Communication method, relay device, and network node

Abstract

This communication method is executed by a relay device that comprises: a repeater for performing relay transmission relaying a wireless signal transmitted between a network node and a user device; and a control terminal used to control the repeater. The communication method comprises: a step in which the control terminal receives, from the network node, power control information for controlling the transmission power of the relay transmission; and a step in which the repeater performs the relay transmission with the transmission power based on the power control information. The power control information includes at least one of the following: first information indicating a maximum transmission power and / or a maximum gain to configure for the repeater; second information indicating a transmission power and / or a gain in periodic relay transmission; and third information indicating a transmission power and / or a gain in aperiodic relay transmission.

Description

Communication method, relay device, and network node

[0001] The present disclosure relates to a communication method, a relay device, and a network node used in a mobile communication system.

[0002] In recent years, fifth-generation (5G) mobile communication systems have been attracting attention. NR (New Radio), a radio access technology of 5G systems, is capable of wideband transmission using higher frequency bands than LTE (Long Term Evolution), a fourth-generation radio access technology.

[0003] Radio signals (radio waves) in high frequency bands such as millimeter waves or terahertz waves have a high degree of directivity, which poses a problem of reducing the coverage of network nodes (e.g., base stations). To solve this problem, attention has been focused on repeater devices, which are a type of relay device that relays radio signals between a network node and a user device and can be controlled from the network node (see, for example, Non-Patent Document 1).

[0004] Such a repeater device can, for example, amplify a radio signal received from a base station and transmit the signal using directional transmission, thereby expanding the coverage of a network node while suppressing interference. Note that such a repeater device is also called an NCR (Network-Controlled Repeater).

[0005] 3GPP contribution: RP-213700, “New SI: Study on NR Network-controlled Repeaters”

[0006] A communication method according to a first aspect is a method executed by a relay device including a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user equipment (UE) and a control terminal used to control the relay. The communication method includes the steps of: receiving, by the control terminal, power control information for controlling a transmit power of the relay transmission from the network node; and performing the relay transmission at the transmit power based on the power control information. The power control information includes at least one of first information indicating a maximum transmit power and / or a maximum gain to be set in the relay device, second information indicating a transmit power and / or a gain in periodic relay transmission, and third information indicating a transmit power and / or a gain in aperiodic relay transmission.

[0007] A relay device according to a second aspect includes a relay that performs relay transmission to relay a radio signal transmitted between a network node and a user equipment, and a control terminal used to control the relay. The control terminal receives power control information for controlling the transmit power of the relay transmission from the network node. The relay performs the relay transmission at the transmit power based on the power control information. The power control information includes at least one of first information indicating a maximum transmit power and / or a maximum gain to be set in the relay, second information indicating a transmit power and / or a gain in periodic relay transmission, and third information indicating a transmit power and / or a gain in aperiodic relay transmission.

[0008] A network node according to a third aspect is a node that communicates with a relay device that performs relay transmission to relay a radio signal transmitted between the network node and a user equipment, and the network node includes a control terminal used to control the relay. The network node includes: a control unit that generates power control information for controlling transmission power of the relay transmission; and a transmission unit that transmits the power control information to the control terminal. The power control information includes at least one of first information indicating a maximum transmission power and / or a maximum gain to be set for the relay, second information indicating a transmission power and / or a gain in periodic relay transmission, and third information indicating a transmission power and / or a gain in aperiodic relay transmission.

[0009] A communication method according to a fourth aspect is a method executed by a relay device including a relay device that relays a radio signal transmitted between a network node and a user equipment and a control terminal used to control the relay device, the communication method comprising the steps of: acquiring maximum values ​​indicating a maximum transmission power and / or a maximum gain set in the relay device and estimates indicating the transmission power and / or the gain of the relayed transmission at the relay device; and transmitting margin information indicating a difference between the maximum values ​​and the estimates from the control terminal to the network node.

[0010] A fifth aspect of the present invention provides a relay device that relays a radio signal transmitted between a network node and a user equipment (UE), and a control terminal that controls the relay device, wherein the control terminal transmits margin information to the network node, the margin information indicating a difference between a maximum value indicating a maximum transmission power and / or a maximum gain set in the relay device and an estimated value indicating the transmission power and / or the gain of the relayed transmission at the relay device, based on the maximum value and the estimated value.

[0011] A network node according to a sixth aspect is a node that communicates with a relay device, the node including a relay device that relays a radio signal transmitted between the network node and a user equipment, and a control terminal used to control the relay device. The network node includes a receiving unit that receives, from the control terminal, margin information based on a maximum value indicating a maximum transmit power and / or a maximum gain set in the relay device and an estimated value indicating the transmit power and / or gain of the relay transmission at the relay device. The margin information is information indicating a difference between the maximum value and the estimated value.

[0012] 1 is a diagram illustrating a configuration of a mobile communication system according to an embodiment. FIG. 1 is a diagram illustrating a protocol stack configuration of a radio interface of a user plane that handles data. FIG. 2 is a diagram illustrating a protocol stack configuration of a radio interface of a control plane that handles signaling (control signals). FIG. 2 is a diagram illustrating an example of an application scenario of an NCR device (relay device) according to the first embodiment. FIG. 3 is a diagram illustrating an example of an application scenario of an NCR device according to the first embodiment. FIG. 4 is a diagram illustrating an example of a control method of an NCR device according to the first embodiment. FIG. 5 is a diagram for explaining an example of a configuration of a protocol stack in an NCR device according to the first embodiment. FIG. 6 is a diagram illustrating an example of a configuration of an NCR device according to the first embodiment. FIG. 7 is a diagram illustrating a configuration of a UE (user equipment) according to an embodiment. FIG. 8 is a diagram illustrating an example of a configuration of a gNB (network node) according to an embodiment. FIG. 9 is a diagram illustrating a first basic operation of an NCR device according to the first embodiment. FIG. 10 is a diagram illustrating an example of a first operation pattern of a mobile communication system according to the first embodiment. FIG. 11 is a diagram illustrating an example of a second operation pattern of a mobile communication system according to the first embodiment. FIG. 12 is a diagram illustrating an example of a third operation pattern of a mobile communication system according to the first embodiment. FIG. 13 is a diagram illustrating an example of a fourth operation pattern of a mobile communication system according to the first embodiment. FIG. 14 is a diagram illustrating an example of an application scenario of a RIS device (relay device) according to the second embodiment. FIG. 15 is a diagram illustrating an example of a configuration of a RIS device according to the second embodiment.

[0013] The relay device described in the background art above is capable of amplifying the radio signal it relays, but no technology has yet been established for performing transmission power control that allows a network node to variably set the transmission power and / or gain.

[0014] Therefore, an object of the present disclosure is to appropriately control the transmission power of a relay device.

[0015] 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.

[0016] (1) First Embodiment A first embodiment will be described. A relay device according to the first embodiment is a repeater device (that is, an NCR device) that can be controlled from a network.

[0017] (1.1) Overview of the Mobile Communication System First, an overview of the mobile communication system 1 according to the first embodiment will be described. Fig. 1 is a diagram showing the configuration of the mobile communication system according to the first embodiment.

[0018] The mobile communication system 1 conforms to the 5th Generation System (5GS) standard of the 3rd Generation Partnership Project (3GPP) (registered trademark; the same applies hereinafter). While the following description will be given using 5GS as an example, the mobile communication system may also be at least partially based on the Long Term Evolution (LTE) system. The mobile communication system may also be at least partially based on the 6th Generation (6G) system.

[0019] The mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN: Next Generation Radio Access Network) 10, and a 5G core network (5GC: 5G Core Network) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. Furthermore, the 5GC 20 may be simply referred to as the core network (CN) 20. The RAN 10 and the CN 20 constitute a network 5 of the mobile communication system 1.

[0020] The UE 100 is a mobile wireless communication device. The UE 100 may be any device that is used by a user. For example, the UE 100 may be a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (which may be a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).

[0021] The NG-RAN 10 includes a base station 200 (referred to as a "gNB" or "NG-RAN node" in a 5G system), which is a type of network node. The gNBs 200 are connected to each other via an Xn interface, which is an inter-node interface (inter-base station interface). The gNB 200 manages one or more cells. The gNB 200 performs wireless communication with a 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. The term "cell" is used to indicate the smallest unit of a wireless communication area. The term "cell" is also used to indicate a function or resource for wireless communication with a UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0022] The gNB200 may be functionally divided into a central unit (CU) and a distributed unit (DU). The CU controls the DU. The CU is a unit including upper layers included in the protocol stack described below, such as an RRC layer, an SDAP layer, and a PDCP layer. The CU is connected to the core network via an NG interface, which is a backhaul interface. The CU is connected to neighboring base stations via an Xn interface. The DU forms a cell. The DU202 is a unit including lower layers included in the protocol stack described below, such as an RLC layer, a MAC layer, and a PHY layer. The DU is connected to the CU via an F1 interface, which is a fronthaul interface.

[0023] In addition, gNBs can also be connected to the Evolved Packet Core (EPC), which is the core network of LTE. LTE base stations can also be connected to 5GC. LTE base stations and gNBs can also be connected via an inter-base station interface.

[0024] The 5GC20 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 controls data forwarding. The AMF and the UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0025] FIG. 2 is a diagram showing the configuration of a protocol stack of a radio interface of a user plane that handles data.

[0026] The user plane radio interface protocol includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0027] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of UE100 and the PHY layer of gNB200 via a physical channel. The PHY layer of UE100 receives downlink control information (DCI) transmitted from gNB200 on a physical downlink control channel (PDCCH). Specifically, UE100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and acquires successfully decoded DCI as DCI addressed to the UE. The DCI transmitted from gNB200 has CRC bits scrambled by the RNTI added.

[0028] In addition, the gNB 200 transmits a synchronization signal block (SSB: Synchronization Signal / PBCH block). For example, the SSB is composed of four consecutive OFDM (Orthogonal Frequency Division Multiplex) symbols, and includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) / master information block (MIB), and a PBCH demodulation reference signal (DMRS). The bandwidth of the SSB is, for example, 240 consecutive subcarriers, that is, a bandwidth of 20 RBs.

[0029] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to the UE 100.

[0030] The RLC layer transmits data to the receiving RLC layer using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0031] The PDCP layer performs header compression / decompression, encryption / decryption, and the like.

[0032] The SDAP layer maps IP (Internet Protocol) flows, which are units for Quality of Service (QoS) control by the core network, to radio bearers, which are units for QoS control by the AS (Access Stratum). Note that if the RAN is connected to the EPC, SDAP may not be required.

[0033] FIG. 3 is a diagram showing the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals).

