Mobile communication systems and control terminals

Abstract

This mobile communication system comprises: a base station; a relay device that relays wireless signals between the base station and a user device; and a control terminal that communicates with the base station and controls the relay device. The relay device has a plurality of elements used for beamforming. By grouping the plurality of elements into a plurality of groups, the control terminal performs independent beam control for each group. Information related to the plurality of groups is communicated between the base station and the control terminal.

Description

Technical Field

[0001] The present disclosure relates to a mobile communication system and a control terminal.

Background Art

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

[0003] Since radio signals (radio waves) in high-frequency bands such as the millimeter-wave band or the terahertz-wave band have high directivity, reducing the coverage of base stations has become an issue. To solve such an issue, a repeater device that relays radio signals between a base station and a user device and can be controlled from a network has attracted attention (see, for example, Non-Patent Document 1). Such a repeater device can expand the coverage of a base station while suppressing the occurrence of interference by, for example, amplifying a radio signal received from a base station and transmitting it by directional transmission.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

[0005] A mobile communication system according to the first embodiment comprises a base station, a relay device that relays radio signals between the base station and user equipment, and a control terminal that communicates with the base station and controls the relay device. The relay device has a plurality of elements used for beamforming. The control terminal groups the plurality of elements into a plurality of groups and performs independent beam control for each group. Information regarding the plurality of groups is communicated between the base station and the control terminal.

[0006] A control terminal according to the second embodiment is a control terminal that relays wireless signals between a base station and one or more user devices and controls a relay device having a plurality of elements used for beamforming, comprising: a control unit that groups the plurality of elements into a plurality of groups and performs independent beam control for each group; and a communication unit that communicates information about the plurality of groups with the base station. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows the configuration of a mobile communication system according to an embodiment. [Figure 2] This diagram shows the protocol stack configuration of the user plane wireless interface that handles data. [Figure 3] This diagram shows the protocol stack configuration of the wireless interface of the control plane that handles signaling (control signals). [Figure 4] This figure shows an application scenario for the NCR device according to the first embodiment. [Figure 5] This figure shows an application scenario for the NCR device according to the first embodiment. [Figure 6] This figure shows the control method for the NCR device according to the first embodiment. [Figure 7] This figure shows an example of the protocol stack configuration in a mobile communication system having an NCR device and NCR-UE according to the first embodiment. [Figure 8]This figure shows an example configuration of the NCR-UE and NCR device according to the first embodiment. [Figure 9] This figure shows an example configuration of gNB according to the first embodiment. [Figure 10] This figure shows an example of downlink signaling from gNB to NCR-UE according to the first embodiment. [Figure 11] This figure shows an example of uplink signaling from NCR-UE to gNB according to the first embodiment. [Figure 12] This is a diagram illustrating the multi-beam operation of an NCR device, which is a relay device according to the first embodiment. [Figure 13] This figure shows an example of the operation of the mobile communication system according to the first embodiment. [Figure 14] This is a diagram illustrating the RIS device according to the second embodiment. [Figure 15] This is a diagram illustrating the RIS device according to the second embodiment. [Figure 16] This is a diagram illustrating the RIS device according to the second embodiment. [Figure 17] This figure shows the configuration of the RIS-UE and RIS device according to the second embodiment. [Figure 18] This is a diagram illustrating the multi-beam operation of a RIS device, which is a relay device according to the second embodiment. [Modes for carrying out the invention]

[0008] When controlling relay devices such as repeater devices from a network, the specific control technology for how to control these relay devices has not yet been established, making it difficult to efficiently expand coverage using relay devices at present.

[0009] Therefore, this disclosure aims to enable appropriate control of relay equipment that performs relay transmission between a base station and user equipment.

[0010] With reference to the drawings, a mobile communication system according to an embodiment will be described. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0011] (1) Outline of the embodiment The mobile communication system of the first aspect includes a base station, a relay device that relays radio signals between the base station and a user device, and a control terminal that communicates with the base station and controls the relay device. The relay device has a plurality of elements used for beamforming. The control terminal performs independent beam control for each group by grouping the plurality of elements into a plurality of groups. Information regarding the plurality of groups is communicated between the base station and the control terminal.

[0012] The mobile communication system of the second aspect is the mobile communication system of the first aspect, wherein the relay device is a repeater device that amplifies and transfers the received radio wave. Each of the plurality of elements includes an antenna of the repeater device.

[0013] The mobile communication system of the third aspect is the mobile communication system of the first aspect, wherein the relay device is a RIS (Reconfigurable Intelligent Surface) device that changes the propagation direction of the incident radio wave by reflection or refraction. Each of the plurality of elements includes a structure of the RIS device.

[0014] The mobile communication system of the fourth aspect is the mobile communication system of any one of the first to third aspects, wherein the control terminal transmits capability information including information indicating the number of the groups to the base station.

[0015] The mobile communication system of the fifth aspect is the mobile communication system of the fourth aspect, wherein the capability information further includes at least one of information indicating the number of elements in each group in the relay device, the total number of elements in the relay device, an identifier of each group in the relay device, and information indicating the beam characteristics of each group in the relay device.

[0016] The sixth embodiment of the mobile communication system is a mobile communication system of any of the first to fifth embodiments in which the base station transmits a configuration message including the grouping settings to the control terminal.

[0017] The seventh aspect of the mobile communication system is the sixth aspect of the mobile communication system, wherein the setting message includes at least one of the following: information specifying the number of groups to be set for the relay device and / or the number of beams to be set for the relay device; an identifier for one or more groups to be associated with each beam; and an identifier for the user device to be associated with each group or each beam.

[0018] The eighth aspect of the mobile communication system is the sixth or seventh aspect of the mobile communication system, wherein the setting message includes a plurality of settings that are switched by time division.

[0019] The ninth aspect of the mobile communication system is the eighth aspect of the mobile communication system, wherein in the setting message, the plurality of settings are each associated with a setting identifier, and the base station transmits a control instruction to the control terminal specifying the setting to be applied by the setting identifier.

[0020] A control terminal in a tenth embodiment is a control terminal that relays radio signals between a base station and one or more user devices and controls a relay device having a plurality of elements used for beamforming, comprising: a control unit that groups the plurality of elements into a plurality of groups and performs independent beam control for each group; and a communication unit that communicates information about the plurality of groups with the base station.

[0021] (2) First Embodiment First, the first embodiment will be described. The relay device according to the first embodiment is a repeater device that can be controlled from a network.

[0022] (2.1) Overview of Mobile Communication Systems Figure 1 shows the configuration of a mobile communication system according to the first embodiment. The mobile communication system 1 conforms to the 5th Generation System (5GS) of the 3rd Generation Partnership Project (3GPP) (registered trademark; hereinafter the same) standards. In the following explanation, 5GS will be used as an example, but the mobile communication system may also have at least a portion of an LTE (Long Term Evolution) system applied to it. Alternatively, the mobile communication system may also have at least a portion of a 6th Generation (6G) system applied to it.

[0023] The mobile communication system 1 comprises User Equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20. Hereafter, NG-RAN 10 may be simply referred to as RAN 10, and 5GC 20 may be simply referred to as core network (CN) 20.

[0024] UE100 is a mobile wireless communication device. UE100 can be any device used by a user. For example, UE100 can be a mobile phone terminal (including a smartphone) or tablet terminal, a notebook PC, a communication module (including a communication card or chipset), a sensor or device attached to a sensor, a vehicle or device attached to a vehicle (Vehicle UE), or an aircraft or device attached to an aircraft (Aerial UE).

