Relay Node and Base Station

Abstract

To provide a relay node and a base station that allow handover procedures for UE handover between a base station and a relay to be performed.SOLUTION: In a system, a relay node includes: a first communication processing unit that communicates with a first base station via a Uu interface, as a user apparatus; and a second communication processing unit that communicates with one or more user apparatuses via the Uu interface, as a second base station. The first communication processing unit of the relay node communicates with the first base station via an inter-base station interface, as the second base station, and performs UE handover.SELECTED DRAWING: Figure 17

Description

Technical Field

[0001] The present disclosure relates to a relay node and a base station.

Background Art

[0002] In 3GPP (3rd Generation Partnership Project), mobile communication technologies have been proposed and standardized as Technical Specifications (TS). In particular, currently, 5G (5th Generation) technologies have been proposed and standardized.

[0003] For example, according to Non-Patent Document 1 and Non-Patent Document 2, relays mounted on vehicles have been studied, and the relays are called mobile base station relays (MBSR) and / or vehicle-mounted relays. According to Non-Patent Document 1, a mobile base station relay communicates with a donor base station via the Uu interface and communicates with a user equipment (UE) via the Uu interface.

[0004] In particular, Non-Patent Document 1 describes that handover of a UE may occur between a donor base station and a relay.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The relay described in Non-Patent Document 1 only communicates with the donor base station as a UE via the Uu interface. Therefore, the inventor has found a problem that the relay and the donor base station cannot perform the normal handover procedure for the handover of the UE between the relay and the donor base station.

[0007] An object of the present disclosure is to provide a relay node and a base station that enable a handover procedure for handover of a UE between a base station and a relay.

Means for Solving the Problems

[0008] A relay node according to an aspect of the present disclosure includes a first communication processing unit that communicates with a first base station via a Uu interface as a user equipment, and a second communication processing unit that communicates with one or more user equipments via a Uu interface as a second base station. The first communication processing unit communicates with the first base station via an inter-base station interface as the second base station.

[0009] The first base station according to one aspect of the present disclosure includes a communication processing unit that communicates with the relay node that communicates with the first base station via the Uu interface as a user equipment and communicates with one or more user equipments via the Uu interface as a second base station. The communication processing unit communicates with the relay node operating as the user equipment via the Uu interface and communicates with the relay node operating as the second base station via the inter-base station interface.

Effect of the Invention

[0010] According to the present disclosure, it becomes possible to perform a handover procedure for handover of a UE between a base station and a relay. Note that according to the present disclosure, other effects may be achieved instead of or together with the above effect.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and drawings, for elements that can be similarly described, duplicate description may be omitted by assigning the same reference numerals.

[0013] The description will be made in the following order. 1. Configuration of the system 2. Configuration of the relay node 3. Configuration of the base station 4. Operation example 5. Modification example

[0014] <1. Configuration of the system> With reference to FIGS. 1 to 3, an example of the configuration of the system 1 according to an embodiment of the present disclosure will be described.

[0015] Referring to FIG. 1, the system 1 includes a relay node 100, a base station 200, a UE 30, and a UE 40.

[0016] For example, the system 1 is a system compliant with 3GPP TS. More specifically, for example, the system 1 is a system compliant with 5G or NR (New Radio) TS.

[0017] (1) Relay node 100 The relay node 100 relays data and control information between the base station and the UE.

[0018] For example, the relay node 100 operates as a UE. Specifically, for example, when the relay node 100 is located within the coverage area of the base station 200, it is connected to the base station 200 as a UE and communicates with the base station 200 via the Uu interface.

[0019] For example, relay node 100 also operates as a base station. Specifically, for example, one or more UEs are connected to relay node 100, and relay node 100 communicates with the one or more UEs via the Uu interface as a base station. Referring to the example of FIG. 1, UE30 is connected to relay node 100, and relay node 100 communicates with UE30 via the Uu interface as a base station. Note that base station 200 may be referred to as the first base station, and relay node 100 (or the base station function of relay node 100) may be referred to as the second base station. In this case, relay node 100 communicates with UE30 as the second base station.

[0020] For example, relay node 100 is a mobile relay node. More specifically, for example, relay node 100 is a device that can be mounted on a mobile object. For example, the mobile object is a vehicle, and relay node 100 is an in-vehicle device. As an example, relay node 100 is an ECU (Electronic Control Unit). Referring to the example of FIG. 2, for example, relay node 100 is mounted on vehicle 10, and UE30 is located inside vehicle 10. For example, in this way, relay node 100 is not installed at a specific position and moves.

[0021] Relay node 100 may be referred to as a Mobile Base Station Relay (MBSR) or a vehicle-mounted relay.