[0034] The protocol stack of the radio interface of the control plane has an RRC (Radio Resource Control) layer and an NAS (Non-Access Stratum) layer instead of the SDAP layer shown in FIG.

[0035] RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of gNB200. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in an RRC connected state. When there is no connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in an RRC idle state. When the connection between the RRC of UE100 and the RRC of gNB200 is suspended, UE100 is in an RRC inactive state.

[0036] The NAS layer, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the AMF 300A. Note that the UE 100 has an application layer and the like in addition to the radio interface protocol. Also, a layer lower than the NAS layer is called an AS (Access Stratum).

[0037] (1.2) Example application scenario of the relay device Next, an application scenario of the NCR device (relay device) according to the first embodiment will be described. Figures 4 and 5 are diagrams showing an example application scenario of the NCR device according to the first embodiment. Note that the NCR device may also be referred to as an NCR node.

[0038] Compared to 4G / LTE, 5G / NR enables broadband transmission using higher frequency bands. Radio signals in high frequency bands, such as the millimeter wave band or terahertz wave band, have high line-of-sight properties, which poses a challenge in reducing the coverage of the gNB 200. In FIG. 4, the UE 100 may be located outside the coverage area of ​​the gNB 200, for example, outside an area where radio signals can be received directly from the gNB 200. A shield may exist between the gNB 200 and the UE 100, preventing the UE 100 from communicating with the gNB 200 within line-of-sight.

[0039] As shown in Figure 4, an NCR device 500A, which is a type of repeater device that relays radio signals between the gNB 200 and the UE 100 and can be controlled from the network 5, is introduced into the mobile communication system 1. Such a repeater device may be referred to as a smart repeater device.

[0040] For example, the NCR device 500A amplifies a radio signal (radio wave) received from the gNB 200 and transmits it by directional transmission. Specifically, the NCR device 500A receives a radio signal transmitted by the gNB 200 by beamforming. The NCR device 500A then amplifies the received radio signal without demodulating or modulating it, and transmits the amplified radio signal by directional transmission. Here, the NCR device 500A may transmit a radio signal with a fixed directivity (beam). The NCR device 500A may also transmit a radio signal with a variable (adaptive) directional beam. This allows the coverage of the gNB 200 to be efficiently expanded.

[0041] Also, as shown in FIG. 5, a new UE (hereinafter referred to as "NCR-MT (Mobile Termination)") 100B, which is a type of control terminal for controlling the NCR device 500A, is introduced. That is, the NCR device 500A relays radio signals transmitted between the gNB 200 and the UE 100, specifically, the radio signals. NCR-Fwd (Forwarding) 510A, which is a type of repeater that changes the propagation state of the radio signal without demodulating or modulating the radio signal, and NCR-MT 520A that performs wireless communication with the gNB 200 and controls the NCR-Fwd 510A.

[0042] In this way, the NCR-MT 520A 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. This enables efficient coverage expansion using the NCR device 500A. The NCR-MT 520A controls the NCR device 500A according to control from the gNB 200. The NCR-MT 520A also has functions similar to those of the UE 100.

[0043] The NCR-MT 520A may be configured separately from the NCR-Fwd 510A. For example, the NCR-MT 520A may be located near the NCR-Fwd 510A and electrically connected to the NCR-Fwd 510A. The NCR-MT 520A may be connected to the NCR-Fwd 510A by wire or wirelessly. Alternatively, the NCR-MT 520A may be configured integrally with the NCR-Fwd 510A. The NCR-MT 520A and the NCR-Fwd 510A may be fixedly installed, for example, at the coverage edge (cell edge) of the gNB 200 or on a wall or window of a building. The NCR-MT 520A and the NCR-Fwd 510A may be installed, for example, in a vehicle or the like and be mobile. Also, one NCR-MT 520A may control multiple NCR-Fwds 510A.

[0044] Note that the configuration is not limited to one in which the NCR-MT 520A directly controls one or more NCR-Fwds 510A, and may be one in which the NCR-MT 520A indirectly controls one or more NCR-Fwds 510A. For example, the NCR-MT 520A may control one or more NCR-Fwds 510A via a higher layer (for example, an application layer).

[0045] In the example shown in FIG. 5, the NCR device 500A (NCR-Fwd 510A) dynamically or quasi-statically changes the beam to be transmitted or received. For example, the NCR-Fwd 510A forms a beam toward each of the UE 100a and the UE 100b. The NCR-Fwd 510A may also form a beam toward the gNB 200. For example, in the communication resources between the gNB 200 and the UE 100a, the NCR-Fwd 510A transmits a radio signal received from the gNB 200 toward the UE 100a by beamforming, and / or transmits a radio signal received from the UE 100a toward the gNB 200 by beamforming. In the communication resources between the gNB 200 and the UE 100b, the NCR-Fwd 510A transmits a radio signal received from the gNB 200 toward the UE 100b by beamforming, and / or transmits a radio signal received from the UE 100b by beamforming toward the gNB 200. Instead of or in addition to beamforming, the NCR-Fwd 510A may form a null (so-called null steering) toward a UE 100 (not shown) and / or a neighboring gNB 200 (not shown) that is not a communication partner for interference suppression.

[0046] FIG. 6 is a diagram showing an example of a control method for the NCR device 500A according to the first embodiment.

[0047] The NCR-Fwd 510A relays radio signals (also referred to as "UE signals") between the gNB 200 and the UE 100. The UE signals include uplink signals (also referred to as "UE-UL signals") transmitted from the UE 100 to the gNB 200 and downlink signals (also referred to as "UE-DL signals") transmitted from the gNB 200 to the UE 100. The NCR-Fwd 510A relays UE-UL signals from the UE 100 to the gNB 200 and relays UE-DL signals from the gNB 200 to the UE 100. The radio link between the NCR-Fwd 510A and the UE 100 is also referred to as an "access link." The radio link between the NCR-Fwd 510A and the gNB 200 is also referred to as a "backhaul link."

[0048] The NCR-MT 520A transmits and receives radio signals (herein referred to as "NCR-MT signals") to and from the gNB 200. The NCR-MT signals include uplink signals (herein referred to as "NCR-MT-UL signals") transmitted from the NCR-MT 520A to the gNB 200, and downlink signals (herein referred to as "NCR-MT-DL signals") transmitted from the gNB 200 to the NCR-MT 520A. The NCR-MT-DL signals include signaling (e.g., NCR control signals) for controlling the NCR device 500A. The radio link between the NCR-MT 520A and the gNB 200 is also referred to as a "control link."

[0049] The gNB200 directs a beam to the NCR-MT520A based on the NCR-MT-UL signal from the NCR-MT520A. Because the NCR device 500A is co-located with the NCR-MT520A, if the backhaul link and the control link have the same frequency, when the gNB200 directs a beam to the NCR-MT520A, the beam will also be directed to the NCR-Fwd510A. The gNB200 uses this beam to transmit an NCR-MT-DL signal and a UE-DL signal. The NCR-MT520A receives the NCR-MT-DL signal. In addition, when the NCR-Fwd 510A and the NCR-MT 520A are at least partially integrated, the functions (e.g., antennas) for transmitting, receiving, or relaying UE signals and / or NCR-MT signals may be integrated in the NCR-Fwd 510A and the NCR-MT 520A. Note that the term "beam" includes a transmitting beam and / or a receiving beam. A beam is a general term for transmission and / or reception controlled to maximize the power of transmitted waves and / or received waves in a specific direction by adjusting / adapting antenna weights, etc.

[0050] FIG. 7 is a diagram for explaining an example of the configuration of a protocol stack in the NCR device 500A according to the first embodiment.

[0051] The NCR-Fwd 510A relays radio signals transmitted and received between the gNB 200 and the UE 100. The NCR-Fwd 510A has an RF (Radio Frequency) function that amplifies and relays received radio signals, and performs directional transmission using beamforming (e.g., analog beamforming).

[0052] The NCR-MT 520A has entities for each of the layers: Layer 1 and / or Layer 2 (L1 / L2), RRC, and NAS. The L1 / L2 (especially PHY and MAC) and RRC of the NCR-MT 520A are also referred to as the "AS of the NCR-MT 520A."

[0053] The NCR-MT 520A may have at least one of an OAM client that communicates with the OAM (Operation, Administration, Maintenance) server 400, a NAS layer that communicates with the AMF 300A, and an F1-AP (Application Protocol) layer. The OAM client, NAS layer, and F1-AP layer of the NCR-MT 520A are also referred to as the "upper layers of the NCR-MT 520A" based on the AS of the NCR-MT 520A.

[0054] A backhaul link is established between the gNB200 and the NCR-Fwd510A. An access link is established between the UE100 and the NCR-Fwd510A. The NCR-Fwd510A relays radio signals transmitted between the gNB200 and the UE100 via the backhaul link and the access link. The NCR-Fwd510A changes the propagation state of the radio signal without demodulating or modulating the radio signal.

[0055] In addition, a control link is established between gNB200 and L1 / L2 of NCR-MT520A. L1 / L2 of NCR-MT520A transmits and receives L1 / L2 signaling with gNB200 via the control link. An RRC connection is established between gNB200 and RRC of NCR-MT520A. RRC of NCR-MT520A transmits and receives RRC messages with gNB200 via the RRC connection. NCR-MT520A receives downlink signaling (also referred to as an "NCR control signal" or simply "control signal") from gNB200 via the RRC connection and / or the control link.

[0056] The gNB 200 (transmitter 210) transmits an NCR control signal to the NCR-MT 520A. The NCR control signal may be an RRC message, which is a control signal of the RRC layer (i.e., Layer 3). The NCR control signal may be a MAC Control Element (CE), which is a control signal of the MAC layer (i.e., Layer 2). The NCR control signal may be downlink control information (DCI), which is a control signal of the PHY layer (i.e., Layer 1). The NCR control signal may be UE-specific signaling. The NCR control signal may be broadcast signaling. The NCR control signal may be a fronthaul message (e.g., an F1-AP message). If the NCR-MT 520A is a type or part of a base station, the NCR-MT 520A may communicate with the gNB 200 via an Xn AP (Xn-AP), which is an inter-base station interface.

[0057] Hereinafter, an NCR control signal transmitted in an RRC message (and / or MAC CE) and used for static or semi-static control of the NCR-Fwd 510A will also be referred to as "NCR configuration information" or simply as "configuration information." Such configuration information may be referred to as "Side Control Configuration." Here, the RRC message may be an RRC Reconfiguration message. The NCR configuration information includes, for example, information for setting the NCR-Fwd 510A to on / off. The NCR configuration information may also include, for example, information for semi-static beam configuration of the NCR-Fwd 510A.