[0025] NG-RAN10 includes base stations (referred to as "gNBs" in 5G systems) 200. The gNBs 200 are interconnected via the Xn interface, which is an inter-base station interface. Each gNB 200 manages one or more cells. The gNB 200 performs wireless communication with UEs 100 that have established a connection with its own cell. The gNB 200 has radio resource management (RRM) functions, user data routing functions (hereinafter simply referred to as "data"), measurement and control functions for mobility control and scheduling, etc. "Cell" is used as a term to indicate the smallest unit of a wireless communication area. "Cell" is also used as a term to indicate a function or resource that performs wireless communication with the UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0026] Furthermore, gNBs can also connect to the EPC (Evolved Packet Core), which is the core network of LTE. LTE base stations can also connect to 5GCs. LTE base stations and gNBs can also be connected via an inter-base station interface.

[0027] The 5GC20 includes the AMF (Access and Mobility Management Function) and the UPF (User Plane Function) 300. The AMF performs various mobility controls for the UE100. The AMF manages the mobility of the UE100 by communicating with it using NAS (Non-Access Stratum) signaling. The UPF controls data transfer. The AMF and UPF are connected to the gNB200 via the NG interface, which is the base station-core network interface.

[0028] Figure 2 shows the configuration of the protocol stack for the user plane's wireless interface that handles data.

[0029] The user plane radio interface protocol consists of a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an SDAP (Service Data Adaptation Protocol) layer.

[0030] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the UE100's PHY layer and the gNB200's PHY layer via a physical channel. The UE100's PHY layer receives downlink control information (DCI) transmitted from the gNB200 over the physical downlink control channel (PDCCH). Specifically, the UE100 performs blind decoding of the PDCCH using a Radio Network Temporary Identifier (RNTI) and acquires the successfully decoded DCI as the DCI addressed to its own UE. The DCI transmitted from the gNB200 has a CRC parity bit added, which is scrambled by the RNTI.

[0031] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat request (HARQ), and random access procedures. Data and control information are transmitted between the MAC layer of the UE100 and the MAC layer of the gNB200 via the transport channel. The MAC layer of the gNB200 includes a scheduler. The scheduler determines the transport format for the up and down links (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to the UE100.

[0032] 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 UE100's RLC layer and the gNB200's RLC layer via a logical channel.

[0033] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0034] The SDAP layer maps IP flows, which are the units under which the core network performs QoS (Quality of Service) control, to wireless bearers, which are the units under which the AS (Access Stratum) performs QoS control. Note that if the RAN is connected to the EPC, the SDAP is not required.

[0035] Figure 3 shows the configuration of the protocol stack of the wireless interface of the control plane that handles signaling (control signals).

[0036] The control plane's wireless interface protocol stack includes an RRC (Radio Resource Control) layer and a NAS (Non-Access Stratum) layer, instead of the SDAP layer shown in Figure 4.

[0037] RRC signaling for various settings is transmitted between the RRC layer of the UE100 and the RRC layer of the gNB200. The RRC layer controls the logical channel, transport channel, and physical channel in response to the establishment, re-establishment, and release of the radio bearer. If there is a connection (RRC connection) between the RRC of the UE100 and the RRC of the gNB200, the UE100 is in the RRC connected state. If there is no connection (RRC connection) between the RRC of the UE100 and the RRC of the gNB200, the UE100 is in the RRC idle state. If the connection between the RRC of the UE100 and the RRC of the gNB200 is suspended, the UE100 is in the RRC inactive state.

[0038] The NAS layer, located above the RRC layer, handles session management and mobility management, among other things. NAS signaling is transmitted between the UE100's NAS layer and the AMF300A's NAS layer. The UE100 also has application layers and other components in addition to its wireless interface protocol. Furthermore, layers below the NAS layer are called AS layers.

[0039] (2.2) Application scenarios for relay devices Figures 4 and 5 show application scenarios for the NCR device according to the first embodiment.

[0040] 5G / NR enables broadband transmission using high frequency bands compared to 4G / LTE. However, since radio signals in high frequency bands such as millimeter waves or terahertz waves have high directivity, reducing the coverage of gNB200 becomes a challenge. In Figure 4, UE100A may be located outside the coverage area of ​​gNB200, for example, outside the area where radio signals can be received directly from gNB200. There may also be obstacles between gNB200 and UE100A, preventing UE100A from communicating with gNB200 within line of sight.

[0041] In the first embodiment, a repeater device (500A), which is a type of relay device that relays wireless signals between gNB200 and UE100A, is introduced into the mobile communication system 1. This repeater device (500A) is controllable from the network. Hereinafter, such a repeater device will be referred to as an NCR (Network-Controlled Repeater) device. Such a repeater device may also be referred to as a smart repeater device.

[0042] For example, the NCR device 500A amplifies the radio signal (radio wave) received from the gNB200 and transmits it by directional transmission. Specifically, the NCR device 500A receives the radio signal transmitted by the gNB200 by beamforming. The NCR device 500A then amplifies the received radio signal and transmits the amplified radio signal by directional transmission. Here, the NCR device 500A may transmit the radio signal with a fixed directionality (beam). Alternatively, the NCR device 500A may transmit the radio signal with a variable (adaptive) directional beam. This allows for efficient expansion of the coverage of the gNB200. In the first embodiment, we mainly assume the application of the NCR device 500A to downlink communication from the gNB200 to the UE100A, but the NCR device 500A can also be applied to uplink communication from the UE100A to the gNB200.

[0043] Furthermore, as shown in Figure 5, a new UE (hereinafter referred to as "NCR-UE") 100B, a type of control terminal for controlling the NCR device 500A, will be introduced. The NCR-UE100B establishes a wireless connection with the gNB200 and communicates wirelessly with the gNB200, thereby controlling the NCR device 500A in cooperation with the gNB200. This enables efficient coverage expansion using the NCR device 500A. The NCR-UE100B controls the NCR device 500A according to the control from the gNB200.

[0044] The NCR-UE100B may be configured separately from the NCR device 500A. For example, the NCR-UE100B may be located near the NCR device 500A and electrically connected to it. The NCR-UE100B may be connected to the NCR device 500A by wire or wireless connection. Alternatively, the NCR-UE100B may be configured integrally with the NCR device 500A. The NCR-UE100B and NCR device 500A may be permanently installed, for example, at the coverage edge (cell edge) of the base station 200, or on the wall or window of some building. The NCR-UE100B and NCR device 500A may be installed in a vehicle, for example, and be movable. Furthermore, one NCR-UE100B may control multiple NCR devices 500A.

[0045] In the example shown in Figure 5, the NCR device 500A dynamically or quasi-statically changes the beam being transmitted or received. For example, the NCR device 500A forms beams toward UE100A1 and UE100A2, respectively. The NCR device 500A may also form a beam toward gNB200. For example, in the communication resource between gNB200 and UE100A1, the NCR device 500A transmits the radio signal received from gNB200 toward UE100A1 by beamforming, and / or transmits the radio signal received from UE100A1 toward gNB200 by beamforming. In the communication resource between gNB200 and UE100A2, the NCR device 500A transmits the radio signal received from gNB200 toward UE100A2 by beamforming, and / or transmits the radio signal received from UE100A2 toward gNB200 by beamforming. The NCR device 500A may, in lieu of or in addition to beam formation, form a null (so-called null steering) toward UE100 (not shown) and / or adjacent gNB200 (not shown) that are not communication partners, for interference suppression.

[0046] Figure 6 shows a control method for the NCR device 500A according to the first embodiment. As shown in Figure 6, the NCR device 500A relays a wireless signal (referred to as the "UE signal") between the gNB200 and the UE100A. The UE signal includes an uplink signal (referred to as the "UE-UL signal") transmitted from the UE100A to the gNB200 and a downlink signal (referred to as the "UE-DL signal") transmitted from the gNB200 to the UE100A. The NCR device 500A relays the UE-UL signal from the UE100A to the gNB200 and also relays the UE-DL signal from the gNB200 to the UE100A.

