Relay device, base station device, and relay method

Abstract

This relay device that relays signals received from a base station device to a terminal device includes a control unit that determines, in accordance with support information indicating whether or not a first base station device has a control function of the relay device, whether or not to implement relay processing of a first signal transmitted by the first base station device under control of the first base station device, and a relay unit that implements the relay processing under control of the first base station device in a case of the control unit determining to implement the relay processing under control of the first base station device.

Description

Relay device, base station device, and relay method

[0001] The present invention relates to a relay device, a base station device, and a relay method.

[0002] In a wireless communication system, wireless communication is achieved by, for example, a terminal device receiving a signal (radio wave) transmitted from a base station device. However, depending on the location of the terminal device, the radio wave from the base station device may not reach the terminal device (the terminal device may not be able to receive the radio wave). To address this issue, there are relay devices known as repeaters that amplify and transmit the radio wave received from the base station device. By installing a repeater, users can transmit amplified radio wave to blind zones where radio waves cannot reach, such as in the shadows of buildings or objects or when located far from the base station device, thereby reducing the areas where wireless communication is not possible for terminal devices.

[0003] However, repeaters simply amplify radio waves and cannot perform beamforming in the direction of a terminal device or transmission control of the amplified radio waves. Therefore, a network controlled repeater (NCR), which is a high-performance repeater that has a control function from a base station device and a beamforming function, is being considered in Rel-18 of 3GPP (registered trademark) (Third Generation Partnership Project).

[0004] Techniques relating to repeaters and NCRs are described in the following prior art documents.

[0005] 3GPP TS36.133 LTE-A Radio Measurement Specification 3GPP TS36.300 LTE-A Overview Specification 3GPP TS36.211 LTE-A PHY Channel Specification 3GPP TS36.212 LTE-A PHY Coding Specification 3GPP TS36.213 LTE-A PHY Procedure Specification 3GPP TS36.214 LTE-A PHY Measurement Specification 3GPP TS36.321 LTE-A MAC Specification 3GPP TS36.322 LTE-A RLC Specification 3GPP TS36.323 LTE-A PDCP Specification 3GPP TS36.331 LTE-A RRC Specification 3GPP TS36.413 LTE-A S1 Specification 3GPP TS36.423 LTE-A X2 Specification 3GPP TS36.425 LTE-A Xn Specification 3GPP TR36.912 NR Radio Access Overview 3GPP TR38.913 NR Requirements 3GPP TR38.913 NR Requirements 3GPP TR38.801 NR Network Architecture Overview 3GPP TR38.802 NR PHY Overview 3GPP TR38.803 NR RF Overview 3GPP TR38.804 NR L2 Overview 3GPP TR38.900 NR Radio Frequency Overview 3GPP TS38.300 NR Overview Specification 3GPP TS37.340 NR Multiple Access Overview Specification 3GPP TS38.201 NR PHY Overview Specification 3GPP TS38.202 NR PHY Service Overview Specification 3GPP TS38.211 NR PHY Channel Specification 3GPP TS38.212 NR PHY Coding Specification 3GPP TS38.213 NR PHY Data Channel Procedure Specification 3GPP TS38.214 NR PHY Control Channel Procedures Specification 3GPP TS38.215 NR PHY Measurement Specification 3GPP TS38.321 NR MAC Specification 3GPP TS38.322 NR RLC Specification 3GPP TS38.323 NR PDCP Specification 3GPP TS37.324 NR SDAP Specification 3GPP TS38.331 NR RRC Specification 3GPP TS38.401 NR Architecture Overview Specification 3GPP TS38.410 NR Core Network Overview Specification 3GPP TS38.413 NR Core Network AP Specification 3GPP TS38.420 NR Xn Interface Overview Specification 3GPP TS38.423 NR XnAP specification 3GPP TS38.470 NR F1 interface overview specification 3GPP TS38.473 NR F1AP specification RP-213700.

