Control terminal, base station, and communication method

Abstract

An NCR-UE (control terminal) that controls an NCR device (relay device) that relays a radio signal between a gNB (base station) and a UE (user equipment) in a mobile communication system receives, from a gNB, configuration information for directing a beam to the UE by the NCR device that relays a radio signal between the gNB and the UE, and controls the NCR device to direct the beam to the UE on the basis of the configuration information.

Description

Technical Field

[0001] The present disclosure relates to a control terminal, a base station and a communication method used in a mobile communication system. Background Art

[0002] In recent years, the fifth generation (5G) mobile communication system has attracted attention. Compared with the long term evolution (LTE) which is the fourth generation radio access technology, the new radio (NR) which is the radio access technology of the 5G system is capable of broadband transmission via a high frequency band.

[0003] Since radio signals (radio waves) in high frequency bands such as the millimeter wave band or the terahertz wave band have high linearity, the reduction in the coverage of the base station is a problem. In order to solve such a problem, a repeater device has attracted attention, which is a relay device that relays radio signals between a base station and a user device and can be link-controlled from a network (see, for example, non-patent document 1). Such a repeater device can expand the coverage of the base station while suppressing the occurrence of interference by, for example, amplifying the radio signal received from the base station and transmitting the radio signal by directional transmission. Reference List Non-patent literature

[0004] Non-patent document 1: 3GPP contribution: RP-213700, "New SI: Study on NR Network-controlled Repeaters" Summary of the invention

[0005] In a first aspect, a control terminal is a device for controlling a relay device that relays radio signals between a base station and a user equipment in a mobile communication system. The control terminal includes: a receiver that receives configuration information used by the relay device to direct a beam to the user equipment from the base station; and a controller that controls the relay device to direct a beam to the user equipment based on the configuration information.

[0006] In a second aspect, a base station is used in a mobile communication system including a control terminal, the control terminal controlling a relay device that relays radio signals between the base station and user equipment. The base station includes a transmitter that sends configuration information used by the relay device to direct a beam toward the user equipment to the control terminal.

[0007] In a third aspect, a communication method is a method performed by a control terminal that controls a relay device that relays a radio signal between a base station and a user equipment in a mobile communication system. The communication method includes: receiving configuration information used by the relay device to direct a beam to the user equipment from the base station; and controlling the relay device to direct the beam to the user equipment based on the configuration information. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. Figure 2 is a diagram showing a configuration of a protocol stack of a radio interface of a user plane processing data. Figure 3 is a diagram showing a configuration of a protocol stack of a radio interface of a control plane that processes signaling (control signals). Figure 4 : is a diagram showing an application scenario of an NCR device (relay device) according to an embodiment. Figure 5 is a diagram showing an application scenario of an NCR device according to an embodiment. Figure 6 is a diagram showing a configuration example of a protocol stack in a mobile communication system including an NCR device and an NCR-UE (control terminal) according to an embodiment. Figure 7 is a diagram of a configuration example of an NCR-UE and an NCR device according to an embodiment. Figure 8 is a diagram showing a configuration example of a gNB (base station) according to an embodiment. Fig. 9 is a diagram showing an example of downlink signaling from a gNB to an NCR-UE according to an embodiment. Fig.10 is a diagram showing an example of an NCR control signal according to an embodiment. Fig.11 is a diagram showing an example of uplink signaling from an NCR-UE to a gNB according to an embodiment. Fig.12 is a diagram showing an example of NCR capability information according to an embodiment. Fig.13 is a diagram showing an example of the operation of the mobile communication system according to the embodiment. Fig.14 is a diagram for describing beamforming control according to an embodiment. Fig.15 : is a diagram showing an example of an operation flow of a first operation mode of beamforming control according to an embodiment. Fig.16 is a diagram showing another example of the operation flow of the first operation mode of the beamforming control according to the embodiment. Fig.17 : is a diagram showing an example of an operation flow of a second operation mode of beamforming control according to an embodiment. Fig.18 is a diagram for describing a RIS device (relay device) according to another embodiment. Fig.19 is a diagram for describing a RIS apparatus according to another embodiment. Fig. 20 is a diagram for describing a RIS apparatus according to another embodiment. Fig.21 is a diagram for describing a RIS apparatus according to another embodiment. DETAILED DESCRIPTION

[0009] When a relay device such as a repeater device is controlled from a network, a control technology for exclusively controlling the relay device has not yet been established, and it is currently difficult to perform effective coverage extension using the relay device.

[0010] The present disclosure provides appropriate control of a relay device that performs relay transmission between a base station and a user equipment.

[0011] The mobile communication system according to the embodiment is described with reference to the accompanying drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0012] (1) Configuration of mobile communication system Figure 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. The mobile communication system 1 complies with the fifth generation system (5GS) of the 3GPP (trade name) standard. The following description takes 5GS as an example, but the long term evolution (LTE) system may be at least partially applied to the mobile communication system. Alternatively, the sixth generation (6G) system may be at least partially applied to the mobile communication system.

[0013] The mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (next generation radio access network (NG-RAN)) 10, and a 5G core network (5GC) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. The 5GC 20 may be simply referred to as the core network (CN) 20.

[0014] UE 100 is a mobile wireless communication device. UE 100 may be any device as long as UE 100 is used by a user. Examples of UE 100 include a mobile phone terminal (including a smart phone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided on a sensor, a vehicle or a device provided on a vehicle (vehicle UE), or a flying object and a device provided on the flying object (air UE).

[0015] The NG-RAN 10 includes a base station (referred to as a "gNB" in a 5G system) 200. The gNBs 200 are interconnected via an Xn interface, which is an inter-base station interface. Each gNB 200 manages one or more cells. The gNB 200 performs wireless communication with the UE 100 that has established a connection to the cell of the gNB 200. The gNB 200 has a radio resource management (RRM) function, a function of routing user data (hereinafter referred to as "data"), a measurement control function for mobility control and scheduling, and the like. "Cell" is used as a term representing the smallest unit of a wireless communication area. "Cell" is also used as a term representing a function or resource used to perform wireless communication with the UE 100. One cell belongs to one carrier frequency (hereinafter referred to as "frequency").

[0016] Note that the gNB can be connected to the Evolved Packet Core (EPC) corresponding to the core network of LTE. The LTE base station can also be connected to the 5GC. The LTE base station and the gNB can be connected via an inter-base station interface.

[0017] The 5GC 20 includes an access and mobility management function (AMF) and a user plane function (UPF) 300. The AMF performs various types of mobility control, etc. for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using non-access stratum (NAS) signaling. The UPF controls data transmission. The AMF and the UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0018] Figure 2 is a diagram showing a configuration of a protocol stack of a radio interface of a user plane processing data.

[0019] The radio interface protocol of the user plane includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0020] The PHY layer performs encoding and decoding, modulation and demodulation, antenna mapping and demapping, and resource mapping and demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the gNB 200 via a physical channel. Note that the PHY layer of the UE 100 receives downlink control information (DCI) transmitted from the gNB 200 through a physical downlink control channel (PDCCH). Specifically, the UE 100 performs blind decoding on the PDCCH using a radio network temporary identifier (RNTI) and acquires the successfully decoded DCI as the DCI addressed to the UE 100. The DCI transmitted from the gNB 200 is attached with CRC parity bits scrambled by the RNTI.

[0021] The MAC layer performs priority control of data, retransmission processing by hybrid ARQ (HARQ: Hybrid Automatic Repeat Request), a random access procedure, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the transport format (transport block size, modulation and coding scheme (MCS)) in uplink and downlink and resource blocks to be allocated to the UE 100.

[0022] The RLC layer transmits data to the RLC layer of the receiving side by using the functions of the MAC layer and the PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0023] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0024] The SDAP layer performs mapping between IP flows (as a unit of QoS (Quality of Service) control performed by the core network) and radio bearers (as a unit of QoS control performed by the access stratum (AS)). Note that when the RAN is connected to the EPC, SDAP does not need to be provided.

[0025] Figure 3 is a diagram showing a configuration of a protocol stack of a radio interface of a control plane that processes signaling (control signals).

[0026] The protocol stack of the radio interface of the control plane includes the Radio Resource Control (RRC) layer and the Non-Access Stratum (NAS) layer, instead of Figure 4 The SDAP layer is shown.

[0027] RRC signaling for various configurations is transmitted between the RRC layer of the UE 100 and the RRC layer of the gNB 200. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, reestablishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in the RRC connected state. When there is no connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in the RRC idle state. When the connection between the RRC of the UE 100 and the RRC of the gNB 200 is suspended, the UE 100 is in the RRC inactive state.

[0028] The NAS layer located above the RRC layer performs session management, mobility management, etc. NAS signaling is sent between the NAS layer of the UE 100 and the NAS layer of the AMF 300A. Note that the UE 100 includes an application layer of a protocol that is not a radio interface. A layer lower than the NAS layer is called an AS layer.

[0029] (2) Application scenarios of relay devices An application scenario of an NCR device is described. According to an embodiment, the NCR device is a relay device. Figure 4 and Figure 5 is a diagram showing an application scenario of an NCR device according to an embodiment.

[0030] Compared to 4G / LTE, 5G / NR is capable of broadband transmission via high-frequency bands. Since radio signals in high-frequency bands such as the millimeter wave band or the terahertz band have high linearity, a reduction in the coverage of the gNB 200 is a problem. Figure 4 UE 100A may be outside the coverage of gNB 200, e.g., outside the area where UE 100A can directly receive radio signals from gNB 200. UE 100A may not be able to communicate with gNB 200 within line of sight due to obstacles between gNB 200 and UE 100A.

[0031] In an embodiment, a repeater device (500A) is a relay device that relays radio signals between a gNB 200 and a UE 100A and can be controlled from a network. The repeater device (500A) is introduced into a mobile communication system 1. Hereinafter, such a repeater device is referred to as a network controlled repeater (NCR) device. Such a repeater device may be referred to as a smart repeater device.