[0047] The NCR-UE100B transmits and receives radio signals (referred to here as "NCR-UE signals") with the gNB200. The NCR-UE signals include an uplink signal (referred to as "NCR-UE-UL signals") transmitted from the NCR-UE100B to the gNB200 and a downlink signal (referred to as "NCR-UE-DL signals") transmitted from the gNB200 to the NCR-UE100B. The NCR-UE-UL signals include signaling for controlling the NCR device 500A.

[0048] The gNB200 directs its beam towards the NCR-UE100B based on the NCR-UE-UL signal from the NCR-UE100B. Since the NCR device 500A is co-located with the NCR-UE100B, when the gNB200 directs its beam towards the NCR-UE100B, the beam is consequently directed towards both the NCR-UE100B and the NCR device 500A. The gNB200 uses this beam to transmit the NCR-UE-DL signal and the UE-DL signal. The NCR-UE100B receives the NCR-UE-DL signal. The NCR device 500A and the NCR-UE100B may be at least partially integrated. For example, the functions for transmitting, receiving, or relaying the UE signal and / or NCR-UE signal (e.g., an antenna) may be integrated in the NCR device 500A and the NCR-UE100B. The beam includes the transmit beam and / or receive beam. A beam is a general term for transmission and / or reception controlled by adjusting / adapting antenna weights, etc., to maximize the power of the transmitted and / or received waves in a specific direction.

[0049] Figure 7 shows an example of the protocol stack configuration in a mobile communication system 1 having an NCR device 500A and an NCR-UE100B according to the first embodiment. The NCR device 500A relays radio signals transmitted and received between the gNB200 and the UE100A. The NCR device 500A has an RF (Radio Frequency) function that amplifies and relays the received radio signals and performs directional transmission by beamforming (for example, analog beamforming).

[0050] The NCR-UE100B has at least one layer (entity) among the PHY, MAC, RRC, and F1-AP (Application Protocol). F1-AP is a type of fronthaul interface. The NCR-UE100B communicates with the gNB200 via downlink signaling and / or uplink signaling, as described below, using at least one of the PHY, MAC, RRC, and F1-AP. If the NCR-UE100B is a type or part of a base station, the NCR-UE100B may communicate with the gNB200 via the AP of Xn, which is an inter-base station interface (Xn-AP).

[0051] (2.3) Example of configuration of control terminal and relay device Figure 8 shows an example configuration of the NCR-UE100B and NCR device 500A according to the first embodiment. The NCR-UE100B includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140.

[0052] 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 receives the radio signals received by the antenna. No. The signal is converted into a baseband signal (received signal) and output to the control unit 130. The transmitting unit 120 performs various types of transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmitted signal) output by the control unit 130 into a wireless signal and transmits it from the antenna.

[0053] The control unit 130 performs various controls in the NCR-UE100B. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation, demodulation, encoding, and decoding of baseband signals. The CPU executes programs stored in memory and performs various processing. The control unit 130 also performs the functions of at least one layer of the PHY, MAC, RRC, and F1-AP.

[0054] Interface 140 is electrically connected to NCR device 500A. Control unit 130 controls NCR device 500A via interface 140. Note that if NCR-UE100B and NCR device 500A are configured as a single unit, NCR-UE100B does not need to have interface 140. Also, the receiving unit 110 and transmitting unit 120 of NCR-UE100B may be configured as a single unit with the wireless unit 510A of NCR device 500A.

[0055] The NCR device 500A includes a wireless unit 510A and an NCR control unit 520A. The wireless unit 510A includes an antenna section 510a containing multiple antennas (multiple antenna elements), an RF circuit 510b including an amplifier, and a directional control unit 510c that controls the directivity of the antenna section 510a. The RF circuit 510b amplifies and relays (transmits) the wireless signals transmitted and received by the antenna section 510a. The RF circuit 510b may convert the analog wireless signals into digital signals and then convert them back to analog signals after digital signal processing. The directional control unit 510c may perform analog beamforming by analog signal processing. Alternatively, the directional control unit 510c may perform digital beamforming by digital signal processing. Alternatively, the directional control unit 510c may perform hybrid analog and digital beamforming.

[0056] The NCR control unit 520A controls the wireless unit 510A in response to control signals from the control unit 130 of the NCR-UE100B. The NCR control unit 520A may include at least one processor. The NCR control unit 520A may output information regarding the capabilities of the NCR device 500A to the NCR-UE100B. If the NCR-UE100B and the NCR device 500A are configured as a single unit, the control unit 130 of the NCR-UE100B and the NCR control unit 520A of the NCR device 500A may also be configured as a single unit.

[0057] In the first embodiment, the receiver 110 of the NCR-UE100B receives signaling (downlink signaling) used to control the NCR device 500A from the gNB200 via wireless communication. The control unit 130 of the NCR-UE100B controls the NCR device 500A based on this signaling. This enables the gNB200 to control the NCR device 500A via the NCR-UE100B.

[0058] In the first embodiment, the control unit 130 of the NCR-UE100B acquires NCR capability information indicating the capabilities of the NCR device 500A from the NCR device 500A (NCR control unit 520A). Alternatively, the control unit 130 may acquire the information by reading NCR capability information that has been pre-written in its own memory. The transmission unit 120 of the NCR-UE100B then transmits the acquired NCR capability information to the gNB200 via wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE100B to the gNB200. This allows the gNB200 to understand the capabilities of the NCR device 500A.

[0059] (2.4) Example of base station configuration Figure 9 shows an example configuration of the gNB200 according to the first embodiment. The gNB200 comprises a transmitting unit 210, a receiving unit 220, a control unit 230, and a backhaul communication unit 240.

[0060] The transmitting unit 210 performs various types of transmissions under the control of the control unit 230. The transmitting unit 210 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna. The receiving unit 220 performs various types of receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts the radio signal received by the antenna into a baseband signal (received 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.

[0061] The control unit 230 performs various controls in the gNB200. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation, demodulation, encoding, and decoding of baseband signals. The CPU executes programs stored in memory and performs various processing.

[0062] The backhaul communication unit 240 is connected to an adjacent base station via an inter-base station interface. The backhaul communication unit 240 is connected to the AMF / UPF300 via a base station-core network interface. The gNB may consist of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally separated), and the two units may be connected via an F1 interface.

[0063] In the first embodiment, the transmitter 210 of the gNB200 transmits signaling (downlink signaling) used to control the NCR device 500A to the NCR-UE100B, which controls the NCR device 500A, via wireless communication. This enables the gNB200 to control the NCR device 500A via the NCR-UE100B.

[0064] In the first embodiment, the receiving unit 220 of the gNB200 receives NCR capability information indicating the capabilities of the NCR device 500A from the NCR-UE100B, which controls the NCR device 500A, via wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE100B to the gNB200. This enables the gNB200 to understand the capabilities of the NCR device 500A.

[0065] (2.5) An example of downlink signaling Figure 10 shows an example of downlink signaling from gNB200 to NCR-UE100B according to the first embodiment.

[0066] The gNB200 (transmitter 210) transmits downlink signaling to the NCR-UE100B. The downlink signaling may be an RRC message, which is signaling at the RRC layer (i.e., Layer 3). The downlink signaling may be a MAC CE (Control Element), which is signaling at the MAC layer (i.e., Layer 2). The downlink signaling may be downlink control information (DCI), which is signaling at the PHY layer (i.e., Layer 1). The downlink signaling may be UE-specific signaling or broadcast signaling. The downlink signaling may be a fronthaul message (e.g., an F1-AP message). If the NCR-UE100B is a type or part of a base station, the NCR-UE100B may communicate with the gNB200 via an AP (Xn-AP) of the inter-base station interface Xn.