[0006] However, NCR is still under consideration, and the details of the processing have not yet been determined. In particular, when base station devices that do not support NCR control coexist with base station devices that do, it has not yet been determined which cell (base station device) the NCR will select and amplify.

[0007] Therefore, one disclosure provides a relay device, a base station device, and a relay method that can appropriately select cells to be amplified by NCR in a communication system that includes a mixture of base station devices that are both compatible and incompatible with NCR control.

[0008] A relay device that relays a signal received from a base station device to a terminal device, comprising: a control unit that determines whether to perform relay processing of a first signal transmitted by a first base station device under the control of the first base station device, depending on support information indicating whether the first base station device has a control function for the relay device; and a relay unit that performs relay processing under the control of the first base station device when the control unit determines that relay processing under the control of the first base station device should be performed.

[0009] One disclosure enables NCR to appropriately select cells to be amplified in a communication system in which base station devices that are both compatible and incompatible with NCR control exist.

[0010] FIG. 1 is a diagram illustrating an example of wireless communication in a wireless communication system 10. FIG. 2 is a diagram illustrating an example of the software configuration of a relay device 300 in the wireless communication system 10. FIG. 3 is a diagram illustrating an example of the configuration of the relay device 300. FIG. 4 is a diagram illustrating an example of the configuration of a base station device 200. FIG. 5 is a diagram illustrating an example of a sequence of relay processing in the relay device 300. FIG. 6 is a diagram illustrating an example of a sequence of relay processing in the relay device 300. FIG. 7 is a diagram illustrating an example of a sequence of relay processing in the relay device 300. FIG. 8 is a diagram illustrating an example of a sequence of relay processing in the relay device 300. FIG. 9 is a diagram illustrating an example of a change in TS 38.304 content. FIG. 10 is a diagram illustrating an example of a change in TS 38.304 content. FIG. 11 is a diagram illustrating an example of a change in TS 38.331 content. FIG. 12 is a diagram illustrating an example of a change in TS 38.331 content.

[0011] [First Embodiment] A first embodiment will be described.

[0012] 1 is a diagram showing an example of the configuration of a wireless communication system 10. The wireless communication system 10 includes a base station device 200, a base station device 201, a relay device 300, and a terminal device 100.

[0013] The terminal device 100 is a communication device, such as a smartphone or tablet terminal, that wirelessly connects to the base station device 200 and the base station device 201 and transmits and receives data. The terminal device 100 also wirelessly connects to the relay device 300 and communicates with the base station device 200 and the base station device 201 via the relay device 300.

[0014] The base station device 200 and the base station device 201 are devices that are wirelessly connected to the terminal device 100 and perform wireless communication, and are, for example, eNodeBs or gNodeBs. The base station device 200 and the base station device 201 support, for example, various communication generations (for example, 4G, 5G, and Beyond 5G). Furthermore, the base station device 200 and the base station device 201 may be configured as a single device, or may be configured as multiple devices such as a CU (Central Unit) and a DU (Distributed Unit).

[0015] Base station device 200 and base station device 201 are equipped with different versions of applications. Base station device 200 is equipped with a version (new version) of an application that is compatible with the control of relay device 300. On the other hand, base station device 201 is equipped with a version (old version) of an application that is not compatible with the control of relay device 300. In other words, wireless communication system 10 is a communication system in which base station devices 200 and 201 of both new and old versions coexist.

[0016] The relay device 300 is a device that receives radio waves from the base station device 200 and the base station device 201 and transmits the amplified radio waves using beamforming, such as an NCR. The relay device 300 is controlled by the base station device 200 as to whether to relay, as well as the direction and strength of beamforming. When receiving radio waves transmitted from multiple base station devices 200 and 201, the relay device 300 determines whether to relay the radio waves for each of the multiple base station devices 200 and 201. Note that the radio waves (signals) that the relay device 300 can amplify may be compatible with multiple base station devices 200 and 201, but in this embodiment, it is assumed that the relay device 300 can amplify only one base station device 200 or 201.