[0022] (2) Base station 200 Base station 200 is a node of a Radio Access Network (RAN), and communicates with a UE located within the coverage area of base station 200 via the Uu interface.

[0023] Referring to the example of FIG. 1, for example, UE 40 is connected to base station 200, and base station 200 communicates with UE 40 via the Uu interface. As described above, for example, relay node 100 is connected to base station 200 as a UE, and base station 200 communicates with relay node 100 via the Uu interface.

[0024] For example, base station 200 is a gNB. A gNB is a node that provides NR user plane and control plane protocol terminations towards the UE and is connected to the 5GC (5G Core Network) via the NG interface. Alternatively, base station 200 may be an en-gNB. An en-gNB is a node that provides NR user plane and control plane protocol terminations towards the UE and operates as a secondary node in EN-DC (E-UTRA-NR Dual Connectivity).

[0025] Base station 200 may be referred to as a donor base station. More specifically, base station 200 may be referred to as a donor gNB.

[0026] (3) Example of Architecture Referring to FIG. 3, an example of the overall architecture including system 1 is shown. In this example, relay node 100 is an MBSR node, and base station 200 is an MBSR donor gNB. The MBSR node (relay node 100) has UE functions and gNB functions. There is a Uu interface between the MBSR node (relay node 100) and the MBSR donor gNB (base station 200). There is also a Uu interface between the MBSR node (relay node 100) and UE 30. Note that there is an Xn interface between the MBSR donor gNB (base station 200) and gNB 50, and there is an NG interface between the MBSR donor gNB (base station 200) and the 5GC (5G Core) 60.

[0027] In particular, in the embodiments of the present disclosure, there is also an inter-base station interface (for example, the Xn interface) between the MBSR node (relay node 100) and the MBSR donor gNB (base station 200). This will be described in detail later.

[0028] <2. Configuration of Relay Node> Referring to FIGS. 4 and 5, an example of the configuration of the relay node 100 according to the embodiments of the present disclosure will be described.

[0029] (1) Functional Configuration First, referring to FIG. 4, an example of the functional configuration of the relay node 100 according to the embodiments of the present disclosure will be described. Referring to FIG. 4, the relay node 100 includes a first wireless communication unit 110, a second wireless communication unit 120, a network communication unit 130, a storage unit 140, and a processing unit 150.

[0030] The first wireless communication unit 110 wirelessly transmits and receives signals. For example, the first wireless communication unit 110 receives signals from other devices and transmits signals to the other devices. For example, the other device is the base station 200.

[0031] The second wireless communication unit 120 wirelessly transmits and receives signals. For example, the second wireless communication unit 120 receives signals from other devices and transmits signals to the other devices. For example, the other device is the UE 30.

[0032] The network communication unit 130 receives signals from the network to which the relay node 100 is connected and transmits signals to the network. As an example, as shown in FIG. 2, the relay node 100 may be an in-vehicle device mounted on the vehicle 10, and the network may be an in-vehicle LAN (Local Area Network). In this case, in addition to the relay node 100, various sensors (for example, driving state sensors, etc.), various ECUs (for example, engine control ECU, driving assistance ECU, etc.), operation switches, and display devices, etc. may be connected to the network.

[0033] The memory unit 140 stores various information for the relay node 100.

[0034] The processing unit 150 provides various functions of the relay node 100. The processing unit 150 includes a first communication processing unit 151 and a second communication processing unit 153. Note that the processing unit 150 may further include other components other than these components. That is, the processing unit 150 may perform operations other than the operations of these components. The specific operations of the first communication processing unit 151 and the second communication processing unit 153 will be described in detail later.

[0035] For example, the processing unit 150 (specifically, the first communication processing unit 151) communicates with other devices (for example, the base station 200) via the first wireless communication unit 110. For example, the processing unit 150 (specifically, the second communication processing unit 153) communicates with other devices (for example, the UE 30) via the second wireless communication unit 120. For example, the processing unit 150 communicates with other devices connected to the network via the network communication unit 130.

[0036] Note that when the relay node 100 is not connected to the network, the relay node 100 may not include the network communication unit 130.

[0037] (2) Hardware configuration Next, with reference to FIG. 5, an example of the hardware configuration of the relay node 100 according to the embodiment of the present disclosure will be described. Referring to FIG. 5, the relay node 100 includes an antenna 181, an RF (Radio Frequency) circuit 183, an antenna 185, an RF circuit 187, a processor 189, a network interface 191, a memory 193, and a storage 195.

[0038] Each of antenna 181 and antenna 185 converts a signal into a radio wave and radiates the radio wave into space. Also, each of antenna 181 and antenna 185 receives a radio wave in space and converts the radio wave into a signal. Each of antenna 181 and antenna 185 may include a transmitting antenna and a receiving antenna, or may be a single antenna for transmission and reception. Each of antenna 181 and antenna 185 may be a directional antenna and may include a plurality of antenna elements.