[0067] For example, the gNB200 (transmitter 210) transmits an NCR control signal specifying the operating status of the NCR device 500A as downlink signaling to the NCR-UE100B, which has established a wireless connection with the gNB200 (step S1A). The NCR control signal specifying the operating status of the NCR device 500A may be MAC CE, which is a MAC layer (layer 2) signaling, or DCI, which is a PHY layer (layer 1) signaling. However, the NCR control signal may also be included in an RRC Reconfiguration message, which is a type of RRC message specific to the UE, and transmitted to the NCR-UE100B. Downlink signaling may also be a message from a layer higher than the RRC layer (e.g., an NCR application). Downlink signaling may also involve encapsulating a message from a layer higher than the RRC layer with a message from a layer below the RRC layer and transmitting it. The NCR-UE100B (transmitter 120) may also send a response message to the downlink signaling from the gNB200 via the uplink. This response message may be sent when the NCR device 500A has completed or received the settings specified in the downlink signaling.

[0068] The NCR control signal may include frequency control information that specifies the center frequency of the radio signal (e.g., component carrier) that the NCR device 500A is to relay. If the NCR control signal received from the gNB200 includes frequency control information, the NCR-UE100B (control unit 130) controls the NCR device 500A to relay the radio signal with the center frequency indicated by the frequency control information (step S2A). The NCR control signal may include multiple frequency control information that specify different center frequencies. By including frequency control information in the NCR control signal, the gNB200 can specify the center frequency of the radio signal that the NCR device 500A should relay via the NCR-UE100B.

[0069] The NCR control signal may include mode control information that specifies the operating mode of the NCR device 500A. The mode control information may be associated with frequency control information (center frequency). The operating mode may be any of the following modes: a mode in which the NCR device 500A performs omnidirectional transmission and / or reception; a mode in which the NCR device 500A performs fixed directional transmission and / or reception; a mode in which the NCR device 500A performs transmission and / or reception with a variable directional beam; or a mode in which the NCR device 500A performs MIMO (Multiple Input Multiple Output) relay transmission. The operating mode may be either a beamforming mode (i.e., a mode that prioritizes desired wave improvement) or a null steering mode (i.e., a mode that prioritizes interference wave suppression). If the NCR control signal received from the gNB200 includes mode control information, the NCR-UE100B (control unit 130) controls the NCR device 500A to operate in the operating mode indicated by the mode control information (step S2A). By including mode control information in the NCR control signal, the gNB200 can specify the operating mode of the NCR device 500A via the NCR-UE100B.

[0070] Here, the mode in which the NCR device 500A performs omnidirectional transmission and / or reception is the mode in which the NCR device 500A performs omnidirectional relay, and may be called the omni mode. The mode in which the NCR device 500A performs fixed directional transmission and / or reception may be a directional mode realized by a single directional antenna. Alternatively, this mode may be a beamforming mode realized by applying fixed phase and amplitude control (antenna weight control) to multiple antennas. Any of these modes may be specified (set) from gNB200 to NCR-UE100B. The mode in which the NCR device 500A performs transmission and / or reception with a variable directional beam may be an analog beamforming mode, a digital beamforming mode, or a hybrid beamforming mode. This mode may be a mode that forms an adaptive beam specific to the UE100A. Any of these modes may be specified (set) from gNB200 to NCR-UE100B. In addition, in the beamforming operation mode, beam control information described later may be provided from gNB200 to NCR-UE100B. The mode in which the NCR device 500A performs MIMO relay transmission may be a SU (Single-User) spatial multiplexing mode, a MU (Multi-User) spatial multiplexing mode, or a transmit diversity mode. Any of these modes may be specified (set) from gNB200 to NCR-UE100B. The operation mode may include a mode that turns on (activates) relay transmission by the NCR device 500A and a mode that turns off (deactivates) relay transmission by the NCR device 500A. Any of these modes may be specified (set) from gNB200 to NCR-UE100B by an NCR control signal.

[0071] The NCR control signal may include beam control information that specifies the transmission direction, transmission weight, or beam pattern when the NCR device 500A performs directional transmission. The beam control information may be associated with frequency control information (center frequency). The beam control information may include PMI (Precoding Matrix Indicator). The beam control information may also include beam formation angle information. When the NCR control signal received from the gNB200 includes beam control information, the NCR-UE100B (control unit 130) controls the NCR device 500A to form the transmission directivity (beam) indicated by the beam control information (step S2A). By including beam control information in the NCR control signal, the gNB200 can control the transmission directivity of the NCR device 500A via the NCR-UE100B.

[0072] The NCR control signal may include output control information that specifies the degree to which the NCR device 500A amplifies the radio signal (amplification gain) or the transmission power. The output control information may also be information that indicates the difference (i.e., relative value) between the current amplification gain or transmission power and the target amplification gain or transmission power. If the NCR control signal received from the gNB200 includes output control information, the NCR-UE100B (control unit 130) controls the NCR device 500A to change to the amplification gain or transmission power indicated by the output control information (step S2A). The output control information may be associated with frequency control information (center frequency). The output control information may also be information that specifies one of the amplifier gain, beamforming gain, or antenna gain of the NCR device 500A. The output control information may also be information that specifies the transmission power of the NCR device 500A.

[0073] When one NCR-UE100B controls multiple NCR devices 500A, the gNB200 (transmitter 210) may transmit an NCR control signal to the NCR-UE100B for each NCR device 500A. In this case, the NCR control signal may include the identifier of the corresponding NCR device 500A (NCR identifier). The NCR-UE100B (control unit 130) controlling multiple NCR devices 500A determines which NCR device 500A to which the NCR control signal is applied based on the NCR identifier included in the NCR control signal received from the gNB200. Note that even when the NCR-UE100B controls only one NCR device 500A, the NCR identifier may be transmitted from the NCR-UE100B to the gNB200 along with the NCR control signal.

[0074] In this way, the NCR-UE100B (control unit 130) controls the NCR device 500A based on the NCR control signal from the gNB200. This allows the gNB200 to control the NCR device 500A via the NCR-UE100B.

[0075] (2.6) An example of uplink signaling Figure 11 shows an example of uplink signaling from NCR-UE100B to gNB200 according to the first embodiment.

[0076] The NCR-UE100B (transmitter 210) transmits uplink signaling to the gNB200. The uplink signaling may be an RRC message, which is signaling at the RRC layer. The uplink signaling may be a MAC CE, which is signaling at the MAC layer. The uplink signaling may be uplink control information (UCI), which is signaling at the PHY layer. The uplink signaling may be a fronthaul message (e.g., an F1-AP message) or an inter-base station message (e.g., an Xn-AP message). The uplink signaling may be a message from a layer higher than the RRC layer (e.g., an NCR application). The uplink signaling may be a message from a layer higher than the RRC layer that is encapsulated and transmitted within a message from a layer below the RRC layer. Furthermore, the gNB200 (transmitter 210) may transmit a response message to the uplink signaling from the NCR-UE100B via the downlink, and the NCR-UE100B (receiver 110) may receive the response message.

[0077] For example, NCR-UE100B (transmitter 120), having established a wireless connection with gNB200, transmits NCR capability information indicating the capabilities of the NCR device 500A to gNB200 as uplink signaling (step S5A). NCR-UE100B (transmitter 120) may also transmit NCR capability information to gNB200 in the form of a UE Capability message or UE Assistant Information message, which are types of RRC messages. NCR-UE100B (transmitter 120) may also transmit NCR capability information (NCR capability information and / or operating status information) to gNB200 in response to a request or inquiry from gNB200.

[0078] The NCR capability information may include corresponding frequency information indicating the frequencies that the NCR device 500A supports. The corresponding frequency information may be a numerical value or index indicating the center frequency of the frequencies that the NCR device 500A supports. Alternatively, the corresponding frequency information may be a numerical value or index indicating the range of frequencies that the NCR device 500A supports. If the NCR capability information received from the NCR-UE100B includes corresponding frequency information, the gNB200 (control unit 230) can determine the frequencies that the NCR device 500A supports based on the corresponding frequency information. The gNB200 (control unit 230) may then set the center frequency of the radio signal targeted by the NCR device 500A within the range of frequencies that the NCR device 500A supports.

