Communication method, control terminal, network node, chipset, program, and system

Abstract

Provided is a communication method that is performed in a control terminal that controls a relay device for relaying radio waves between a base station and a user device, the communication method comprising: a step for receiving, from the base station wirelessly connecting to the control terminal, a control signal designating an operation state of the relay device as layer-1 or layer-2 signaling; and a step for controlling the relay device so as to apply the operation state designated by the control signal. The step for receiving includes a step for receiving the control signal in a time interval prior to a time interval in which the operation state designated by the control signal is applied.

Description

Technical Field

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

Background Art

[0002] In recent years, the fifth-generation (5G) mobile communication system has attracted attention. NR (New Radio), which is a radio access technology of the 5G system, enables broadband transmission in a high-frequency band compared to LTE (Long Term Evolution), which is a fourth-generation radio access technology.

[0003] Since radio waves in high-frequency bands such as the millimeter-wave band or the terahertz-wave band have high directivity, reducing the coverage of the base station becomes an issue. To solve such an issue, a repeater device that relays radio waves between a base station and a user device and can be controlled from a network has attracted attention (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, for example, by amplifying radio waves received from the base station and transmitting them by directional transmission.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

[0005] The communication method according to the first aspect is a method executed by a control terminal that controls a relay device that relays radio waves between a base station and a user equipment. The communication method includes receiving, as layer 1 or layer 2 signaling, a control signal that specifies an operating state of the relay device from the base station wirelessly connected to the control terminal, and controlling the relay device so as to apply the operating state specified by the control signal. The receiving step includes receiving the control signal in a time interval prior to a time interval in which the operating state specified by the control signal is to be applied.

[0006] The control terminal according to the second aspect is a device that controls a relay device that relays radio waves between a base station and a user equipment. The control terminal includes a receiving unit that receives, by layer 1 or layer 2 signaling, a control signal that specifies an operating state of the relay device from the base station wirelessly connected to the control terminal, and a control unit that controls the relay device so as to apply the operating state specified by the control signal. The receiving unit receives the control signal in a time interval prior to a time interval in which the operating state specified by the control signal is to be applied.

[0007] The base station according to the third aspect is the base station wirelessly connected to a control terminal that controls a relay device that relays radio waves between the base station and a user equipment. The base station includes a transmitting unit that transmits, as layer 1 or layer 2 signaling, a control signal that specifies an operating state of the relay device. The transmitting unit transmits the control signal in a time interval prior to a time interval in which the operating state specified by the control signal is to be applied.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

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

[0010] Therefore, an object of the present disclosure is to appropriately control a relay device that relays radio waves between a base station and a user device.

[0011] A mobile communication system according to an embodiment will be described with reference to the 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 the mobile communication system FIG. 1 is a diagram showing the configuration of a mobile communication system according to an embodiment. The mobile communication system 1 complies with the 5th generation system (5GS) of the 3GPP standard. Hereinafter, 5GS will be described as an example, but the LTE (Long Term Evolution) system may be at least partially applied to the mobile communication system. Also, the 6th 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 (NG-RAN) 10, and a 5G core network (5GC) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. Also, the 5GC 20 may be simply referred to as the core network (CN) 20.

[0014] The UE 100 is a movable wireless communication device. The UE 100 can be any device as long as it is used by a user. For example, the UE 100 can be a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided on the sensor, a vehicle or a device provided on the vehicle (Vehicle UE), an aircraft or a device provided on the aircraft (Aerial UE).

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

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

[0017] The 5GC 20 includes an AMF (Access and Mobility Management Function) and a UPF (User Plane Function) 300. The AMF performs various mobility controls for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using NAS (Non-Access Stratum) signaling. The UPF performs data transfer control. The AMF and the UPF are connected to the gNB 200 via the NG interface, which is an interface between the base station and the core network.

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

[0019] The radio interface protocol of the user plane has a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an SDAP (Service Data Adaptation Protocol) layer.

[0020] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Between the PHY layer of UE100 and the PHY layer of gNB200, data and control information are transmitted via physical channels. Note that the PHY layer of UE100 receives downlink control information (DCI) transmitted on the physical downlink control channel (PDCCH) from gNB200. Specifically, UE100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and obtains the DCI that has been successfully decoded as DCI addressed to itself. The DCI transmitted from gNB200 has CRC parity bits scrambled by the RNTI added to it.

[0021] The MAC layer performs priority control of data, retransmission processing by hybrid automatic repeat request (HARQ), and random access procedures, etc. Between the MAC layer of UE100 and the MAC layer of gNB200, data and control information are transmitted via transport channels. The MAC layer of gNB200 includes a scheduler. The scheduler determines the uplink and downlink transport formats (transport block size, modulation and coding scheme (MCS)) and the resource blocks allocated to UE100.

[0022] The RLC layer uses the functions of the MAC layer and the PHY layer to transmit data to the RLC layer on the receiving side. Between the RLC layer of UE100 and the RLC layer of gNB200, data and control information are transmitted via logical channels.

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

[0024] The SDAP layer performs the mapping between the IP flow, which is the unit for the core network to perform QoS (Quality of Service) control, and the radio bearer, which is the unit for the AS (Access Stratum) to perform QoS control. Note that when the RAN is connected to the EPC, the SDAP may not be necessary.

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

[0026] The protocol stack of the radio interface of the control plane has an RRC (Radio Resource Control) layer and a NAS (Non-Access Stratum) layer instead of the SDAP layer shown in 2 the figure.

[0027] Between the RRC layer of UE100 and the RRC layer of gNB200, RRC signaling for various settings is transmitted. The RRC layer controls the logical channel, transport channel, and physical channel in response to the establishment, re-establishment, and release of the radio bearer. When there is a connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in the RRC connected state. When there is no connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in the RRC idle state. When the connection between the RRC of UE100 and the RRC of gNB200 is suspended, UE100 is in the RRC inactive state.

[0028] The NAS layer located above the RRC layer performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of UE100 and the NAS layer of AMF300A. Note that UE100 has an application layer, etc. in addition to the protocol of the radio interface. Also, the layer below the NAS layer is called the AS layer.

[0029] (2) Application Scenario of the Relay Device Next, the application scenario of the NCR device, which is a relay device according to the embodiment, will be described. FIGS. 4 and 5 are diagrams showing the application scenario of the NCR device according to the embodiment.

[0030] 5G / NR can perform broadband transmission using a high-frequency band compared to 4G / LTE. Since radio waves in high-frequency bands such as the millimeter-wave band or the terahertz wave band have high directivity, reducing the coverage of gNB200 becomes an issue. In FIG. 4, UE100A may be located outside the coverage area of gNB200, for example, outside the area where radio waves can be directly received from gNB200. There may be an obstacle between gNB200 and UE100A, and UE100A may not be able to communicate within the line of sight with gNB200.

[0031] In the embodiment, a repeater device (500A), which is a type of relay device that relays radio waves between gNB200 and UE100A and can be controlled from the network, is introduced into the mobile communication system 1. Hereinafter, such a repeater device is referred to as an NCR (Network-Controlled Repeater) device. Such a repeater device may also be referred to as a smart repeater device.

[0032] For example, the NCR device 500A amplifies radio waves (wireless signals) received from the gNB 200 and transmits them by directional transmission. Specifically, the NCR device 500A receives the wireless signals transmitted by the gNB 200 by beamforming. Then, the NCR device 500A amplifies the received wireless signals and transmits the amplified wireless signals by directional transmission. Here, the NCR device 500A may transmit wireless signals with a fixed directivity. Also, the NCR device 500A may transmit wireless signals with a variable (adaptive) directional beam. Thereby, the coverage of the gNB 200 can be efficiently extended. In the embodiment, it is mainly assumed that the NCR device 500A is applied to the downlink communication from the gNB 200 to the UE 100A, but the NCR device 500A can also be applied to the uplink communication from the UE 100A to the gNB 200.