[0039] RF circuit 183 performs analog processing of signals transmitted and received via antenna 181. RF circuit 187 performs analog processing of signals transmitted and received via antenna 185. Each of RF circuit 183 and RF circuit 187 may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, and the like.

[0040] Processor 189 performs digital processing of signals transmitted and received via antenna 181 and RF circuit 183. Also, processor 189 performs digital processing of signals transmitted and received via antenna 185 and RF circuit 187. Furthermore, processor 189 also processes signals transmitted and received via network interface 191. Processor 189 may include a plurality of processors or may be a single processor. The plurality of processors may include one or more baseband processors that perform the above digital processing and one or more processors that perform other processing.

[0041] Network interface 191 is, for example, a network adapter. Processor 189 communicates with a device connected to the network via network interface 191.

[0042] Memory 193 stores a program executed by processor 189, parameters related to the program, and various other information. Memory 193 may include at least one of ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Memory), and flash memory. All or part of Memory 193 may be included within processor 189.

[0043] Storage 195 stores various information. Storage 195 may include at least one of SSD (Solid State Drive) and HDD (Hard Disc Drive).

[0044] The first wireless communication unit 110 may be implemented by antenna 181 and RF circuit 183. The second wireless communication unit 120 may be implemented by antenna 185 and RF circuit 187. The network communication unit 130 may be implemented by network interface 191. The storage unit 140 may be implemented by storage 195. The processing unit 150 may be implemented by processor 189 and memory 193.

[0045] Note that when relay node 100 is not connected to the above network, relay node 100 may not be provided with network interface 191.

[0046] Considering the above hardware configuration, for example, the relay node 100 includes a memory for storing a program and one or more processors for executing the program to operate the first communication processing unit 151 and the second communication processing unit 153. For example, the memory is the memory 193, and the one or more processors are the processor 189. Note that the program is a program for causing a computer to execute the operations of the first communication processing unit 151 and the second communication processing unit 153.

[0047] <3. Configuration of Base Station> With reference to FIGS. 6 and 7, an example of the configuration of the base station 200 according to an embodiment of the present disclosure will be described.

[0048] (1) Functional Configuration First, with reference to FIG. 6, an example of the functional configuration of the base station 200 according to an embodiment of the present disclosure will be described. Referring to FIG. 6, the base station 200 includes a wireless communication unit 210, a network communication unit 220, a storage unit 230, and a processing unit 240.

[0049] The wireless communication unit 210 wirelessly transmits and receives signals. For example, the wireless communication unit 210 receives signals from the UE and transmits signals to the UE.

[0050] The network communication unit 220 receives signals from the network and transmits signals to the network.

[0051] The storage unit 230 stores various information for the base station 200.

[0052] The processing unit 240 provides various functions of the base station 200. The processing unit 240 includes a communication processing unit 241. Note that the processing unit 240 may further include other components other than the communication processing unit 241. That is, the processing unit 240 may perform operations other than the operations of the communication processing unit 241. The specific operations of the communication processing unit 241 will be described in detail later.

[0053] For example, the processing unit 240 (communication processing unit 241) communicates with a UE (e.g., UE40 or relay node 100) via the wireless communication unit 210. For example, the processing unit 240 communicates with other nodes (e.g., core network nodes) via the network communication unit 220.

[0054] (2) Hardware Configuration Next, with reference to FIG. 7, an example of the hardware configuration of the base station 200 according to an embodiment of the present disclosure will be described. Referring to FIG. 7, the base station 200 includes an antenna 281, an RF circuit 283, a network interface 285, a processor 287, a memory 289, and a storage 291.

[0055] The antenna 281 converts a signal into a radio wave and radiates the radio wave into space. Also, the antenna 281 receives a radio wave in space and converts the radio wave into a signal. The antenna 281 may include a transmitting antenna and a receiving antenna, or may be a single antenna for transmission and reception. The antenna 281 may be a directional antenna or may include a plurality of antenna elements.

[0056] The RF circuit 283 performs analog processing of signals transmitted and received via the antenna 281. The RF circuit 283 may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, and the like.

[0057] The network interface 285 is, for example, a network adapter, and transmits a signal to the network and receives a signal from the network.

[0058] The processor 287 performs digital processing of signals transmitted and received via the antenna 281 and the RF circuit 283. The processor 287 also processes signals transmitted and received via the network interface 285. The processor 287 may include a plurality of processors or may be a single processor. The plurality of processors may include a baseband processor that performs the above digital processing and one or more processors that perform other processing.