[0032] For example, the NCR device 500A amplifies the radio waves (radio frequency signals) received from the gNB 200, and transmits the radio signals through directional transmission. Specifically, the NCR device 500A receives the radio signals transmitted by the gNB 200 through beamforming. The NCR device 500A amplifies the received radio signals, and transmits the amplified radio signals through directional transmission. Here, the NCR device 500A may transmit a radio signal having a fixed directivity. Alternatively, the NCR device 500A may transmit a radio signal having a variable (adaptive) directional beam. This can effectively extend the coverage of the gNB 200. Although in the embodiment, it is assumed that the NCR device 500A is applied to downlink communication from the gNB 200 to the UE 100A, the NCR device 500A may also be applied to uplink communication from the UE 100A to the gNB 200.

[0033] like Figure 5 As shown, a new UE (hereinafter referred to as "NCR-UE") 100B is introduced, which is a control terminal for controlling the NCR device 500A. The NCR-UE 100B controls the NCR device 500A in cooperation with the gNB 200 by establishing a wireless connection with the gNB 200 and performing wireless communication with the gNB 200. By doing so, effective coverage extension can be achieved using the NCR device 500A. The NCR-UE 100B controls the NCR device 500A according to the control from the gNB 200.

[0034] The NCR-UE 100B may be configured separately from the NCR device 500A. For example, the NCR-UE 100B may be located near the NCR device 500A and may be electrically connected to the NCR device 500A. The NCR-UE 100B may be connected to the NCR device 500A by wire or wirelessly. The NCR-UE 100B may be configured to be integrated with the NCR device 500A. The NCR-UE 100B and the NCR device 500A may be fixedly installed at the edge of the coverage (cell edge) of the base station 200, or, for example, installed on the wall or window of any building. The NCR-UE 100B and the NCR device 500A may be installed in, for example, a vehicle so as to be movable. One NCR-UE 100B may control multiple NCR devices 500A.

[0035] exist Figure 5In the example shown, the NCR device 500A dynamically or semi-statically changes the beam to be transmitted or received. For example, the NCR device 500A forms a beam toward each of the UE 100A1 and the UE 100A2. The NCR device 500A may also form a beam toward the gNB 200. For example, in the communication resources between the gNB 200 and the UE 100A1, the NCR device 500A transmits a radio signal received from the gNB 200 to the UE 100A1 by beamforming and / or transmits a radio signal received from the UE 100A1 to the gNB 200 by beamforming. In the communication resources between the gNB 200 and the UE 100A2, the NCR device 500A transmits a radio signal received from the gNB 200 to the UE 100A2 by beamforming and / or transmits a radio signal received from the UE 100A2 to the gNB 200 by beamforming. As an alternative or supplement to beamforming, the NCR device 500A may also perform null formation (so-called null generation) on a UE 100 (not shown) and / or a neighboring gNB 200 (not shown) that is not a communication partner to suppress interference. In the following, beam (beamforming) may be interpreted as null (null generation). Beam (beamforming) may be interpreted as beam and null (beamforming and null generation).

[0036] Figure 6 is a diagram showing a configuration example of a protocol stack in a mobile communication system 1 including an NCR device 500A and an NCR-UE 100B according to the embodiment.

[0037] like Figure 6 As shown, the NCR device 500A relays radio signals transmitted and received between the gNB 200 and the UE 100A. The NCR device 500A has a radio frequency (RF) function of amplifying and relaying received radio signals, and performs directional transmission through beamforming (e.g., analog beamforming).

[0038] The NCR-UE 100B includes at least one layer (entity) selected from the group consisting of PHY, MAC, RRC, and F1-application protocol (AP). F1-AP is a type of fronthaul interface. The NCR-UE 100B transmits downlink signaling and / or uplink signaling (to be described below) with the gNB 200 through at least one selected from the group consisting of PHY, MAC, RRC, and F1-AP. When the NCR-UE 100B is a type of base station or is part of a base station, the NCR-UE 100B can communicate with the gNB 200 through an Xn's AP (Xn-AP), which is an inter-base station interface.

[0039] (3) Configuration example of control terminal and relay device In the embodiment, the configuration of the NCR-UE 100B (control terminal) and the NCR device 500A (relay device) is described. Figure 7 is a diagram showing a configuration example of an NCR-UE 100B and an NCR device 500A according to the embodiment.

[0040] like Figure 7 As shown, the NCR-UE 100B includes a receiver 110 , a transmitter 120 , a controller 130 , and an interface 140 .

[0041] The receiver 110 performs various types of reception under the control of the controller 130. The receiver 110 includes an antenna and a receiving device. The receiving device converts a radio signal (radio frequency signal) received through the antenna into a baseband signal (received signal), and outputs the resulting signal to the controller 130. The transmitter 120 performs various types of transmission under the control of the controller 130. The transmitter 120 includes an antenna and a transmitting device. The transmitting device converts a baseband signal (transmitted signal) output by the controller 130 into a radio signal, and transmits the resulting signal through the antenna.

[0042] The controller 130 performs various types of control in the NCR-UE 100B. The controller 130 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used by the processor for processing. The processor may include a baseband processor and a central processing unit (CPU). The baseband processor performs modulation and demodulation, encoding and decoding of baseband signals, etc. The CPU executes the program stored in the memory, thereby performing various types of processing. The controller 130 performs the function of at least one layer selected from the group consisting of PHY, MAC, RRC, and F1-AP.

[0043] The interface 140 is electrically connected to the NCR device 500A. The controller 130 controls the NCR device 500A via the interface 140. Note that when the NCR-UE 100B is configured to be integrated with the NCR device 500A, the NCR-UE 100B may not need to include the interface 140. The receiver 110 and the transmitter 120 of the NCR-UE 100B may be configured to be integrated with the wireless unit 510A of the NCR device 500A.

[0044] The NCR device 500A includes a wireless unit 510A and an NCR controller 520A. The wireless unit 510A includes: an antenna unit 510a, which includes a plurality of antennas; an RF circuit 510b, which includes an amplifier; and a directivity controller 510c, which controls the directivity of the antenna unit 510a. The RF circuit 510b amplifies and relays (transmits) a radio signal transmitted and received by the antenna unit 510a. The RF circuit 510b can convert a radio signal, which is an analog signal, into a digital signal, and can reconvert the digital signal into an analog signal after digital signal processing. The directivity controller 510c can perform analog beamforming through analog signal processing, perform digital beamforming through digital signal processing, or perform mixed analog and digital beamforming.

[0045] The NCR controller 520A controls the wireless unit 510A in response to a control signal from the controller 130 of the NCR-UE 100B. The NCR controller 520A may include at least one processor. The NCR controller 520A may output information related to the capabilities of the NCR device 500A to the NCR-UE 100B. Note that when the NCR-UE 100B is configured to be integrated with the NCR device 500A, the controller 130 of the NCR-UE 100B may also be configured to be integrated with the NCR controller 520A of the NCR device 500A.

[0046] In an embodiment, the receiver 110 of the NCR-UE 100B receives signaling (downlink signaling) for controlling the NCR device 500A from the gNB 200 through wireless communication. The controller 130 of the NCR-UE 100B controls the NCR device 500A based on the signaling. This enables the gNB 200 to control the NCR device 500A via the NCR-UE 100B.

[0047] In an embodiment, the controller 130 of the NCR-UE 100B controls the NCR device 500A. The controller 130 of the NCR-UE 100B acquires NCR capability information indicating the capability of the NCR device 500A from the NCR device 500A (NCR controller 520A). The transmitter 120 of the NCR-UE 100B transmits the acquired NCR capability information to the gNB 200 through wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE 100B to the gNB 200. This enables the gNB 200 to understand the capability of the NCR device 500A.

[0048] (4) Base station configuration example In the embodiment, the configuration of gNB 200 (base station) is described. Figure 8is a diagram showing a configuration example of gNB 200 according to an embodiment.

[0049] like Figure 8 As shown, gNB 200 includes a transmitter 210, a receiver 220, a controller 230 and a backhaul communicator 240.

[0050] The transmitter 210 performs various types of transmission under the control of the controller 230. The transmitter 210 includes an antenna and a transmitting device. The transmitting device converts a baseband signal (transmitting signal) output by the controller 230 into a radio signal, and transmits the resulting signal through the antenna. The receiver 220 performs various types of reception under the control of the controller 230. The receiver 220 includes an antenna and a receiving device. The receiving device converts a radio signal received by the antenna into a baseband signal (receiving signal), and outputs the resulting signal to the controller 230. The transmitter 210 and the receiver 220 may be able to use multiple antennas for beamforming.

[0051] The controller 230 performs various types of control of the gNB 200. The controller 230 includes at least one processor and at least one memory. The memory stores programs to be executed by the processor and information to be used by the processor for processing. The processor may include a baseband processor and a CPU. The baseband processor performs modulation and demodulation, encoding and decoding, etc. of a baseband signal. The CPU executes the program stored in the memory, thereby performing various types of processing.

[0052] The backhaul communicator 240 is connected to the neighboring base station via the inter-base station interface. The backhaul communicator 240 is connected to the AMF / UPF 300 via the interface between the base station and the core network. Note that the gNB may include a central unit (CU) and a distributed unit (DU) (ie, the functions are divided), and these two units may be connected via the F1 interface.

[0053] The transmitter 210 of the gNB 200 transmits signaling (downlink signaling) for controlling the NCR device 500A to the NCR-UE 100B that controls the NCR device 500A through wireless communication. This enables the gNB 200 to control the NCR device 500A via the NCR-UE 100B.

[0054] The receiver 220 of the gNB 200 receives NCR capability information indicating the capability of the NCR device 500A from the NCR-UE 100B controlling the NCR device 500A through wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE 100B to the gNB 200. This enables the gNB 200 to understand the capability of the NCR device 500A.

[0055] (5) Examples of operation scenarios Now, in the embodiment, an example of an operation scenario of the mobile communication system 1 will be described.

