each step will be described below.

[0113] S301: NTN GW30M stores a list (list of [UPF ID, UPF MAC address, IMS AGW ID, IMS AGW MAC address, time information, UPF SA orbit to cover (accommodate)]) of pairs of UPF identifier, UPF MAC address, IMS AGW identifier corresponding to UPF, IMS AGW MAC address, connectable time information, and covering (accommodating) orbital plane UPF service area.

[0114] S302: The NTN GW30M stores the MAC address of each UPF and the MAC address of each IMS AGW.

[0115] S303: The NTN GW 30M stores information on the TA (=TAorbit) associated with the IP address of the terminal 20. That is, the NTN GW 30M stores a list of IP address ranges set for each terminal's area of ​​coverage to be assigned to the terminal 20.

[0116] S304: The NTN GW 30M stores information on the TA (=TAorbit) associated with the representative IP address of the terminal 20. That is, the NTN GW 30M stores a list of IP address ranges set for each terminal area to be assigned to the termination point representing the terminal 20.

[0117] The process of receiving DL data from the UPF 30A to the terminal 20 in steps S305 to S313 will be described.

[0118] S305: NTN GW30M receives the IP packet destined for terminal 20.

[0119] S306: The NTN GW30M identifies the terminal area (TA (=TAorbit)) from the IP address of the terminal 20 based on the list stored in S303.

[0120] S307: The NTN GW 30M identifies the UPF 30A that currently accommodates the terminal area (TA (=TAorbit)) based on the list stored in S301.

[0121] S308: The NTN GW 30M identifies the MAC address of the UPF 30A based on the list stored in S302.

[0122] S309: The NTN GW 30M generates an Ethernet frame in which the MAC address of the UPF 30A is added as the destination to the IP packet.

[0123] S310: The NTN GW30M may cache the combination of the terminal IP address and the UPF MAC address and apply it to subsequent incoming IP packets.

[0124] S311: The NTN GW 30M transmits the Ethernet frame generated in S309 to the UPF 30A as an incoming IP packet to the terminal 20.

[0125] S312: The UPF 30A may cache the pair of the terminal IP address and the MAC address of the NTN GW 30M and apply it to subsequent outgoing IP packets.

[0126] S313: The UPF 30A transmits the incoming IP packet to the terminal 20.

[0127] The process from S314 to S323 in which DL data arrives at the terminal 20 from the IMS AGW 30B via the UPF 30A will be described.

[0128] S314: NTN GW30M receives the IP packet destined for terminal 20.

[0129] S315: The NTN GW30M identifies the terminal area (TA (=TAorbit)) from the representative IP address of the terminal 20 based on the list stored in S304.

[0130] S316: The NTN GW 30M identifies the UPF 30A that currently accommodates the terminal's service area (TA (= TAorbit)) based on the list stored in S301, and further identifies the IMS AGW 30B that corresponds to the UPF 30A. Alternatively, the NTN GW 30M may directly identify the IMS AGW 30B that currently accommodates the terminal's service area (TA (= TAorbit)).

[0131] S317: The NTN GW 30M identifies the MAC address of the IMS AGW 30B based on the list stored in S302.

[0132] S318: The NTN GW 30M adds the MAC address of the IMS AGW 30B to the destination of the IP packet, and generates an Ethernet frame.

[0133] S319: The NTN GW 30M may cache the set of the representative terminal IP address and the MAC address of the IMS AGW 30B, and apply it to subsequent incoming IP packets.

[0134] S320: The NTN GW 30M transmits the Ethernet frame generated in S318 to the IMS AGW 30B as an incoming IP packet of the voice media to the terminal 20.

[0135] S321: The IMS AGW 30B may cache the pair of the representative terminal IP address and the MAC address of the NTN GW 30M, and apply this to subsequent outgoing IP packets.

[0136] S322: The IMS AGW 30B transmits to the UPF 30A an incoming IP packet of the voice media destined for the terminal 20. The UPF 30A and the IMS AGW 30B do not switch addresses due to satellite switching and have a one-to-one relationship, so they can always use the same settings.

[0137] S323: The UPF 30A transmits the incoming IP packet of the audio media to the terminal 20.

[0138] (Uplink Data Arrival) The process related to uplink data arrival in this embodiment will be described in detail using a sequence diagram. Fig. 8 is a diagram showing an example of a fourth sequence diagram in the embodiment of the present invention. The process of each step will be described below.

[0139] S401: UPF 30A stores a list of pairs of an on-orbit position, an identifier of a connectable NTN GW, and a MAC address of the NTN GW.

[0140] S402: The IMS AGW 30B stores a list of pairs of an on-orbit position, an identifier of a connectable NTN GW, and a MAC address of the NTN GW.

[0141] S403: The terminal 20 transmits an outgoing IP packet to the UPF 30A.

[0142] S404: The UPF 30A identifies the currently connectable NTN GW 30M from the current position of the UPF 30A on the orbit, based on the list stored in S401.

[0143] S405: The UPF 30A identifies the MAC address information of the NTN GW 30M based on the list stored in S401.