[0059] The memory 289 stores a program executed by the processor 287, parameters related to the program, and various other information. The memory 289 may include at least one of ROM, EPROM, EEPROM, RAM, and flash memory. All or part of the memory 289 may be included in the processor 287.

[0060] The storage 291 stores various information. The storage 291 may include at least one of SSD and HDD.

[0061] The wireless communication unit 210 may be implemented by the antenna 281 and the RF circuit 283. The network communication unit 220 may be implemented by the network interface 285. The storage unit 230 may be implemented by the storage 291. The processing unit 240 may be implemented by the processor 287 and the memory 289

[0062] Part or all of the processing unit 240 may be virtualized. In other words, part or all of the processing unit 240 may be implemented as a virtual machine. In this case, part or all of the processing unit 240 may operate as a virtual machine on a physical machine (i.e., hardware) including a processor and a memory, etc. and a hypervisor.

[0063] Considering the above hardware configuration, the base station 200 may include a memory (i.e., the memory 289) that stores a program, and one or more processors (i.e., the processor 287) capable of executing the program, and the one or more processors may execute the above program to perform the operation of the processing unit 240. The above program may be a program for causing the processor to execute the operation of the processing unit 240.

[0064] <4. Operation Example> With reference to FIGS. 8 to 19, an example of the operation of the relay node 100 and the base station 200 according to the embodiment of the present disclosure will be described.

[0065] The relay node 100 (the first communication processing unit 151) communicates with the base station 200 via the Uu interface as a UE. In other words, the base station 200 (the communication processing unit 241) communicates with the relay node 100 operating as a UE via the Uu interface.

[0066] Furthermore, the relay node 100 (the second communication processing unit 153) communicates with one or more UEs via the Uu interface as a base station. For example, the one or more UEs include UE30.

[0067] In particular, the relay node 100 (the first communication processing unit 151) communicates with the base station 200 via the inter-base station interface as a base station. In other words, the base station 200 (the communication processing unit 241) communicates with the relay node 100 operating as a base station via the inter-base station interface.

[0068] Thereby, for example, it becomes possible to perform a handover procedure for handover of a UE between the base station 200 and the relay node 100. More specifically, for example, the relay node 100 and the base station 200 can perform a normal handover procedure via the inter-base station interface.

[0069] For example, the inter-base station interface is an Xn interface.

[0070] (1) Setup of the inter-base station interface For example, the relay node 100 (the first communication processing unit 151) performs a setup procedure of the inter-base station interface with the base station 200 as a base station. In other words, the base station 200 (the communication processing unit 241) performs a setup procedure of the inter-base station interface with the relay node 100 operating as a base station. For example, the setup procedure is an Xn setup procedure.

[0071] As a result, for example, the relay node 100 can communicate with the base station 200 via an interface between base stations (e.g., the Xn interface).

[0072] - First example As a first example, the relay node 100 (the first communication processing unit 151) transmits, as a UE, information indicating that the UE is a relay node (hereinafter referred to as "relay indication information") to the base station 200, and the base station 200 (the communication processing unit 241) receives the relay indication information from the relay node 100 operating as a UE. The relay indication information may indicate that the UE is an MBSR, or may indicate that the UE is a vehicle-mounted relay. The relay node 100 (the first communication processing unit 151) may transmit the relay indication information to the base station 200 during or after the procedure for establishing a connection to the base station 200. Alternatively, the relay node 100 (the first communication processing unit 151) may transmit the relay indication information to the base station 200 in response to the generation of the first user data.

[0073] For example, the base station 200 (the communication processing unit 241) performs the setup procedure with the relay node 100 operating as a base station in response to the reception of the relay indication information. As described above, the setup procedure is an Xn setup procedure. Specifically, as shown in FIG. 8, the base station 200 (the communication processing unit 241) transmits an XN SETUP REQUEST message to the relay node 100 (S310), and the relay node 100 (the first communication processing unit 151) receives the XN SETUP REQUEST message from the base station 200. Further, the relay node 100 (the first communication processing unit 151) transmits an XN SETUP RESPONSE message to the base station 200 (S320), and the base station 200 (the communication processing unit 241) receives the XN SETUP RESPONSE message from the relay node 100.

[0074] In this way, the setup procedure of the base station interface (for example, Xn setup procedure) can be triggered by the relay indication information.

[0075] - Second example As a second example, the relay node 100 (the first communication processing unit 151) may start the setup procedure (for example, Xn setup procedure) by itself without transmitting the relay indication information.

[0076] Specifically, as shown in FIG. 9, the relay node 100 (the first communication processing unit 151) may transmit an XN SETUP REQUEST message to the base station 200 (S330), and the base station 200 (the communication processing unit 241) may receive the XN SETUP REQUEST message from the relay node 100. The base station 200 (the communication processing unit 241) may transmit an XN SETUP RESPONSE message to the relay node 100 (S340), and the relay node 100 (the first communication processing unit 151) may receive the XN SETUP RESPONSE message from the base station 200.