[0058] On the other hand, an NCR control signal transmitted in L1 / L2 signaling, i.e., DCI (and / or MAC CE), and used for dynamic control of the NCR-Fwd 510A is also referred to as "NCR control information" or simply "control information." The NCR control information may also be referred to as "side control information." The CRC (Cyclic Redundancy Code) bits of the PDCCH carrying the NCR control information are scrambled by a newly introduced dedicated RNTI. This dedicated RNTI is also referred to as "NCR-RNTI." The NCR control information may include, for example, information on dynamic beam control of the NCR-Fwd 510A. The NCR setting information may include information instructing dynamic on / off of the NCR-Fwd 510A.

[0059] For example, when the NCR-MT 520A is in the RRC connected state, the NCR device 500A can turn on or off the NCR-Fwd 510A according to the NCR control information received from the gNB 200. On the other hand, after the NCR-MT 520A transitions to the RRC inactive state, the NCR device 500A can turn on or off the NCR-Fwd 510A according to the latest (last) setting information received from the gNB 200.

[0060] In addition, the NCR control signal (e.g., NCR setting information by RRC and / or NCR control information by L1 / L2 signaling) held by the NCR device 500A (NCR-MT 520A) may be referred to as an NCR-Fwd context.

[0061] Also, if a radio link failure (RLF) with the gNB200 is detected by the NCR-MT520A, the NCR-MT520A performs cell selection and triggers RRC connection re-establishment (also referred to as "RRC re-establishment"). Here, if the NCR-MT520A enters an RRC idle state because a suitable cell cannot be found in the cell selection, the NCR device 500A turns off the NCR-Fwd510A. Note that the NCR-Fwd510A is off during the RRC connection re-establishment procedure.

[0062] The NCR control signal may include frequency control information that specifies the center frequency of the radio signal (e.g., component carrier) to be relayed by the NCR-Fwd 510A. When the NCR control signal received from the gNB 200 includes frequency control information, the NCR-MT 520A (control unit 523) controls the NCR-Fwd 510A to relay the radio signal having the center frequency indicated by the frequency control information (step S2A). The NCR control signal may include multiple pieces of frequency control information that specify different center frequencies. By including frequency control information in the NCR control signal, the gNB 200 can specify the center frequency of the radio signal to be relayed by the NCR-Fwd 510A via the NCR-MT 520A.

[0063] The NCR control signal may include mode control information that specifies the operation mode of the NCR-Fwd 510A. The mode control information may be associated with frequency control information (center frequency). The operation mode may be any of a mode in which the NCR-Fwd 510A performs omnidirectional transmission and / or reception, a mode in which the NCR-Fwd 510A performs fixed-directivity transmission and / or reception, a mode in which the NCR-Fwd 510A performs transmission and / or reception using a variable directional beam, and a mode in which the NCR-Fwd 510A performs MIMO (Multiple Input Multiple Output) relay transmission. The operation mode may be any of a beamforming mode (i.e., a mode that emphasizes improving the desired wave) and a null steering mode (i.e., a mode that emphasizes suppressing interference waves). When the NCR control signal received from the gNB 200 includes mode control information, the NCR-MT 520A (control unit 523) controls the NCR-Fwd 510A to operate in the operating mode indicated by the mode control information (step S2A). By including the mode control information in the NCR control signal, the gNB 200 can specify the operating mode of the NCR-Fwd 510A via the NCR-MT 520A.

[0064] Here, the mode in which the NCR device 500A performs omnidirectional transmission and / or reception is a mode in which the NCR-Fwd 510A performs omnidirectional relaying, and may be referred to as omni-mode. The mode in which the NCR-Fwd 510A performs fixed directional transmission and / or reception may be a directional mode realized by a single directional antenna. This mode may be a beamforming mode realized by applying fixed phase / amplitude control (antenna weight control) to multiple antennas. Any of these modes may be specified (set) by the gNB 200 to the NCR-MT 520A. The mode in which the NCR-Fwd 510A performs transmission and / or reception using a variable directional beam may be a mode in which analog beamforming is performed. This mode may be a mode in which digital beamforming is performed. This mode may be a mode in which hybrid beamforming is performed. This mode may be a mode in which an adaptive beam specific to the UE 100 is formed. Any of these modes may be specified (set) from the gNB 200 to the NCR-MT 520A. Note that in an operation mode in which beamforming is performed, beam control information, described below, may be provided from the gNB 200 to the NCR-MT 520A. The mode in which the NCR device 500A performs MIMO relay transmission may be a mode in which SU (Single-User) spatial multiplexing is performed. This mode may also be a mode in which MU (Multi-User) spatial multiplexing is performed. This mode may also be a mode in which transmit diversity is performed. Any of these modes may be specified (set) from the gNB 200 to the NCR-MT 520A. The operation modes may include a mode in which relay transmission by the NCR-Fwd 510A is turned on (activated) and a mode in which relay transmission by the NCR-Fwd 510A is turned off (deactivated). Any of these modes may be specified (set) by an NCR control signal from gNB200 to NCR-MT520A.

[0065] The NCR control signal may include beam control information that specifies the transmission direction, transmission weight, or beam pattern when the NCR-Fwd 510A 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). The beam control information may include beam formation angle information. When the NCR control signal received from the gNB 200 includes beam control information, the NCR-MT 520A (control unit 523) controls the NCR-Fwd 510A to form the transmission directivity (beam) indicated by the beam control information. By including beam control information in the NCR control signal, the gNB 200 can control the transmission directivity of the NCR device 500A via the NCR-MT 520A.

[0066] The NCR control signal may include power control information that specifies the degree (gain) or transmission power by which the NCR-Fwd 510A amplifies the radio signal. The power control information may be information indicating a difference value (i.e., a relative value) between the current gain or transmission power and the target gain or transmission power. When the NCR control signal received from the gNB 200 includes power control information, the NCR-MT 520A (control unit 523) controls the NCR-Fwd 510A to change the gain or transmission power to the gain or transmission power indicated by the transmission power control. The power control information may be associated with frequency control information (center frequency). The power control information may be information that specifies any of the amplifier gain, beamforming gain, and antenna gain of the NCR-Fwd 510A. The power control information may be information that specifies the transmission power of the NCR-Fwd 510A.

[0067] When one NCR-MT 520A controls multiple NCR-Fwds 510A, the gNB 200 (transmitter 210) may transmit an NCR control signal to the NCR-MT 520A for each NCR-Fwd 510A. In this case, the NCR control signal may include an identifier (NCR identifier) ​​of the corresponding NCR-Fwd 510A. The NCR-MT 520A (controller 523) that controls multiple NCR-Fwds 510A determines the NCR-Fwd 510A to which the NCR control signal is applied based on the NCR identifier included in the NCR control signal received from the gNB 200. Note that the NCR identifier may be transmitted from the NCR-MT 520A to the gNB 200 together with the NCR control signal, even when the NCR-MT 520A controls only one NCR-Fwd 510A.

[0068] In this way, the NCR-MT 520A (control unit 523) controls the NCR-Fwd 510A based on the NCR control signal from the gNB 200. This enables the gNB 200 to control the NCR-Fwd 510A via the NCR-MT 520A.

[0069] (1.3) Example of Configuration of Each Device Next, an example of the configuration of each device in the mobile communication system 1 according to the first embodiment will be described.

[0070] 8 is a diagram showing an example of the configuration of an NCR device 500A (relay device) according to the first embodiment. The NCR device 500A includes an NCR-Fwd 510A, an NCR-MT 520A, and an interface 530.

[0071] The NCR-Fwd 510A includes a radio unit 511A and an NCR control unit 512A. The radio unit 511A includes an antenna unit 511a including multiple antennas (multiple antenna elements), an RF circuit 511b including an amplifier, and a directivity control unit 511c that controls the directivity of the antenna unit 511a. The RF circuit 511b amplifies and relays (transmits) radio signals transmitted and received by the antenna unit 511a. The RF circuit 511b may convert analog radio signals into digital signals and then reconvert them to analog signals after digital signal processing. The directivity control unit 511c may perform analog beamforming using analog signal processing. The directivity control unit 511c may perform digital beamforming using digital signal processing. The directivity control unit 511c may perform hybrid analog and digital beamforming. The NCR control unit 512A controls the radio unit 511A in response to control signals from the NCR-MT 520A. The NCR control unit 512A may include at least one processor.

[0072] The NCR-MT 520A has a receiving unit 521, a transmitting unit 522, and a control unit 523. The receiving unit 521 performs various receptions under the control of the control unit 523. The receiving unit 521 includes an antenna and a receiver. The receiver converts a radio signal (wireless signal) received by the antenna into a baseband signal (received signal) and outputs it to the control unit 523. The transmitting unit 522 performs various transmissions under the control of the control unit 523. The transmitting unit 522 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmitted signal) output by the control unit 523 into a radio signal and transmits it from the antenna. The control unit 523 performs various controls on the NCR-MT 520A. The operations of the NCR-MT 520A (and the NCR device 500A) described above and below may be operations controlled by the control unit 523. The control unit 523 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in processing by the processor. 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. The CPU executes programs stored in the memory to perform various processes. In addition, the control unit 523 executes the functions of at least one layer of PHY, MAC, RRC, and F1-AP.

[0073] The interface 530 electrically or logically connects the NCR-Fwd 510A and the NCR-MT 520A. The control unit 523 of the NCR-MT 520A controls the NCR-Fwd 510A via the interface 530. The interface 530 may be a logical entity of an upper layer (e.g., an application layer).

[0074] In the first embodiment, the receiver 521 of the NCR-MT 520A receives signaling (NCR control signal) used to control the NCR device 500A from the gNB 200 via wireless communication. The controller 523 of the NCR-MT 520A controls the NCR device 500A based on the signaling. This enables the gNB 200 to control the NCR-Fwd 510A via the NCR-MT 520A.

[0075] (1.3.2) Example of configuration of user device Figure 9 is a diagram showing the configuration of the UE 100 (user device) according to the first embodiment. The UE 100 has a receiving unit 110, a transmitting unit 120, and a control unit 130. The receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200.

[0076] The receiving unit 110 performs various types of reception under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 130.

[0077] 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 a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0078] The control unit 130 performs various controls and processes in the UE 100. Such processes include processes of each layer described below. The operations of the UE 100 described above and below may be operations controlled by the control unit 130. 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 in the 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. The CPU executes programs stored in the memory to perform various processes.

[0079] (1.3.3) Example of network node configuration Figure 10 is a diagram showing an example of the configuration of a gNB 200 (network node) according to the first embodiment. The gNB 200 has a transmitter 210, a receiver 220, a controller 230, and a backhaul communication unit 240.