[0144] S406: The UPF 30A adds the MAC address of the NTN GW 30M to the destination of the IP packet, and generates an Ethernet frame.

[0145] S407: The UPF 30A may cache the combination of the terminal IP address and the MAC address of the NTN GW 30M and apply it to subsequent outgoing IP packets.

[0146] S408: The UPF 30A transmits the Ethernet frame generated in S406 to the NTN GW 30M as an IP packet sent from the terminal 20.

[0147] S409: The NTN GW 30M may cache the pair of the terminal IP address and the MAC address of the UPF 30A and apply it to subsequent incoming IP packets. For example, the NTN GW 30M may store the source IP address of an outgoing IP packet in association with the source MAC address of an Ethernet frame containing the IP packet.

[0148] S410: The NTN GW30M sends the outgoing IP packet received in S408 to the external server.

[0149] S411: The terminal 20 transmits an outgoing IP packet of the voice media to the UPF 30A.

[0150] S412: The UPF 30A transmits the outgoing IP packet of the voice media received in S411 to the IMS AGW 30B.

[0151] S413: The IMS AGW 30B identifies the currently connectable NTN GW 30M from the current position of the IMS AGW 30B on the orbit, based on the list stored in S402.

[0152] S414: The IMS AGW 30B identifies the MAC address information of the NTN GW 30M based on the list stored in S402.

[0153] S415: The IMS AGW 30B adds the MAC address of the NTN GW 30M to the destination of the IP packet, and generates an Ethernet frame.

[0154] S416: The IMS AGW 30B may cache the pair of the representative terminal IP address and the MAC address of the NTN GW 30M, and apply this to subsequent outgoing IP packets.

[0155] S417: The IMS AGW 30B transmits the Ethernet frame generated in S415 to the NTN GW 30M as an outgoing IP packet of the voice media from the terminal 20.

[0156] S418: The NTN GW 30M may cache the pair of the representative IP address of the terminal and the MAC address of the IMS AGW 30B and apply it to subsequent incoming IP packets. For example, the NTN GW 30M may store the source IP address of an outgoing IP packet in association with the source MAC address of an Ethernet frame containing the IP packet.

[0157] S419: The NTN GW30M sends the outgoing IP packet of the voice media received in S417 to the external server.

[0158] According to the above-described embodiment, it is possible to appropriately transmit and receive user data via satellite in a wireless communication system.

[0159] (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.

[0160] <Base Station 10 and Network Node 30> Fig. 9 is a diagram showing an example of the functional configuration of the base station 10 and the network node 30. As shown in Fig. 9, 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. 9 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] <Terminal 20> Fig. 10 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 10, 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. 10 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.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] (Hardware Configuration) The block diagrams (FIGS. 9 and 10) 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.

[0169] 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.

[0170] 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. 11 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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. 9 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. 10 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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).

[0179] 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.

[0180] 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.

[0181] Fig. 12 shows an example configuration of a vehicle 2001. As shown in Fig. 12, 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.

[0182] 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.

[0183] 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).

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] <Additional Notes> (Additional Note 1) A network node comprising: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal coverage area to be assigned to a terminal; and a receiving unit that receives a first message from a first network node, the first message including information indicating the terminal coverage area and information indicating a request for establishment of a PDU (Protocol Data Unit) session, wherein the control unit identifies an IP address range based on the information indicating the terminal coverage area, and assigns an IP address to the terminal based on the IP address range; and a transmitting unit that transmits a second message to the first network node, the second message including information indicating that the IP address has been assigned to the terminal and information accepting the establishment of a PDU session. (Supplementary Item 2) A network node comprising: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal region to be assigned to a terminal; and a control unit that stores a list of IP address ranges set for each terminal region to be assigned to an endpoint within the network node that represents the terminal; a receiving unit that receives from a first network node a first message including an IP address of the terminal, requesting that the IP address be assigned to the endpoint within the network node that represents the terminal; wherein the control unit identifies the terminal region based on the IP address, identifies an IP address range based on the terminal region, and assigns an IP address from the IP address range to the endpoint within the network node that represents the terminal; and a transmitting unit that transmits to the first network node a second message including information indicating that the IP address has been assigned to the endpoint within the network node that represents the terminal.(Supplementary Item 3) A network node having: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal's area of ​​coverage to be assigned to a terminal; and a list of pairs each consisting of an identifier of a first network node, a physical address of the first network node, connectable time information, and an area covered by the first network node; a receiving unit that receives IP packets delivered to a terminal; wherein the control unit identifies the terminal's area of ​​coverage based on the destination IP address of the IP packet; identifies the first network node that currently covers the terminal's area of ​​coverage; identifies the physical address of the first network node; generates an Ethernet frame by adding the physical address as the destination to the IP packet; and a transmitting unit that transmits the Ethernet frame to the first network node. (Addendum 4) A network node comprising: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal coverage area to be assigned to an endpoint representing the terminal; and a list of pairs each consisting of an identifier of a first network node, an identifier of a second network node corresponding to the first network node having an endpoint representing the terminal, a physical address of the second network node, connectable time information, and an area served by the first network node; and a receiving unit that receives IP packets delivered to a terminal, wherein the control unit: identifies the terminal coverage area from the destination IP address of the IP packet; identifies the first network node that currently serves the terminal coverage area; identifies the second network node corresponding to the first network node; identifies the physical address of the second network node; creates an Ethernet frame by adding the physical address as the destination to the IP packet; and transmits the Ethernet frame to the second network node.(Addendum 5) A network node comprising: a control unit that stores a list of pairs each containing a position on an orbit, a connectable first network node, and a physical address of the first network node; and a receiving unit that receives IP (Internet Protocol) packets originating from a terminal, wherein the control unit identifies a connectable first network node from the position of the device on the orbit, identifies the physical address of the first network node, generates an Ethernet frame by adding the physical address as a destination to the IP packet, and further comprises a transmitting unit that transmits the Ethernet frame to the first network node. (Addendum 6) A network node comprising: a receiving unit that receives an IP (Internet Protocol) packet originating from a terminal from a first network node; and a control unit that associates and stores a source IP address of the IP packet with a source physical address of an Ethernet frame including the IP packet, wherein the receiving unit receives the IP packet originating from the terminal; the control unit generates an Ethernet frame by adding the physical address as a destination to the IP packet; and a transmitting unit that transmits the generated Ethernet frame to the first network node.