[0077] In this way, the setup procedure of the base station interface (for example, Xn setup procedure) can be started by the relay node 100.

[0078] (2) Protocol - Uu interface between relay node 100 and UE30 As shown in FIG. 10, for example, the user plane protocol stack of the Uu interface between the relay node 100 and the UE30 includes protocols of the SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and Physical (PHY) layer.

[0079] As shown in FIG. 11, for example, the control plane protocol stack of the Uu interface between relay node 100 and UE 30 includes protocols of the RRC (Radio Resource Control), PDCP, RLC, MAC, and PHY layers.

[0080] - The Uu interface between relay node 100 and base station 200 As shown in FIG. 12, for example, the user plane protocol stack of the Uu interface between relay node 100 and base station 200 includes protocols of the SDAP, PDCP, RLC, MAC, and PHY layers.

[0081] As shown in FIG. 13, for example, the control plane protocol stack of the Uu interface between relay node 100 and base station 200 includes protocols of the RRC, PDCP, RLC, MAC, and PHY layers.

[0082] - The interface between base stations between relay node 100 and base station 200 For example, the interface between base stations includes an interface between user planes of base stations and an interface between control planes of base stations. As described above, for example, the interface between base stations is an Xn interface, and the Xn interface includes an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface.

[0083] As shown in FIG. 14, for example, the protocol stack of the Xn-U interface between relay node 100 and base station 200 includes GTP-U (GTP Tunneling Protocol for User Plane), UDP (User Datagram Protocol), and IP (Internet Protocol). Further, the protocol stack includes an L1 / L2 protocol below IP. The L1 / L2 protocol is, for example, the user plane protocol stack of the Uu interface (see FIG. 12).

[0084] As shown in FIG. 15, for example, the protocol stack of the Xn-C interface between the relay node 100 and the base station 200 includes XnAP (Xn Application Protocol), SCTP (Stream Control Transmission Protocol), and IP. Further, the protocol stack includes an L1 / L2 protocol under IP. The L1 / L2 protocol is, for example, the user plane protocol stack of the Uu interface (see FIG. 12). Note that the above XnAP is defined in 3GPP TS 38.423 V16.4.0.

[0085] (3) Handover For example, the relay node 100 (the first communication processing unit 151) performs a handover procedure for the target UE between the base station 200 and the relay node 100 via the above base station interface (for example, the Xn interface). The base station 200 (the communication processing unit 241) also performs the above handover procedure via the above base station interface (for example, the Xn interface).

[0086] Thereby, for example, it becomes possible to switch the connection to the target UE between the relay node 100 and the base station 200.

[0087] - Handover from the relay node 100 to the base station 200 For example, a handover of the target UE from the relay node 100 to the base station 200 is performed. Referring to the example of FIG. 16, for example, the target UE is UE30, and a handover of UE30 from the relay node 100 to the base station 200 is performed.

[0088] Referring to FIG. 17, an example of a handover procedure for the above handover will be described. First, the UE 30 transmits a MeasurementReport message to the relay node 100 via the Uu interface (S410). The relay node 100 (the second communication processing unit 153), as a base station, determines a handover of the UE 30 from the relay node 100 to the base station 200 based on the information included in the measurement report message (S420). The relay node 100 (the first communication processing unit 151) transmits a HANDOVER REQUEST message requesting the handover to the base station 200 via the inter-base station interface (for example, the Xn interface) (S430). The base station 200 (the communication processing unit 241) receives the handover request message from the relay node 100 via the inter-base station interface (for example, the Xn interface). The base station 200 (the communication processing unit 241) performs admission control (S440) and transmits a HANDOVER REQUEST ACKNOWLEDGE message to the relay node 100 via the inter-base station interface (for example, the Xn interface) (S450). The relay node 100 (the first communication processing unit 151) receives the handover request acknowledgement message from the base station 200 via the inter-base station interface (for example, the Xn interface). Thereafter, the relay node 100 (the second communication processing unit 153), as a base station, transmits an RRCReconfiguration message to the UE 30 via the Uu interface (S460). Thereafter, the remaining processes of the handover procedure are performed.

[0089] Thereby, for example, it becomes possible to switch the connection to the target UE from the relay node 100 to the base station 200.

[0090] - Handover from the first base station to the second base station For example, a handover of a target UE from the base station 200 to the relay node 100 is performed. Referring to the example of FIG. 18, for example, the target UE is UE40, and a handover of UE40 from the base station 200 to the relay node 100 is performed.