[0056] (5.1) Example of downlink signaling Fig. 9 is a diagram showing an example of downlink signaling from gNB 200 to NCR-UE 100B according to an embodiment.

[0057] The gNB 200 (transmitter 210) sends downlink signaling to the NCR-UE 100B. The downlink signaling may be an RRC message as RRC layer (i.e., layer 3) signaling. The downlink signaling may be a MAC control element (CE) as MAC layer (i.e., layer 2) signaling. The downlink signaling may be downlink control information (DCI) as PHY layer (i.e., layer 1) signaling. The downlink signaling may be UE-specific signaling or broadcast signaling. The downlink signaling may be a fronthaul message (e.g., an F1-AP message). When the NCR-UE 100B is a type of base station or is part of a base station, the NCR-UE 100B may communicate with the gNB 200 through an Xn's AP (Xn-AP), which is an inter-base station interface.

[0058] For example, Fig. 9 As shown, the gNB 200 (transmitter 210) transmits an NCR control signal specifying the operating state of the NCR device 500A to the NCR-UE 100B that has established a wireless connection with the gNB 200 (step S1). In the following embodiment, an example in which the NCR control signal specifying the operating state of the NCR device 500A is a MAC CE as a MAC layer (layer 2) signaling or a DCI as a PHY layer (layer 1) signaling is mainly described. However, the NCR control signal may be included in an RRC reconfiguration message, which is a UE-specific RRC message to be sent to the NCR-UE 100B. The downlink signaling may be a message of a layer higher than the RRC layer (e.g., NCR application). The downlink signaling may transmit a message of a layer higher than the RRC layer encapsulated with a message of the RRC layer or a layer lower than the RRC layer. Note that the NCR-UE 100B (transmitter 120) may transmit a response message to the downlink signaling from the gNB 200 in the uplink. The response message may be sent in response to the NCR device 500A completing the configuration specified in the downlink signaling or receiving the configuration.

[0059] like Fig.10As shown, the NCR control signal may include frequency control information for specifying the center frequency of the radio signal (e.g., component carrier) to be relayed by the NCR device 500A. When the NCR control signal received from the gNB 200 includes the frequency control information, the NCR-UE 100B (controller 130) controls the NCR device 500A so that the NCR device 500A relays the radio signal as a target, the center frequency of which is indicated by the frequency control information (step S2). The NCR control signal may include multiple pieces of frequency control information for specifying center frequencies that are different from each other. Since the NCR control signal includes the frequency control information, the gNB 200 can specify the center frequency of the radio signal to be relayed by the NCR device 500A via the NCR-UE 100B.

[0060] The NCR control signal may include mode control information for specifying an operation mode of the NCR device 500A. The mode control information may be associated with the frequency control information (center frequency). The operation mode may be any one of the following modes: a mode in which the NCR device 500A performs non-directional transmission and / or reception, a mode in which the NCR device 500A performs fixed directional transmission and / or reception, a mode in which the NCR device 500A performs transmission and / or reception with a variable directional beam, and a mode in which the NCR device 500A performs multiple-input multiple-output (MIMO) relay transmission. The operation mode may be any one of a beamforming mode (i.e., a mode emphasizing improvement of a desired wave) and a null generation mode (i.e., a mode emphasizing suppression of an interference wave). When the NCR control signal received from the gNB 200 includes the mode control information, the NCR-UE 100B (controller 130) controls the NCR device 500A so that the NCR device 500A operates in the operation mode indicated by the mode control information (step S2). Since the NCR control signal includes mode control information, the gNB 200 can specify the operating mode of the NCR device 500A via the NCR-UE 100B.

[0061] Here, a mode in which the NCR device 500A performs non-directional transmission and / or reception is a mode in which the NCR device 500A performs relaying in all directions, and may be referred to as an omni-directional mode.

[0062] The mode in which the NCR device 500A performs fixed directional transmission and / or reception may be a directional mode implemented by one directional antenna. Alternatively, the mode may be a beamforming mode implemented by applying fixed phase and amplitude control (antenna weight control) to multiple antennas. Any of these modes may be specified (configured) from the gNB 200 to the NCR-UE 100B.

[0063] The mode in which the NCR device 500A performs transmission and / or reception using a variable directional beam may be a mode for performing analog beamforming, a mode for performing digital beamforming, or a mode for performing hybrid beamforming. The mode may be a mode for forming an adaptive beam specific to the UE 100A. Any of these modes may be specified (configured) from the gNB 200 to the NCR-UE 100B.

[0064] Note that in the operation mode of performing beamforming, the following beam control information can be provided from gNB 200 to NCR-UE 100B.

[0065] The mode in which the NCR device 500A performs MIMO relay transmission may be a mode in which single-user (SU) spatial multiplexing is performed, a mode in which multi-user (MU) spatial multiplexing is performed, or a mode in which transmit diversity is performed. Any of these modes may be specified (configured) from the gNB 200 to the NCR-UE 100B.

[0066] The operation mode may include a mode in which the relay transmission performed by the NCR device 500A is turned on (activated) and a mode in which the relay transmission performed by the NCR device 500A is turned off (deactivated). Any of these modes may be specified (configured) from the gNB 200 to the NCR-UE 100B.

[0067] The NCR control signal may include beam control information for specifying a transmission direction, a transmission weight, or a beam pattern of the NCR device 500A to perform directional transmission. The beam control information may be associated with the frequency control information (center frequency). The beam control information may include a precoding matrix indicator (PMI). When the NCR control signal received from the gNB 200 includes the beam control information, the NCR-UE 100B (controller 130) controls the NCR device 500A so that the NCR device 500A forms a transmission directivity (beam) indicated by the beam control information (step S2). Since the NCR control signal includes the beam control information, the gNB 200 can control the transmission directivity of the NCR device 500A via the NCR-UE 100B.

[0068] The NCR control signal may include output control information for specifying the degree (amplification gain) or transmission power of the NCR device 500A to amplify the radio signal. The output control information may be information indicating the difference (i.e., relative value) between the current amplification gain or transmission power and the target amplification gain or transmission power. When the NCR control signal received from the gNB 200 includes the output control information, the NCR-UE 100B (controller 130) controls the NCR device 500A so that the NCR device 500A changes the amplification gain or transmission power to the amplification gain or transmission power indicated by the output control information (step S2). The output control information may be associated with the frequency control information (center frequency). The output control information may be information for specifying any one of the amplification gain, beamforming gain, and antenna gain of the NCR device 500A. The output control information may be information for specifying the transmission power of the NCR device 500A.

[0069] When one NCR-UE 100B controls a plurality of NCR devices 500A, the gNB 200 (transmitter 210) may transmit an NCR control signal for a corresponding one of the NCR devices 500A to the NCR-UE 100B. In this case, the NCR control signal may include an identifier (NCR identifier) ​​of the corresponding NCR device 500A. The NCR-UE 100B (controller 130) that controls a plurality of NCR devices 500A determines the NCR device 500A to which the NCR control signal is applied based on the NCR identifier included in the NCR control signal received from the gNB 200. Note that even when the NCR-UE 100B controls only one NCR device 500A, the NCR identifier may be transmitted from the NCR-UE 100B to the gNB 200 together with the NCR control signal.

[0070] As described above, the NCR-UE 100B (controller 130) controls the NCR device 500A based on the NCR control signal from the gNB 200. This enables the gNB 200 to control the NCR device 500A via the NCR-UE 100B.

[0071] (5.2) Example of uplink signaling Fig.11 is a diagram showing an example of uplink signaling from NCR-UE 100B to gNB 200 according to an embodiment.

[0072] The NCR-UE 100B (transmitter 210) transmits uplink signaling to the gNB 200. The uplink signaling may be an RRC message as RRC layer signaling. The uplink signaling may be a MAC CE as MAC layer signaling. The uplink signaling may be uplink control information (UCI) as PHY layer signaling. The uplink signaling may be a fronthaul message (e.g., an F1-AP message) or an inter-base station message (e.g., an Xn-AP message). The uplink signaling may be a message of a layer higher than the RRC layer (e.g., an NCR application). The uplink signaling may transmit a message of a layer higher than the RRC layer encapsulated with a message of the RRC layer or a layer lower than the RRC layer. Note that the gNB 200 (transmitter 210) may transmit a response message to the uplink signaling from the NCR-UE 100B in a downlink, and the NCR-UE 100B (receiver 110) may receive the response message.

[0073] For example, the NCR-UE 100B (transmitter 120) having established a wireless connection with the gNB 200 transmits NCR capability information indicating the capability of the NCR device 500A to the gNB 200 through wireless communication (step S5). The NCR-UE 100B (transmitter 120) may include the NCR capability information in a UE capability message or a UE assistance information message (which is a type of RRC message to be transmitted to the gNB 200). The NCR-UE 100B (transmitter 120) may transmit the NCR capability information (NCR capability information and / or operation status information) to the gNB 200 in response to a request or inquiry from the gNB 200.

[0074] like Fig.12 As shown, the NCR capability information may include supported frequency information, which indicates the frequencies supported by the NCR device 500A. The supported frequency information may be a numerical value or an index indicating the center frequency of the frequencies supported by the NCR device 500A. Alternatively, the supported frequency information may be a numerical value or an index indicating the range of frequencies supported by the NCR device 500A. When the NCR capability information received from the NCR-UE 100B includes the supported frequency information, the gNB 200 (controller 230) may understand the frequencies supported by the NCR device 500A based on the supported frequency information. The gNB 200 (controller 230) may configure the center frequency of the radio signal targeted by the NCR device 500A within the range of frequencies supported by the NCR device 500A.