[0080] The transmitting unit 210 performs various transmissions under the control of the control unit 230. The transmitting unit 210 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna. The receiving unit 220 performs various receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (reception signal) and outputs it to the control unit 230. The transmitting unit 210 and the receiving unit 220 may be capable of beamforming using multiple antennas.

[0081] The control unit 230 performs various controls in the gNB 200. The operations of the gNB 200 described above and below may be operations controlled by the control unit 230. 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 in 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. The CPU executes programs stored in the memory to perform various processes.

[0082] The backhaul communication unit 240 is connected to adjacent base stations via an inter-base station interface. The backhaul communication unit 240 is connected to the AMF / UPF 300 via a base station-core network interface. The gNB is composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally divided), and the two units may be connected via an F1 interface.

[0083] In the first embodiment, the transmitter 210 of the gNB 200 transmits signaling (NCR control signal) used to control the NCR-Fwd 510A to the NCR-MT 520A via wireless communication. This enables the gNB 200 to control the NCR device 500A via the NCR-MT 520A.

[0084] (1.4) Operation of the Mobile Communication System Next, the operation of the mobile communication system 1 according to the first embodiment will be described.

[0085] (1.4.1) Basic Operation The basic operation according to the first embodiment is the operation related to the NCR device 500A. The NCR device 500A is a RAN node having an NCR-Fwd 510A and an NCR-MT 520A. The NCR-Fwd 510A performs relay transmission between the gNB 200 and the UE 100, specifically, amplifies and relays (forwarding) UL / DL RF signals. The operation of the NCR-Fwd 510A is controlled according to side control information (NCR control signal) received by the NCR-MT 520A from the gNB 200. The NCR-MT 520A communicates with the gNB 200 via a control link to receive the side control information. The control link is based on the NR Uu interface.

[0086] Although the NCR-Fwd 510A can amplify the radio signal (RF signal) to be relayed, a technology for performing transmission power control (Power Control) that allows the gNB 200 to variably set the transmission power and / or gain has not yet been established. In the following first embodiment, an operation that enables appropriate transmission power control of the NCR-Fwd 510A will be described.

[0087] (1.4.1.1) First Basic Operation FIG. 11 is a diagram showing the first basic operation of the NCR device 500A according to the first embodiment.

[0088] In step S11, the NCR-MT 520A receives power control information for controlling the transmission power of relay transmission from the gNB 200. The power control information may be a type of side control information (NCR control signal) transmitted on a control link. The gNB 200 may transmit at least one of a radio resource control (RRC) message including power control information, a medium access control / control element (MAC CE) including power control information, and downlink control information (DCI) including power control information to the NCR-MT 520A.

[0089] The power control information may be information for controlling transmission power in the downlink (DL) direction from the NCR-Fwd 510A to the UE 100. The power control information may be information for controlling transmission power in the uplink (UL) direction from the NCR-Fwd 510A to the gNB 200. The power control information may be information for controlling transmission power in both the DL and UL directions.

[0090] The power control information for controlling the transmission power of relay transmission includes at least one of the following pieces of information 1) to 3): 1) First information indicating the maximum transmission power (also referred to as "maximum operational transmission power") and / or maximum gain (also referred to as "maximum operational gain") to be set in NCR-Fwd510A: A specific example of operation using the first information will be described later in the first operation pattern.

[0091] 2) Second information indicating the transmission power (also referred to as "repeated transmission power") and / or gain (also referred to as "repeated gain") in periodic relay transmission (repeated relay transmission): A specific example of operation using the second information will be described later in the second operation pattern.

[0092] 3) Third information indicating the transmission power (also referred to as "dynamic transmission power") and / or gain (also referred to as "dynamic gain") in non-periodic relay transmission (single relay transmission): A specific example of operation using the third information will be described in the first operation pattern below.

[0093] In step S12, the NCR-Fwd 510A performs relay transmission at a transmission power based on the power control information received in step S11. If the power control information received in step S11 includes first information, step S12 includes a step of performing relay transmission so as not to exceed the maximum transmission power and / or maximum gain based on the first information. If the power control information received in step S11 includes second information, step S12 includes a step of performing periodic relay transmission at a transmission power based on the second information. If the power control information received in step S11 includes third information, step S12 includes a step of performing non-periodic relay transmission at a transmission power based on the third information.

[0094] The transmission power (output power) of the NCR-Fwd 510A that relays and transmits a wireless signal is determined according to the received power and power amplification (gain) of the wireless signal. The power amplification is the ratio of the transmission power to the received power, and the gain may be the power amplification expressed in decibels (dB). When the maximum transmission power (and / or maximum gain) is specified by the first information, the NCR-Fwd 510A may control the gain (specifically, the amplifier) ​​so that the specified maximum transmission power (and / or maximum gain) is not exceeded. When the transmission power (and / or gain) is specified by the second information or the third information, the NCR-Fwd 510A may control the amplifier so that the specified transmission power (and / or gain) is achieved.

[0095] According to the first basic operation, the gNB 200 can variably set the transmission power and / or gain when the NCR-Fwd 510A relays a radio signal (RF signal). Therefore, the gNB 200 can appropriately control the transmission power of the NCR-Fwd 510A.

[0096] The NCR device 500A that performs such operations has an NCR-MT 520A that receives power control information for controlling the transmission power of relay transmission from the gNB 200, and an NCR-Fwd 510A that performs relay transmission at a transmission power based on the power control information. Meanwhile, the gNB 200 that communicates with the NCR device 500A (NCR-MT 520A) has a control unit 230 that generates power control information for controlling the transmission power of relay transmission, and a transmission unit 210 that transmits the power control information to the NCR-MT 520A.

[0097] The power control information may include information specifying a period (timing) during which transmission power control according to the power control information is applied. The NCR-MT 520A may perform relay transmission at a transmission power based on the power control information during the specified period (timing).

[0098] Step S11 may include receiving first power control information including a configuration list that associates transmission power or gain setting values ​​with indexes indicating the setting values, and receiving second power control information including the indexes. For example, the NCR-MT 520A may receive the first power control information including the configuration list from the gNB 200 via an RRC message, and then receive an index (second power control information) indicating the setting value in the configuration list from the gNB 200 via a MAC CE or DCI. Step S12 may include identifying a setting value corresponding to the index included in the second power control information based on the configuration list, and performing transmission power control using the identified setting value. In this way, the gNB 200 may set a list in which value ranges of transmission power or gain are indexed in the NCR-MT 520A in advance, and use the index when specifying the actual transmission power or gain.

[0099] (1.4.1.2) Second Basic Operation Fig. 12 is a diagram showing a second basic operation of the NCR device 500A according to the first embodiment. The second basic operation may be performed in combination with the first basic operation.

[0100] In step S21, the NCR device 500A acquires a maximum value indicating the maximum transmission power and / or maximum gain set in the NCR-Fwd 510A and an estimated value indicating the transmission power and / or gain of relay transmission in the NCR-Fwd 510A. Here, the maximum transmission power and / or maximum gain may be a variable value (maximum operational transmission power, maximum operational gain) designated by the gNB 200 in the first basic operation. The maximum transmission power and / or maximum gain may be a fixed value determined depending on the capabilities of the NCR-Fwd 510A or legal regulations (e.g., regulations under the Radio Act). The maximum transmission power and / or maximum gain may selectively be the lowest value of the variable value and the fixed value. The estimated value indicating the transmission power and / or gain may be a measured value (actual measured value) obtained by measuring the transmission power and / or gain. The estimated value may be a calculated value (theoretical value) obtained using a calculation formula for the transmission power and / or gain.

[0101] In step S22, the NCR-MT 520A transmits margin information indicating the difference between the maximum value acquired in step S21 and the estimated value to the gNB 200 over the control link. The margin information may be referred to as headroom information. The margin information may be a difference value indicating the difference between the maximum value acquired in step S21 and the estimated value or an index thereof. The margin information may further include the maximum value acquired in step S21.

[0102] This allows the gNB200 to grasp the margin (remaining capacity) of the transmission power and / or gain in the NCR device 500A (NCR-Fwd 510A) based on the margin information. Therefore, the gNB200 can appropriately control the transmission power of the NCR-Fwd 510A. For example, the gNB200 may grasp the margin (remaining capacity) and then perform transmission power control using the second information and / or third information described above within the range of the margin (remaining capacity). The gNB200 may perform resource scheduling for the NCR device 500A based on the margin (remaining capacity). Specific examples of operations using margin information will be described in the fourth operation pattern below.

[0103] In the NCR device 500A that performs such operations, the NCR-MT 520A transmits margin information indicating the difference between a maximum value indicating the maximum transmission power and / or maximum gain set in the NCR-Fwd 510A and an estimated value indicating the transmission power and / or gain of relay transmission in the NCR-Fwd 510A to the gNB 200. Meanwhile, the gNB 200 has a receiving unit 220 that receives the margin information from the NCR-MT 520A.

[0104] In step S22, NCR-MT520A may transmit a medium access control element (MAC CE) including availability information to gNB200 over the control link.

[0105] The margin information may include power margin information indicating a difference between a maximum value indicating a maximum transmission power and an estimated value indicating the transmission power, and gain margin information indicating a difference between a maximum value indicating a maximum gain and an estimated value indicating the gain. Step S22 may include a step of transmitting a first MAC CE including the power margin information and a step of transmitting a second MAC CE including the gain margin information. This allows the power margin information and the gain margin information to be transmitted independently to the gNB 200. Here, the first MAC CE may include a first logical channel identifier (LCID), and the second MAC CE may include a second LCID different from the first LCID. That is, the MAC CE including the power margin information (first MAC CE) and the MAC CE including the gain margin information (second MAC CE) may be identified by different LCIDs.

[0106] The second basic operation may further include a step in which the NCR-MT 520A receives a signal that sets or requests the transmission of margin information from the gNB 200. The NCR-MT 520A may transmit the margin information to the gNB 200 based on the signal. The signal may include at least one of information that sets the timing for acquiring the maximum value and the estimated value and information that sets a transmission trigger for the margin information.

[0107] The margin information may be any one of the following 1) to 3).

[0108] 1) Margin information regarding the uplink direction (uplink) from NCR-Fwd 510A to gNB 200: In this case, in step S21, the NCR device 500A may acquire a maximum value indicating the maximum transmission power and / or maximum gain in the uplink direction, and an estimated value indicating the transmission power and / or gain in the uplink direction.

[0109] 2) Margin information regarding the downlink direction (downlink) from NCR-Fwd 510A to UE 100: In this case, in step S21, the NCR device 500A may acquire a maximum value indicating the maximum downlink transmission power and / or maximum gain, and an estimated value indicating the downlink transmission power and / or gain.

[0110] 3) Overall margin information including both uplink and downlink.