[0091] Referring to FIG. 19, an example of a handover procedure for the above handover will be described. First, UE40 transmits a MeasurementReport message to the base station 200 via the Uu interface (S510). The base station 200 (communication processing unit 241) determines a handover of UE40 from the base station 200 to the relay node 100 based on the information included in the measurement report message (S520). The base station 200 (communication processing unit 241) transmits a HANDOVER REQUEST message requesting the handover to the relay node 100 via the inter-base-station interface (for example, the Xn interface) (S530). The relay node 100 (first communication processing unit 151) receives the handover request message from the base station 200 via the inter-base-station interface (for example, the Xn interface). The relay node 100 performs admission control (S540) and transmits a HANDOVER REQUEST ACKNOWLEDGE message to the base station 200 via the inter-base-station interface (for example, the Xn interface) (S550). The base station 200 (communication processing unit 241) receives the handover request acknowledgment message from the relay node 100 via the inter-base-station interface (for example, the Xn interface). Thereafter, the base station 200 (communication processing unit 241) transmits an RRCReconfiguration message to UE40 via the Uu interface (S560). Thereafter, the remaining processing of the handover procedure is performed.

[0092] Thereby, for example, it becomes possible to switch the connection to the target UE from the base station 200 to the relay node 100.

[0093] <5. Modification Example> The first to third modification examples according to the embodiments of the present disclosure will be described. Note that two or more of the first to third modification examples may be combined.

[0094] (1) First Modification Example In the above example of the embodiment of the present disclosure, the base station - to - base station interface is the Xn interface. However, the base station - to - base station interface according to the embodiment of the present disclosure is not limited to this example.

[0095] In the 1 modification example of the embodiment of the present disclosure, the base station - to - base station interface may be an interface with another name instead of the "Xn interface". As an example, the base station - to - base station interface may be called the Z1 interface or the Zn interface.

[0096] Although the base station - to - base station interface is called by the above other name, the protocol stack of the base station - to - base station interface may include the protocols shown in FIGS. 14 and 15 similar to the Xn interface. The base station - to - base station control plane interface may include a control protocol including procedures similar to XnAP instead of XnAP. The control protocol may include a setup procedure of the base station - to - base station interface and a handover procedure. The setup procedure may include the transmission and reception of a setup request message and the transmission and reception of a setup response message, similar to the examples in FIGS. 8 and 9. The handover procedure may include the transmission and reception of a handover request message and the transmission and reception of a handover request confirmation message, similar to the examples in FIGS. 17 and 19.

[0097] (2) Second Modification Example In the above example of the embodiment of the present disclosure, the relay node 100 is a device that can be mounted on a mobile body. Further, for example, the mobile body is a vehicle, and the relay node 100 is an in - vehicle device. However, the relay node 100 according to the embodiment of the present disclosure is not limited to this example.

[0098] In the second modification example of the embodiment of the present disclosure, the relay node 100 may be a device other than the in-vehicle device.

[0099] The relay node 100 may not be a device mountable on the moving body, but may be a communication module included in the device, or may be the moving body (for example, a vehicle) itself including the device.

[0100] The above-mentioned moving body may be other than a vehicle, and may be, for example, an aircraft.

[0101] (3) Third modification example In the above-described example of the embodiment of the present disclosure, the system 1 is a system compliant with the 5G or NR TS. However, the system 1 according to the embodiment of the present disclosure is not limited to this example.

[0102] In the third modification example of the embodiment of the present disclosure, the system 1 may be a system compliant with the next-generation (for example, 6G) TS. In this case, the Uu interface according to the third modification example may mean the interface between the base station and the UE in the next generation, and the base station-to-base station interface according to the third modification example may mean the interface between the base stations in the next generation. The setup procedure of the base station-to-base station interface according to the third modification example may also mean the setup procedure of the base station-to-base station interface in the next generation.

[0103] As described above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the embodiments. It will be understood by those skilled in the art that the embodiments are merely illustrative and that various modifications can be made without departing from the scope and spirit of the present disclosure.

[0104] For example, the steps in the processes described in this specification do not necessarily have to be executed in chronological order according to the order described in the flowchart or sequence diagram. For example, the steps in the process may be executed in an order different from the order described as a flowchart or sequence diagram, or may be executed in parallel. Also, some of the steps in the process may be deleted, or additional steps may be added to the process.

[0105] For example, a method may be provided that includes the operations of one or more components of the apparatus described in this specification, and a program may be provided for causing a computer to execute the operations of the above components. Also, a non-transitory tangible computer-readable storage medium recording the program may be provided. Naturally, such a method, program, and non-transitory tangible computer-readable storage medium are also included in the present disclosure.