[0075] The NCR capability information may include mode capability information related to the operation mode that the NCR device 500A can support or the switching between these operation modes. As described above, the operation mode may be any mode selected from the group consisting of the following modes: a mode in which the NCR device 500A performs non-directional transmission and / or reception, a mode in which the NCR device 500A performs fixed directional transmission and / or reception, a mode in which the NCR device 500A performs transmission and / or reception with a variable directional beam, and a mode in which the NCR device 500A performs multiple-input multiple-output (MIMO) relay transmission. The operation mode may be any one of a beamforming mode (i.e., a mode that emphasizes improving the desired wave) and a null point generation mode (i.e., a mode that emphasizes suppressing interference waves). The mode capability information may be information indicating which operation mode among these operation modes the NCR device 500A can support. The mode capability information may be information indicating which operation modes among these operation modes can be switched in mode. When the NCR capability information received from the NCR-UE 100B includes the mode capability information, the gNB 200 (controller 230) can understand the operation modes and mode switching supported by the NCR device 500A based on the mode capability information. The gNB 200 (controller 230) can configure the operation mode of the NCR device 500A within the range of the understood operation modes and mode switching.

[0076] The NCR capability information may include beam capability information indicating a beam variable range, a beam variable resolution, or the number of variable directivity patterns when the NCR device 500A performs transmission and / or reception using a variable directional beam. The beam capability information may, for example, be information indicating a variable range of a beam angle relative to a horizontal direction or a vertical direction (for example, control of 30° to 90° is possible) or information indicating an absolute angle. The beam capability information may be represented by the direction and / or elevation angle to which the beam is pointed. The beam capability information may be information indicating an angle change for each variable step (for example, 5° / step horizontally, 10° / step vertically). Alternatively, the beam capability information may be information indicating the number of variable steps (for example, 10 steps horizontally and 20 steps vertically). The beam capability information may be information indicating the number of variable directivity patterns of the beam in the NCR device 500A (for example, beam directions Figures 1 to 10, a total of 10 directional patterns). When the NCR capability information received from the NCR-UE 100B includes beam capability information, the gNB 200 (controller 230) can understand the beam angle changes or beam patterns that the NCR device 500A can support based on the beam capability information. The gNB 200 (controller 230) can configure the beam of the NCR device 500A within the range of the understood beam angle changes or beam patterns. These beam capability information can be zeroing capability information. For the zeroing capability information, it indicates the zeroing control capability when performing zero point generation.

[0077] The NCR capability information may include control delay information indicating a control delay time in the NCR device 500A. For example, the control delay information is information indicating a delay time (e.g., 1 ms, 10 ms, ...) from the moment when the UE 100 receives the NCR control signal or the moment when the UE 100 sends the configuration completion for the NCR control signal to the gNB 200 to the moment when the UE 100 completes the control (change of operation mode or change of beam) according to the NCR control signal. When the NCR capability information received from the NCR-UE 100B includes the control delay information, the gNB 200 (controller 230) may understand the control delay time in the NCR device 500A based on the control delay information.

[0078] The NCR capability information may include amplification characteristic information related to radio signal amplification characteristics or output power characteristics in the NCR device 500A. The amplification characteristic information may be information indicating an amplifier gain (dB), a beamforming gain (dB), and an antenna gain (dBi) of the NCR device 500A. The amplification characteristic information may be information indicating an amplification variable range (e.g., 0 dB to 60 dB) in the NCR device 500A. The amplification characteristic information may be information indicating the number of steps (e.g., 10 steps) of the amplification degree that the NCR device 500A can change or the amplification degree of each variable step (e.g., 10 dB / step). The amplification characteristic information may be information indicating an output power variable range (e.g., 0 dBm to 30 dBm) of the NCR device 500A. The amplification characteristic information may be information indicating the number of steps (e.g., 10 steps) of the output power that the NCR device 500A can change or the output power of each variable step (e.g., 10 dBm / step).

[0079] The NCR capability information may include location information indicating the installation location of the NCR device 500A. The location information may include any one or more of latitude, longitude, and altitude. The location information may include information indicating the distance and / or installation angle of the NCR device 500A relative to the gNB 200. The installation angle may be a relative angle relative to the gNB 200 or a relative angle relative to, for example, north, a vertical plane, or a horizontal plane. The installation location may be location information of the location where the antenna unit 510a of the NCR device 500A is installed.

[0080] The NCR capability information may include antenna information indicating the number of antennas included in the NCR device 500A. The antenna information may be information indicating the number of antenna ports included in the NCR device 500A. The antenna information may be information indicating the degree of freedom of directivity control (beam or null formation). The degree of freedom indicates how many beams can be formed (controlled), and is generally "(the number of antennas) - 1". For example, in the case of two antennas, the degree of freedom is 1. In the case of two antennas, an 8-shaped beam pattern is formed, but directivity control is performed only in one direction, so the degree of freedom is 1.

[0081] When the NCR-UE 100B controls a plurality of NCR devices 500, the NCR-UE 100B (transmitter 120) may transmit NCR capability information of each NCR device 500A to the gNB 200. In this case, the NCR capability information may include an identifier (NCR identifier) ​​of the corresponding NCR device 500A. When the NCR-UE 100B controls a plurality of NCR devices 500A, the NCR-UE 100B (transmitter 120) may transmit information indicating the identifiers of each of the plurality of NCR devices 500A and / or the number of the plurality of NCR devices 500A. Note that even when the NCR-UE 100B controls only one NCR device 500A, the NCR identifier may be transmitted from the NCR-UE 100B to the gNB 200 together with the NCR capability information.

[0082] (5.3) General operation examples Fig.13 is a diagram showing an example of the operation of the mobile communication system 1 according to the embodiment.

[0083] In step S11, the NCR-UE 100B is in the RRC idle state or the RRC inactive state.

[0084] In step S12, gNB 200 (transmitter 210) broadcasts NCR support information, which indicates that gNB 200 supports NCR-UE 100B. For example, gNB 200 (transmitter 210) broadcasts a system information block (SIB) including the NCR support information. The NCR support information may be information indicating that NCR-UE 100B is accessible. gNB 200 (transmitter 210) may broadcast NCR non-support information, which indicates that gNB 200 does not support NCR-UE 100B. The NCR non-support information may be information indicating that NCR-UE 100B is not accessible.

[0085] The NCR-UE 100B (controller 130) that has not established a wireless connection with the gNB 200 may determine that it is allowed to access the gNB 200 in response to receiving the NCR support information from the gNB 200, and may perform an access operation to establish a wireless connection with the gNB 200. The NCR-UE 100B (controller 130) may regard the gNB 200 (cell) allowed to access as the highest priority and perform cell reselection.

[0086] On the other hand, when the gNB 200 does not broadcast the NCR support information (or when the gNB 200 broadcasts the NCR non-support information), the NCR-UE 100B (controller 130) that has not yet established a wireless connection with the gNB 200 may determine that the gNB 200 cannot be accessed (cannot be connected to the gNB 200). This enables the NCR-UE 100B to establish a wireless connection only with the gNB 200 that can handle the NCR-UE 100B.

[0087] Note that when the gNB 200 is congested, the gNB 200 may broadcast access restriction information to restrict access from the UE 100. However, unlike the normal UE 100, the NCR-UE 100B may be regarded as a network-side entity. Therefore, the NCR-UE 100B may ignore the access restriction information from the gNB 200. For example, the NCR-UE 100B (controller 130), in the case where the NCR support information is received from the gNB 200, may perform an operation of establishing a wireless connection with the gNB 200 even if the gNB 200 broadcasts the access restriction information. For example, the NCR-UE 100B (controller 130) may not need to perform (or may ignore) unified access control (UAC). Alternatively, either or both of the access category / access identity (AC / AI) used in the UAC may be a special value indicating that the access is made by the NCR-UE.

[0088] In step S13, the NCR-UE 100B (controller 130) starts a random access procedure for the gNB 200. In the random access procedure, the NCR-UE 100B (transmitter 120) transmits a random access preamble (Msg1) and an RRC message (Msg3) to the gNB 200. In the random access procedure, the NCR-UE 100B (receiver 110) receives a random access response (Msg2) and an RRC message (Msg4) from the gNB 200.

[0089] In step S14, the NCR-UE 100B (transmitter 120), when establishing a wireless connection with the gNB 200, may transmit NCR-UE information indicating that the NCR-UE 100B itself is an NCR-UE to the gNB 200. For example, the NCR-UE 100B (transmitter 120), during a random access procedure with the gNB 200, includes the NCR-UE information in a message (e.g., Msg1, Msg3, Msg5) to be transmitted to the gNB 200 for the random access procedure. The gNB 200 (controller 230) may recognize that the accessing UE 100 is the NCR-UE 100B based on the NCR-UE information received from the NCR-UE 100B, and exclude, for example, the NCR-UE 100B from the access restriction target (in other words, accept access from, for example, the NCR-UE 100B).

[0090] In step S15, the NCR-UE 100B transits from the RRC idle state or the RRC inactive state to the RRC connected state.

[0091] In step S16, the gNB 200 (transmitter 120) transmits a capability inquiry message for inquiring about the capability of the NCR-UE 100B to the NCR-UE 100B. The NCR-UE 100B (receiver 110) receives the capability inquiry message.

[0092] In step S17, NCR-UE 100B (transmitter 120) sends a capability information message including the above-mentioned NCR capability information to gNB 200. gNB 200 (receiver 220) receives the capability information message. gNB 200 (controller 230) understands the capability of NCR device 500A based on the received capability information message.

[0093] In step S18, the gNB 200 (transmitter 120) transmits an NCR control signal specifying the operation state of the NCR device 500A to the NCR-UE 100B. The gNB 200 (transmitter 120) may transmit a MAC CE as MAC layer (layer 2) signaling or a DCI as PHY layer (layer 1) signaling to the NCR-UE 100B as the NCR control signal. The NCR-UE 100B (receiver 110) receives the NCR control signal.

[0094] In step S19, the NCR-UE 100B (controller 130) controls the NCR device 500A based on the NCR control signal received from the gNB 200. The NCR-UE 100B (controller 130) can control the NCR device 500A by notifying the NCR device 500A (NCR controller 520A) of the NCR control signal received from the gNB 200.