[0111] (1.4.2) Specific Examples of Operation First to fourth operation patterns will be described as specific examples of the operation of the mobile communication system 1 according to the first embodiment. Each of these operation patterns may be implemented independently, or two or more operation patterns may be implemented in combination.

[0112] (1.4.2.1) First operation pattern Figure 13 is a diagram showing an example of the first operation pattern of the mobile communication system 1 according to the first embodiment. In the first operation pattern, the gNB 200 sets the maximum operational transmission power and / or maximum operational gain of the NCR-Fwd 510A to the NCR-MT 520A.

[0113] In step S101, NCR-MT520A of NCR device 500A is in an RRC connected state in the cell of gNB200.

[0114] In step S102, the gNB 200 determines the maximum operational transmit power and / or maximum operational gain of the NCR-Fwd 510A of the NCR device 500A. The gNB 200 may acquire capability information indicating the maximum transmit power and / or maximum gain determined according to the capabilities of the NCR-Fwd 510A, and determine the maximum operational transmit power and / or maximum operational gain so as not to exceed the maximum transmit power and / or maximum gain. The gNB 200 may acquire the capability information from an OAM (Operation, Administration and Maintenance) entity. The gNB 200 may also acquire the capability information from the NCR-MT 520A. Here, the NCR-MT 520A may transmit an RRC message including the capability information of the NCR-Fwd 510A to the gNB 200, and the gNB 200 may acquire the capability information included in the RRC message. For example, gNB200 may determine the maximum operating transmission power and / or maximum operating gain of NCR-Fwd510A within the range of the allowable maximum transmission power of NCR-Fwd510A (maximum transmission power determined depending on the capabilities of NCR-Fwd510A or legal regulations) to suppress interference to adjacent cells.

[0115] In step S103, the gNB200 transmits power control information indicating the maximum operational transmit power and / or maximum operational gain of the NCR-Fwd510A determined in step S102 to the NCR-MT520A. The NCR-MT520A receives the power control information. Here, the gNB200 may transmit the power control information to the NCR-MT520A by including it in an RRC reconfiguration message, a MAC CE, or a DCI. In the first operation pattern, the power control information may include at least one of the following information 1) to 4).

[0116] 1) Maximum operational transmission power [dBm]: Information indicating the maximum operational transmission power of the NCR-Fwd 510A determined in step S102. This does not have to be the actual value of the maximum operational transmission power, but may be an index of the maximum operational transmission power.

[0117] 2) Maximum operating gain [dB]: Information indicating the maximum operating gain of the NCR-Fwd 510A determined in step S102. This may be an index of the maximum operating gain instead of the actual value of the maximum operating gain.

[0118] 3) Validity period: Information indicating the period during which the power control information of step S103 is valid. This information may be, for example, the value of an expiration monitoring timer, the number of valid radio frames, or the number of an invalid (or last valid) radio frame. The gNB 200 may specify the validity period to temporarily suppress the maximum transmission power, for example, when the time required for interference suppression is limited.

[0119] 4) NCR-Fwd ID (or NCR-RNTI): This is information for specifying which NCR-Fwd 510A is the target when the NCR-MT 520A manages a plurality of NCR-Fwds 510A.

[0120] In step S104, the NCR-MT 520A controls the transmission power of the NCR-Fwd 510A in accordance with the power control information received in step S103. The NCR-MT 520A may notify (set) the NCR-Fwd 510A of the power control information received in step S103 and operate the NCR-Fwd 510A in accordance with the power control information. If the power control information includes a timer value indicating a validity period, the NCR-MT 520A may start a timer set to the timer value and, when the timer expires, determine that the power control information is invalid. Note that if the NCR-MT 520A does not have valid power control information (e.g., if the power control information has not been received from the gNB 200 or has expired), the NCR-Fwd 510A may operate at the maximum transmission power and / or maximum gain specified by its capabilities or the Radio Law upper limit. The NCR-MT520A may adopt as its maximum transmission power the smaller of the maximum transmission power according to its capacity or the Radio Law upper limit and the maximum operational transmission power set by the gNB200.

[0121] (1.4.2.2) Second Operation Pattern The second operation pattern will be described, focusing on the differences from the first operation pattern. FIG. 14 is a diagram showing an example of the second operation pattern of the mobile communication system 1 according to the first embodiment. In the second operation pattern, the gNB 200 specifies (notifies) the NCR-MT 520A of the transmission power (repetition transmission power) and / or gain (repetition gain) in the periodic relay transmission by the NCR-Fwd 510A. The second operation pattern may be an operation that assumes that the maximum transmission power (or maximum gain) is specified in the first operation pattern, or may be an operation that does not assume the first operation pattern.

[0122] In step S201, NCR-MT520A of NCR device 500A is in an RRC connected state in the cell of gNB200.

[0123] In step S202, the gNB200 may transmit power control information (first power control information) including a list associating transmission power and / or gain with its index to the NCR-MT520A. The NCR-MT520A may receive the power control information. The gNB200 may include the power control information of step S202 in an RRC Reconfiguration message and transmit it to the NCR-MT520A. The list entries included in the power control information of step S202 may include at least one of the following information 1) to 4).

[0124] 1) Setting ID (index): An index indicating the corresponding transmission power and / or gain.

[0125] 2) Transmission power [dBm] and / or gain [dB]: This may be a range (value range) of transmission power and / or a range (value range) of transmission power.

[0126] 3) NCR-Fwd ID (or NCR-RNTI): This is information for specifying which NCR-Fwd 510A is the target when the NCR-MT 520A manages multiple NCR-Fwds 510A.

[0127] 4) Information about the repetition period: This may include the start timing (e.g., slot number) of the periodic relay transmission and the repetition period (e.g., number of slots). It may also be bitmap information indicating each timing at which the repetition transmission power and / or the repetition gain is applied.

[0128] In step S203, gNB200 determines the repetition transmission power and / or repetition gain of NCR-Fwd510A of NCR device 500A. gNB200 may determine the repetition transmission power and / or repetition gain so as not to exceed the maximum transmission power and / or maximum gain of NCR-Fwd510A.

[0129] In step S204, the gNB200 transmits power control information (second power control information) indicating the repetition transmission power and / or repetition gain determined in step S203 to the NCR-MT520A. The NCR-MT520A receives the power control information. The gNB200 may transmit the power control information of step S204 to the NCR-MT520A by including it in an RRC Reconfiguration message, MAC CE, or DCI. The power control information of step S204 may include at least one of the following information 1) to 4).

[0130] 1) Information about the repetition period: This may include the start timing (e.g., slot number) of the periodic relay transmission and the repetition period (e.g., number of slots). It may also be bitmap information indicating each timing at which the repetition transmission power and / or the repetition gain is applied.

[0131] 2) Information Indicating the Repetition Transmission Power and / or the Repetition Gain: This may be the value of the repetition transmission power [dBm] and / or the repetition gain [dB] itself, or an index corresponding to any entry in the list in step S202. When the value of the repetition transmission power [dBm] and / or the repetition gain [dB] is notified, the value may be set using a different information element for each digit. For example, an information element for the tens digit and an information element for the ones digit may be defined separately, and the set value may be expressed by a combination of these. In this case, for example, information element 1 is defined as {50, 40, 30, 20, 10, 0}, and information element 2 is defined as {9, 8, 7, ..., 3, 2, 1, 0}, and the set value is expressed as information element 1 + information element 2. Alternatively, values ​​or indexes indicating the repetition transmission power and / or the repetition gain may be listed, and each entry in the list may be associated with one slot.

[0132] 3) Validity period: Information indicating the period during which the power control information of step S204 is valid. This information may be, for example, the value of an expiration monitoring timer, the number of valid radio frames, or the number of an invalid (or last valid) radio frame. The gNB 200 may specify the validity period to temporarily suppress the maximum transmission power, for example, when the time required for interference suppression is limited.

[0133] 4) NCR-Fwd ID (or NCR-RNTI): This is information for specifying which NCR-Fwd 510A is the target when the NCR-MT 520A manages a plurality of NCR-Fwds 510A.

[0134] In step S205, the NCR-MT 520A controls the transmission power of the NCR-Fwd 510A in accordance with the power control information received in step S204. The NCR-MT 520A may notify (set) the NCR-Fwd 510A of the power control information received in step S204 and cause the NCR-Fwd 510A to operate in accordance with the power control information. If the power control information includes a timer value indicating a validity period, the NCR-MT 520A may start a timer set to the timer value, and when the timer expires, determine that the power control information is invalid.

[0135] In the second operation pattern, even if the maximum operational transmission power (or maximum operational gain) is set by the first operation pattern, the NCR-MT 520A may perform transmission power control by prioritizing the power control information received in step S204 at the timing of periodic relay transmission. For example, even if the repeat transmission power (or repeat gain) at that timing exceeds the maximum operational transmission power (or maximum operational gain), the NCR-MT 520A may perform relay transmission by applying the repeat transmission power (or repeat gain) at that timing. Alternatively, if the maximum operational transmission power (or maximum operational gain) is set by the first operation pattern, the NCR-MT 520A may perform transmission power control by prioritizing the maximum operational transmission power (or maximum operational gain) at the timing of periodic relay transmission. In this case, the NCR-Fwd 510A does not operate at a transmission power (or gain) greater than the maximum operational transmission power (or maximum operational gain).

[0136] Note that the NCR-MT 520A may operate the NCR-Fwd 510A at the maximum operational transmission power (and / or maximum operational gain) when it has not received the power control information in step S204 or when periodic relay transmission is not performed. Furthermore, the NCR-Fwd 510A may not operate at a power level exceeding the maximum transmission power (and / or maximum gain) set by its own capabilities (or the upper limit set by the Radio Law) under any circumstances.

[0137] In the second operation pattern, an example has been described in which the repetitive transmission power (and repetitive gain) is the transmission power (and gain) applied in periodic relay transmission. However, the repetitive transmission power (and repetitive gain) may be the upper limit of the transmission power (and gain) applicable in periodic relay transmission. In other words, the repetitive transmission power (and repetitive gain) may be the maximum repetitive transmission power (and maximum repetitive gain). In this case, the NCR device 500A may autonomously determine the transmission power (and gain) within a range that does not exceed the maximum repetitive transmission power (and maximum repetitive gain) at the timing of performing periodic relay transmission.

[0138] (1.4.2.3) Third Operation Pattern The third operation pattern will be described, focusing on the differences from the first and second operation patterns. FIG. 15 is a diagram showing an example of the third operation pattern of the mobile communication system 1 according to the first embodiment. In the third operation pattern, the gNB 200 specifies (notifies) the NCR-MT 520A of the transmission power (dynamic transmission power) and / or gain (dynamic gain) in the non-periodic relay transmission of the NCR-Fwd 510A. The third operation pattern may be an operation that assumes that the maximum transmission power (or maximum gain) is specified in the first operation pattern, or may be an operation that does not assume the first operation pattern.