[0033] Also, as shown in FIG. 5, a new UE (hereinafter referred to as "NCR-UE") 100B, which is a type of control terminal for controlling the NCR device 500A, is introduced. The NCR-UE 100B establishes a wireless connection with the gNB 200 and performs wireless communication with the gNB 200, thereby controlling the NCR device 500A in cooperation with the gNB 200. Thereby, efficient coverage expansion can be realized 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-UE100B may be configured separately from the NCR device 500A. For example, the NCR-UE100B may be in the vicinity of the NCR device 500A and electrically connected to the NCR device 500A. The NCR-UE100B may be connected to the NCR device 500A by wire or wirelessly. Alternatively, the NCR-UE100B may be configured integrally with the NCR device 500A. The NCR-UE100B and the NCR device 500A may be fixedly installed, for example, at the coverage edge (cell edge) of the base station 200, or on the wall or window of some building. The NCR-UE100B and the NCR device 500A may be installed on a vehicle or the like and may be movable. Also, one NCR-UE100B may control a plurality of NCR devices 500A.

[0035] In the example shown in FIG. 5, the NCR device 500A dynamically or quasi-statically changes the beams to be transmitted or received. For example, the NCR device 500A forms beams toward each of the UEs 100A1 and 100A2. Also, the NCR device 500A may 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 the radio waves received from the gNB 200 toward the UE 100A1 by beamforming. And / or, the NCR device 500A transmits the radio waves received from the UE 100A1 toward the gNB 200 by beamforming. The NCR device 500A transmits the radio waves received from the gNB 200 toward the UE 100A2 by beamforming in the communication resources between the gNB 200 and the UE 100A2. And / or, the NCR device 500A transmits the radio waves received from the UE 100A2 toward the gNB 200 by beamforming. Instead of or in addition to forming beams, the NCR device 500A may perform null formation (so-called null steering) toward UEs 100 (not shown) that are not communication partners and / or adjacent gNBs 200 (not shown) for interference suppression. In the following, a beam (beamforming) may be read as a null (null steering). Alternatively, a beam (beamforming) may be read as a beam and a null (beamforming and null steering).

[0036] FIG. 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 an embodiment.

[0037] As shown in FIG. 6, the NCR device 500A relays radio signals transmitted and received between the gNB 200 and the UE 100A. The NCR device 500A has an RF (Radio Frequency) function of amplifying and relaying the received radio signals, and performs directional transmission by beamforming (for example, analog beamforming).

[0038] The NCR-UE100B has at least one layer (entity) among the PHY, MAC, RRC, and F1-AP (Application Protocol). The F1-AP is a type of fronthaul interface. The NCR-UE100B communicates with the gNB200 through at least one of the PHY, MAC, RRC, and F1-AP for the following downlink signaling and / or uplink signaling. If the NCR-UE100B is a type or part of a base station, the NCR-UE100B may communicate with the gNB200 through the Xn-AP (Xn Application Protocol) which is an interface between base stations.

[0039] (3) Configuration Examples of Control Terminals and Relay Devices Next, the configurations of the NCR-UE100B (control terminal) and the NCR device 500A (relay device) according to the embodiment will be described. FIG. 7 is a diagram showing a configuration example of the NCR-UE100B and the NCR device 500A according to the embodiment.

[0040] As shown in FIG. 7, the NCR-UE100B includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140.

[0041] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts the radio wave (wireless signal) received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130. The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmitted signal) output by the control unit 130 into a wireless signal and transmits it from the antenna.

[0042] The control unit 130 performs various controls in the NCR-UE 100B. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for the processor's processing. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals, etc. The CPU executes programs stored in the memory to perform various processes. Also, the control unit 130 executes the functions of at least one layer of PHY, MAC, RRC, and F1-AP.

[0043] The interface 140 is electrically connected to the NCR device 500A. The control unit 130 controls the NCR device 500A via the interface 140. When the NCR-UE 100B and the NCR device 500A are integrally configured, the NCR-UE 100B may not have the interface 140. Also, the receiving unit 110 and the transmitting unit 120 of the NCR-UE 100B may be integrally configured with the radio unit 510A of the NCR device 500A.

[0044] The NCR device 500A has a radio unit 510A and an NCR control unit 520A. The radio unit 510A has an antenna unit 510a including a plurality of antennas, an RF circuit 510b including an amplifier, and a directivity control unit 510c for controlling the directivity of the antenna unit 510a. The RF circuit 510b amplifies and relays (transmits) the radio signals transmitted and received by the antenna unit 510a. The RF circuit 510b may convert the radio signals, which are analog signals, into digital signals, and then reconvert them into analog signals after digital signal processing. The directivity control unit 510c may perform analog beamforming by analog signal processing. Also, the directivity control unit 510c may perform digital beamforming by digital signal processing. Also, the directivity control unit 510c may perform an analog and digital hybrid type of beamforming.

[0045] The NCR control unit 520A controls the radio unit 510A according to the control signal from the control unit 130 of the NCR-UE 100B. The NCR control unit 520A may include at least one processor. The NCR control unit 520A may output information regarding the capabilities of the NCR device 500A to the NCR-UE 100B. Note that when the NCR-UE 100B and the NCR device 500A are integrally configured, the control unit 130 of the NCR-UE 100B and the NCR control unit 520A of the NCR device 500A may also be integrally configured.

[0046] In an embodiment, the receiving unit 110 of the NCR-UE 100B receives signaling (downlink signaling) used for controlling the NCR device 500A from the gNB 200 by wireless communication. The control unit 130 of the NCR-UE 100B controls the NCR device 500A based on the signaling. Thereby, the gNB 200 can control the NCR device 500A via the NCR-UE 100B.

[0047] In an embodiment, the control unit 130 of the NCR-UE 100B controls the NCR device 500A. The control unit 130 of the NCR-UE 100B acquires NCR capability information indicating the capabilities of the NCR device 500A from the NCR device 500A (NCR control unit 520A). Then, the transmitting unit 120 of the NCR-UE 100B transmits the acquired NCR capability information to the gNB 200 by wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE 100B to the gNB 200. Thereby, the gNB 200 can grasp the capabilities of the NCR device 500A.

[0048] (4) Configuration example of the base station Next, the configuration of the gNB 200 (base station) according to the embodiment will be described. FIG. 8 is a diagram showing a configuration example of the gNB 200 according to the embodiment.

[0049] As shown in FIG. 8, the gNB 200 includes a transmitting unit 210, a receiving unit 220, a control unit 230, and a backhaul communication unit 240.

[0050] The transmission unit 210 performs various transmissions under the control of the control unit 230. The transmission unit 210 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna. The reception unit 220 performs various receptions under the control of the control unit 230. The reception unit 220 includes an antenna and a receiver. The receiver converts the radio signal received by the antenna into a baseband signal (reception signal) and outputs it to the control unit 230. The transmission unit 210 and the reception unit 220 may be capable of beamforming using a plurality of antennas.

[0051] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals, etc. The CPU executes programs stored in the memory to perform various processes.

[0052] The backhaul communication unit 240 is connected to an adjacent base station via a base station interface. The backhaul communication unit 240 is connected to the AMF / UPF 300 via a base station-core network interface. Note that the gNB is composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally split), and the two units may be connected by an F1 interface.

[0053] In the embodiment, the transmission unit 210 of the gNB 200 transmits, by wireless communication, signaling (downlink signaling) used for controlling the NCR device 500A to the NCR-UE 100B that controls the NCR device 500A. Thereby, the gNB 200 can control the NCR device 500A via the NCR-UE 100B.

[0054] In an embodiment, the receiving unit 220 of the gNB 200 receives, via wireless communication, NCR capability information indicating the capabilities of the NCR device 500A from the NCR-UE 100B that controls the NCR device 500A. 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 grasp the capabilities of the NCR device 500A.

[0055] (5) Operation of the mobile communication system Next, the operation of the mobile communication system 1 according to the embodiment will be described.

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

[0057] The gNB 200 (transmitting unit 210) transmits downlink signaling to the NCR-UE 100B. The downlink signaling may be an RRC message which is signaling of the RRC layer (i.e., layer 3). Also, the downlink signaling may be a MAC CE (Control Element) which is signaling of the MAC layer (i.e., layer 2). Also, the downlink signaling may be downlink control information (DCI) which is signaling of the PHY layer (i.e., layer 1). The downlink signaling may be UE-specific signaling. Also, the downlink signaling may be broadcast signaling. The downlink signaling may be a fronthaul message (e.g., an F1-AP message). If the NCR-UE 100B is a type or part of a base station, the NCR-UE 100B may communicate with the gNB 200 via the Xn-AP which is an interface between base stations.