[0095] In step S20, the NCR-UE 100B (transmitter 120) may send a completion message to the gNB 200 upon completing the control (of the configuration change) of the NCR device 500A. Here, the NCR-UE 100B (controller 130) may determine that the control is completed based on the notification (feedback) from the NCR device 500A (NCR controller 520A). The gNB 200 (receiver 220) receives the completion message.

[0096] (6) Overview of beamforming control between relay devices and user equipment An overview of beamforming control between a relay device and a user equipment according to an embodiment will be described.

[0097] (6.1) A control terminal (NCR-UE 100B) for controlling a relay device (NCR device 500A) that relays radio signals between a base station (gNB 200) and a user equipment (UE 100A) in a mobile communication system (mobile communication system 1), the control terminal comprising: a receiver (receiver 110) that receives configuration information used by the relay device to direct a beam toward the user equipment from the base station; and a controller (controller 130) that controls the relay device to direct a beam toward the user equipment based on the configuration information.

[0098] The configuration information as described above is another example of the downlink signaling described above. The configuration information may be information included in the downlink signaling described above. Although the details will be described below, the relay device is not limited to the NCR device and may be a reconfigurable intelligent surface (RIS) device. The control terminal is not limited to the NCR-UE but may be a RIS-UE. In the following embodiments, an example in which the relay device is an NCR device and the control terminal is an NCR-UE will be mainly described.

[0099] (6.2) In the above (6.1), the configuration information may include resource configuration information indicating resources for controlling the terminal to receive an uplink signal from the user equipment, the receiver may receive the uplink signal from the user equipment by using the resources indicated by the resource configuration information, and the controller may control the relay device to direct the beam to the user equipment according to the received uplink signal.

[0100] (6.3) In the above (6.2), the controller may estimate a channel state between the control terminal and the user equipment by using the received uplink signal, and control the relay device to direct the beam toward the user equipment according to the estimated channel state.

[0101] (6.4) In the above (6.2), the uplink signal may include beam control information, and the controller may acquire the beam control information included in the received uplink signal and control the relay device to direct the beam toward the user equipment according to the acquired beam control information.

[0102] (6.5) In any of the above (6.2) to (6.4), the receiver may receive a radio resource control (RRC) message including resource configuration information from the base station.

[0103] (6.6) In any of the above (6.2) to (6.5), the resource configuration information may include at least one item selected from the group consisting of: PUCCH configuration information indicating the configuration of a physical uplink control channel (PUCCH) of the user equipment, PUSCH configuration information indicating the configuration of a physical uplink shared channel (PUSCH) of the user equipment, sounding reference signal (SRS) configuration information indicating the configuration of SRS of the user equipment, and a cell radio network temporary identifier (C-RNTI) assigned to the user equipment.

[0104] (6.7) In the above (6.1), the configuration information may include mode configuration information for switching a control mode related to beamforming between a plurality of control modes, and the controller may control the relay device to direct the beam toward the user equipment by using the control mode configured according to the mode configuration information.

[0105] (6.8) In the above (6.7), the plurality of control modes may include a base station control mode in which the control terminal controls the relay device according to control from the base station.

[0106] (6.9) In the above (6.7) or (6.8), the plurality of control modes may include an autonomous control mode in which the control terminal autonomously controls the relay device without relying on control from the base station.

[0107] (6.10) In any of the above (6.7) to (6.9), the plurality of control modes may further include a hybrid control mode in which control from the base station and autonomous control of the control terminal are used in combination.

[0108] (6.11) In any of the above (6.7) to (6.10), the plurality of control modes may further include a beam scanning control mode in which the beam direction of the relay device is sequentially switched.

[0109] (6.12) In any of the above (6.7) to (6.11), the receiver may receive, from the base station, a radio resource control (RRC) message including the mode configuration information, a medium access control (MAC) control element (CE) including the mode configuration information, or downlink control information (DCI) including the mode configuration information.

[0110] (6.13) In any of the above (6.7) to (6.12), the mode configuration information may include information for switching any of the following control modes: a control mode of beamforming of the relay device, a control mode of timed switching of the relay device, and a control mode of on / off control of the relay device.

[0111] (6.14) In any of the above (6.7) to (6.13), the mode configuration information may include information specifying a timing of switching of the control information.

[0112] (6.15) A base station for use in a mobile communication system (mobile communication system 1) including a control terminal (NCR-UE 100B), the control terminal controlling a relay device (NCR device 500A) that relays radio signals between the base station (gNB 200) and a user equipment (UE 100A), the base station including a transmitter (transmitter 210) that sends configuration information to the control terminal that is used by the relay device to direct a beam toward the user equipment.

[0113] (6.16) A communication method performed by a control terminal (NCR-UE 100B) which controls a relay device (NCR device 500A) which relays radio signals between a base station (gNB 200) and a user equipment (UE 100A) in a mobile communication system (mobile communication system 1), the communication method comprising the steps of: receiving configuration information used by the relay device to direct a beam toward the user equipment from the base station; and controlling the relay device to direct the beam toward the user equipment based on the configuration information.

[0114] (7) Example of operation related to beamforming between a relay device and a user equipment Next, we will refer to Fig.14 An operation example related to beamforming between a relay device and a user equipment according to an embodiment is described.

[0115] like Fig.14 As shown, the NCR device 500A relays radio signals (referred to as "UE signals") transmitted and received between the gNB 200 and the UE 100A. The UE signals include uplink signals (referred to as "UE-UL signals") transmitted from the UE 100A to the gNB 200 and downlink signals (referred to as "UE-DL signals") transmitted from the gNB 200 to the UE 100A. The NCR device 500A relays the UE-UL signals from the UE 100A to the gNB 200, and relays the UE-DL signals from the gNB 200 to the UE 100A.

[0116] NCR-UE 100B transmits and receives radio signals (referred to herein as “NCR-UE signals”) to and from gNB 200. NCR-UE signals include uplink signals (referred to herein as “NCR-UE-UL signals”) transmitted from NCR-UE 100B to gNB 200 and downlink signals (referred to herein as “NCR-UE-DL signals”) transmitted from gNB 200 to NCR-UE 100B. NCR-UE-UL signals include the above-mentioned uplink signaling. NCR-UE-DL signals include the above-mentioned downlink signaling.

[0117] The gNB 200 directs the beam toward the NCR-UE 100B based on the NCR-UE-UL signal from the NCR-UE 100B. The NCR device 500A and the NCR-UE 100B are co-located, so the gNB 200 directing the beam toward the NCR-UE 100B results in directing the beam toward both the NCR-UE 100B and the NCR device 500A. The gNB 200 uses the beam to send the NCR-UE-DL signal and the UE-DL signal. The NCR-UE 100B receives the NCR-UE-DL signal. Note that the NCR device 500A and the NCR-UE 100B may be at least partially integrated together. For example, in the NCR device 500A and the NCR-UE 100B, functions (e.g., antennas) for sending and receiving or relaying UE signals and / or NCR-UE signals are integrated together.

[0118] The question here is how the NCR device 500A directs the beam to the UE 100A. In an embodiment, the NCR-UE 100B receives configuration information used by the NCR device 500A to direct the beam to the UE 100A from the gNB 200. The configuration information is downlink signaling included in the NCR-UE-DL signal. The NCR-UE 100B controls the NCR device 500A to direct the beam to the UE 100A based on the configuration information. This facilitates the NCR device 500A to smoothly direct the beam to the UE 100A. Hereinafter, a first operating mode and a second operating mode related to the beamforming control as described above will be described.

[0119] (7.1) First operating mode In this first operation mode, the configuration information sent from the gNB 200 to the NCR-UE 100B includes resource configuration information indicating resources required for the NCR-UE 100B to receive the UE-UL signal from the UE 100A. The NCR-UE 100B receives the UE-UL signal from the UE 100A by using the resources indicated by the resource configuration information, and controls the NCR device 500A to direct the beam to the UE 100A according to the received UE-UL signal.

[0120] For example, the NCR-UE 100B estimates the channel state between the NCR-UE 100B and the UE 100A using the received UE-UL signal. The NCR-UE 100B may estimate the channel state using a reference signal included in the UE-UL signal. The reference signal may be an SRS. Alternatively, the reference signal may be a demodulation reference signal (DMRS) included in the PUSCH (and PUCCH). The estimation of the channel state may include an estimation of the direction of arrival and / or the distance of arrival of the UE-UL signal. The NCR-UE 100B controls the NCR device 500A to direct the beam toward the UE 100A based on the estimated channel state.

[0121] The resource configuration information sent from the gNB 200 to the NCR-UE 100B may include at least one item selected from the group including: PUCCH configuration information indicating the PUCCH configuration of the UE 100A, PUSCH configuration information indicating the PUSCH configuration of the UE 100A, SRS configuration information indicating the SRS configuration of the UE 100A, and a C-RNTI assigned to the UE 100A.

[0122] Fig.15 is a diagram showing an example of the operation flow of the first operation mode. Fig.15 In the figure, dotted lines indicate non-essential steps.

[0123] In step S101, the gNB 200 establishes an RRC connection to the UE 100A and configures various resources (e.g., PUCCH resources, PUSCH resources, SRS resources, and C-RNTI) for the UE 100A. At this stage, the relay transmission of the NCR device 500A may not need to be performed. Alternatively, the gNB 200 may not need to configure various resources for the UE 100A at this stage, but may be performed in the following steps S108 to S109.

[0124] In step S102, NCR-UE 100B sends a capability notification (NCR capability information) to gNB 200, which indicates that NCR-UE 100B has uplink reception capability. gNB 200 receives the capability notification (NCR capability information).

[0125] In step S103, the gNB 200 sends a message to the NCR-UE 100B, the message including resource configuration information indicating resources for the NCR-UE 100B to receive the UE-UL signal from the UE 100A. The NCR-UE 100B receives the message. The message may be the same and / or similar to the above-mentioned downlink signaling. For example, the message may be an RRC reconfiguration, a MAC CE, or a DCI. The resource configuration information includes at least one of the following information elements (A1) to (A4).