[0139] In step S301, NCR-MT520A of NCR device 500A is in an RRC connected state in the cell of gNB200.

[0140] In step S302, the gNB200 may transmit to the NCR-MT520A power control information (first power control information) including a list associating transmission power and / or gain with its index, and / or information indicating the timing of non-periodic relay transmission. The NCR-MT520A may receive the power control information. The gNB200 may transmit the power control information of step S302 to the NCR-MT520A by including it in an RRC Reconfiguration message. The list entries included in the power control information of step S302 may include at least one of the following information 1) to 4).

[0141] 1) Setting ID (index): An index indicating the corresponding transmission power and / or gain.

[0142] 2) Transmission power [dBm] and / or gain [dB]: This may be a range (value range) of transmission power and / or a range (value range) of transmission power.

[0143] 3) NCR-Fwd ID (or NCR-RNTI): This is information for specifying which NCR-Fwd 510A is the target when the NCR-MT 520A manages multiple NCR-Fwds 510A.

[0144] 4) Information indicating timing for non-periodic relay transmission: This may be a radio frame number, a subframe number, a slot number, and / or a symbol number.

[0145] In step S303, gNB200 determines the dynamic transmission power and / or dynamic gain of NCR-Fwd510A of NCR device 500A. gNB200 may determine the dynamic transmission power and / or dynamic gain so as not to exceed the maximum transmission power and / or maximum gain of NCR-Fwd510A.

[0146] In step S304, the gNB200 transmits power control information (second power control information) indicating the dynamic transmission power and / or dynamic gain determined in step S303 to the NCR-MT520A. The NCR-MT520A receives the power control information. The gNB200 may transmit the power control information of step S304 to the NCR-MT520A by including it in an RRC Reconfiguration message, MAC CE, or DCI. The power control information of step S304 may include at least one of the following information 1) to 3).

[0147] 1) Information indicating the timing of aperiodic relay transmission: This may be a radio frame number, a subframe number, a slot number, and / or a symbol number. Alternatively, the timing of aperiodic relay transmission may be determined in step S302, for example, by an RRC Reconfiguration message. Alternatively, the timing of aperiodic relay transmission may be determined in advance by specifications based on the timing of receiving the power control information in step S304 (for example, to be applied four slots after receiving a MAC CE).

[0148] 2) Information indicating dynamic transmission power and / or dynamic gain: This may be the value of the dynamic transmission power [dBm] and / or the dynamic gain [dB] itself, or an index corresponding to any entry in the list in step S302. When the value of the dynamic transmission power [dBm] and / or the dynamic gain [dB] is notified, the value may be set in an information element that differs for each digit.

[0149] 3) NCR-Fwd ID (or NCR-RNTI): This is information for specifying which NCR-Fwd 510A is the target when the NCR-MT 520A manages multiple NCR-Fwds 510A.

[0150] In step S305, the NCR-MT 520A controls the transmission power of the non-periodic relay transmission of the NCR-Fwd 510A in accordance with the power control information received in step S304. The NCR-MT 520A may notify (set) the NCR-Fwd 510A of the power control information received in step S304 and cause the NCR-Fwd 510A to operate in accordance with the power control information. If the power control information includes a timer value indicating a validity period, the NCR-MT 520A may start a timer set to the timer value, and when the timer expires, determine that the power control information is invalid.

[0151] In the third operation pattern, even if the maximum operational transmit power (or maximum operational gain) is set by the first operation pattern, the NCR-MT 520A may perform transmit power control by prioritizing the power control information received in step S304 at the timing of non-periodic relay transmission. For example, even if the dynamic transmit power (or dynamic gain) at that timing exceeds the maximum operational transmit power (or maximum operational gain), the NCR-MT 520A may apply the dynamic transmit power (or dynamic gain) at that timing to perform relay transmission. Alternatively, if the maximum operational transmit power (or maximum operational gain) is set by the first operation pattern, the NCR-MT 520A may perform transmit power control by prioritizing the maximum operational transmit power (or maximum operational gain) at the timing of non-periodic relay transmission. In this case, the NCR-Fwd 510A does not operate at a transmit power (or gain) greater than the maximum operational transmit power (or maximum operational gain).

[0152] Note that the NCR-MT 520A may operate the NCR-Fwd 510A at the maximum operational transmission power (and / or maximum operational gain) when it has not received the power control information in step S304 or when non-periodic relay transmission is not performed. Furthermore, the NCR-Fwd 510A may not operate at a power level exceeding the maximum transmission power (and / or maximum gain) set by its own capabilities (or the upper limit set by the Radio Law) under any circumstances.

[0153] In the third operation pattern, an example has been described in which the dynamic transmit power (and dynamic gain) is the transmit power (and gain) applied in aperiodic relay transmission. However, the dynamic transmit power (and dynamic gain) may be the upper limit of the transmit power (and gain) applicable in aperiodic relay transmission. That is, the dynamic transmit power (and dynamic gain) may be the dynamic maximum transmit power (and dynamic maximum gain). In this case, the NCR device 500A may autonomously determine the transmit power (and gain) within a range not exceeding the dynamic maximum transmit power (and dynamic maximum gain) at the timing of performing aperiodic relay transmission.

[0154] (1.4.2.4) Fourth Operation Pattern The fourth operation pattern will be described, focusing on the differences from the first to third operation patterns.

[0155] The gNB 200 may not have sufficient information when determining the transmission power (and / or gain) of the NCR-Fwd 510A. For example, the transmission power of the NCR-Fwd 510A is determined according to the reception power of the NCR-Fwd 510A and the gain of the NCR-Fwd 510A. The reception power of the NCR-Fwd 510A varies depending on its installation location and / or transmission path conditions. The gain of the NCR-Fwd 510A is subject to limitations on the reception power of the NCR-Fwd 510A and the maximum transmission power of the NCR-Fwd 510A. For example, assuming that the NCR device 500A performs closed-loop control of the gain (e.g., by monitoring the transmission power and controlling the gain) so as not to exceed the maximum transmission power (including the regulated value under the Radio Law), it is conceivable that the maximum gain of the NCR-Fwd 510A and the maximum gain that can actually be set currently (the gain for maintaining the maximum transmission power) may differ. In addition, the capability information of the NCR-Fwd 510A is not provided to the gNB 200, and the gNB 200 may not be able to grasp the maximum transmission power (and gain) due to the capabilities of the NCR-Fwd 510A. Therefore, there is a concern that the gNB 200 may not be able to appropriately determine the transmission power (and / or gain) of the NCR-Fwd 510A.

[0156] Therefore, in the fourth operation pattern, the NCR device 500A acquires a maximum value indicating the maximum transmission power and / or maximum gain set in the NCR-Fwd 510A and an estimated value indicating the transmission power and / or gain of relay transmission in the NCR-Fwd 510A, and transmits margin information indicating the difference between the acquired maximum value and the estimated value to the gNB 200. This allows the gNB 200 to appropriately determine the transmission power (and / or gain) of the NCR-Fwd 510A.

[0157] 16 is a diagram showing an example of a fourth operation pattern of the mobile communication system 1 according to the first embodiment. The fourth operation pattern may be an operation pattern that is premised on at least one of the first to third operation patterns.

[0158] In step S401, NCR-MT520A of NCR device 500A is in an RRC connected state in the cell of gNB200.

[0159] In step S402, the gNB 200 may transmit a setting (or request) regarding the transmission of margin information to the NCR-MT 520A by an RRC Reconfiguration message, a MAC CE, or a DCI. The NCR-MT 520A may receive a setting (or request) regarding the transmission of margin information. The setting (or request) may include at least one of the following information 1) to 4).

[0160] 1) Information specifying the period (timing) of the margin measurement: In the case of a single measurement, the information may be the number of a radio frame, a subframe, a slot, and / or a symbol. In the case of a continuous measurement, the information may include the start frame number, the end frame number, and / or the period (e.g., the number of slots).

[0161] 2) Information specifying the transmission trigger and threshold of margin information: NCR-MT520A may transmit margin information to gNB200 when the measured margin or the reception status (RSRP / RSRQ / SINR) of NCR-Fwd510A satisfies the threshold conditions specified in the information.

[0162] 3) Information specifying the maximum transmission power (and / or maximum gain) to be used as a reference: The reference may be any of the following: a maximum transmission power (or maximum gain) depending on NCR capability or radio law, an operational maximum transmission power (or operational maximum gain) specified by gNB200, a repeated maximum transmission power (or repeated maximum gain), or a dynamic maximum transmission power (or dynamic maximum gain).

[0163] 4) Measurement target: This may be information specifying the margin of transmission power and / or the margin of gain.

[0164] In step S402, the NCR device 500A measures the margin of the transmission power (and / or gain). Specifically, the NCR device 500A derives the difference between the actual transmission power (and / or gain) and the reference transmission power (and / or gain) as the margin. If a measurement period is specified, the NCR device 500A measures the margin during that measurement period. If a measurement period is not specified, the NCR device 500A may measure the margin for a predetermined period, such as the past radio frame. The NCR device 500A may use a statistical value (average, maximum, or minimum) of the results of multiple measurements during the measurement period or measurement period as the margin measurement value. The NCR-Fwd 510A may perform the measurement and notify the NCR-MT 520A of the measurement results. In this case, the NCR-MT 520A may configure the NCR-Fwd 510A to perform the measurement.

[0165] In step S403, the NCR-MT 520A transmits margin information indicating the result of the margin measurement in step S402 to the gNB 200. The gNB 200 receives the margin information. The NCR-MT 520A may transmit the margin information to the gNB 200 by including it in a MAC CE, an RRC message (e.g., a Measurement Report message), or uplink control information (UCI). When a MAC CE is used, the transmit power margin and gain margin may be identified by different LCIDs, with the MAC CE format being common to both. The margin information includes the following information 1) and / or 2).

[0166] 1) Margin Measurement Value: The margin measurement value may be included in the margin information as a series of consecutive values, where the first measurement value corresponds to slot #1, the second measurement value corresponds to slot #2, and so on.