[0058] For example, as shown in FIG. 9, the gNB 200 (transmission unit 210) transmits an NCR control signal for specifying the operating state of the NCR device 500A to the NCR-UE 100B that has established a radio connection with the gNB 200 (step S1). In the following embodiments, an example in which the NCR control signal for specifying the operating state of the NCR device 500A is a MAC CE that is signaling of the MAC layer (layer 2) or DCI that is signaling of the PHY layer (layer 1) will be mainly described. However, an NCR control signal may be included in an RRC Reconfiguration message, which is a type of RRC message for each UE, and transmitted to the NCR-UE 100B. The downlink signaling may be a message of a layer higher than the RRC layer (for example, the NCR application). The downlink signaling may encapsulate a message of a layer higher than the RRC layer and transmit it as a message of a layer below the RRC layer. Note that the NCR-UE 100B (transmission unit 120) may transmit an uplink response message to the downlink signaling from the gNB 200. The response message may be transmitted in response to the NCR device 500A completing or receiving the setting specified by the downlink signaling.

[0059] As shown in FIG. 10, the NCR control signal may include frequency control information for specifying the center frequency of a radio wave (for example, a component carrier) to be relayed by the NCR device 500A. When the NCR control signal received by the NCR-UE 100B (control unit 130) includes frequency control information, the NCR-UE 100B controls the NCR device 500A to relay the radio wave having the center frequency indicated by the frequency control information (step S2). The NCR control signal may include a plurality of pieces of frequency control information specifying different center frequencies. By including the frequency control information in the NCR control signal, the gNB 200 can specify, via the NCR-UE 100B, the center frequency of the radio wave to be relayed by the NCR device 500A.

[0060] The NCR control signal may include mode control information that specifies the operation mode of the NCR device 500A. The mode control information may be associated with frequency control information (center frequency). The operation mode may be any one of a mode in which the NCR device 500A performs omnidirectional 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 using a variable-directional beam, and a mode in which the NCR device 500A performs MIMO (Multiple Input Multiple Output) relay transmission. The operation mode may be any one of a beamforming mode (i.e., a mode that emphasizes desired wave improvement) and a null steering mode (i.e., a mode that emphasizes interference wave suppression). When the NCR control signal received by the NCR-UE100B (control unit 130) from the gNB200 includes mode control information, the NCR device 500A is controlled to operate in the operation mode indicated by the mode control information (step S2). By including the mode control information in the NCR control signal, the gNB200 can specify the operation mode of the NCR device 500A via the NCR-UE100B.

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

[0062] The mode in which the NCR device 500A performs fixed-directional transmission and / or reception may be a directional mode realized by one directional antenna. Also, the mode for performing the transmission and / or reception may be a beamforming mode realized by applying fixed phase and amplitude control (antenna weight control) to a plurality of antennas. Any of these modes may be specified (set) by the gNB200 for the NCR-UE100B.

[0063] The mode in which the NCR device 500A performs transmission and / or reception using a variable directivity beam may be a mode of performing analog beamforming. Also, the mode of performing the said transmission and / or reception may be a mode of performing digital beamforming. Further, the mode of performing the said transmission and / or reception may be a mode of performing hybrid beamforming. The said mode may be a mode of forming an adaptive beam specific to the UE100A. Any of these modes may be specified (configured) by the gNB200 for the NCR-UE100B.

[0064] Note that in the operation mode of performing beamforming, the beam control information described later may be provided from the gNB200 to the NCR-UE100B.

[0065] The mode in which the NCR device 500A performs MIMO relay transmission may be a mode of performing SU (Single-User) spatial multiplexing. Also, the mode of performing the said MIMO relay transmission may be a mode of performing MU (Multi-User) spatial multiplexing. Further, the mode of performing the said MIMO relay transmission may be a mode of performing transmit diversity. Any of these modes may be specified (configured) by the gNB200 for the NCR-UE100B.

[0066] The operation mode may include a mode of turning on (activating) the relay transmission by the NCR device 500A and a mode of turning off (deactivating) the relay transmission by the NCR device 500A. Any of these modes may be specified (configured) for the NCR-UE100B by the gNB200 using an NCR control signal.

[0067] The NCR control signal may include beam control information that specifies the transmission direction, transmission weight, or beam pattern when the NCR device 500A performs directional transmission. The beam control information may be associated with frequency control information (center frequency). The beam control information may include a PMI (Precoding Matrix Indicator). When the NCR control signal received by the NCR-UE 100B (control unit 130) includes beam control information, the NCR device 500A is controlled to form the transmission directivity (beam) indicated by the beam control information (step S2). By including the beam control information in the NCR control signal, 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 that specifies the degree of amplification (amplification gain) of the radio wave by the NCR device 500A or the transmission power. The output control information may be information indicating the difference value (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 by the NCR-UE 100B (control unit 130) includes output control information, the NCR device 500A is controlled to change to the amplification gain or transmission power indicated by the output control information (step S2). The output control information may be associated with frequency control information (center frequency). The output control information may be information specifying any one of the amplifier gain, beamforming gain, and antenna gain of the NCR device 500A. The output control information may be information 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 (transmission unit 210) may transmit an NCR control signal to the NCR-UE 100B for each NCR device 500A. In this case, the NCR control signal may include an identifier (NCR identifier) of the corresponding NCR device 500A. The NCR-UE 100B (control unit 130) that controls the plurality of NCR devices 500A determines the NCR device 500A to which the NCR control signal is to be 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 with the NCR control signal NB200 from NCR-UE100B to

[0070] In this way, the NCR-UE 100B (control unit 130) controls the NCR device 500A based on the NCR control signal from the gNB 200. Thereby, the gNB 200 can control the NCR device 500A via the NCR-UE 100B.

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

[0072] The NCR-UE100B (transmission unit 210) transmits uplink signaling to the gNB200. The uplink signaling may be an RRC message, which is signaling at the RRC layer. Also, the uplink signaling may be a MAC CE, which is signaling at the MAC layer. Further, the uplink signaling may be uplink control information (UCI), which is signaling at the PHY layer. The uplink signaling may be a fronthaul message (e.g., an F1-AP message). Also, the uplink signaling may be an inter-base station message (e.g., an Xn-AP message). The uplink signaling may be a message from a layer higher than the RRC layer (e.g., an NCR application). The uplink signaling may encapsulate a message from a layer higher than the RRC layer and transmit it as a message from a layer below the RRC layer. Note that the gNB200 (transmission unit 210) may transmit a response message to the uplink signaling from the NCR-UE100B over the downlink, and the NCR-UE100B (reception unit 110) may receive the response message.

[0073] For example, the NCR-UE100B (transmission unit 120) that has established a radio connection with the gNB200 transmits NCR capability information indicating the capabilities of the NCR device 500A to the gNB200 by wireless communication (step S5). The NCR-UE100B (transmission unit 120) may transmit the NCR capability information to the gNB200 by including it in a UE Capability message or a UE Assistant Information message, which are types of RRC messages. The NCR-UE100B (transmission unit 120) may transmit the NCR capability information (NCR capability information and / or operating state information) to the gNB200 in response to a request or inquiry from the gNB200.

[0074] As shown in FIG. 12, the NCR capability information may include corresponding frequency information indicating the frequency to which the NCR device 500A corresponds. The corresponding frequency information may be a numerical value or index indicating the center frequency of the frequency to which the NCR device 500A corresponds. Further, the corresponding frequency information may be a numerical value or index indicating the range of the frequency to which the NCR device 500A corresponds. When the NCR capability information received from the NCR-UE 100B by the gNB 200 (control unit 230) includes the corresponding frequency information, the gNB 200 (control unit 230) can grasp the frequency to which the NCR device 500A corresponds based on the corresponding frequency information. Then, the gNB 200 (control unit 230) may set the center frequency of the radio wave targeted by the NCR device 500A within the range of the frequency to which the NCR device 500A corresponds.

[0075] The NCR capability information may include mode capability information regarding the operation mode that the NCR device 500A can support or the switching between operation modes. As described above, the operation mode includes at least one of a mode in which the NCR device 500A performs omnidirectional 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 using a variable-directional beam, and a mode in which the NCR device 500A performs MIMO (Multiple Input Multiple Output) relay transmission. The operation mode may be either a beamforming mode (i.e., a mode that emphasizes improving the desired wave) or a null steering mode (i.e., a mode that emphasizes suppressing interference waves). The mode capability information may be information indicating which of these operation modes the NCR device 500A can support. The mode capability information may be information indicating between which of these operation modes mode switching is possible. When the NCR capability information received from the NCR-UE 100B by the gNB 200 (control unit 230) includes the mode capability information, the gNB 200 (control unit 230) can grasp the operation mode and mode switching to which the NCR device 500A corresponds based on the mode capability information. Then, the gNB 200 (control unit 230) may set the operation mode of the NCR device 500A within the grasped range of the operation mode and mode switching.