[0017] 2 is a diagram illustrating an example of the software configuration of the relay device 300 in the wireless communication system 10. The relay device 300 includes an NCR-MT (Mobile Termination) 301 and an NCR-Fwd (Forwarding) 302.

[0018] The NCR-MT 301 is a control unit that wirelessly communicates with the base station device 200 via a control link L1, enabling transmission and reception of side control information and the like. The control link L1 uses, for example, an NR (New Radio) Uu interface. The side control information includes, for example, information related to the control of the NCR-Fwd 302 described below.

[0019] The NCR-Fwd 302 is a relay unit that amplifies and forwards signals (radio waves) between the base station device 200 and the terminal device 100 via a backhaul link L2 and an access link L3. The NCR-Fwd 302 determines processing in accordance with side control information received from the base station device 200. Note that forwarding includes amplifying signals received from the base station device 200 and transmitting them to the terminal device 100, and amplifying signals received from the terminal device 100 and transmitting them to the base station device 200.

[0020] Hereinafter, relaying includes relaying in the control mode and relaying in the independent mode, and further includes processing such as signal amplification, beamforming, and signal forwarding.

[0021] 3 is a diagram showing an example of the configuration of the relay device 300. The relay device 300 includes a CPU (Central Processing Unit) 310, a storage 320, a memory 330, a wireless communication circuit 350, and a wireless communication circuit 351.

[0022] The storage 320 is an auxiliary storage device that stores programs and data, such as a flash memory, a hard disk drive (HDD), or a solid state drive (SSD). The storage 320 stores a relay program 321.

[0023] The memory 330 is an area into which the programs stored in the storage 320 are loaded. The memory 330 may also be used as an area in which the programs store data.

[0024] The wireless communication circuit 350 is a device that performs wireless communication with the base station device 200 and the base station device 201. The relay device 300 transmits and receives signals to and from the base station device 200 and the base station device 201 via the wireless communication circuit 350.

[0025] The wireless communication circuit 351 is a device that performs wireless communication with the terminal device 100 and the base station device 201. The relay device 300 transmits and receives signals to and from the terminal device 100 via the wireless communication circuit 350. The wireless communication circuit 351 has, for example, a directional antenna that can control the direction of transmission and reception of radio waves. The wireless communication circuit 351 can, for example, transmit signals at a radio wave intensity specified by a control unit and perform beamforming that specifies the transmission direction.

[0026] The CPU 310 is a processor that loads programs stored in the storage 320 into the memory 330, executes the loaded programs, configures each unit, and realizes each process.

[0027] The CPU 310 executes the relay program 321 to configure a control unit and a relay unit and perform relay processing. The relay processing is processing for receiving signals from the base station device 200 and the base station device 201 and relaying (amplifying and transferring) the signals. The relay processing includes determining whether or not to perform relay processing. The relay processing also includes relay processing in an independent mode and relay processing in a controlled mode. Details of the independent mode and the controlled mode will be described later.

[0028] The CPU 310 configures a relay unit and performs the independent mode process by executing the independent mode module 3211 included in the relay program 321. The independent mode process is a process for performing relay in the independent mode.

[0029] The CPU 310 configures a relay unit and performs control mode processing by executing the control mode module 3212 of the relay program 321. The control mode processing is processing for performing relay in control mode.

[0030] 4 is a diagram illustrating an example of the configuration of the base station device 200. The base station device 200 includes a CPU 210, a storage 220, a memory 230, and a wireless communication circuit 250.

[0031] The storage 220 is an auxiliary storage device such as a flash memory, HDD, or SSD that stores programs and data. The storage 220 stores a wireless communication program 221 and a relay control program 222.

[0032] The memory 230 is an area into which the programs stored in the storage 220 are loaded. The memory 230 may also be used as an area in which the programs store data.

[0033] The wireless communication circuit 250 is a device that performs wireless communication with the terminal device 100. The wireless communication circuit 250 may also perform wireless communication with the relay device 300.

[0034] The CPU 210 is a processor that loads programs stored in the storage 220 into the memory 230, executes the loaded programs, configures each unit, and realizes each process.