[0167] The specifications may dictate that the headroom measurement value is the measurement value of the slot k slots before (for example, the measurement value of the slot four slots before). When only one headroom measurement value is included in the headroom information, if the transmission timing of the headroom information is slot n, then, for example, the headroom measurement value is the measurement value of slot (n-4). On the other hand, when the headroom information includes multiple headroom measurement values, the mapping relationship may be such that the first measurement value is slot (n-4), the second measurement value is slot (n-5), the third measurement value is slot (n-6), and so on. Alternatively, the mapping relationship may be such that, starting from the first measurement value, the first measurement value is slot n-4, the second measurement value is slot (n-5), the third measurement value is slot (n-6), and so on. Alternatively, the starting point (m slots before) of the first measurement value is determined, and based on that starting point, the mapping relationship may be such that the first measurement value is slot n-m, the second measurement value is slot n-(m-1), the third measurement value is slot n-(m-2), and so on. These mapping relationships are merely examples, and the reverse mapping relationships, such as nm, n-(m+1), and n-(m+2), may also be used.

[0168] 2) Information indicating measurement timing or period: In the case of a single measurement, the information may be the number of a radio frame, subframe, slot, and / or symbol. In the case of a continuous measurement, the information may include the start frame number, the end frame number, and / or the period (e.g., the number of slots).

[0169] In step S405, gNB200 may determine the transmission power (and / or gain) of NCR-Fwd510A based on the margin information received from NCR-MT520A in step S404, and may specify the transmission power (and / or gain) of NCR-Fwd510A to NCR-MT520A in the same manner as the second operation pattern or the third operation pattern.

[0170] In the operation example of FIG. 16, the NCR-MT 520A is in the RRC connected state, but the NCR device 500A that relays and transmits in the RRC inactive state (or the RRC idle state) may perform the margin measurement in step S402. In this case, the NCR device 500A may store the margin measurement value as a log and transmit the log to the gNB 200 after transitioning to the RRC connected state. The log may include additional information such as the cell ID of the cell at the time of margin measurement and / or a timestamp indicating the time at which the margin was measured.

[0171] (2) Second Embodiment Next, a second embodiment will be described, focusing on differences from the above-described embodiments. As shown in Fig. 17, the relay device according to the second embodiment is a Reconfigurable Intelligent Surface (RIS) device 500B that performs relay transmission by changing the propagation direction of incident radio waves (wireless signals) through reflection or refraction. The term "NCR" in the above-described embodiments can be read as "RIS."

[0172] RIS is a type of repeater (hereinafter also referred to as "RIS-Fwd") that can perform beamforming (directivity control) similar to NCR by changing the properties of a metamaterial. In the case of RIS, the range (distance) of the beam may also be changed by controlling the reflection direction and / or refraction direction of each unit element. For example, the RIS may be configured to control the reflection direction and / or refraction direction of each unit element and to focus (direct the beam) on a nearby UE or a distant UE.

[0173] The RIS device 500B has a new UE (hereinafter referred to as "RIS-MT") 520B, which is a control terminal for controlling the RIS-Fwd 510B. The RIS-MT 520B establishes a wireless connection with the gNB 200 and performs wireless communication with the gNB 200, thereby controlling the RIS-Fwd 510B in cooperation with the gNB 200. The RIS-Fwd 510B may be a reflective RIS. Such a RIS-Fwd 510B changes the propagation direction of incident radio waves by reflecting the radio waves. Here, the reflection angle of the radio waves is variably settable. The RIS-Fwd 510B reflects radio waves incident from the gNB 200 toward the UE 100. The RIS-Fwd 510B may be a transparent RIS. Such a RIS-Fwd 510B changes the propagation direction of the radio waves by refracting the incident radio waves. Here, the refraction angle of the radio wave can be variably set.

[0174] FIG. 18 is a diagram showing an example configuration of a RIS-Fwd (repeater) 510B and a RIS-MT (control terminal) 520B according to the second embodiment. The RIS-MT 520B includes a receiver 521, a transmitter 522, and a controller 523. This configuration is similar to that of the above-described embodiment. The RIS-Fwd 510B includes a RIS 511B and a RIS controller 512B. The RIS 511B is a metasurface constructed using a metamaterial. For example, the RIS 511B is constructed by arranging structures that are very small relative to the wavelength of radio waves in an array. By making the structures different shapes depending on their placement, it is possible to arbitrarily design the direction and / or beam shape of the reflected waves. The RIS 511B may also be a transparent dynamic metasurface. The RIS 511B may be configured by overlaying a transparent glass substrate on a transparent metasurface substrate on which a large number of small structures are regularly arranged, and by slightly moving the overlaid glass substrate, it may be possible to dynamically control three patterns: a mode that transmits incident radio waves, a mode that transmits some of the radio waves and reflects some of them, and a mode that reflects all of the radio waves. The RIS control unit 512B controls the RIS 511B in response to a RIS control signal from the control unit 523 of the RIS-MT 520B. The RIS control unit 512B may include at least one processor and at least one actuator. The processor decodes the RIS control signal from the control unit 523 of the RIS-MT 520B and drives the actuator in response to the RIS control signal.

[0175] In the second embodiment, the transmission power control in the RIS-Fwd 510B may include controlling the reflectance, attenuation rate, and / or transmittance of the RIS-Fwd 510B. That is, the transmission power (and gain) of the RIS-Fwd 510B may be controlled by changing the reflectance, attenuation rate, and / or transmittance of the RIS-Fwd 510B.

[0176] (3) Other Embodiments In the above-described embodiment, an example has been described in which the relay device that performs relay transmission is the NCR device 500A or the RIS device 500B. However, the relay device that performs relay transmission is not limited to the NCR device 500A or the RIS device 500B, and may be an IAB (Integrated Access and Backhaul) node defined in the 3GPP technical specifications.

[0177] The above-described operational flows are not limited to being implemented independently, but can also be implemented by combining two or more operational flows. For example, some steps of one operational flow may be added to another operational flow, or some steps of one operational flow may be replaced with some steps of another operational flow. In each flow, it is not necessary to execute all steps, and only some steps may be executed.

[0178] In the above embodiment, an example in which the base station is an NR base station (gNB) has been described, but the base station may be an LTE base station (eNB). The base station may also be a relay node such as an IAB node. The base station may also be a Distributed Unit (DU) of the IAB node. The UE 100 may also be a Mobile Termination (MT) of the IAB node.

[0179] That is, the UE 100 may be a terminal function unit (a type of communication module) for a base station to control a repeater that relays signals. Such a terminal function unit is referred to as an MT. Examples of the MT include, in addition to the IAB-MT, an NCR (Network Controlled Repeater)-MT and a RIS (Reconfigurable Intelligent Surface)-MT.

[0180] The term "network node" primarily refers to a base station, but may also refer to a core network device or a part of a base station (CU, DU, or RU). A network node may also be configured by a combination of at least a part of a core network device and at least a part of a base station.

[0181] A program may be provided that causes a computer to execute each process performed by the communication device according to the above-described embodiment, for example, the UE100 (NCR-MT520A, RIS-MT520B) or the gNB200. The program may be recorded on a computer-readable medium. Using a computer-readable medium, the program can be installed on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. Furthermore, circuits that execute each process performed by the UE100 or the gNB200 may be integrated, and at least a portion of the UE100 or the gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

[0182] The functions performed by the UE 100 or the gNB 200 (network node) may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), CPUs (Central Processing Units), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered to be circuitry or processing circuitry. A processor may also be a programmed processor that executes a program stored in memory. In this specification, circuitry, unit, or means refers to hardware that is programmed to perform the described functions or hardware that executes them. The hardware may be any hardware disclosed herein or any hardware known to be programmed or capable of performing the described functions. If the hardware is a processor, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0183] As used in this disclosure, the terms "based on" and "depending on / in response to" do not mean "based only on" or "depending only on," unless expressly stated otherwise. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "depending only on" and "depending at least in part on." The terms "include," "comprise," and variations thereof do not mean including only the listed items, but may mean including only the listed items or may include additional items in addition to the listed items. Additionally, the term "or," as used in this disclosure, is not intended to mean an exclusive or. Furthermore, any reference to elements using designations such as "first," "second," etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall include the plural unless the context clearly indicates otherwise.

[0184] The above describes the embodiments in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes can be made within the scope that does not deviate from the gist of the invention.

[0185] This application claims priority to Japanese Patent Application No. 2023-138390 (filed August 28, 2023) and Japanese Patent Application No. 2023-138395 (filed August 28, 2023), the entire contents of which are incorporated herein by reference.

[0186] (4) Supplementary Notes The following are additional notes regarding the features of the above-described embodiment.

[0187] (Supplementary Note 1) A communication method executed by a relay device having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user equipment, and a control terminal used to control the relay device, the communication method comprising: a step by the control terminal receiving power control information for controlling a transmission power of the relay transmission from the network node; and a step by the relay device performing the relay transmission at the transmission power based on the power control information, wherein the power control information includes at least one of first information indicating a maximum transmission power and / or a maximum gain to be set in the relay device, second information indicating a transmission power and / or a gain in periodic relay transmission, and third information indicating a transmission power and / or a gain in aperiodic relay transmission.

[0188] (Supplementary Note 2) The communication method according to Supplementary Note 1, wherein the receiving step includes receiving at least one of a Radio Resource Control (RRC) message including the power control information, a Medium Access Control (MAC) Control Element (CE) including the power control information, and Downlink Control Information (DCI) including the power control information.

[0189] (Supplementary Note 3) The communication method according to Supplementary Note 1 or 2, wherein the power control information is information for controlling the transmission power in a downlink direction from the repeater to the user equipment.

[0190] (Supplementary Note 4) The communication method according to any one of Supplementary Notes 1 to 3, wherein the power control information is information for controlling the transmission power in an uplink direction from the repeater to the network node.

[0191] (Supplementary Note 5) The communication method according to any one of Supplementary Notes 1 to 4, wherein the power control information includes information specifying a period during which transmission power control in accordance with the power control information is to be applied, and wherein the step of performing relay transmission includes a step of performing the relay transmission at the transmission power based on the power control information during the specified period.

[0192] (Supplementary Note 6) The communication method according to any one of Supplementary Notes 1 to 5, wherein the receiving step includes: receiving first power control information including a setting list in which setting values ​​of transmission power or gain correspond to indexes indicating the setting values; and receiving second power control information including the indexes; and the performing relay transmission step includes: specifying the setting value corresponding to the index included in the second power control information based on the setting list; and performing transmission power control using the specified setting value.

[0193] (Supplementary Note 7) The communication method according to any one of Supplementary Notes 1 to 6, wherein the power control information includes the first information, and wherein the step of performing relay transmission includes the step of performing the relay transmission so as not to exceed the maximum transmission power and / or the maximum gain based on the first information.

[0194] (Supplementary Note 8) The communication method according to any one of Supplementary Notes 1 to 7, wherein the power control information includes the second information, and wherein the step of performing relay transmission includes the step of performing the periodic relay transmission with the transmission power based on the second information.