[0079] The NCR capability information may include mode capability information relating to the operating modes that the NCR device 500A can support or switching between operating modes. The operating modes may be at least one of the following modes, as described above: a mode in which the NCR device 500A performs omnidirectional transmission and / or reception; a mode in which the NCR device 500A performs fixed directional transmission and / or reception; a mode in which the NCR device 500A performs transmission and / or reception with a variable directional beam; and a mode in which the NCR device 500A performs MIMO (Multiple Input Multiple Output) relay transmission. The operating modes may be either beamforming mode (i.e., a mode that prioritizes desired wave improvement) or null steering mode (i.e., a mode that prioritizes interference wave suppression). The mode capability information may indicate which of these operating modes the NCR device 500A can support. The mode capability information may also indicate which of these operating modes mode switching is possible. If the NCR capability information received from the NCR-UE100B includes mode capability information, the gNB200 (control unit 230) can determine the corresponding operating mode and mode switching of the NCR device 500A based on that mode capability information. The gNB200 (control unit 230) may then set the operating mode of the NCR device 500A within the range of the determined operating mode and mode switching.

[0080] The NCR capability information may include beam capability information indicating the beam variable range, beam variable resolution, or number of variable patterns when the NCR device 500A transmits and / or receives with a variable directional beam. The beam capability information may, for example, indicate the variable range of the beam angle relative to the horizontal or vertical direction (e.g., controllable from 30° to 90°). Alternatively, the beam capability information may, for example, indicate the absolute angle. The beam capability information may be expressed in terms of the direction and / or elevation angle to which the beam is directed. The beam capability information may indicate the angle change for each variable step (e.g., 5° horizontally / step, 10° vertically / step). Alternatively, the beam capability information may indicate the number of variable steps (e.g., 10 horizontal steps, 20 vertical steps). The beam capability information may also indicate the number of variable beam patterns in the NCR device 500A (e.g., a total of 10 patterns from beam patterns 1 to 10). If the NCR capability information received from the NCR-UE100B includes beam capability information, the gNB200 (control unit 230) can determine the beam angle change or beam pattern that the NCR device 500A can handle based on that beam capability information. The gNB200 (control unit 230) may then set the beam of the NCR device 500A within the range of the determined beam angle change or beam pattern. This beam capability information may also be null capability information. In the case of null capability information, it indicates the null control capability when null steering is performed.

[0081] The NCR capability information may include control delay information indicating the control delay time in the NCR device 500A. For example, the control delay information is information indicating the delay time (e.g., 1ms, 10ms, etc.) from the time when the UE100 receives the NCR control signal or when it transmits to the gNB200 that the setting for the NCR control signal is complete until the control (change of operating mode and / or beam change) in accordance with the NCR control signal is completed. If the NCR capability information received from the NCR-UE100B includes control delay information, the gNB200 (control unit 230) can determine the control delay time in the NCR device 500A based on that control delay information.

[0082] The NCR capability information may include amplification characteristic information relating to the amplification characteristics or output power characteristics of the radio signal in the NCR device 500A. The amplification characteristic information may also indicate the amplifier gain (dB), beamforming gain (dB), and antenna gain (dBi) of the NCR device 500A. The amplification characteristic information may also indicate the variable amplification range (e.g., 0dB to 60dB) of the NCR device 500A. The amplification characteristic information may also indicate the number of steps (e.g., 10 steps) for the changeable amplification level of the NCR device 500A, or the amplification level per variable step (e.g., 10dB / step). The amplification characteristic information may also indicate the variable range (e.g., 0dBm to 30dBm) for the output power of the NCR device 500A. The amplification characteristic information may also indicate the number of steps (e.g., 10 steps) for the changeable output power of the NCR device 500A, or the output power per variable step (e.g., 10dBm / step).

[0083] The NCR capability information may include location information indicating the installation location of the NCR device 500A. The location information may include one or more of latitude, longitude, and altitude. The location information may also include information indicating the distance and / or installation angle of the NCR device 500A relative to the gNB200. The installation angle may be a relative angle with respect to the gNB200, or a relative angle with respect to, for example, north, vertical, or horizontal. The installation location may be location information of the place where the antenna section 510a of the NCR device 500A is installed.

[0084] The NCR capability information may include antenna information indicating the number of antennas the NCR device 500A has. The antenna information may also indicate the number of antenna ports the NCR device 500A has. The antenna information may also indicate the degrees of freedom for directional control (beam or null formation). Degrees of freedom indicate how many beams can be formed (controlled), and are usually "(number of antennas) - 1". For example, in the case of two antennas, the degrees of freedom is 1. In the case of two antennas, a figure-eight-like beam pattern is formed, but since directional control is possible in only one direction, the degrees of freedom is 1.

[0085] When NCR-UE100B controls multiple NCR devices 500A, NCR-UE100B (transmitter 120) may transmit NCR capability information to gNB200 for each NCR device 500A. In this case, the NCR capability information may include the number of NCR devices 500A and / or the identifier of the corresponding NCR device 500A (NCR identifier). Furthermore, when NCR-UE100B controls multiple NCR devices 500A, NCR-UE100B (transmitter 120) may transmit information indicating at least one of the identifiers of each of the multiple NCR devices 500A and the number of the multiple NCR devices 500A. Note that even when NCR-UE100B controls only one NCR device 500A, the NCR identifier may be transmitted from NCR-UE100B to gNB200 along with the NCR capability information.

[0086] (2.7) Multibeam operation of relay equipment Here, we assume that the NCR device 500A performs beamforming using multiple antennas (multiple antenna elements) included in the antenna section 510a. Specifically, the NCR device 500A simultaneously forms multiple beams using multiple antennas. Multiple antennas are an example of multiple elements used for beamforming. For example, as shown in Figure 5, the NCR device 500A simultaneously forms separate beams (independent beams) for UE100A and 100B. Under these assumptions, the NCR-UE100B groups the multiple antennas into multiple groups and performs independent beam control for each group.

[0087] Figure 12 is a diagram illustrating the multi-beam operation of the NCR device 500A, which is a relay device according to the first embodiment. In Figure 12, communication on the downlink is illustrated as an example, and the configuration of the receiving system (receiving circuit, etc.) in the NCR device 500A is omitted from the illustration. However, a similar configuration may be applied to the receiving circuit, or to communication on the uplink. Furthermore, an example in which the NCR-UE100B is configured integrally with the NCR device 500A is shown.

[0088] The NCR device 500A has a transmission system configuration consisting of a power amplifier (PA) 512, a plurality of phase shifters 513 (513a to 513d), and a plurality of antennas 514 (514a to 514d). Each phase shifter 513 is provided in a one-to-one relationship with an antenna 514. The phase shifters 513 and antennas 514 are part of the antenna section 510a described above. In Figure 12, an example is shown in which there are four antennas 514, but the number of antennas 514 may be four or more. Also, in Figure 12, an example is shown in which there is one PA 512, but there may be four PAs, and these multiple PAs 512 may correspond one-to-one with antennas 514. In Figure 12, an analog beamforming configuration is shown, but digital beamforming using digital signal processing may also be performed.

[0089] PA512 is part of the RF circuit 510b described above. The signal received by the receiving circuit is input to PA512. PA512 amplifies the input signal (transmit signal) and outputs the amplified transmit signal to each phase shifter 513. Each phase shifter 513 adjusts the phase of the transmit signal by multiplying it by the antenna weight output by the directional control unit 510c described above, and outputs the phase-adjusted transmit signal to the corresponding antenna 514. Each antenna 514 radiates the input transmit signal into space as radio waves.