[0035] The CPU 210 establishes a communication unit and performs communication processing by executing the wireless communication program 221. The base station communication processing is processing for performing wireless communication with the terminal device 100 and the relay device 300. In the base station communication processing, the base station device 200 wirelessly connects with the terminal device 100 and the relay device 300, and transmits and receives signals to destinations.

[0036] The CPU 210 executes the relay control program 222 to establish a relay control unit and perform relay control processing. The relay control processing is processing for controlling the relay processing performed by the relay device 300. In the relay control processing, the base station device 200 notifies (transmits) to the relay device 300 information on whether the base station device 200 has a control function for the relay device 300, side link control information, and the like.

[0037] <Relay Processing> The relay processing will be described. The relay processing is a process in which, when a signal is received from the base station device 200 or the base station device 201, a determination is made as to whether or not to camp on the signal, and whether or not to perform forwarding according to the determination. Camping on indicates, for example, establishing a control link L1 with the base station device in order to perform forwarding with control. The determination to camp on a certain base station device may be considered as a determination to perform cell selection (cell reselection) to the certain base station device. When the relay device 300 does not establish the control link L1 and performs forwarding without control, the relay device 300 does not camp on the base station device.

[0038] Hereinafter, processing sequences will be described for the cases where the base station device has a control function for relay device 300 and where it does not have such a function.

[0039] 5 is a diagram showing an example of a sequence of relay processing in relay device 300. In FIG. 5, relay device 300 receives a signal from base station device 200 that has a control function for relay device 300.

[0040] The base station device 200 transmits SIB (System Information Block) 1 (S100). The SIB is information broadcast to, for example, a certain base station device 200 or a terminal device 100 under a certain cell. The SIB is transmitted, for example, using a PDSCH (Physical Downlink Shared Channel). The SIB 1 includes, for example, NCR support information (ncr-Support) indicating whether or not the relay device 300 has a control function, and access control information.

[0041] Note that base station device 200 may notify that it has (or does not have) the control function of relay device 300 by a method other than transmitting SIB1. For example, base station device 200 may notify that it has the control function of relay device 300 by using other broadcast information or other message. Furthermore, relay device 300 may, for example, recognize in advance which base station device has the control function of relay device 300 and determine this based on the base station device identifier included in the signal.

[0042] When the NCR support information is true, it indicates that the base station device has the control function of the relay device 300. In FIG. 5, "ncr-Support = true" indicates that the base station device 200 has the control function of the relay device 300.

[0043] If ncr-Support is not present or if ncr-Support is set to a value other than true (for example, false), this indicates that the base station does not have the function of controlling relay device 300.

[0044] The access control information includes information related to access, such as whether access to the base station device is permitted or not (permitted or not permitted), access conditions, etc. The access restriction information includes, for example, the following parameters:

[0045] cellBarred: parameter related to access prohibition to the cell. If it is Barred, it indicates that access to the cell is prohibited.

[0046] cellReservedForOperatorUse: Parameter related to reservation by operator. If it is Reserved, it indicates that access by general users to the cell is prohibited.

[0047] cellReservedForFutureUse: A parameter related to the reservation of use of the cell. If true, it indicates that access to the cell is prohibited.

[0048] intraFreqReselection: Parameter related to permission to select the cell. If "notAllowed", it indicates that access to the cell is prohibited.

[0049] The access control information also includes, for example, restrictions based on CAG-IDs and NIDs broadcast by the cell. Furthermore, the access control information also includes, for example, information regarding the cell status being future use (indicating that the cell is expected to be used in the future but is currently unavailable).

[0050] Furthermore, the relay device 300 does not need to apply restrictions based on UAC (Unified Access Control).

[0051] The NCR-MT 301 of the relay device 300 receives the SIB1 (S100) and determines whether to camp on the base station device 200 or not.