[0076] The NCR capability information may include beam capability information indicating the beam variable range, beam variable resolution, or the number of variable patterns when the NCR device 500A performs transmission and / or reception using a variable directional beam. The beam capability information may be, for example, information indicating the variable range of the beam angle (e.g., controllable within 30° to 90°) based on the horizontal or vertical direction. Also, the beam capability information may be information indicating the absolute angle. The beam capability information may be expressed by the azimuth and / or elevation angle at which the beam is directed. The beam capability information may be information indicating the angle change for each variable step (e.g., 5° / step horizontally, 10° / step vertically). Also, the beam capability information may be information indicating the number of variable steps (e.g., 10 steps horizontally, 20 steps vertically). The beam capability information may be information indicating the number of variable patterns of the beam in the NCR device 500A (e.g., a total of 10 patterns from beam pattern 1 to 10). When the NCR capability information received from the NCR-UE 100B includes beam capability information, the gNB 200 (control unit 230) can grasp the beam angle change or beam pattern that the NCR device 500A can handle based on the beam capability information. Then, the gNB 200 (control unit 230) may set the beam of the NCR device 500A within the grasped range of the beam angle change or beam pattern. These beam capability information may be null capability information. In the case of null capability information, it indicates the null control capability when null steering is performed.

[0077] The NCR capability information may include control delay information indicating the control delay time in the NCR device 500A. For example, the control delay information is information indicating the delay time (e.g., 1 ms, 10 ms, etc.) from the timing when the UE 100 receives the NCR control signal or the timing when the completion of the setting for the NCR control signal is transmitted to the gNB 200 until the control (change of the operation mode, change of the beam, etc.) according to the NCR control signal is completed. When the NCR capability information received from the NCR-UE 100B by the gNB 200 (control unit 230) includes the control delay information, the gNB 200 can grasp 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 regarding the amplification characteristic or output power characteristic of radio waves in the NCR device 500A. The amplification characteristic information may be information indicating the amplifier gain (dB), beamforming gain (dB), and antenna gain (dBi) of the NCR device 500A. The amplification characteristic information may be information indicating the variable amplification 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 of the amplification degree that can be changed by the NCR device 500A (e.g., 10 steps), or the amplification degree per variable step (e.g., 10 dB / step). The amplification characteristic information may be information indicating the variable range of the output power of the NCR device 500A (e.g., 0 dBm to 30 dBm). The amplification characteristic information may be information indicating the number of steps of the output power that can be changed by the NCR device 500A (e.g., 10 steps), or the output power per variable step (e.g., 10 dBm / step).

[0079] The NCR capability information may include position information indicating the installation position of the NCR device 500A. The position information may include any one or more of latitude, longitude, and altitude. The position information may include information indicating the distance and / or installation angle of the NCR device 500A with respect to the gNB 200. The installation angle may be the relative angle with the gNB 200, or may be the relative angle based on, for example, north, vertical, or horizontal. The installation position may be the position information of the place 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 of the NCR device 500A. The antenna information may be information indicating the number of antenna ports of 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 usually "(number of antennas)-1". For example, in the case of two antennas, the degree of freedom is 1. In the case of two antennas, a figure-eight beam pattern is formed, but since directivity control is possible in only one direction, the degree of freedom is 1.

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

[0082] (5.3) Overall operation example 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, gNB200 (transmission unit 210) broadcasts NCR support information indicating that gNB200 supports NCR-UE100B. For example, gNB200 (transmission unit 210) broadcasts a system information block (SIB) including the NCR support information. The NCR support information may be information indicating that NCR-UE100B is accessible. Alternatively, gNB200 (transmission unit 210) may broadcast NCR non-support information indicating that gNB200 does not support NCR-UE100B. The NCR non-support information may be information indicating that NCR-UE100B is inaccessible.

[0085] NCR-UE100B (control unit 130) that has not established a radio connection with gNB200 may, in response to receiving the NCR support information from gNB200, determine that access to the gNB200 is permitted, and perform an access operation to establish a radio connection with gNB200. NCR-UE100B (control unit 130) may perform cell reselection considering the gNB200 (cell) that permits access as having the highest priority.

[0086] On the other hand, NCR-UE100B (control unit 130) that has not established a radio connection with gNB200 may determine that access (connection establishment) to the gNB200 is not possible when gNB200 is not broadcasting the NCR support information (or when broadcasting the NCR non-support information). As a result, NCR-UE100B can establish a radio connection only with a gNB200 that can handle NCR-UE100B.

[0087] In addition, when gNB200 is congested, gNB200 may broadcast access control information for restricting access from UE100. However, different from the normal UE100, NCR-UE100B can be regarded as an entity on the network side. Therefore, NCR-UE100B may ignore the access control information from gNB200. For example, when NCR-UE100B (control unit 130) receives NCR support information from gNB200, even if the gNB200 is broadcasting access control information, it may perform operations for establishing a radio connection with the gNB200. For example, NCR-UE100B (control unit 130) may not (or may ignore) execute UAC (Unified Access Control). Or, either one or both of the AC / AI (Access Category / Access Identity) used in UAC may use special values indicating that it is an access by the NCR-UE.

[0088] In step S13, NCR-UE100B (control unit 130) starts a random access procedure for gNB200. In the random access procedure, NCR-UE100B (transmission unit 120) transmits a random access preamble (Msg1) and an RRC message (Msg3) to gNB200. Also, in the random access procedure, NCR-UE100B (reception unit 110) receives a random access response (Msg2) and an RRC message (Msg4) from gNB200.

[0089] In step S14, when establishing a radio connection with gNB200, NCR-UE100B (transmission unit 120) may transmit NCR-UE information indicating that the own UE is an NCR-UE to gNB200. For example, during the random access procedure with gNB200, NCR-UE100B (transmission unit 120) includes the NCR-UE information in a message for the random access procedure (e.g., Msg1, Msg3, Msg5) and transmits it to gNB200. Based on the NCR-UE information received from NCR-UE100B, gNB200 (control unit 230) recognizes that the accessed UE100 is NCR-UE100B, and for example, can remove NCR-UE100B from the access restriction target (i.e., accept the access).

[0090] In step S15, NCR-UE100B transitions from the RRC idle state or the RRC inactive state to the RRC connected state.

[0091] In step S16, gNB200 (transmission unit 120) transmits a capability inquiry message for inquiring about the capabilities of NCR-UE100B to NCR-UE100B. NCR-UE100B (reception unit 110) receives the capability inquiry message.

[0092] In step S17, NCR-UE100B (transmission unit 120) transmits a capability information message including the above-mentioned NCR capability information to gNB200. gNB200 (reception unit 220) receives the capability information message. Based on the received capability information message, gNB200 (control unit 230) grasps the capabilities of NCR device 500A.

[0093] In step S18, gNB200 (transmission unit 120) transmits an NCR control signal for designating the operating state of NCR device 500A to NCR-UE100B. gNB200 (transmission unit 120) may transmit, as the NCR control signal, a MAC CE which is signaling of the MAC layer (layer 2) or DCI which is signaling of the PHY layer (layer 1) to NCR-UE100B. NCR-UE100B (reception unit 110) receives the NCR control signal.

[0094] In step S19, NCR-UE100B (control unit 130) controls NCR device 500A based on the NCR control signal received from gNB200. NCR-UE100B (control unit 130) may control NCR device 500A by notifying the NCR control signal received from gNB200 to NCR device 500A (NCR control unit 520A).

[0095] In step S20, NCR-UE100B (transmission unit 120) may transmit a completion message to gNB200 when the control (setting change) of NCR device 500A is completed. Here, NCR-UE100B (control unit 130) may determine control completion based on a notification (feedback) from NCR device 500A (NCR control unit 520A). gNB200 (reception unit 220) receives the completion message.