[0090] For the NCR device 500A configured in this way, the NCR-UE100B groups the multiple antennas 514 (and multiple phase shifters 513) into multiple groups 511A (511A1 and 511A2), thereby performing independent beam control for each group. A PA 512 may be provided individually for each group 511A. Figure 12 shows an example where there are two groups 511A, but there may be three or more groups. Such groups may be called "ports". In that case, group 511A1 may be Port#1 and group 511A2 may be Port#2. The number of antennas 514 constituting each group may be uneven. For example, there may be two antennas 514 constituting Port#1 and three antennas 514 constituting Port#2. Furthermore, the configuration is not limited to grouping physically adjacent antennas 514; antennas 514 that are not physically adjacent may also be grouped. While this explanation describes one example of grouping the transmission system configuration into multiple groups, the reception system configuration can also be grouped into multiple groups in a similar manner.

[0091] The NCR-UE100B may have a separate control interface for each group 511A. The NCR-UE100B may control the beam for each group 511A via a separate control interface for each group 511A. In the example in Figure 12, there are two groups 511A, and the NCR-UE100B controls the beam to be directed towards UE100A1 by one group 511A1 and towards UE100A2 by the other group 511A2. However, it is possible to form N beams by using N groups.

[0092] NCR-UE100B may control all antennas 514 to form a single beam without performing such grouping. In other words, NCR-UE100B may switch grouping on and off. When grouping is performed, NCR-UE100B may configure the above-mentioned uplink signaling individually for each group 511A. For example, NCR-UE100B may configure the above-mentioned NCR capability information individually for each group 511A. In that case, NCR-UE100B may transmit one or more sets of group identifiers and NCR capability information to gNB200 as uplink signaling. Also, gNB200 may configure the above-mentioned downlink signaling individually for each group 511A. For example, gNB200 may configure the above-mentioned NCR control signals individually for each group 511A. In that case, the gNB200 may send one or more sets of group identifiers and NCR control signals to the NCR-UE100B as downlink signaling.

[0093] Figure 13 shows an example of the operation of the mobile communication system 1 according to the first embodiment. Steps that are not essential are shown with dashed lines in Figure 13. Details will be explained in the second embodiment, but "NCR" in Figure 13 may be read as "RIS".

[0094] In step S101, the gNB200 (transmitter 210) broadcasts NCR support information indicating that the gNB200 supports the NCR-UE100B (and / or supports the grouping described above). For example, the gNB200 (transmitter 210) broadcasts a system information block (SIB) containing the NCR support information. The NCR support information may also be information indicating that the NCR-UE100B is accessible. Alternatively, the gNB200 (transmitter 210) may broadcast NCR non-support information indicating that the gNB200 does not support the NCR-UE100B. The NCR non-support information may also be information indicating that the NCR-UE100B is inaccessible.

[0095] At this stage, the NCR-UE100B may be in an RRC idle state or an RRC inactive state. The NCR-UE100B (control unit 130), which has not established a wireless connection with the gNB200, may, upon receiving NCR support information from the gNB200, determine that access to the gNB200 is permitted and perform an access operation to establish a wireless connection with the gNB200. The NCR-UE100B (control unit 130) may re-select a cell, considering the gNB200 (cell) to which access is permitted as having the highest priority.

[0096] On the other hand, if the NCR-UE100B (control unit 130) has not established a wireless connection with the gNB200, it may determine that it cannot access (establish a connection with) the gNB200 if the gNB200 is not broadcasting NCR support information (or is broadcasting NCR non-support information). As a result, the NCR-UE100B can only establish a wireless connection with gNB200s that are capable of handling the NCR-UE100B.

[0097] Furthermore, if the gNB200 is congested, the gNB200 may broadcast access restriction information that restricts access from the UE100. However, unlike a normal UE100, the NCR-UE100B can be considered a network-side entity. Therefore, the NCR-UE100B may ignore the access restriction information from the gNB200. For example, if the NCR-UE100B (control unit 130) receives NCR support information from the gNB200, it may perform actions to establish a wireless connection with the gNB200 even if the gNB200 is broadcasting access restriction information. For example, the NCR-UE100B (control unit 130) does not have to perform (or may ignore) UAC (Unified Access Control). Alternatively, one or both of the AC / AI (Access Category / Access Identity) used in UAC may be special values ​​that indicate that the access is from the NCR-UE.

[0098] In step S102, the NCR-UE100B (control unit 130) initiates a random access procedure to the gNB200. During the random access procedure, the NCR-UE100B (transmitter 120) sends a random access preamble (Msg1) and an RRC message (Msg3) to the gNB200. Also during the random access procedure, the NCR-UE100B (receiver 110) receives a random access response (Msg2) and an RRC message (Msg4) from the gNB200.

[0099] In step S103, when establishing a wireless connection with gNB200, NCR-UE100B (transmitter 120) may transmit NCR-UE information to gNB200 indicating that its own UE is an NCR-UE. For example, during a random access procedure with gNB200, NCR-UE100B (transmitter 120) transmits messages for the random access procedure (e.g., Msg1, Msg3, Msg5) to gNB200 including NCR-UE information. Based on the NCR-UE information received from NCR-UE100B, gNB200 (control unit 230) recognizes that the accessed UE100 is NCR-UE100B and can, for example, remove NCR-UE100B from the access restriction list (i.e., accept access). Once the random access procedure is complete, NCR-UE100B transitions from the RRC idle state or RRC inactive state to the RRC connected state.

[0100] In step S104, the gNB200 (transmitter 120) sends a capability inquiry message to the NCR-UE100B to inquire about its capabilities. The NCR-UE100B (receiver 110) receives the capability inquiry message.

[0101] In step S105, the NCR-UE100B (transmitter 120) transmits a capability information message containing NCR capability information to the gNB200. The capability information message may also be an RRC message, for example, a UE Capability message. The gNB200 (receiver 220) receives the capability information message. The gNB200 (control unit 230) determines the capability of the NCR device 500A based on the received capability information message. The NCR capability information (capability information message) includes information indicating the number of groups 511A in the NCR device 500A. This information may also include information indicating the maximum number of groups and / or the minimum number of groups. The NCR capability information (capability information message) may further include at least one of the following: information indicating the number of elements (e.g., antennas 514) in each group 511A in the NCR device 500A, the total number of elements in the NCR device 500A, the identifier of each group 511A, and information indicating the beam characteristics of each group 511A. Information indicating beam characteristics may, for example, be part of the NCR capability information mentioned above.

[0102] In step S106, gNB200 (transmitter unit) 210 The NCR unit 500A sends a configuration message to the NCR-UE100B that includes various settings related to the NCR device 500A. The NCR-UE100B (receiving unit 110) receives the configuration message. The configuration message is a type of downlink signaling as described above. The configuration message may also be an RRC message, for example, an RRC Reconfiguration message. The configuration message includes settings related to grouping.

[0103] For example, the configuration message may include information specifying the number of groups 511A to be configured for the NCR device 500A and / or the number of beams to be configured for the NCR device 500A. This information may include identifiers (group identifiers) for the groups 511A to be configured for the NCR device 500A. The number of group identifiers may implicitly indicate the number of groups 511A to be configured for the NCR device 500A and / or the number of beams to be configured for the NCR device 500A. The configuration message may also include information specifying whether grouping is on or off. The configuration message may also include information specifying the number of elements (e.g., antennas 514) that make up each group 511A.

[0104] A beam may be configured to be formed by two or more groups. For example, a 6-group NCR device 500A may be configured to have two beams, forming one beam for every three groups. In this case, the configuration message may include identifiers for one or more groups 511A associated with each beam.

[0105] Regarding the group identifier in the configuration message, if the group identifier has been notified to the gNB200 in the capability information described above, that group identifier may be reused. On the other hand, if the group identifier has not been notified to the gNB200 in the capability information, the gNB200 may assign a group identifier.

[0106] The configuration message may include an identifier for the UE100A that is associated with each group or beam.

[0107] The configuration message may include multiple settings that can be switched in a time-sharing manner, as described above for grouping. For example, the grouping settings may be dynamically switched by the control instructions described later. In this case, the configuration message may include an index (configuration identifier) ​​associated with each setting.