[0052] For example, the NCR-MT 301 determines to camp on the base station device 200 based only on the NCR support information, regardless of the access restriction information (even if the cell is access-prohibited). If ncr-Support is true, the NCR-MT 301 determines to camp on the base station device 200. Furthermore, if ncr-Support is false, the relay device 300 determines not to camp on the base station device 200.

[0053] Furthermore, if access is not prohibited by the access restriction information and the NCR support information is true, the NCR-MT 301 may determine to camp on the base station device 200 .

[0054] 5, since the NCR support information is true, the NCR-MT 301 determines to camp on the base station device 200. Note that the sequence when the NCR-MT 301 determines not to camp on the base station device 200 having the control function is the same as the sequence in the case of the base station device 201 not having the control function, which will be described below.

[0055] When the NCR-MT 301 determines to camp on the base station device 200, it performs RACH processing (S101). The RACH processing is a process performed by the relay device 300 to synchronize with the base station device 200, and is also called a RACH procedure (Random Access CHannel procedure). By performing the RACH processing S101, the NCR-MT 301 establishes a control link L1.

[0056] In the RACH process S101, the NCR-MT 301 notifies the base station apparatus 200 that it is the relay apparatus 300.

[0057] For example, if NCR-MT301 enters the RRC_CONNECTED state (RRC is connected) but does not establish SRB1 (Signaling Radio Bearer: for example, used to transmit RRC messages using DCCH (Dedicate control Channel)), it notifies in the following manner.

[0058] - Notify in RACH preamble (RACH partitioning).

[0059] ・Notify by establishment cause.

[0060] - By setting the upper 39 bits of the 5G-S-TMSI used by the RP to a fixed value, it is indicated that it is a relay device 300.

[0061] In addition, if NCR-MT301 enters the RRC_CONNECTED state but does not establish SRB1 and detects a Radio Link Failure (RLF), it will transition, for example, from the RRC_CONNECTED state to the RRC_IDLE state (a state in which RRC is not connected) and then transition again to the RRC_CONNECTED state.

[0062] Furthermore, when NCR-MT301 establishes SRB1 but does not configure security, it notifies in the following manner in addition to the three methods described above.

[0063] - Notify with RRCSetupComplete message.

[0064] The RRCSetupComplete message may include the capability of the relay device 300. The capability of the relay device 300 may include, for example, frequency bands supported by the relay device 300, a combination of frequency bands, an uplink setting (from the relay device 300 to the base station device 200), a downlink setting (from the base station device 200 to the relay device 300), a physical layer setting, and the like.

[0065] Furthermore, when NCR-MT301 establishes SRB1 but does not configure security, if it detects a radio link failure, it transitions, for example, from the RRC_CONNECTED state to the RRC_IDLE state, and then transitions again to the RRC_CONNECTED state.

[0066] In addition, if NCR-MT301 establishes SRB1 and also performs security settings, but does not establish either or both of SRB2 and DRB (Data Radio Bearer), it notifies using the following method in addition to the four methods described above.

[0067] ・Notify via UE capability.

[0068] The UE capability may include the capabilities of the relay device 300 described above.

[0069] In the sequence of FIG. 5, the NCR-MT 301 notifies that it is the relay device 300 in the RACH preamble in the RACH processing S101.

[0070] In the RACH processing S101, when the base station device 200 recognizes that the other device in the RACH processing is the relay device 300, the base station device 200 starts controlling the relay device 300. The base station device 200 transmits side control information to the relay device 300 (S102). The side link control information is transmitted over the control link L1 established in the RACH processing S101, for example, over the PDCCH. The side link control information also includes, for example, information on the symbol interval for transmitting SSB, a beam ID (identifier), information on the interval for turning off reception, and information on beamforming. The side link control information is an example of a control signal for controlling the relay processing of the relay device 300.

[0071] When the NCR-MT 301 receives the side link control information (S102), it transmits a transfer start instruction to the NCR-Fwd 302 in accordance with the side link control information (S103). The transfer start instruction includes an instruction to start transfer in control mode. The control mode is a mode in which the NCR-MT 301 controls the NCR-Fwd 302, and the NCR-MT 301 issues instructions such as the amplification, transmission direction, and transmission timing of received signals.