[0096] (5.4) NCR Control Signal Timing and NCR Control Application Timing As described above, the NCR-UE100B (receiver 110) receives, as layer 1 or layer 2 signaling (hereinafter referred to as "L1 / L2 signaling"), an NCR control signal that specifies the operating state of the NCR device 500A from the gNB200 that is wirelessly connected to the NCR-UE100B. Then, the NCR-UE100B (control unit 130) controls the NCR device 500A so as to apply the operating state specified by the NCR control signal. Here, a certain control delay occurs in order to change the operating state of the NCR device 500A. Therefore, the NCR-UE100B needs to receive the NCR control signal in a time interval prior to the time interval in which the operating state specified by the NCR control signal is applied. Thus, the gNB200 (transmitter 210) transmits the NCR control signal in a time interval prior to the time interval in which the operating state specified by the NCR control signal is applied.

[0097] Here, the time interval may be a symbol (OFDM symbol), a slot, a subframe, or a frame. One subframe is composed of a plurality of OFDM symbols in the time domain. Note that a resource block is a resource allocation unit and is composed of a plurality of OFDM symbols and a plurality of subcarriers. A frame can be composed of 10 ms and can include 10 subframes composed of 1 ms. A subframe can include a number of slots corresponding to the subcarrier spacing. In the following, although a slot is taken as an example of the time interval for explanation, the slot may be read as a symbol, a subframe, or a frame.

[0098] FIG. 14 is a diagram showing an example of NCR control signal timing and NCR control application timing. Here, an example where the NCR control signal is DCI is shown. Also, in the example of "Pattern 1" in FIG. 14, it is assumed that the duplex mode is FDD (Frequency Division Duplex), and in the example of "Pattern 2" in FIG. 14, it is assumed that the duplex mode is TDD (Time Division Duplex). In FIG. 14, the NCR control signal is denoted as "Side Control Info.", the downlink is denoted as "DL", and the uplink is denoted as "UL".

[0099] As shown in "Pattern 1" of FIG. 14, the gNB 200 (transmission unit 210) transmits the NCR control signal in a slot before the slot in which the operation state specified by the DCI, which is the NCR control signal, is applied. Here, it is assumed that the NCR control signal (DCI) specifies the operation state of the NCR device 500A two slots later. Specifically, the gNB 200 (transmission unit 210) transmits the NCR control signal (DCI) in slot #0, which is before slot #2 in which the operation state specified by the NCR control signal (DCI) is applied. Also, the gNB 200 (transmission unit 210) transmits the NCR control signal (DCI) in slot #3, which is before slot #5 in which the operation state specified by the NCR control signal (DCI) is applied. Further, the gNB 200 (transmission unit 210) transmits the NCR control signal (DCI) in slot #6, which is before slot #8 in which the operation state specified by the NCR control signal (DCI) is applied.

[0100] gNB200 (transmission unit 210) may transmit notification information (configuration information from another perspective) indicating the time difference (i.e., time interval) between the reception slot in which NCR-UE100B receives the NCR control signal (transmission slot from the perspective of gNB200) and the application slot in which NCR-UE100B applies the operation state specified by the NCR control signal to NCR-UE100B. The notification information may be information indicating after how many slots the control should be applied after the NCR control signal is transmitted. In the example of "Pattern 1" in FIG. 14, the information is "2". The notification information may be information indicating the number of slots between the reception slot of the NCR control signal (transmission slot from the perspective of gNB200) and the application slot. In the example of "Pattern 1" in FIG. 14, the information is "1".

[0101] NCR-UE100B (reception unit 110) receives the notification information from gNB200. Then, NCR-UE100B (control unit 130) specifies the application slot based on the reception slot and the notification information. The notification information may be information indicating the number of slots representing the time interval between the reception slot and the application slot. Also, the notification information may be information about the slot number of the application slot. The notification information may be included in the NCR control signal which is L1 / L2 signaling. Also, the notification information may be included in signaling of a layer higher than L1 / L2 signaling (hereinafter referred to as "higher layer signaling"). The higher layer signaling may be RRC signaling (RRC message).

[0102] However, the time difference between the reception slot in which NCR-UE100B receives the NCR control signal (transmission slot from the perspective of gNB200) and the application slot in which NCR-UE100B applies the operation state specified by the NCR control signal may be predefined in the technical specifications of the mobile communication system 1. In that case, the above notification information is unnecessary.

[0103] The NCR control signal may include information specifying the operating state of the NCR device 500A for each of a plurality of slots. In that case, the gNB 200 (transmission unit 210) may transmit notification information (or configuration information from another perspective) for identifying the number of slots to which the operating state specified by the NCR control signal is to be applied, to the NCR-UE 100B.

[0104] For example, as shown in "Pattern 2" of FIG. 14, the gNB 200 (transmission unit 210) designates the operating state of the NCR device 500A for a total of 5 slots from consecutive slots #2 to #6, by means of the NCR control signal (DCI) transmitted in slot #0. In this case, the number of slots to which the operating state designated by the NCR control signal (DCI) transmitted in slot #0 is to be applied is "5". The NCR control signal (DCI) transmitted in slot #0 may include information designating the same operating state for slots #2 to #6. Further, the NCR control signal (DCI) may include information designating individual operating states for each of slots #2 to #6.

[0105] Note that in the example of "Pattern 2" of FIG. 14, the gNB 200 (transmission unit 210) designates the operating state of the NCR device 500A in slot #7, by means of the NCR control signal (DCI) transmitted in slot #5. The gNB 200 (transmission unit 210) designates the operating state of the NCR device 500A in slot #8, by means of the NCR control signal (DCI) transmitted in slot #6. The gNB 200 (transmission unit 210) designates the operating state of the NCR device 500A in slot #9, by means of the NCR control signal (DCI) transmitted in slot #7.

[0106] The notification information for identifying the number of slots to which the operating state designated by the NCR control signal is to be applied may be included in the NCR control signal which is L1 / L2 signaling. Further, the notification information may be included in higher layer signaling higher than L1 / L2 signaling. The higher layer signaling may be RRC signaling (RRC message). Below, an example in which the notification information is included in higher layer signaling will be described.

[0107] FIG. 15 is a diagram showing an operation example regarding the NCR control signal timing and the NCR control application timing. Prior to such an operation, the NCR-UE 100B may notify the gNB 200 of its control delay based on the above-described NCR capability information.

[0108] In step S101, the gNB 200 (transmission unit 210) transmits the above-described notification information to the NCR-UE 100B by upper layer signaling. The NCR-UE 100B (reception unit 110) receives the notification information. The NCR-UE 100B (control unit 130) may specify the time difference between the reception slot for receiving the NCR control signal and the application slot for applying the operation state specified by the NCR control signal by the NCR-UE 100B based on the notification information. The NCR-UE 100B (control unit 130) may specify the number of slots for applying the operation state specified by the NCR control signal based on the notification information.

[0109] In step S102, the gNB 200 (transmission unit 210) transmits the above-described NCR control signal to the NCR-UE 100B by L1 / L2 signaling. The NCR-UE 100B (reception unit 110) receives the NCR control signal. The NCR-UE 100B (control unit 130) specifies one or more slots in which the operation state specified by the NCR control signal received in step S102 should be applied to the NCR device 500A based on the notification information received in step S101.

[0110] In step S103, the NCR-UE 100B (control unit 130) controls the NCR device 500A so as to apply the operation state specified by the NCR control signal received in step S102 in the slots specified based on the notification information received in step S101. As a result, the operation state of the NCR device 500A is changed in the specified slots.

[0111] In this embodiment, although the operation state (control state) specified by the NCR control signal is strictly defined for each slot, it is not limited to this. The NCR-UE100B controls the NCR device 500A in response to the reception of the NCR control signal and may maintain the current operation state until the next NCR control signal is received (or until the control timing of the NCR device 500A associated with the next NCR control signal). For example, in "Pattern 1" of FIG. 14, in accordance with the NCR control signal received in slot #0, the control of the NCR device 500A is completed before slot #2 starts. Thereafter, the NCR-UE100B maintains the operation state unless it receives an NCR control signal. When the next NCR control signal is received in slot #3, the control of the NCR device 500A is completed before slot #5 starts.

[0112] (5.5) Control ID Assuming that the NCR control signal is transmitted by L1 / L2 signaling, since the L1 / L2 signaling has a small message size, it may be difficult to include information specifying the operation state of the NCR device 500A in the NCR control signal. Therefore, an identifier (hereinafter referred to as "control ID") may be set for each operation state of the NCR device 500A by upper layer signaling, and the control ID may be specified in the NCR control signal (L1 / L2 signaling).