[0195] (Supplementary Note 9) The communication method according to any one of Supplementary Notes 1 to 8, wherein the power control information includes the third information, and wherein the step of performing relay transmission includes the step of performing the non-periodic relay transmission with the transmission power based on the third information.

[0196] (Supplementary Note 10) A relay device comprising: a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device; and a control terminal used to control the relay device, wherein the control terminal receives power control information for controlling a transmission power of the relay transmission from the network node, and the relay device performs the relay transmission at the transmission power based on the power control information, and the power control information includes at least one of first information indicating a maximum transmission power and / or a maximum gain to be set in the relay device, second information indicating a transmission power and / or a gain in periodic relay transmission, and third information indicating a transmission power and / or a gain in aperiodic relay transmission.

[0197] (Supplementary Note 11) A network node that communicates with a relay device having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device, and a control terminal used to control the relay device, the network node comprising: a controller that generates power control information for controlling transmission power of the relay transmission; and a transmitter that transmits the power control information to the control terminal, wherein the power control information includes at least one of first information indicating a maximum transmission power and / or a maximum gain to be set for the relay device, second information indicating transmission power and / or gain in periodic relay transmission, and third information indicating transmission power and / or gain in aperiodic relay transmission.

[0198] (Supplementary Note 12) A communication method executed by a relay device having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device, and a control terminal used to control the relay device, the communication method comprising the steps of: acquiring a maximum value indicating a maximum transmission power and / or a maximum gain set in the relay device, and an estimated value indicating the transmission power and / or the gain of the relay transmission in the relay device; and transmitting margin information indicating a difference between the maximum value and the estimated value from the control terminal to the network node.

[0199] (Supplementary Note 13) The communication method according to Supplementary Note 12, wherein the transmitting step includes the step of transmitting a Medium Access Control Element (MAC CE) including the headroom information.

[0200] (Supplementary Note 14) The communication method according to Supplementary Note 13, wherein the margin information includes: power margin information indicating a difference between the maximum value indicating the maximum transmission power and the estimated value indicating the transmission power; and gain margin information indicating a difference between the maximum value indicating the maximum gain and the estimated value indicating the gain; and the transmitting step includes: transmitting a first MAC CE including the power margin information; and transmitting a second MAC CE including the gain margin information.

[0201] (Supplementary Note 15) The communication method according to Supplementary Note 14, wherein the first MAC CE includes a first logical channel identifier (LCID); and the second MAC CE includes a second LCID different from the first LCID.

[0202] (Supplementary Note 16) The communication method according to any one of Supplementary Notes 12 to 15, further comprising a step in which the control terminal receives from the network node a signal that sets or requests transmission of the margin information, and the transmitting step includes a step in which the control terminal transmits the margin information to the network node based on the signal.

[0203] (Supplementary Note 17) The communication method according to Supplementary Note 16, wherein the signal includes at least one of information for setting timing for acquiring the maximum value and the estimated value and information for setting a transmission trigger for the margin information.

[0204] (Supplementary Note 18) The communication method according to any one of Supplementary Notes 12 to 17, wherein the maximum value indicates the maximum transmission power and / or the maximum gain in an uplink direction from the repeater to the network node, and the estimated value indicates the transmission power and / or the gain in the uplink direction.

[0205] (Supplementary Note 19) The communication method according to any one of Supplementary Notes 12 to 17, wherein the maximum value indicates the maximum transmission power and / or the maximum gain in a downlink direction from the repeater to the user equipment, and the estimated value indicates the transmission power and / or the gain in the downlink direction.

[0206] (Supplementary Note 20) A relay device comprising: a repeater that performs relay transmission to relay a radio signal transmitted between a network node and a user device; and a control terminal used to control the repeater, wherein the control terminal transmits margin information to the network node, based on a maximum value indicating a maximum transmission power and / or a maximum gain set in the repeater and an estimated value indicating the transmission power and / or the gain of the relay transmission in the repeater, the margin information indicating a difference between the maximum value and the estimated value.

[0207] (Supplementary Note 21) A network node that communicates with a relay device, the network node having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device, and a control terminal used to control the relay device, the network node comprising: a receiving unit that receives from the control terminal margin information based on a maximum value indicating a maximum transmission power and / or a maximum gain set in the relay device and an estimated value indicating the transmission power and / or gain of the relay transmission in the relay device, the margin information being information indicating a difference between the maximum value and the estimated value.

[0208] 1: Mobile communication system 100: UE 200: gNB 210: Transmitter 220: Receiver 230: Controller 240: Backhaul communication unit 300A: AMF 400: OAM server 500A: NCR device 510A: NCR-Fwd 520A: NCR-MT 500B: RIS device 510B: RIS-Fwd 520B: RIS-MT 511A: Wireless unit 511a: Antenna unit 511b: RF circuit 511c: Directivity control unit 512A: NCR control unit 512B: RIS control unit 521: Receiver 522: Transmitter 523: Controller 530: Interface

Claims

1. A communication method executed by a relay device having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device, and a control terminal used to control the relay device, wherein the control terminal receives power control information for controlling the transmission power of the relay transmission from the network node, and the relay device performs the relay transmission at the transmission power based on the power control information, wherein the power control information includes at least one of first information indicating a maximum transmission power and / or maximum gain to be set in the relay device, second information indicating the transmission power and / or gain in periodic relay transmission, and third information indicating the transmission power and / or gain in non-periodic relay transmission.

2. The communication method of claim 1, wherein the receiving includes receiving at least one of a radio resource control (RRC) message including the power control information, a medium access control and control element (MAC CE) including the power control information, and a downlink control information (DCI) including the power control information.

3. The communication method according to claim 1, wherein the power control information is information for controlling the transmission power in a downlink direction from the repeater to the user equipment.

4. The communication method according to claim 1, wherein the power control information is information for controlling the transmission power in an uplink direction from the repeater to the network node.

5. The communication method according to claim 1, wherein the power control information includes information specifying a period during which transmission power control in accordance with the power control information is to be applied, and performing the relay transmission includes performing the relay transmission at the transmission power based on the power control information during the specified period.

6. The communication method of claim 1, wherein the receiving includes: receiving first power control information including a setting list associating a setting value of transmission power or gain with an index indicating the setting value; and receiving second power control information including the index; and performing relay transmission includes: identifying the setting value corresponding to the index included in the second power control information based on the setting list; and performing transmission power control using the identified setting value.

7. A communication method according to any one of claims 1 to 6, wherein the power control information includes the first information, and performing the relay transmission includes performing the relay transmission so as not to exceed the maximum transmission power and / or the maximum gain based on the first information.

8. A communication method according to any one of claims 1 to 6, wherein the power control information includes the second information, and performing the relay transmission includes performing the periodic relay transmission with the transmission power based on the second information.

9. A communication method according to any one of claims 1 to 6, wherein the power control information includes the third information, and performing the relay transmission includes performing the non-periodic relay transmission with the transmission power based on the third information.

10. A relay device comprising: a repeater that performs relay transmission to relay a radio signal transmitted between a network node and a user equipment; and a control terminal used to control the repeater, wherein the control terminal receives power control information for controlling the transmission power of the relay transmission from the network node, and the repeater performs the relay transmission at the transmission power based on the power control information, and the power control information includes at least one of first information indicating a maximum transmission power and / or maximum gain to be set in the repeater, second information indicating the transmission power and / or gain in periodic relay transmission, and third information indicating the transmission power and / or gain in non-periodic relay transmission.

11. A network node that communicates with a relay device having a relay device that performs relay transmission to relay a radio signal transmitted between a network node and a user device, and a control terminal used to control the relay device, the network node comprising: a control unit that generates power control information for controlling the transmission power of the relay transmission; and a transmission unit that transmits the power control information to the control terminal, the power control information including at least one of first information indicating a maximum transmission power and / or maximum gain to be set for the relay device, second information indicating the transmission power and / or gain in periodic relay transmission, and third information indicating the transmission power and / or gain in non-periodic relay transmission.

12. A communication method executed by a relay device having a relay device that performs relay transmission to relay radio signals transmitted between a network node and a user device, and a control terminal used to control the relay device, the communication method comprising: acquiring a maximum value indicating a maximum transmission power and / or maximum gain set in the relay device, and an estimated value indicating the transmission power and / or gain of the relay transmission in the relay device; and transmitting margin information indicating the difference between the maximum value and the estimated value from the control terminal to the network node.

13. The method of claim 12, wherein said transmitting includes transmitting a Medium Access Control and Control Element (MAC CE) including said headroom information.

14. The communication method according to claim 13, wherein the margin information includes: power margin information indicating a difference between the maximum value indicating the maximum transmission power and the estimated value indicating the transmission power; and gain margin information indicating a difference between the maximum value indicating the maximum gain and the estimated value indicating the gain, and the transmitting step includes: transmitting a first MAC CE including the power margin information; and transmitting a second MAC CE including the gain margin information.

15. The method of claim 14, wherein the first MAC CE includes a first logical channel identifier (LCID), and the second MAC CE includes a second LCID that is different from the first LCID.

16. The communication method according to claim 12, further comprising the control terminal receiving a signal from the network node that sets or requests the transmission of the margin information, and the transmitting step includes transmitting the margin information from the control terminal to the network node based on the signal.

17. The communication method according to claim 16, wherein the signal includes at least one of information for setting the timing for acquiring the maximum value and the estimated value and information for setting a transmission trigger for the margin information.

18. A communications method according to any one of claims 12 to 17, wherein the maximum value indicates the maximum transmission power and / or the maximum gain in the uplink direction from the repeater to the network node, and the estimated value indicates the transmission power and / or the gain in the uplink direction.

19. A communication method according to any one of claims 12 to 17, wherein the maximum value indicates the maximum transmission power and / or the maximum gain in a downlink direction from the repeater to the user equipment, and the estimated value indicates the transmission power and / or the gain in the downlink direction.

20. A relay device comprising: a repeater that performs relay transmission to relay a radio signal transmitted between a network node and a user device; and a control terminal used to control the repeater, wherein the control terminal transmits margin information to the network node, indicating a difference between a maximum value indicating a maximum transmission power and / or maximum gain set in the repeater and an estimated value indicating the transmission power and / or gain of the relay transmission in the repeater, based on the maximum value and the estimated value.

21. A network node that communicates with a relay device having a relay device that performs relay transmission to relay radio signals transmitted between a network node and a user device, and a control terminal used to control the relay device, the network node having a receiving unit that receives from the control terminal margin information based on a maximum value indicating a maximum transmission power and / or maximum gain set in the relay device and an estimated value indicating the transmission power and / or gain of the relay transmission in the relay device, the margin information being information indicating the difference between the maximum value and the estimated value.

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