[0072] When the NCR-Fwd 302 receives the transfer start instruction (control mode) (S 103 ), it starts transferring the signal of the base station device 200 under the control of the NCR-MT 301 .

[0073] The base station device 200 transmits the side link control information to the relay device 300 at a predetermined timing (S104). The predetermined timing is, for example, the time of data transmission (immediately before transmission). The side link information includes, for example, information on beamforming and amplification of the data signal to be transmitted. Upon receiving the side link control information (S104), the NCR-MT 301 controls the NCR-Fwd 302 in accordance with the side link control information.

[0074] When the NCR-Fwd 302 receives a data signal from the base station device 200 (S105), it amplifies and beamforms the data signal in accordance with instructions from the NCR-MT 301, and transmits the data signal to the terminal device 100 (S106).

[0075] 2. Base Station Device 201 Without Control Function 2.1 Forwarding Process in Standalone Mode Fig. 6 is a diagram showing an example of the sequence of relaying process in relay device 300. In Fig. 6, relay device 300 receives a signal from base station device 201 without the control function of relay device 300.

[0076] The base station device 200 transmits SIB1 (S200). The SIB1 transmitted by the base station device 201 does not include NCR support information. That is, the base station device 201 does not have a function for controlling the relay device 300.

[0077] The NCR-MT 301 of the relay device 300 receives the SIB1 (S200) and determines not to camp on the base station device 201. If the NCR-MT 301 determines not to camp on, it transmits a transfer start instruction to the NCR-Fwd 302 to transfer the signal of the base station device 201 in the standalone mode (S201). The standalone mode is a mode in which the relay device 300 amplifies and transfers signals without being controlled by the base station device.

[0078] The autonomous mode is, for example, a mode in which beamforming is not performed and only one beam from the base station device 200 is forwarded. The relay device 300 does not receive instructions from the base station device 200 and performs beam control using a method unique to the relay device 300.

[0079] 6, the relay device 300 performs relay processing in the standalone mode for the base station device that it has determined not to camp on. However, the relay device 300 may not perform relay processing (amplification and forwarding) for the base station device that it has determined not to camp on, and may discard signals that it subsequently receives.

[0080] When the NCR-Fwd 302 receives a data signal from the base station device 201 (S202), it amplifies the data signal and transmits the data signal to the terminal device 100 (S202). Note that the NCR-Fwd 302 performs relay processing in the autonomous mode, and therefore does not perform processing associated with control functions such as beamforming.

[0081] 2.2 Forwarding Process in Standalone Mode (with Timing Information) Figure 7 is a diagram showing an example of the sequence of relaying process in relay device 300. In Figure 7, relay device 300 receives a signal from base station device 200, which has the control function of relay device 300. Furthermore, relay device 300 performs RACH processing to acquire the reception timing of the signal. By acquiring the reception timing, it becomes possible to perform intermittent reception, thereby realizing power saving.

[0082] The base station device 201 transmits SIB1 (S300). The SIB1 transmitted by the base station device 201 does not include NCR support information. That is, the base station device 201 does not have a function for controlling the relay device 300.

[0083] The NCR-MT 301 of the relay device 300 receives the SIB1 (S300) and determines not to camp on the base station device 201. If the NCR-MT 301 determines not to camp on, it performs RACH processing (S301) and acquires the signal reception timing.

[0084] When the NCR-MT 301 acquires the reception timing, it includes it in timing information and transmits it to the NCR-Fwd 302 (S302). Then, the NCR-MT 301 transmits a transfer start instruction to the NCR-Fwd 302 to transfer the signal of the base station device 201 in standalone mode (S303). Note that the NCR-MT 301 may also acquire tdd-UL-DL-ConfigurationCommon as another method of acquiring the reception timing.

[0085] When the NCR-Fwd 302 receives a data signal from the base station device 201 (S304), it amplifies the data signal and transmits the data signal to the terminal device 100 (S305).