[0113] That is, the gNB200 transmits to the NCR-UE100B, by upper layer signaling, association information associating the operation state of the NCR device 500A with the control ID. The NCR-UE100B receives the association information. Thereafter, when the NCR-UE100B receives, by L1 / L2 signaling, an NCR control signal including the control ID from the gNB200, it specifies the operation state corresponding to the control ID included in the received NCR control signal based on the association information received by the upper layer signaling. Then, the NCR-UE100B controls the NCR device 500A to apply the specified operation state.

[0114] Here, the operating state of the NCR device 500A may be the transmission direction, transmission weight, or beam pattern specified by the above-described beam control information. In this case, for example, a control ID may be assigned for each set of transmission weights (PMI). The operating state of the NCR device 500A may be the operating mode specified by the above-described mode control information. In this case, for example, a control ID may be assigned for each operating mode. The operating state of the NCR device 500A may be the transmission power specified by the above-described output control information. In this case, for example, a control ID may be assigned for each absolute value or relative value of the transmission power.

[0115] When the NCR control signal is DCI, different DCI formats or different RNTIs may be defined for each type of operating state of the NCR device 500A (for example, beam control, mode control, output control). In this case, for example, the DCI format or RNTI may be different between the DCI including the control ID for beam control, the DCI including the control ID for mode control, and the DCI including the control ID for output control. The NCR device 500A can identify the type of operating state specified by the received DCI based on the DCI format or RNTI applied to the received DCI. When varying the RNTI, for example, RNTIs such as RNTI for transmission power control, RNTI for antenna weight control, and RNTI for mode control may be defined.

[0116] When the NCR control signal is MAC CE (however, it may also be DCI), a type ID may be defined for each type of operating state of the NCR device 500A (for example, beam control, mode control, output control). In this case, the NCR control signal may include at least one set of a type ID and a control ID. The NCR device 500A can identify the type of operating state specified by the control ID associated with the type ID based on the type ID included in the received NCR control signal. As described above, the NCR control signal may include an NCR identifier. In the NCR control signal, the control ID may be associated with the NCR identifier (and type ID).

[0117] It may be possible to notify a plurality of control IDs in one NCR control signal. For example, a control ID indicating a transmission power of 20 dBm and a control ID indicating PMI No. 3 may be included in one NCR control signal. It may be possible to notify a plurality of control IDs for a plurality of slots in one NCR control signal. For example, as shown in "Pattern 1" of FIG. 16, gNB 200 (transmission unit 210) includes control IDs for each of slots #2 to #6 in the NCR control signal (DCI) transmitted in slot #0.

[0118] It may be possible to notify a downlink control ID and an uplink control ID in one NCR control signal. For example, as shown in "Pattern 2" of FIG. 16, gNB 200 (transmission unit 210) designates a downlink control ID #2 and an uplink control ID #3 to be applied in slot #2 by the NCR control signal (DCI) transmitted in slot #0.

[0119] Control IDs may be allocated for a combination of a plurality of operating states. In this case, for example, one control ID may be allocated to the combination of a transmission power of 20 dBm and PMI No. 3.

[0120] Note that the NCR control signal may include the value of the control ID itself. Further, the NCR control signal may include a bitmap indicating the value of the control ID in bit positions. The bitmap includes, for example, bits corresponding to control ID #0, bits corresponding to control ID #1, and bits corresponding to control ID #2, and indicates that the corresponding control ID is to be applied when the value of the bit is a specific value.

[0121] FIG. 17 is a diagram showing an operation example related to a control ID.

[0122] In step S201, the gNB 200 (transmission unit 210) transmits the above-mentioned association information to the NCR-UE 100B by upper layer signaling. In the example of FIG. 17, control ID #0 is set for the operation state A of the NCR device 500A, control ID #1 is set for the operation state B of the NCR device 500A, and control ID #2 is set for the operation state C of the NCR device 500A.

[0123] In step S202, the gNB 200 (transmission unit 210) transmits an NCR control signal including a control ID to the NCR-UE 100B by L1 / L2 signaling. The NCR-UE 100B (reception unit 110) receives the NCR control signal.

[0124] In step S203, the NCR-UE 100B (control unit 130) identifies the operation state associated with the control ID included in the NCR control signal received in step S202 based on the association information received in step S201.

[0125] In step S204, the NCR-UE 100B (control unit 130) controls the NCR device 500A to apply the operation state identified in step S203. Thereby, the operation state of the NCR device 500A is changed.

[0126] (5.6) RNTI When the NCR control signal is DCI, the NCR-UE 100B can receive from the gNB 200 a DCI for controlling the operation of the NCR-UE 100B itself (hereinafter referred to as "first DCI") and a DCI for controlling the operation of the NCR device 500A (hereinafter referred to as "second DCI"). If all these controls (control of the NCR-UE 100B itself and control of the NCR device 500A) are performed using one RNTI, specifically, C-RNTI (Cell Radio Network Temporary Identifier), the control of the NCR-UE 100B may become complicated. Also, the NCR-UE 100B may not be able to receive a plurality of DCIs in the same slot. Therefore, in order to enable the NCR-UE 100B to identify whether the DCI received from the gNB 200 is the first DCI or the second DCI, the RNTIs applied to the first DCI and the second DCI may be made different.

[0127] FIG. 18 is a diagram showing an operation example regarding RNTI.

[0128] In step S301, the gNB 200 (transmission unit 210) transmits the C-RNTI assigned to the NCR-UE 100B to the NCR-UE 100B. The NCR-UE 100B (reception unit 110) receives the C-RNTI. The C-RNTI is used for the transmission of the first DCI for controlling the operation of the NCR-UE 100B itself. The NCR-UE 100B starts blind decoding of the PDCCH using the received C-RNTI.

[0129] In step S302, the gNB 200 (transmission unit 210) transmits the NCR-RNTI (that is, the RNTI for NCR control) assigned to the NCR-UE 100B to the NCR-UE 100B. The NCR-UE 100B (reception unit 110) receives the NCR-RNTI. The NCR-RNTI is used for the transmission of the second DCI for controlling the operation of the NCR device 500A. The NCR-UE 100B starts blind decoding of the PDCCH using the received NCR-RNTI.

[0130] Note that as a prerequisite for step S302, gNB 200 knows that NCR-UE 100B is the UE 100 that controls NCR device 500A. As described above, NCR-UE 100B may notify gNB 200 that it is NCR-UE 100B when accessing gNB 200. NCR-UE 100B may be authenticated by gNB 200 or the core network as NCR-UE 100B.

[0131] Also, when one NCR-UE 100B controls a plurality of NCR devices 500A, different NCR-RNTIs may be assigned to each NCR device 500A. In this case, gNB 200 may notify NCR-UE 100B of the association information between the identifier of NCR device 500A and NCR-RNTI. As described above, the identifier of NCR device 500A may be notified from NCR-UE 100B to gNB 200.

[0132] In step S303, gNB 200 (transmission unit 210) transmits DCI (i.e., the second DCI) to NCR-UE 100B by applying NCR-RNTI. Specifically, gNB 200 (transmission unit 210) transmits DCI with CRC parity bits scrambled by NCR-RNTI on PDCCH.

[0133] In step S304, NCR-UE 100B performs blind decoding of PDCCH using NCR-RNTI, and acquires the DCI that has been successfully decoded as the second DCI. NCR-UE 100B (control unit 130) controls NCR device 500A so as to apply the operation state specified by the second DCI. Thereby, the operation state of NCR device 500A is changed.

[0134] (6) Modification example In the above-described embodiment, an example of a relay device that relays radio waves between the gNB 200 and the UE 100 (UE 100A) is the NCR device 500A that amplifies and transfers the received radio waves. On the other hand, in this modified example, the relay device that relays radio waves between the gNB 200 and the UE 100 (UE 100A) is a RIS (Reconfigurable Intelligent Surface) device that changes the propagation direction of the incident radio waves by reflection or refraction. "NCR" in the above-described embodiment can be read as "RIS".

[0135] FIGS. 19 to 21 are diagrams showing application scenarios of the relay device according to the modified example of the embodiment. In the modified example, the RIS device 500B using the metasurface technology is introduced into the mobile communication system 1. The RIS device 500B can efficiently expand the coverage of the gNB 200 by dynamically changing the propagation direction of the radio waves (beams) incident from the gNB 200, for example, by reflection or refraction. The RIS device 500B has characteristics such as Reconfigurable, Dynamic, and Flexible (beam direction controllable). In FIGS. 19 and 20, an example of applying the RIS device 500B to the downlink communication from the gNB 200 to the UE 100A1 and the UE 100A2 is shown, but the RIS device 500B can also be applied to the uplink communication from the UE 100A1 and the UE 100A2 to the gNB 200.