[0106] For example, in the present disclosure, a user equipment (UE) may be referred to by another name such as a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, or a remote unit.

[0107] For example, in the present disclosure, "transmit" may mean performing processing on at least one layer within the protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or by wire. Alternatively, "transmit" may mean a combination of performing processing on the at least one layer and physically transmitting a signal wirelessly or by wire. Similarly, "receive" may mean performing processing on at least one layer within the protocol stack used for reception, or may mean physically receiving a signal wirelessly or by wire. Alternatively, "receive" may mean a combination of performing processing on the at least one layer and physically receiving a signal wirelessly or by wire. The at least one layer may be equivalently referred to as at least one protocol.

[0108] For example, in the present disclosure, "obtain / acquire" may mean obtaining information from stored information, may mean obtaining information from information received from other nodes, or may mean obtaining the information by generating the information.

[0109] For example, in the present disclosure, "include" and "comprise" do not mean including only the recited items, and may mean including only the recited items or may mean including additional items in addition to the recited items.

[0110] For example, in the present disclosure, "or" does not mean exclusive disjunction and means inclusive disjunction.

[0111] Note that the technical features included in the above-described embodiments may be expressed as the following features. Of course, the present disclosure is not limited to the following features.

[0112] (Feature 1) A relay node (100), A first communication processing unit (151) that communicates with a first base station (200) via a Uu interface as a user equipment; A second communication processing unit (153) that communicates with one or more user equipments (30) via a Uu interface as a second base station; Comprising; The first communication processing unit communicates with the first base station via a base station interface as the second base station. Relay node.

[0113] (Feature 2) The first communication processing unit performs a setup procedure of the base station interface between the first base station as the second base station. The relay node according to Feature 1.

[0114] (Feature 3) The base station interface is an Xn interface, The first communication processing unit transmits an XN SETUP REQUEST message to the first base station and receives an XN SETUP RESPONSE message from the first base station. The relay node according to Feature 2.

[0115] (Feature 4) The base station interface is an Xn interface, The first communication processing unit receives an XN SETUP REQUEST message from the first base station and transmits an XN SETUP RESPONSE message to the first base station. The relay node according to Feature 2.

[0116] (Feature 5) The first communication processing unit transmits, as the user equipment, information indicating that the user equipment is a relay node to the first base station. The relay node according to any one of Features 1 to 4.

[0117] (Feature 6) The first communication processing unit performs a handover procedure for handover of a target user equipment between the first base station and the relay node via the inter-base station interface, the relay node according to any one of Features 1 to 5.

[0118] (Feature 7) The first communication processing unit transmits, to the first base station via the inter-base station interface, a handover request message for requesting handover of a target user equipment (30) from the relay node to the first base station, the relay node according to any one of Features 1 to 6.

[0119] (Feature 8) The second communication processing unit determines the handover as the second base station, the relay node according to Feature 7.

[0120] (Feature 9) The first communication processing unit receives, from the first base station via the inter-base station interface, a handover request message for requesting handover of a target user equipment (40) from the first base station to the relay node, and transmits, to the first base station via the inter-base station interface, a handover request confirmation message, the relay node according to any one of Features 1 to 8.

[0121] (Feature 10) The relay node is a mobile body, a device mountable on a mobile body, or a communication module included in a device mountable on a mobile body, the relay node according to any one of Features 1 to 9.

[0122] (Feature 11) The mobile body is a vehicle, the relay node according to Feature 10.

[0123] (Feature 12) A first base station (200), A communication processing unit (241) that communicates with the first base station via a Uu interface as a user equipment and communicates with a relay node (100) that communicates with one or more user equipments (30) via the Uu interface as a second base station, comprising: The communication processing unit communicates with the relay node operating as the user equipment via the Uu interface and communicates with the relay node operating as the second base station via an inter-base station interface. A first base station.

[0124] (Feature 13) The communication processing unit performs a setup procedure for the inter-base station interface with the relay node operating as the second base station. The first base station according to Feature 12.

[0125] (Feature 14) The communication processing unit receives information indicating that the user equipment is a relay node from the relay node operating as the user equipment, and in response to the reception of the information, performs the setup procedure with the relay node operating as the second base station. The first base station according to Feature 13.

[0126] (Feature 15) The communication processing unit performs a handover procedure for handover of a target user equipment between the first base station and the relay node via the inter-base station interface. The first base station according to any one of Features 12 to 14.

[0127] (Feature 16) The communication processing unit receives a handover request message for requesting handover of a target user equipment (30) from the relay node to the first base station from the relay node via the inter-base station interface, and transmits a handover request confirmation message to the relay node via the inter-base station interface. The first base station according to any one of Features 12 to 15.