[0108] In step S107, gNB200 (transmitter unit)210 The NCR-UE100B transmits a control instruction to the NCR-UE100B that specifies the operating state of the NCR device 500A. This control instruction may be the NCR control signal described above (for example, L1 / L2 signaling). The NCR-UE100B (receiving unit 110) receives the control instruction. The NCR-UE100B (control unit 130) controls the NCR device 500A in accordance with the control instruction. The control instruction may include a group identifier of the target group 511A. In that case, the NCR-UE100B (control unit 130) applies the operating state specified in the control instruction to the group 511A indicated by the group identifier. The control instruction may also include an index (setting identifier) ​​indicating the setting to be switched (setting after switching). In that case, the NCR-UE100B (control unit 130) controls the NCR device 500A to switch to the setting indicated by the index from among the multiple settings set in the setting message.

[0109] In step S108, NCR-UE100B controls NCR device 500A according to the above settings (and control instructions). NCR-UE100B may autonomously control NCR device 500A for at least one group 511A without relying on control instructions from gNB200. For example, NCR-UE100B may autonomously control NCR device 500A based on the location of UE100A and / or information received by NCR-UE100B from UE100A.

[0110] (3) Second embodiment Next, the differences between the second embodiment and the first embodiment described above will be explained. The overview of the mobile communication system 1 and the configuration of the gNB200 according to the second embodiment are the same as those of the first embodiment described above.

[0111] The relay device according to the second embodiment is a RIS (Reconfigurable Intelligent Surface) device that changes the propagation direction of incident radio waves (wireless signals) by reflection or refraction. In the first embodiment described above, "NCR" can be read as "RIS". The RIS can perform beamforming (directivity control) in the same way as the NCR by changing the properties of the metamaterial. In the case of the RIS, the beam range (distance) may also be changed in the same way as a lens by controlling the reflection direction and / or refraction direction of each unit element. For example, the configuration may control the reflection direction and / or refraction direction of each unit element and also allow focusing on a nearby UE (directing the beam) or focusing on a distant UE (directing the beam).

[0112] As shown in Figure 14, the RIS device 500B according to the second embodiment may be a reflective type RIS device 500B. Such a RIS device 500B changes the propagation direction of radio waves by reflecting the incident radio waves. Here, the reflection angle of the radio waves is variably set. The RIS device 500B reflects the radio waves incident from gNB200 toward UE100A1 and UE100A2, respectively. Alternatively, the RIS device 500B may reflect the radio waves incident from UE100A1 and UE100A2 toward gNB200. The RIS device 500B dynamically changes the reflection angle of the radio waves. For example, in a communication resource between gNB200 and UE100A1, the RIS device 500B reflects the radio waves incident from gNB200 toward UE100A1, and / or reflects the radio waves incident from UE100A1 toward gNB200. Here, communication resources include resources in the time domain and / or resources in the frequency domain. The RIS device 500B, in the communication resources between gNB200 and UE100A2, reflects radio waves incident from gNB200 toward UE100A2 and / or reflects radio waves incident from UE100A2 toward gNB200.

[0113] As shown in Figure 15, the RIS device 500B may be a transmissive type RIS device 500B. Such a RIS device 500B changes the propagation direction of radio waves by refracting the incident radio waves. Here, the refraction angle of the radio waves is variably set. The RIS device 500B refracts the radio waves incident from gNB200 toward UE100A1 and UE100A2, respectively. Alternatively, the RIS device 500B may refract the radio waves incident from UE100A1 and UE100A2 toward gNB200. The RIS device 500B dynamically changes the refraction angle of the radio waves. For example, in a communication resource between gNB200 and UE100A1, the RIS device 500B refracts the radio waves incident from gNB200 toward UE100A1, and / or refracts the radio waves incident from UE100A1 toward gNB200. The RIS device 500B refracts radio waves incident from gNB200 toward UE100A2 and / or radio waves incident from UE100A2 toward gNB200 in the communication resource between gNB200 and UE100A2.

[0114] In the second embodiment, as shown in Figure 16, a new UE (hereinafter referred to as "RIS-UE") 100C, which is a control terminal for controlling the RIS device 500B, is introduced. The RIS-UE 100C controls the RIS device 500B in cooperation with the gNB 200 by establishing a wireless connection with the gNB 200 and performing wireless communication with the gNB 200. This makes it possible to achieve efficient coverage expansion using the RIS device 500B while suppressing an increase in installation costs and a decrease in installation flexibility for the RIS device 500B. The RIS-UE 100C controls the RIS device 500B according to the RIS control signals from the gNB 200.

[0115] The RIS-UE100C may be configured separately from the RIS device 500B. For example, the RIS-UE100C may be located near the RIS device 500B and electrically connected to it. The RIS-UE100C may be connected to the RIS device 500B by wire or wireless connection. Alternatively, the RIS-UE100C may be configured integrally with the RIS device 500B. The RIS-UE100C and the RIS device 500B may be fixedly installed, for example, on a wall or window. The RIS-UE100C and the RIS device 500B may be installed, for example, on a vehicle and be movable. Furthermore, one RIS-UE100C may control multiple RIS devices 500B.

[0116] Figure 17 shows the configuration of the RIS-UE100C and RIS device 500B according to the second embodiment. As shown in Figure 17, the RIS-UE100C includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140. This configuration is the same as that of the first embodiment described above.

[0117] The RIS device 500B includes a RIS 510B and a RIS control unit 520B. The RIS 510B is a metasurface constructed using metamaterials. For example, the RIS 510B is constructed by arranging very small structures in an array relative to the wavelength of radio waves, and by making the shape of the structures different depending on their placement, it is possible to arbitrarily design the direction of the reflected waves and / or the beam shape. The RIS 510B may also be a transparent dynamic metasurface. The RIS 510B may be constructed by making a metasurface substrate, which has a large number of small structures arranged regularly, transparent, and then placing a transparent glass substrate on top of it. By moving the stacked glass substrates slightly, it may be possible to dynamically control three patterns: a mode in which incident radio waves are transmitted, a mode in which some radio waves are transmitted and some are reflected, and a mode in which all radio waves are reflected.

[0118] The RIS control unit 520B controls the RIS 510B in accordance with the RIS control signals from the control unit 130 of the RIS-UE 100C. The RIS control unit 520B may include at least one processor and at least one actuator. The processor decodes the RIS control signals from the control unit 130 of the RIS-UE 100C and drives the actuators in accordance with the RIS control signals. In the case where the RIS-UE 100C and the RIS device 500B are configured as a single unit, the control unit 130 of the RIS-UE 100C and the RIS control unit 520B of the RIS device 500B may also be configured as a single unit.

[0119] Figure 18 is a diagram illustrating the multi-beam operation of the RIS device 500B, which is a relay device according to the second embodiment. In Figure 18, communication on the downlink is illustrated.

[0120] The RIS device 500B has multiple structures 515 arranged periodically in the horizontal and vertical directions. These structures 515 are an example of multiple elements used for beamforming. The RIS device 500B achieves electromagnetic properties not found in nature through the periodic arrangement of the structures 515. By adjusting the shape and / or electromagnetic properties of the structures 515, desired properties (e.g., bending radio waves in any direction) can be obtained.

[0121] In the RIS device 500B configured in this way, the RIS-UE100C groups multiple structures 515 into multiple groups 511B (511B1 and 511B2), and performs independent beam control for each group. Figure 18 shows an example where there are two groups 511B, but there may be three or more groups. Such groups may be called "grids". In that case, group 511B1 may be Grid#1 and group 511B2 may be Grid#2. The number of structures 515 constituting each group may be uneven. Although physically adjacent structures 515 are grouped, physically non-adjacent structures 515 may also be grouped, for example, alternating groups with one structure in between.