[0126] (A1) PUCCH configuration The PUCCH configuration is an information element indicating the configuration of the PUCCH resource of the UE 100A. By the NCR-UE 100B acquiring such a PUCCH configuration, the NCR-UE 100B can receive the PUCCH of the UE 100A (and demodulate and decode the PUCCH). For example, the NCR-UE 100B uses the reference signal included in the PUCCH for channel estimation. The NCR-UE 100B can acquire the beam control information (e.g., precoding matrix indicator (PMI)) included in the PUCCH. An example of acquiring the beam control information will be described below.

[0127] (A2) PUSCH configuration The PUSCH configuration is an information element indicating the configuration of the PUSCH resource of the UE 100A. By acquiring such a PUSCH configuration by the NCR-UE 100B, the NCR-UE 100B can receive (and demodulate and decode) the PUSCH of the UE 100A. For example, the NCR-UE 100B uses the reference signal included in the PUSCH for channel estimation.

[0128] (A3) SRS configuration The PUSCH configuration is an information element indicating the configuration of the SRS resource of the UE 100A. By the NCR-UE 100B acquiring such SRS configuration, the NCR-UE 100B can receive (and demodulate) the SRS of the UE 100A. The NCR-UE 100B uses the SRS for channel estimation.

[0129] (A4) C-RNTI C-RNTI is a temporary identifier assigned to UE 100A by gNB 200. This C-RNTI can be used when NCR-UE 100B receives (and demodulates) signals of the above channels (e.g., PUCCH and PUSCH). Therefore, when NCR-UE 100B obtains the C-RNTI of UE 100A, it can smoothly receive (and demodulate) signals of the above channels.

[0130] In step S104, UE 100A transmits a UE-UL signal. NCR device 500A receives the UE-UL signal. The UE-UL signal includes at least one selected from the group consisting of PUCCH, PUSCH, and SRS. Here, NCR-UE 100B receives the UE-UL signal based on the resource configuration information received from gNB 200 in step S103.

[0131] In step S105, the NCR device 500A relays (transmits) the UE-UL signal received from the UE 100A in step S104 to the gNB 200. The gNB 200 receives the relayed UE-UL signal. The gNB 200 performs channel estimation based on the received UE-UL signal and determines the antenna weights for directing the beam to the NCR-UE 100B (i.e., the NCR device 500A). The antenna weights may be referred to as a precoding matrix.

[0132] In step S106 , the NCR-UE 100B performs channel estimation based on the UE-UL signal received from the UE 100A in step S104 .

[0133] In step S107, NCR-UE 100B controls the beam of NCR device 500A by using the channel estimation result in step S106 (beamforming control). For example, NCR-UE 100B determines the antenna weight that directs the beam to UE 100A and configures NCR device 500A using the antenna weight.

[0134] In step S108, the gNB 200 transmits a UE-DL signal to the NCR-UE 100B (NCR device 500A) while directing the beam toward the NCR-UE 100B. The NCR device 500A receives the UE-DL signal.

[0135] In step S109, the NCR device 500A relays (transmits) the UE-DL signal received from the gNB 200 in step S108 to the UE 100A. Here, the NCR device 500A transmits the UE-DL signal while directing the beam to the UE 100A according to the beamforming control in step S107.

[0136] In step S110, the UE 100A transmits a UE-UL signal. The NCR device 500A receives the UE-UL signal. The NCR device 500A may receive the UE-UL signal using the antenna weight configured in step S107 (ie, the directivity configured in step S107).

[0137] In step S111, the NCR device 500A relays (transmits) the UE-UL signal received from the UE 100A in step S104 to the gNB 200. The gNB 200 receives the relayed UE-UL signal.

[0138] Fig.16 Another example of the operation flow of the first operation mode is shown. Fig.16 In the figure, the dashed lines indicate non-essential steps. Fig.15 The differences in the operations.

[0139] In step S103, gNB 200 sends a message to NCR-UE 100B, the message including resource configuration information indicating resources for NCR-UE 100B to receive UE-UL signals from UE 100A. NCR-UE 100B receives the message. In addition to at least one of the above-mentioned information elements (A1) to (A4), the message may also include channel state information between gNB 200 and NCR device 500A and / or antenna weight information (precoding matrix information) of gNB 200.

[0140] In step S131, UE 100A transmits a UE-UL signal including beam control information. NCR device 500A receives the UE-UL signal. NCR-UE 100B receives the UE-UL signal based on the resource configuration information received from gNB 200 in step S103. The UE-UL signal may be a PUCCH. PUCCH may include PMI as beam control information. The beam control information is information based on a result of channel estimation performed on the UE 100A side. More specifically, the beam control information is information reflecting a channel state between gNB 200 and UE 100A (including NCR device 500A). The beam control information may be information indicating an antenna weight for directing a beam from NCR device 500A to UE 100A.

[0141] In step S132, the NCR-UE 100B acquires the antenna weight information included in the UE-UL signal received from the UE 100A in step S131.

[0142] In step S133, the NCR-UE 100B controls the beam of the NCR device 500A (beamforming control) using the antenna weight information acquired in step S132. For example, the NCR-UE 100B configures the NCR device 500A using the antenna weight indicated by the antenna weight information. When the antenna weight information indicates the channel state between the gNB 200 and the UE 100A, the NCR-UE 100B may also consider the channel state sent from the gNB 200 in step S103 (i.e., the channel state between the gNB 200 and the NCR device 500A) to derive the channel state between the NCR device 500A and the UE 100A. The NCR-UE 100B uses the derived channel state to determine the antenna weight for directing the beam to the UE 100A, and configures the NCR device 500A using the antenna weight.

[0143] Fig.16 Other operations in Fig.15 The operations in are the same and / or similar.

[0144] In the first operation mode, an example has been described in which one UE 100A is a relay target of the NCR device 500A, but there may be multiple UEs 100A as relay targets of the NCR device 500A. The NCR-UE 100B may perform the operation of the first operation mode for each of the multiple UEs 100A. In step S103, the gNB 200 may send a message to the NCR-UE 100B, the message including resource configuration information of each of the multiple UEs 100A.

[0145] Here, in the message, an index may be assigned to the resource configuration information of each UE 100A in the plurality of UEs 100A. After sending the resource configuration information in step S103, the gNB 200 may send an activation command (e.g., DCI or MAC CE) to the NCR-UE 100B, the activation command including an index specifying the resource configuration information to be actually applied. The NCR-UE 100B may apply the resource configuration information specified by the index in response to receiving the activation command.

[0146] It can be assumed that there are multiple UEs 100A as relay targets of the NCR device 500A and the multiple UEs 100A are close to each other. In this case, the NCR-UE 100B can perform the operation of the first operation mode on one UE 100A as a representative of the multiple UEs 100A. In step S103, the gNB 200 can send a message to the NCR-UE 100B, which includes resource configuration information of the one UE 100A.

[0147] (7.2) Second operating mode In the second operation mode, the configuration information sent from the gNB 200 to the NCR-UE 100B includes mode configuration information for switching a control mode related to beamforming between multiple control modes. The NCR-UE 100B controls the NCR device 500A to direct the beam to the UE 100A by using the control mode configured according to the mode configuration information. Such mode configuration information may be sent through an RRC message, a MAC CE, or a DCI. The mode configuration information may be information indicating to the NCR-UE 100B the control mode to be used after the switch. Alternatively, the mode configuration information may be information allowing a specific control mode of the NCR-UE 100B.

[0148] The multiple control modes may be two or more of the following modes: a “gNB control mode” in which the NCR-UE 100B controls the NCR device 500A according to the control from the gNB 200, an “autonomous control mode” in which the NCR-UE 100B autonomously controls the NCR device 500A regardless of the control from the gNB 200, a “hybrid control mode” in which the control from the gNB 200 and the autonomous control of the NCR-UE 100B are combined, and a “beam scanning control mode” in which the beam direction of the NCR device 500A is sequentially switched.

[0149] The "gNB control mode" is a mode in which the NCR-UE 100B controls the NCR device 500A based on specific control from the gNB 200. In the "gNB control mode", for example, the gNB 200 sequentially indicates to the NCR-UE 100B through the DCI or MAC CE the beam (antenna weight) to be applied to the NCR-UE 100B.

[0150] The "autonomous control mode" is a mode in which the gNB 200 does not provide specific control and the NCR-UE 100B autonomously controls the NCR device 500A. In the "autonomous control mode", for example, the NCR-UE 100B determines the beam (antenna weight) to be applied to the NCR-UE 100B, and the NCR-UE 100B performs beam steering on the NCR device 500A. The above-mentioned first operation mode can be regarded as a type of "autonomous control mode". In the "autonomous control mode", the NCR-UE 100B can estimate the position of the UE 100A using a sensor such as a short-range radar, and perform beam steering on the NCR device 500A based on the estimated position.

[0151] The "hybrid control mode" is a mode in which the gNB 200 performs coarse control on the NCR device 500A and the NCR-UE 100B autonomously performs specific control on the NCR device 500A. In the "hybrid control mode", for example, the gNB 200 specifies the beam direction (directivity direction) in increments of 45 degrees, and the NCR-UE 100B autonomously performs fine adjustment in increments of 45 degrees ± 5 degrees.

[0152] The "beam scanning control mode" is a mode in which the NCR-UE 100B sequentially switches the beam direction of the NCR device 500A. For example, the NCR device 500A sequentially switches the beam direction in a manner of rotating the beam 360° horizontally. The UE 100A detects a signal from the NCR device 500A in any beam direction and responds to it. Therefore, the direction in which the UE 100A is located can be estimated. Once the direction in which the UE 100A is located is estimated, the gNB 200 can switch the NCR-UE 100B to the "autonomous control mode".