[0128] (Feature 17) The communication processing unit transmits a handover request message for requesting a handover of a target user equipment (40) from the first base station to the relay node to the relay node via an interface between base stations, and the first base station according to any one of Features 12 to 16.

[0129] (Feature 18) A method performed by a relay node (100), communicating with a first base station (200) via a Uu interface as a user equipment, communicating with one or more user equipments (30) via a Uu interface as a second base station, communicating with the first base station via an interface between base stations as the second base station, and including.

[0130] (Feature 19) A method performed by a first base station (200), communicating with the relay node (100) that communicates with the first base station via a Uu interface as a user equipment and communicates with one or more user equipments (30) via a Uu interface as a second base station, including, communicating with the relay node communicating with the relay node operating as the user equipment via a Uu interface, communicating with the relay node operating as the second base station via an interface between base stations, and including method.

[0131] (Feature 20) communicating with a first base station (200) via a Uu interface as a user equipment, communicating with one or more user equipments (30) via a Uu interface as a second base station, communicating with the first base station via a base station interface as the second base station; A program for causing a computer to execute.

[0132] (Feature 21) communicating with a relay node (100) that communicates with a first base station (200) via a Uu interface as a user equipment and communicates with one or more user equipments (30) via a Uu interface as a second base station; A program for causing a computer to execute, wherein communicating with the relay node includes communicating with the relay node operating as the user equipment via a Uu interface, and communicating with the relay node operating as the second base station via a base station interface; including Program.

[0133] (Feature 22) communicating with a first base station (200) via a Uu interface as a user equipment; communicating with one or more user equipments (30) via a Uu interface as a second base station; communicating with the first base station via a base station interface as the second base station; A computer-readable non-transitory tangible recording medium recording a program for causing a computer to execute.

[0134] (Feature 23) communicating with a relay node (100) that communicates with a first base station (200) via a Uu interface as a user equipment and communicates with one or more user equipments (30) via a Uu interface as a second base station; A computer-readable non-transitory tangible recording medium recording a program for causing a computer to execute, wherein communicating with the relay node Communicating with the relay node operating as the user equipment via a Uu interface; Communicating with the relay node operating as the second base station via an interface between base stations; including a computer-readable non-transitory tangible recording medium.

Explanation of Signs

[0135] 1 System 10 Vehicle 10 30, 40 UE 100 Relay Node 151 First Communication Processing Unit 153 Second Communication Processing Unit 200 Base Station 241 Communication Processing Unit

Claims

1. A mobile relay node (100), comprising: a first communication processing unit (151) that communicates with a first base station (200) via a Uu interface as a user equipment; a second communication processing unit (153) that communicates with one or more user equipments (30) via a Uu interface as a second base station; wherein a handover procedure for a target user equipment between the mobile relay node and each base station is performed via an Xn interface, a setup procedure of the Xn interface is performed, the setup procedure includes transmission of an XN SETUP REQUEST message and reception of an XN SETUP RESPONSE message, the first communication processing unit transmits, as the user equipment, information indicating that the user equipment is a relay node to the first base station, and performs, as the second base station, the setup procedure of the Xn interface by the first base station in response to reception of the information; A mobile relay node.

2. The mobile relay node according to claim 1, wherein the handover includes a handover of a target user equipment (30) from the mobile relay node.

3. The mobile relay node according to claim 2, wherein the handover procedure includes transmitting, via the Xn interface, a handover request message for requesting a handover of a target user equipment (30) from the mobile relay node.

4. The mobile relay node according to any one of claims 1 to 3, wherein the handover includes a handover of a target user equipment (40) to the mobile relay node.

5. The mobile relay node according to claim 4, wherein the handover procedure includes receiving, via the Xn interface, a handover request message for requesting a handover of a target user equipment (40) to the mobile relay node, and transmitting, via the Xn interface, a handover request confirmation message.

6. The mobile relay node according to any one of claims 1 to 3, wherein the mobile relay node is a mobile body, a device mountable on a mobile body, or a communication module included in a device mountable on a mobile body.

7. The mobile relay node according to claim 6, wherein the mobile body is a vehicle.

8. A first base station (200), A communication processing unit (241) that communicates with the mobile relay node (100) which communicates with the first base station via a Uu interface as a user equipment and communicates with one or more user equipments (30) via the Uu interface as a second base station, Comprising: The communication processing unit performs a handover procedure for handover of a target user equipment (30) from the mobile relay node or handover of a target user equipment (40) to the mobile relay node via an Xn interface, The communication processing unit receives information indicating that the user equipment is a relay node from the mobile relay node operating as the user equipment, and performs a setup procedure of the Xn interface in response to the reception of the information, The setup procedure includes reception of an XN SETUP REQUEST message and transmission of an XN SETUP RESPONSE message, The first base station.

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