[0086] The NCR-Fwd 302 (relay device 300) starts up the communication device at the timing when it can receive a signal according to the timing information, and keeps the communication device off at other times, which enables the relay device 300 to save power.

[0087] 3. When a signal from a base station device 200 with control function is received during relay processing in standalone mode> Figure 8 is a diagram showing an example of the sequence of relay processing in the relay device 300. In Figure 8, the relay device 300 is relaying a signal from the base station device 201 in standalone mode. At this timing, the relay device 300 receives a signal from a new base station device 200.

[0088] The NCR-MT 301 transmits a transfer start instruction to the NCR-Fwd 302 to transfer, for example, a signal from the base station device 201 in the independent mode (S400).

[0089] The NCR-MT 301 performs a search process for other base station devices during relay processing in the standalone mode (S401). The search process is a process for searching for signals from base station devices other than the target base station device 201 in the standalone mode. The NCR-MT 301 performs the search process periodically or irregularly, for example, to detect the base station device 200 that has the control function. The search process is performed, for example, after a predetermined time has elapsed since the start of relay processing in the standalone mode.

[0090] In the search process S401, the NCR-MT301 searches for carriers with the same center frequency, for example. Alternatively, the NCR-MT301 may search for carriers with different center frequencies, for example. In this case, the search order follows a signal broadcast from the base station device, such as CellReselectionPriority.

[0091] The NCR-MT 301 detects the base station device 200 in search processing S401 and receives SIB1 from the base station device 200 (S402). The subsequent processing from processing S402 to processing S405 is the same as the processing from processing S100 to processing S103 in FIG.

[0092] For example, the relay device 300 may repeat the search process until it finds a base station that can perform relaying in the control mode, rather than performing relaying in the autonomous mode. Also, even if the relay device 300 is performing relaying in the control mode, it may perform the search process and camp on another base station.

[0093] <Reflection in Specifications> Examples of how the specifications will be reflected in the 3GPP specifications are shown below. In the following figures, additional specifications are indicated in bold underlined type. Furthermore, the specifications, chapter numbers, item numbers, names, values, insertion locations, etc. shown in the figures as additional specifications are merely examples and are not limited to these.

[0094] 9 is a diagram showing an example of changes to the contents of TS 38.304. A statement that Unified Access Control does not apply to NCR-MTs is added to "5.3.0 Introduction."

[0095] FIG. 10 is a diagram showing an example of changes to the content of TS 38.304. NCR-MTs adds content related to CellBarred, similar to IAB-MTs. Note that if the relay device 300 does not have a NAS function and does not perform authentication, ncr-Support is defined as a parameter common to PLMNs and SNPNs. In this case, the last three lines (including "ncr-Support (IE type: "true")") are unnecessary. However, if the relay device 300 has a NAS function and performs authentication, ncr-Support is defined for each PLMN and SNPN, and this fact is added to the last three lines.

[0096] 11 is a diagram showing an example of a change in the contents of TS 38.331. A description of the process performed by the relay device 300 upon receiving SIB1 is added to "5.2.2.4.2 Actions upon reception of the SIB1."

[0097] 12 is a diagram showing an example of changes to the contents of TS 38.331. A definition of ncr-Support is added as the "CellAccessRelatedInfo Information element" of "6 Protocol data units, formats and parameters (ASN.1)."

[0098] [Other Embodiments] The requirements described in the first embodiment may be combined with each other, and may be used differently depending on the requirements of the wireless communication system, surrounding conditions, radio wave conditions, etc.