[0192] Any of supplementary items 1 to 6 makes it possible to appropriately transmit and receive user data via a satellite in a wireless communication system.

[0193] (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.

[0194] 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.

[0195] 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).

[0196] 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.

[0197] 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).

[0198] 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.

[0199] 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.

[0200] 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).

[0201] 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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," and the like may be used interchangeably.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0219] 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."

[0220] 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.

[0221] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0222] 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.

[0223] 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.

[0224] 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."

[0225] 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).

[0226] 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.

[0227] 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 comprising: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal coverage area to be assigned to a terminal; and a receiving unit that receives a first message from a first network node, the first message including information indicating the terminal coverage area and information indicating a request to establish a PDU (Protocol Data Unit) session, wherein the control unit identifies an IP address range based on the information indicating the terminal coverage area, and assigns an IP address to the terminal based on the IP address range; and a transmitting unit that transmits a second message to the first network node, the second message including information indicating that the IP address has been assigned to the terminal and information accepting the establishment of a PDU session.

2. A network node comprising: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal's service area to be assigned to a terminal; and a control unit that stores a list of IP address ranges set for each terminal's service area to be assigned to an endpoint within the device that represents the terminal; a receiving unit that receives from a first network node a first message including the IP address of the terminal and requesting that the IP address be assigned to the endpoint within the device that represents the terminal; wherein the control unit identifies the terminal's service area based on the IP address, identifies an IP address range based on the terminal's service area, and assigns an IP address from the IP address range to the endpoint within the device that represents the terminal; and a transmitting unit that transmits to the first network node a second message including information indicating that the IP address has been assigned to the endpoint within the device that represents the terminal.

3. A network node having: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal's area of ​​coverage to be assigned to a terminal; and a list of pairs each consisting of an identifier of a first network node, a physical address of the first network node, connectable time information, and an area served by the first network node; a receiving unit that receives IP packets delivered to a terminal; wherein the control unit identifies the terminal's area of ​​coverage based on the destination IP address of the IP packet; identifies the first network node that currently serves the terminal's area of ​​coverage; identifies the physical address of the first network node; generates an Ethernet frame by adding the physical address as the destination to the IP packet; and a transmitting unit that transmits the Ethernet frame to the first network node.

4. A network node having: a control unit that stores a list of IP (Internet Protocol) address ranges set for each terminal coverage area to be assigned to an endpoint representing the terminal; and a list of pairs each consisting of an identifier of a first network node, an identifier of a second network node corresponding to the first network node having an endpoint representing the terminal, a physical address of the second network node, connectable time information, and an area served by the first network node; and a receiving unit that receives IP packets delivered to a terminal, wherein the control unit: identifies the terminal coverage area from the destination IP address of the IP packet; identifies the first network node that currently serves the terminal coverage area; identifies the second network node corresponding to the first network node; identifies the physical address of the second network node; creates an Ethernet frame by adding the physical address as the destination to the IP packet; and transmits the Ethernet frame to the second network node.

5. A network node comprising: a control unit that stores a list of pairs each containing a position on the trajectory, a connectable first network node, and a physical address of the first network node; and a receiving unit that receives IP (Internet Protocol) packets originating from a terminal, wherein the control unit identifies a connectable first network node from the position on the trajectory of the device itself; identifies the physical address of the first network node; generates an Ethernet frame by adding the physical address as the destination to the IP packet; and a transmitting unit that transmits the Ethernet frame to the first network node.

6. A network node comprising: a receiving unit that receives an IP (Internet Protocol) packet originating from a terminal from a first network node; and a control unit that associates and stores a source IP address of the IP packet with a source physical address of an Ethernet frame containing the IP packet, wherein the receiving unit receives the IP packet originating from the terminal; the control unit generates an Ethernet frame by adding the physical address as a destination to the IP packet; and a transmitting unit that transmits the generated Ethernet frame to the first network node.

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