[0153] Although an example has been described here in which the mode configuration information includes an information element for switching the "beamforming control mode" of the NCR device 500A, these information elements may be used to switch other control modes. For example, the mode configuration information may include an identifier indicating which of the "beamforming control mode", "timing switching control mode" and "on / off control mode" is to be applied. "Timing switching" is, for example, timing switching between uplink and downlink under TDD (time division duplex). "On / off control" is, for example, switching the operation of the NCR device 500A between stop (off) and start (on).

[0154] Fig.17 is a diagram showing an example of the operation flow of the second operation mode. Fig.17 In the figure, dotted lines indicate non-essential steps.

[0155] In step S201, the gNB 200 sends a message to the NCR-UE 100B, the message including mode configuration information for switching a control mode related to beamforming between multiple control modes. The NCR-UE 100B receives the message. The message may be the same and / or similar to the above-mentioned downlink signaling. For example, the message may be an RRC reconfiguration, a MAC CE, or a DCI. The mode configuration information includes at least one of the following information elements (B1) to (B3).

[0156] (B1) Identifier indicating the application target The identifier indicates, for example, any one of "beamforming control mode", "timing switching control mode", and "on / off control mode".

[0157] (B2) Mode identifier The identifier indicates, for example, any one of "gNB control mode", "autonomous control mode", "hybrid control mode", and "beam scanning control mode". Note that the present embodiment is not limited to specifying the control mode by such an explicit identifier, and the NCR-UE 100B may determine the control mode based on the configuration from the gNB 200. In other words, the gNB 200 may implicitly indicate the control mode to the NCR-UE 100B. For example, when various configurations are performed for the gNB control mode, the NCR-UE 100B may determine that the control mode is the gNB control mode, and when various configurations are performed for the autonomous control mode, the NCR-UE 100B may determine that the control mode is the autonomous control mode.

[0158] (B3) Timing information The timing information indicates the timing of applying or allowing application of the control mode indicated by the mode identifier through a period, a time slot number, etc. When the period is specified, periodic mode switching is enabled.

[0159] In step S202, the NCR-UE 100B determines the control mode based on the mode configuration information received from the gNB 200 in step S201. For example, the NCR-UE 100B may switch the "beamforming control mode" between the "gNB control mode" and the "autonomous control mode".

[0160] In the case of "gNB control mode", in step S203, the gNB 200 transmits beam control information for controlling the beam of the NCR-UE 100B to the NCR-UE 100B. The NCR-UE 100B receives the beam control information.

[0161] In step S204, the NCR-UE 100B controls the beam of the NCR device 500A according to the control mode determined in step S202 (beamforming control). The subsequent operations are the same and / or similar to those of the first operation mode described above.

[0162] (8) Variations of relay devices and control terminals The above embodiment describes an example in which the relay device that relays radio signals between the gNB 200 and the UE 100 (UE 100A) is a repeater device (NCR device 500A) that amplifies and transmits the received radio signal. However, the relay device that relays radio signals between the gNB 200 and the UE 100 (UE 100A) may be a reconfigurable smart surface (RIS) device that changes the propagation direction of the incident radio wave (radio signal) by reflection or refraction. "NCR" in the above embodiment may be changed to "RIS". RIS may perform beamforming (directivity control) in the same and / or similar manner as NCR by changing the characteristics of the metamaterial. In the case of RIS, by controlling the reflection direction and the refraction direction of each unit element, the range (distance) of the beam may be changed as in the case of a lens. For example, this configuration may allow the reflection direction and the refraction direction of each unit element to be controlled, and allow focusing to a nearby UE (directing the beam to a nearby UE) or focusing to a distant UE (directing the beam to a distant UE).

[0163] Fig.18 The RIS device 500B shown is a reflection type RIS device 500B. Such a RIS device 500B reflects incident radio waves to change the propagation direction of the radio waves. Here, the reflection angle of the radio waves can be variably configured. The RIS device 500B reflects the radio waves incident from the gNB 200 toward each of the UEs 100A1 and 100A2. The RIS device 500B can reflect the radio waves incident from each of the UEs 100A1 and 100A2 toward the gNB 200. The RIS device 500B dynamically changes the reflection angle of the radio waves. For example, in the communication resources between the gNB 200 and the UE 100A1, the RIS device 500B reflects the radio waves incident from the gNB 200 toward the UE 100A1 and / or reflects the radio waves incident from the UE 100A1 toward the gNB 200. Here, the communication resources include time direction resources and / or frequency direction resources. In the communication resources between gNB 200 and UE 100A2, RIS device 500B reflects radio waves incident from gNB 200 toward UE 100A2 and / or reflects radio waves incident from UE 100A2 toward gNB 200.

[0164] Fig.19The RIS device 500B shown is a transmission type RIS device 500B. Such a RIS device 500B refracts incident radio waves to change the propagation direction of the radio waves. Here, the refraction angle of the radio waves can be variably configured. The RIS device 500B refracts the radio waves incident from the gNB 200 toward each of the UEs 100A1 and 100A2. The RIS device 500B can refract the radio waves incident from each of the UEs 100A1 and 100A2 toward the gNB 200. The RIS device 500B dynamically changes the refraction angle of the radio waves. For example, in a communication resource between the gNB 200 and the UE 100A1, the RIS device 500B refracts the radio waves incident from the gNB 200 toward the UE 100A1 and / or refracts the radio waves incident from the UE 100A1 toward the gNB 200. In the communication resources between gNB 200 and UE 100A2, RIS device 500B refracts radio waves incident from gNB 200 toward UE 100A2 and / or refracts radio waves incident from UE 100A2 toward gNB 200.

[0165] like Fig. 20 As shown, a new UE (hereinafter referred to as "RIS-UE") 100C is introduced, which is a control terminal for controlling the RIS device 500B. The RIS-UE 100C controls the RIS device 500B in cooperation with the gNB 200 by establishing a wireless connection with the gNB 200 and performing wireless communication with the gNB 200. This can achieve effective coverage extension using the RIS device 500B while suppressing an increase in the installation cost of the RIS device 500B and a decrease in the degree of freedom of installation. The RIS-UE 100C controls the RIS device 500B according to the RIS control signal from the gNB 200.

[0166] The RIS-UE 100C may be configured separately from the RIS device 500B. For example, the RIS-UE 100C may be located near the RIS device 500B and may be electrically connected to the RIS device 500B. The RIS-UE 100C may be connected to the RIS device 500B by wire or wirelessly. The RIS-UE 100C may be configured integrally with the RIS device 500B. The RIS-UE 100C and the RIS device 500B may be fixedly mounted on, for example, a wall or a window. The RIS-UE 100C and the RIS device 500B may be mounted in, for example, a vehicle so as to be movable. One RIS-UE 100C may control a plurality of RIS devices 500B.

[0167] Fig.2122 is a diagram showing the configuration of a RIS-UE 100C and a RIS device 500B according to the present variation. As shown in FIG22 , the RIS-UE 100C includes a receiver 110, a transmitter 120, a controller 130, and an interface 140. This configuration is the same and / or similar to that in the above-described embodiment.

[0168] RIS device 500B includes RIS 510B and RIS controller 520B. RIS 510B is a metasurface configured using metamaterials. For example, RIS 510B is configured by arranging very small structures in an array form with respect to the wavelength of radio waves, wherein the direction and beam shape of the reflected wave can be arbitrarily designed by forming structures of different shapes depending on the arrangement position. RIS 510B can be a transparent dynamic metasurface. RIS 510B can be configured by stacking a transparent glass substrate on a metasurface substrate on which a large number of tiny structures are regularly arranged and which is transparent, and can be capable of dynamically controlling the following three modes by finely moving the stacked glass substrates: a mode of transmitting incident radio waves, a mode of transmitting a portion of radio waves and reflecting a portion thereof, and a mode of reflecting all radio waves.

[0169] RIS controller 520B controls RIS 510B in response to RIS control signals from controller 130 in RIS-UE 100C. RIS controller 520B may include at least one processor and at least one actuator. The processor interprets the RIS control signals from controller 130 in RIS-UE 100C to drive the actuator in response to the RIS control signals. Note that when RIS-UE 100C and RIS device 500B are configured as one body, controller 130 in RIS-UE 100C and RIS controller 520B in RIS device 500B may also be configured as one body.

[0170] (9) Other embodiments The NCR / RIS control information transmitted from the gNB 200 to the NCR-UE 100B or the RIS-UE 100C may be information for controlling the direction or focal length of a beam relayed (output) by the NCR device 500A or the RIS device 500B. The information for controlling the direction is, for example, the antenna weight as described above. The information for controlling the focal length is information for the NCR device 500A or the RIS device 500B to focus the beam according to the distance between the NCR device 500A or the RIS device 500B and the UE 100A. Such information may be information indicating the distance between the NCR device 500A or the RIS device 500B and the UE 100A. Alternatively, such information may be information indicating the focal length (e.g., a focal length range such as near or far). Based on the information, the NCR device 500A or the RIS device 500B adjusts the focal length of the beam. In the case of the RIS device 500B, the focus of the beam is adjusted like in the case of a lens by controlling the reflection (or refraction) angle of an element outside the metasurface and the reflection (or refraction) angle of an element inside the metasurface at different angles (causing a difference between the reflection (or refraction) angles).

[0171] In the above embodiments, the frequency control information may include a cell ID identifying a cell and / or a bandwidth part (BWP) ID identifying a BWP. A BWP is a part of a frequency band of a cell.

[0172] The above operation flows can be implemented separately and independently, and can also be implemented in a combination of two or more of the operation flows. For example, some steps in one operation flow can be added to another operation flow, or some steps in one operation flow can be replaced by some steps in another operation flow. In each flow, not all steps must be executed, but only some steps can be executed.

[0173] In the above embodiments, an example in which the base station is an NR base station (i.e., gNB) is described; however, the base station may be an LTE base station (i.e., eNB). The base station may be a relay node, such as an integrated access and backhaul (IAB) node. The base station may be a distributed unit (DU) of an IAB node.