[0099] 10: Wireless communication system 100: Terminal device 200: Base station device 201: Base station device 210: CPU 220: Storage 221: Wireless communication program 222: Relay control program 230: Memory 250: Wireless communication circuit 300: Relay device 310: CPU 320: Storage 321: Relay program 3211: Independent mode module 3212: Control mode module 330: Memory 350: Wireless communication circuit 351: Wireless communication circuit

Claims

1. A relay device that relays a signal received from a base station device to a terminal device, a control unit that determines whether or not to perform relay processing of a first signal transmitted by the first base station device under the control of the first base station device according to support information indicating whether or not the first base station device has a control function of the relay device; a relay unit that performs relay processing under the control of the first base station device when the control unit determines that relay processing under the control of the first base station device is to be performed; The relay process includes an amplification and forwarding process of the first signal. Relay device.

2. The control unit determines to perform relay processing under the control of the first base station device when the first base station device has the control function in the support information. The relay device according to claim 1.

3. the support information is transmitted by the first base station device; The control unit receives the support information. The relay device according to claim 2.

4. the first base station device transmits access restriction information regarding access restriction to the first base station device; The control unit acquires the access restriction information, and determines whether or not to perform a relay process under the control of the first base station device, depending on the support information and the access restriction information. The relay device according to claim 3.

5. The control unit determines not to perform relay processing under the control of the first base station device when the access restriction information indicates that access to the first base station device is prohibited.

5. The relay device according to claim 4.

6. The control unit determines to perform relay processing under the control of the first base station device when the access restriction information does not prohibit access to the first base station device and when the support information indicates that the first base station device has the control function. The relay device according to claim 5.

7. When the control unit determines that the relay process under the control of the first base station device is not to be performed, The relay unit performs relay processing of the first signal without being controlled by the first base station device. The relay device according to claim 1.

8. When the control unit determines that the relay process under the control of the first base station device is not to be performed, The relay unit does not relay the first signal. The relay device according to claim 1.

9. when it is determined that relay processing under the control of the first base station device is not to be performed, after a predetermined time has elapsed, the control unit searches for a second signal transmitted by a second base station device other than the first base station device, and when the control unit receives the second signal, determines whether or not to perform relay processing under the control of the second base station device; When the control unit determines that the relay process under the control of the second base station device is to be performed, the relay unit stops the relay process of the first signal and performs the relay process under the control of the second base station device. The relay device according to claim 7.

10. when it is determined that relaying under the control of the first base station device is not to be performed, after a predetermined time has elapsed, the control unit searches for a second signal transmitted by a second base station device other than the first base station device, and when the control unit receives the second signal, determines whether or not to perform relaying under the control of the second base station device; When the control unit determines that the relay process is to be performed under the control of the second base station device, the relay unit performs the relay process under the control of the second base station device. The relay device according to claim 8.

11. When the control unit determines that relay processing under the control of the first base station device is not to be performed, the control unit acquires timing information regarding a transmission timing of a signal to be transmitted by the first base station device; The relay unit controls power in accordance with the timing information and performs relay processing of the first signal without being controlled by the first base station device. The relay device according to claim 7.

12. The control unit performs a Random Access CHannel (RACH) process with the first base station device and acquires the timing information. The relay device according to claim 11.

13. The amplifying and forwarding process includes a process of amplifying the received first signal and transmitting the first signal to the terminal device by beamforming. The relay device according to claim 1.

14. When the control unit determines that relay processing under the control of the first base station device is to be performed, the control unit wirelessly connects to the first base station device and receives a control signal for controlling the relay device from the first base station device via the wireless connection. The relay device according to claim 1.

15. A base station device in a communication system having a relay device that relays a signal received from the base station device to a terminal device, a communication unit that transmits support information indicating whether the relay device has a control function for the relay device; a relay control unit that transmits relay control information related to a relay process performed by the relay device and controls the relay process performed by the relay device; having The relay process includes an amplification and forwarding process of the first signal. Base station equipment.

16. A relay method in a relay device that relays a signal received from a base station device to a terminal device, comprising: determining whether to perform relay processing of a first signal transmitted by the first base station device under the control of the first base station device according to support information indicating whether the first base station device has a control function of the relay device; When it is determined that relay processing under the control of the first base station device is to be performed, the relay processing under the control of the first base station device is performed; The relay process includes an amplification and forwarding process of the first signal. Relay method.