[0136] The RIS device 500B shown in FIG. 19 is a reflective RIS device 500B. Such a RIS device 500B changes the propagation direction of the incident radio wave by reflecting it. Here, the reflection angle of the radio wave can be variably set. The RIS device 500B reflects the radio wave incident from the gNB 200 toward each of the UEs 100A1 and 100A2. Further, the RIS device 500B may reflect the radio wave 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 wave. For example, the RIS device 500B reflects the radio wave incident from the gNB 200 toward the UE 100A1 and / or reflects the radio wave incident from the UE 100A1 toward the gNB 200 in the communication resource between the gNB 200 and the UE 100A1. Here, the communication resource includes a resource in the time direction and / or a resource in the frequency direction. The RIS device 500B reflects the radio wave incident from the gNB 200 toward the UE 100A2 and / or reflects the radio wave incident from the UE 100A2 toward the gNB 200 in the communication resource between the gNB 200 and the UE 100A2.

[0137] The RIS device 500B shown in FIG. 20 is a transmissive RIS device 500B. Such a RIS device 500B changes the propagation direction of the incident radio wave by refracting the incident radio wave. Here, the refraction angle of the radio wave can be variably set. The RIS device 500B refracts the radio wave incident from the gNB 200 toward each of the UEs 100A1 and 100A2. Further, the RIS device 500B may refract the radio wave 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 wave. For example, in the communication resource between the gNB 200 and the UE 100A1, the RIS device 500B refracts the radio wave incident from the gNB 200 toward the UE 100A1 and / or refracts the radio wave incident from the UE 100A1 toward the gNB 200. In the communication resource between the gNB 200 and the UE 100A2, the RIS device 500B refracts the radio wave incident from the gNB 200 toward the UE 100A2 and / or refracts the radio wave incident from the UE 100A2 toward the gNB 200.

[0138] In this modification example, as shown in FIG. 21, a new UE (hereinafter referred to as "RIS-UE") 100C, which is a control terminal for controlling the RIS device 500B, is introduced. 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. Thereby, while suppressing an increase in installation cost and a decrease in installation freedom for the RIS device 500B, efficient coverage expansion can be realized using the RIS device 500B. The RIS-UE 100C controls the RIS device 500B according to the RIS control signal from the gNB 200.

[0139] The RIS-UE100C may be configured separately from the RIS device 500B. For example, the RIS-UE100C may be in the vicinity of the RIS device 500B and electrically connected to the RIS device 500B. The RIS-UE100C may be connected to the RIS device 500B by wire or wirelessly. Alternatively, the RIS-UE100C may be configured integrally with the RIS device 500B. The RIS-UE100C and the RIS device 500B may be fixedly installed on, for example, a wall surface or a window. The RIS-UE100C and the RIS device 500B may be installed on, for example, a vehicle or the like and be movable. Also, one RIS-UE100C may control a plurality of RIS devices 500B.

[0140] FIG. 22 is a diagram showing the configurations of the RIS-UE100C and the RIS device 500B according to the embodiment.

[0141] As shown in FIG. 22, the RIS-UE100C includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140. Such a configuration is the same as that of the above-described embodiment.

[0142] The RIS device 500B has a RIS 510B and a RIS control unit 520B. The RIS 510B is a metasurface configured using a metamaterial. For example, the RIS 510B is configured by arranging very small structures in an array with respect to the wavelength of radio waves, and by making the structures have different shapes depending on the placement location, it is possible to arbitrarily design the direction of the reflected wave and the beam shape. The RIS 510B may be a transparent dynamic metasurface. The RIS 510B is configured by stacking a transparent glass substrate on a metasurface substrate in which a large number of small structures are regularly arranged and made transparent, and by slightly moving the stacked glass substrates, it is possible to dynamically control three modes: a mode in which incident radio waves are transmitted, a mode in which part of the radio waves are transmitted and part are reflected, and a mode in which all radio waves are reflected.

[0143] The RIS control unit 520B controls the RIS 510B according to the RIS control signal from the control unit 130 of the RIS-UE 100C. The RIS control unit 520B may include at least one processor and at least one actuator. The processor decodes the RIS control signal from the control unit 130 of the RIS-UE 100C and drives the actuator according to the RIS control signal. When the RIS-UE 100C and the RIS device 500B are integrally configured, the control unit 130 of the RIS-UE 100C and the RIS control unit 520B of the RIS device 500B may also be integrally configured.

[0144] As shown in FIG. 23, the gNB 200 (transmission unit 210) transmits a RIS control signal specifying the operating state of the RIS device 500B to the RIS-UE 100C that has established a radio connection with the gNB 200 (step S1a). The RIS control signal specifying the operating state of the RIS device 500B may be a MAC CE that is signaling at the MAC layer (layer 2) or a DCI that is signaling at the PHY layer (layer 1). The RIS-UE 100C (control unit 130) controls the RIS device 500B to apply the operating state specified by the RIS control signal (step S2a).

[0145] As shown in FIG. 24, the RIS control signal may include frequency control information for setting the center frequency of the radio wave (e.g., component carrier) targeted by the RIS device 500B. When the RIS control signal received from the gNB 200 by the RIS-UE 100C (control unit 130) includes frequency control information, the RIS device 500B is controlled to operate (e.g., reflect, transmit (refract), or block) the radio wave at the center frequency indicated by the frequency control information. The RIS control signal may include a plurality of pieces of frequency control information that set different center frequencies. By including the frequency control information in the RIS control signal, the gNB 200 can specify, via the RIS-UE 100C, the center frequency of the radio wave that the RIS device 500B should target.

[0146] The RIS control signal may include mode control information for setting the operation mode of the RIS device 500B. The mode control information may be associated with frequency control information (center frequency). The operation mode may be any one of a reflection mode for reflecting radio waves, a refraction mode for refracting radio waves, a transmission mode for transmitting radio waves, and a blocking mode for blocking radio waves. When the RIS control signal received by the RIS-UE 100C (control unit 130) includes mode control information, the RIS device 500B is controlled to operate in the operation mode indicated by the mode control information. By including the mode control information in the RIS control signal, the gNB 200 can specify the operation mode of the RIS device 500B via the RIS-UE 100C.

[0147] The RIS control signal may include direction control information for setting the propagation direction of the radio wave after being changed by the RIS device 500B. The direction control information may be associated with frequency control information (center frequency). The direction control information may be information for setting the reflection angle in the RIS device 500B. Further, the direction control information may be information for setting the refraction angle in the RIS device 500B. By including the direction control information in the RIS control signal, the gNB 200 can specify the propagation direction of the radio wave after being changed by the RIS device 500B via the RIS-UE 100C.

[0148] In this way, the RIS-UE 100C (control unit 130) controls the RIS device 500B based on the RIS control signal from the gNB 200. Thereby, the gNB 200 can control the RIS device 500B via the RIS-UE 100C.

[0149] (7) Other Embodiments In the above description, the frequency control information may include a cell ID for identifying a cell and / or a BWP ID for identifying a bandwidth part (BWP). The BWP refers to a part of the frequency band of a cell.

[0150] Each of the above operation flows can be implemented not only separately and independently, but also by combining two or more operation flows. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow. In each flow, it is not always necessary to execute all steps, and only some steps may be executed.

[0151] In the above embodiments, an example where the base station is an NR base station (gNB) has been described, but the base station may be an LTE base station (eNB). Further, the base station may be a relay node such as an IAB (Integrated Access and Backhaul) node. The base station may be a DU (Distributed Unit) of an IAB node.

[0152] A program may be provided to cause a computer to execute each process performed by UE100 (NCR-UE100B, RIS-UE100C) or gNB200. The program may be recorded on a computer-readable medium. By using a computer-readable medium, it is possible to install the program 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 particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. Further, a circuit for executing each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chipset, SoC: System on a chip).

[0153] As used in this disclosure, the terms "based on" and "depending on" do not mean "only based on" or "only depending on" unless otherwise specified. The term "based on" means both "only based on" and "at least partially based on". Similarly, the term "depending on" means both "only depending on" and "at least partially depending on". Also, the terms "include", "comprise", and their variants do not mean to include only the listed items, but may include only the listed items or may further include additional items in addition to the listed items. Also, the term "or" used in this disclosure is not intended to be an exclusive disjunction. Further, any reference to an element using designations such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this specification as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed there or that the first element must precede the second element in some form. In this disclosure, for example, when articles are added by translation, such as a, an, and the in English, these articles are assumed to include a plurality if not otherwise shown to be otherwise from the context.