[0174] A program that causes a computer to perform each of the processes performed by UE 100 (NCR-UE 100B, RIS-UE 100C) or gNB 200 may be provided. The program may be recorded in a computer-readable medium. The use of a computer-readable medium enables the program to be installed on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not specifically limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. A circuit for performing the processes to be performed by UE 100 or gNB 200 may be integrated, and at least a portion of UE 100 or gNB 200 may be implemented as a semiconductor integrated circuit (chip set, system on chip (SoC)).

[0175] Unless otherwise expressly stated, the phrases "based on" and "depending on" used in this disclosure do not mean "based only on" and "depending only on". The phrase "based on" means both "based only on" and "based at least in part on". The phrase "depending on" means both "depending only on" and "depending at least in part on". "Obtaining" or "obtaining" can mean obtaining information from stored information, can mean obtaining information from information received from another node, or can mean obtaining information by generating information. The terms "including", "comprising" and their variations do not mean "including only the items", but mean "may only include the items" or "may include not only the items but also other items". The term "or" used in this disclosure is not intended to be an "exclusive or". Any reference to elements using names such as "first" and "second" in this disclosure does not generally limit the number or order of these elements. These names can be used as a convenient method to distinguish two or more elements in this article. Therefore, the reference to the first element and the second element does not mean that only two elements can be used there or that the first element needs to be in some way before the second element. For example, when English articles such as "a", "an" and "the" are added in this disclosure by translation, these articles include plural unless the context clearly indicates otherwise.

[0176] The embodiments have been described in detail above with reference to the accompanying drawings, but the specific configuration is not limited to the above configuration, and various design changes may be made without departing from the gist of the present disclosure.

[0177] This application claims priority from Japanese Patent Application No. 2022-071094 (filed on April 22, 2022), the entire contents of which are incorporated herein by reference.

[0178] Additional Notes Features related to the above-described embodiment are described below as supplements. (1) A control terminal for controlling a relay device, the relay device relaying a radio signal between a base station and a user equipment in a mobile communication system, the control terminal comprising: a receiver, the receiver receiving, from a base station, configuration information used by a relay device to direct a beam toward a user equipment; and A controller controls the relay device to direct the beam toward the user equipment based on the configuration information. (2) The control terminal according to (1) above, wherein: The configuration information includes resource configuration information indicating resources used to control the terminal to receive an uplink signal from the user equipment, and The receiver receives an uplink signal from the user equipment by using the resource indicated by the resource configuration information, and The controller controls the relay device to direct the beam toward the user equipment according to the received uplink signal. (3) The control terminal according to (1) or (2) above, wherein: Controller estimating a channel state between the control terminal and the user equipment by using the received uplink signal, and The relay device is controlled to direct the beam toward the user equipment according to the estimated channel state. (4) The control terminal according to (2) or (3) above, wherein: The uplink signal includes beam control information, and Controller obtaining beam control information included in the received uplink signal, and The relay device is controlled to direct the beam toward the user equipment according to the acquired beam control information. (5) A control terminal according to any one of (2) to (4) above, wherein: The receiver receives a radio resource control (RRC) message including resource configuration information from a base station. (6) A control terminal according to any one of (2) to (5) above, wherein: The resource configuration information includes at least one item selected from the group consisting of: PUCCH configuration information indicating configuration of a physical uplink control channel (PUCCH) of the user equipment, PUSCH configuration information indicating configuration of a physical uplink shared channel (PUSCH) of the user equipment, sounding reference signal (SRS) configuration information indicating configuration of SRS of the user equipment, and a cell radio network temporary identifier (C-RNTI) assigned to the user equipment. (7) A control terminal according to any one of (1) to (6) above, wherein: The configuration information includes mode configuration information, the mode configuration information being used to switch a control mode related to beamforming between a plurality of control modes, and The controller controls the relay device to direct the beam toward the user equipment by using the control mode configured according to the mode configuration information. (8) The control terminal according to (7) above, wherein: The plurality of control modes include a base station control mode in which the control terminal controls the relay device according to control from the base station. (9) The control terminal according to (7) or (8) above, wherein: The various control modes include an autonomous control mode in which the control terminal autonomously controls the relay device without relying on control from the base station. (10) A control terminal according to any one of (7) to (9) above, wherein: The various control modes also include a hybrid control mode in which control from a base station and autonomous control of a control terminal are used in combination. (11) A control terminal according to any one of (7) to (10) above, wherein: The plurality of control modes also include a beam scanning control mode in which the beam direction of the relay device is sequentially switched. (12) A control terminal according to any one of (7) to (11) above, wherein: The receiver receives a radio resource control (RRC) message including mode configuration information, a medium access control (MAC) control element (CE) including mode configuration information, or downlink control information (DCI) including mode configuration information from a base station. (13) A control terminal according to any one of (7) to (12) above, wherein: The mode configuration information includes information for switching any one of the following control modes: a control mode of beamforming of the relay device, a control mode of timed switching of the relay device, and a control mode of on / off control of the relay device. (14) A control terminal according to any one of (7) to (13) above, wherein: The mode configuration information includes information specifying the timing of switching of the control mode. (15) A base station used in a mobile communication system including a control terminal, the control terminal controlling a relay device, the relay device relaying a radio signal between the base station and a user equipment, the base station comprising: A transmitter sends configuration information used by the relay device to direct the beam to the user equipment to the control terminal. (16) A communication method performed by a control terminal, the control terminal controlling a relay device for relaying a radio signal between a base station and a user equipment in a mobile communication system, the communication method comprising: receiving, from the base station, configuration information used by the relay device to direct the beam toward the user equipment; and The relay device is controlled to direct the beam toward the user equipment based on the configuration information. Reference numerals

[0195] 1: Mobile communication system 100: UE 100B: NCR-UE 100C:RIS-UE 110: Receiver 120: Transmitter 130: Controller 140: Interface 200: gNB 210: Transmitter 220: Receiver 230: Controller 240: Backhaul Communicator 500A: NCR device 500B:RIS device 510A: Wireless unit 510a: Antenna unit 510b: RF circuit 510c: Directional Controller 520A: NCR controller 520B:RIS controller.

Claims

1. A control terminal configured to control a relay device configured to relay a radio signal between a base station and a user equipment in a mobile communication system, the control terminal comprising: a receiver configured to receive, from the base station, configuration information used by the relay device to direct the beam toward the user equipment; as well as The controller is configured to control the relay device to direct the beam toward the user equipment based on the configuration information.

2. The control terminal according to claim 1, wherein: The configuration information includes resource configuration information, the resource configuration information indicating resources used for the control terminal to receive an uplink signal from the user equipment, and The receiver is configured to: receive an uplink signal from the user equipment by using resources indicated by the resource configuration information, and The controller is configured to control the relay device to direct the beam toward the user equipment according to the received uplink signal.

3. The control terminal according to claim 2, wherein: The controller is configured to: estimating a channel state between the control terminal and the user equipment by using the received uplink signal, and The relay device is controlled to direct the beam toward the user equipment according to the estimated channel state.

4. The control terminal according to claim 2, wherein: The uplink signal includes beam control information, and The controller is configured to: obtaining beam control information included in the received uplink signal, and The relay device is controlled to direct the beam toward the user equipment according to the acquired beam control information.

5. The control terminal according to claim 2, wherein: The receiver is configured to receive a Radio Resource Control (RRC) message including the resource configuration information from the base station.

6. The control terminal according to any one of claims 2 to 5, wherein: The resource configuration information includes at least one item selected from the group consisting of: PUCCH configuration information indicating the configuration of a physical uplink control channel PUCCH of the user equipment, PUSCH configuration information indicating the configuration of a physical uplink shared channel PUSCH of the user equipment, SRS configuration information indicating the configuration of a sounding reference signal SRS of the user equipment, and a cell radio network temporary identifier C-RNTI assigned to the user equipment.

7. The control terminal according to claim 1, wherein: The configuration information includes mode configuration information, wherein the mode configuration information is used to switch a control mode related to beamforming between multiple control modes, and The controller is configured to control the relay device to direct the beam toward the user equipment by using a control mode configured according to the mode configuration information.

8. The control terminal according to claim 7, wherein: The plurality of control modes include a base station control mode in which the control terminal controls the relay device according to control from the base station.

9. The control terminal according to claim 7 or 8, wherein: The plurality of control modes include an autonomous control mode in which the control terminal autonomously controls the relay device without relying on control from the base station.

10. The control terminal according to claim 7 or 8, wherein: The plurality of control modes also include a hybrid control mode in which control from the base station and autonomous control of the control terminal are used in combination.

11. The control terminal according to claim 7 or 8, wherein: The plurality of control modes further include a beam scanning control mode in which the beam directions of the relay device are sequentially switched.

12. The control terminal according to claim 7 or 8, wherein: The receiver is configured to receive, from the base station, a radio resource control RRC message including the mode configuration information, a medium access control MAC control element CE including the mode configuration information, or downlink control information DCI including the mode configuration information.

13. The control terminal according to claim 7 or 8, wherein: The mode configuration information includes information for switching any one of the following control modes: a control mode of beamforming of the relay device, a control mode of timing switching of the relay device, and a control mode of on / off control of the relay device.

14. The control terminal according to claim 7 or 8, wherein: The mode configuration information includes information specifying a timing of switching of the control mode.

15. A base station for use in a mobile communication system comprising a control terminal, the control terminal being configured to control a relay device, the relay device being configured to relay a radio signal between the base station and a user equipment, the base station comprising: The transmitter is configured to send configuration information used by the relay device to direct the beam to the user equipment to the control terminal.

16. A communication method performed by a control terminal, the control terminal being configured to control a relay device, the relay device being configured to relay a radio signal between a base station and a user equipment in a mobile communication system, the communication method comprising the steps of: receiving, from the base station, configuration information used by the relay device to direct a beam toward the user equipment; and The relay device is controlled based on the configuration information to direct the beam toward the user equipment.

Images