[0154] As described above in detail with reference to the drawings, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the gist.

[0155] This application claims the priority of Japanese Patent Application No. 2022-030325 (filed on February 28, 2022), and all of its contents are incorporated herein by reference.

[0156] (Supplementary Note) The features regarding the above-described embodiments are noted below.

[0157] (1) A communication method executed by a control terminal that controls a relay device that relays radio waves between a base station and a user device, receiving, as layer 1 or layer 2 signaling, a control signal for specifying an operating state of the relay device from the base station wirelessly connected to the control terminal; controlling the relay device so as to apply the operating state specified by the control signal, and the receiving step includes receiving the control signal in a time interval prior to a time interval in which the operating state specified by the control signal is applied communication method.

[0158] (2) receiving, from the base station, notification information indicating a time difference between a reception time interval for receiving the control signal and an application time interval for applying the operating state specified by the control signal; further comprising specifying the application time interval based on the reception time interval and the notification information The communication method according to (1) above.

[0159] (3) The control signal includes information specifying an operating state of the relay device for each of a plurality of time intervals The communication method according to (1) or (2) above.

[0160] (4) further comprising receiving, from the base station, notification information for specifying the number of time intervals for applying the operating state specified by the control signal The communication method according to any one of (1) to (3) above.

[0161] (5) The step of receiving the notification information includes receiving the notification information by upper layer signaling of a layer higher than the signaling The communication method according to any one of (1) to (4) above.

[0162] (6) Further comprising the step of receiving, by upper layer signaling of a layer higher than the signaling, association information associating the operating state of the relay device with an identifier The step of receiving the control signal includes the step of receiving the control signal including the identifier The step of controlling includes the step of specifying the operating state corresponding to the identifier included in the received control signal based on the association information The communication method according to any one of (1) to (5) above

[0163] (7) Receiving, from the base station, a cell radio network temporary identifier (C-RNTI) assigned to the control terminal Receiving, from the base station, a control RNTI that is an RNTI different from the C-RNTI and is used for controlling the relay device The step of receiving the control signal includes the step of receiving, as the control signal, physical downlink control information (DCI) to which the control RNTI is applied The communication method according to any one of (1) to (6) above

[0164] (8) The relay device is a repeater device that amplifies and transfers the received radio wave The communication method according to any one of (1) to (7) above

[0165] (9) The relay device is a RIS (Reconfigurable Intelligent Surface) device that changes the propagation direction of the incident radio wave by reflection or refraction The communication method according to any one of (1) to (8) above

[0166] (10) A control terminal for controlling a relay device that relays radio waves between a base station and a user device A receiving unit that receives, by signaling of layer 1 or layer 2, a control signal for designating an operating state of the relay device from the base station that wirelessly connects to the control terminal; A control unit that controls the relay device so as to apply the operating state designated by the control signal, and The receiving unit receives the control signal in a time period prior to a time period in which the operating state designated by the control signal is to be applied Control terminal.

[0167] (11) The base station that wirelessly connects to a control terminal that controls a relay device that relays radio waves between the base station and a user device, Comprises a transmission unit that transmits, as signaling of layer 1 or layer 2, a control signal for designating an operating state of the relay device, The transmission unit transmits the control signal in a time period prior to a time period in which the operating state designated by the control signal is to be applied Base station.

Explanation of Signs

[0168] 1: Mobile communication system 100: UE 100B: NCR-UE 110: Receiving unit 120: Transmission unit 130: Control unit 140: Interface 200: gNB 210: Transmission unit 220: Receiving unit 230: Control unit 240: Backhaul communication unit 500A: NCR device 500B: RIS device 510A: Radio unit 510a: Antenna unit 510b: RF circuit 510c: Directivity control unit 520A: NCR control unit 520B: RIS control unit

Claims

1. A communication method executed by a control terminal for controlling a relay device that relays radio waves between a network node and a user device, comprising: receiving, from the network node wirelessly connected to the control terminal, association information associating two or more operating states of the relay device with one identifier by upper layer signaling of a layer higher than layer 2 signaling; receiving, from the network node, a control signal including the one identifier as the layer 2 signaling; identifying, based on the association information, the two or more operating states corresponding to the one identifier included in the received control signal; controlling the relay device to apply the identified two or more operating states; Receiving the control signal as the layer 2 signaling includes receiving the control signal in a second slot a predetermined slot before a first slot in which the two or more operating states corresponding to the one identifier included in the control signal are applied; One of the two or more operating states is a beam state of the relay device Communication method.

2. The control signal includes information specifying an operating state of the relay device for each of a plurality of time intervals. The communication method according to claim 1.

3. Further comprising receiving, from the network node, notification information for identifying the number of symbols for applying the operating state. The communication method according to claim 1.

4. Receiving the notification information includes receiving the notification information by upper layer signaling of a layer higher than the signaling. The communication method according to claim 3.

5. A control terminal for controlling a relay device that relays radio waves between a network node and a user device, comprising: receiving, from the network node wirelessly connected to the control terminal, association information associating two or more operating states of the relay device with one identifier by upper layer signaling of a layer higher than layer 2 signaling; a receiving unit that receives, from the network node, a control signal including the one identifier as the layer 2 signaling; identifying, based on the association information, the operating state corresponding to the one identifier included in the received control signal; A control unit that controls the relay device so as to apply the specified two or more operating states. The receiving unit receives the control signal in a second slot that is a predetermined slot before a first slot in which the two or more operating states corresponding to the one identifier included in the control signal are applied. One of the two or more operating states is the beam state of the relay device. Control terminal.

6. A network node wirelessly connected to a control terminal that controls a relay device that relays radio waves between the network node and a user device, Association information associating two or more operating states of the relay device with one identifier is transmitted by a higher layer signaling of a layer higher than the layer 2 signaling. A transmission unit that transmits a control signal including the one identifier as the layer 2 signaling. The transmission unit transmits the control signal in a second slot that is a predetermined slot before a first slot in which the two or more operating states corresponding to the one identifier included in the control signal are applied. One of the two or more operating states is the beam state of the relay device. Network node.

7. A chipset for a control terminal that controls a relay device that relays radio waves between a network node and a user device, A process of receiving, by the higher layer signaling of a layer higher than the layer 2 signaling, association information associating two or more operating states of the relay device with one identifier from the network node wirelessly connected to the control terminal, A process of receiving, by the layer 2 signaling, a control signal including the one identifier from the network node, A process of specifying the two or more operating states corresponding to the one identifier included in the received control signal based on the association information, A process of controlling the relay device so as to apply the specified two or more operating states. The process of receiving the control signal as the layer 2 signaling includes a process of receiving the control signal in a second slot that is a predetermined slot before a first slot in which the two or more operating states corresponding to the one identifier included in the control signal are applied. One of the two or more operating states is the beam state of the relay device. Chipset.

8. A control terminal that controls a relay device that relays radio waves between a network node and a user device, from the network node wirelessly connected to the control terminal, receiving, by upper layer signaling of a layer higher than layer 2 signaling, association information associating two or more operating states of the relay device with one identifier; from the network node, receiving a control signal including the one identifier by layer 2 signaling; based on the association information, identifying the two or more operating states corresponding to the one identifier included in the received control signal; controlling the relay device to apply the identified two or more operating states, and executing the following processing: The process of receiving the control signal as the layer 2 signaling includes receiving the control signal in a second slot a predetermined slot before a first slot for applying the two or more operating states corresponding to the one identifier included in the control signal; One of the two or more operating states is a beam state of the relay device Program.

9. A system comprising a control terminal that controls a relay device that relays radio waves between a network node and a user device, wherein the control terminal receives, by upper layer signaling of a layer higher than layer 2 signaling, association information associating two or more operating states of the relay device with one identifier from the network node wirelessly connected to the control terminal; receives a control signal including the one identifier as the layer 2 signaling from the network node; identifies the two or more operating states corresponding to the one identifier included in the received control signal based on the association information; controls the relay device to apply the identified two or more operating states; receives the control signal in a second slot a predetermined slot before a first slot for applying the two or more operating states corresponding to the one identifier included in the control signal; One of the two or more operating states is a beam state of the relay device System.

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