[0122] The RIS-UE100C may have a separate control interface for each group 511B. The RIS-UE100C may control the beam for each group 511B via a separate control interface for each group 511B. In the example in Figure 18, there are two groups 511B, and the RIS-UE100C controls the beam to be directed towards UE100A1 by one group 511B1 and towards UE100A2 by the other group 511B2. However, it may be possible to form N beams by using N groups.

[0123] RIS-UE100C may control all structures 515 to form a single beam without performing such grouping. In other words, RIS-UE100C may control the switching of grouping on and off. When grouping is performed, RIS-UE100C may configure the uplink signaling described above individually for each group 511B. For example, RIS-UE100C may configure the capability information described above individually for each group 511B. In that case, RIS-UE100C may transmit one or more sets of group identifiers and NCR capability information to gNB200 as uplink signaling. Also, gNB200 may configure the downlink signaling described above individually for each group 511B. For example, gNB200 may configure control signals similar to the NCR control signals described above individually for each group 511B. In that case, the gNB200 may send one or more sets of group identifiers and NCR control signals to the RIS-UE100C as downlink signaling.

[0124] (4) Other embodiments The NCR / RIS control information transmitted from gNB200 to NCR-UE100B or RIS-UE100C may be information that controls the direction and / or focal length of the beam relayed (output) by the NCR device 500A or RIS device 500B. The information that controls the direction is, as mentioned above, for example, the antenna weight. The information that controls the focal length is information that allows the NCR device 500A or RIS device 500B to focus the beam according to the distance between the NCR device 500A or RIS device 500B and the UE100A. Such information may be information indicating the distance between the NCR device 500A or RIS device 500B and the UE100A. Alternatively, such information may be information indicating the focal length (for example, a focal range such as near or far). The NCR device 500A or RIS device 500B adjusts the focal length of the beam based on this information. In the case of the RIS device 500B, the focal length of the beam is adjusted, like a lens, by controlling (creating a difference in) the reflection (or refraction) angles of the elements on the outside of the metasurface and the reflection (or refraction) angles of the elements on the inside to different angles.

[0125] In the embodiments described above, the frequency control information may include a cell ID that identifies a cell and / or a BWP ID that identifies a bandwidth portion (BWP). BWP refers to a portion of the frequency band of a cell.

[0126] Each of the above-described operation flows can be performed not only independently, but also in combination of two or more operation flows. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow. It is not necessary to execute all steps in each flow; only some steps may be executed.

[0127] In the above embodiment, an example was described in which the base station is an NR base station (gNB), but the base station may also be an LTE base station (eNB). Furthermore, the base station may be a relay node such as an IAB (Integrated Access and Backhaul) node. The base station may also be a DU (Distributed Unit) of an IAB node.

[0128] A program may be provided that causes a computer to execute each process performed by the UE100 (NCR-UE100B, RIS-UE100C) or gNB200. The program may be recorded on a computer-readable medium. Using a computer-readable medium, it is possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, but may be a recording medium such as a CD-ROM or DVD-ROM. Furthermore, the circuits that execute each process performed by the UE100 or gNB200 may be integrated, and at least a part of the UE100 or gNB200 may be configured as a semiconductor integrated circuit (chipset, SoC: System on a chip).

[0129] The terms "based on" and "depending on" used in this disclosure do not mean "based solely on" or "depending solely on" unless otherwise specified. The term "based on" means both "based solely on" and "at least partially on." Similarly, the term "depending on" means both "at least partially on" and "at least partially on." Also, "obtain / acquire" may mean obtaining information from stored information, obtaining information from information received from other nodes, or obtaining information by generating it. The terms "include," "comprise," and their variations do not mean to include only the listed items, but may include only the listed items, or may include additional items in addition to the listed items. Also, the term "or" used in this disclosure is not intended to mean exclusive OR. Furthermore, any reference to elements using designations such as "first," "second," etc., used in this disclosure does not limit the quantity or order of those elements in general. These designations may be used herein as a convenient way to distinguish between two or more elements. Therefore, references to the first and second elements do not imply that only two elements may be employed therein, or that the first element must precede the second element in any way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall be plural unless it is clearly indicated otherwise by the context.

[0130] Although the embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to those described above, and various design changes can be made without departing from the gist of the invention.

[0131] This application claims priority to Japanese Patent Application No. 2022-075425 (filed on April 28, 2022), and all of its contents are incorporated into the specification of this application.

[0132] (Note) The features of the above-described embodiment are noted below.

[0133] (1) Base station and A relay device that relays wireless signals between the base station and the user equipment, The system includes a control terminal that communicates with the base station and controls the relay device, The relay device has a plurality of elements used for beamforming, The control terminal groups the multiple elements into multiple groups, thereby performing independent beam control for each group. Information regarding the plurality of groups is communicated between the base station and the control terminal. Mobile communication system.

[0134] (2) The relay device is a repeater device that amplifies and transmits the received radio waves. Each of the aforementioned elements includes the antenna of the repeater device. The mobile communication system described in (1) above.

[0135] (3) The relay device is a RIS (Reconfigurable Intelligent Surface) device that changes the propagation direction of incident radio waves by reflection or refraction. Each of the aforementioned plurality of elements includes a structure of the RIS device. The mobile communication system described in (1) or (2) above.

[0136] (4) The control terminal transmits capability information, including information indicating the number of groups, to the base station. A mobile communication system as described in any of (1) to (3) above.

[0137] (5) The capability information further includes at least one of the following: information indicating the number of elements in each group in the relay device, the total number of elements in the relay device, an identifier for each group in the relay device, and information indicating the beam characteristics of each group in the relay device. The mobile communication system described in (4) above.

[0138] (6) The base station transmits a configuration message to the control terminal that includes the settings related to the grouping. A mobile communication system as described in any of (1) to (3) above.

[0139] (7) The configuration message includes at least one of the following: information specifying the number of groups and / or the number of beams to be configured for the relay device; an identifier for one or more groups associated with each beam; and an identifier for the user device associated with each group or each beam. The mobile communication system described in (6) above.

[0140] (8) The aforementioned configuration message includes multiple settings that can be switched in a time-division manner. The mobile communication system described in (6) or (7) above.

[0141] (9) In the aforementioned setting message, each of the multiple settings is associated with a setting identifier. The base station transmits a control instruction to the control terminal specifying the settings to be applied using the setting identifier. The mobile communication system described in (8) above.

[0142] (10) A control terminal for controlling a relay device that relays radio signals between a base station and one or more user devices and has multiple elements used for beamforming, By grouping the aforementioned multiple elements into multiple groups, a control unit is provided that performs independent beam control for each group, The system includes a communication unit that communicates information about the aforementioned plurality of groups with the base station. Control terminal. [Explanation of symbols]

[0143] 1: Mobile communication systems 100 :UE 100B : NCR-UE 100C :RIS-UE 110: Receiver 120: Transmitter 130: Control Unit 140: Interface 200 :gNB 210: Transmitter 220: Receiving unit 230: Control Unit 240: Backhaul Communications Department 500A:NCR device 500B :RIS device 510A: Wireless Unit 510a: Antenna section 510b :RF circuit 510c: Directivity control section 511 A :group 511B: Group 512: PA 513: Phase shifter 514: Antenna 515 :Structure 520A: NCR Control Unit 520B: RIS Control Unit

Claims

1. A network and A relay device that relays wireless signals between the network and the user device, The system includes a control terminal that is in a wireless resource control (RRC) connected state, communicates with the network, and controls the relay device, The relay device has multiple antennas used to form multiple beams, The control terminal receives an RRC message from the network containing setting information for grouping the multiple beams, and, based on the setting information, controls the relay device to form beams according to the groups set in the setting information. Mobile communication system.

2. The relay device is a repeater device that amplifies and transmits the received radio waves. The mobile communication system according to claim 1.

3. The aforementioned configuration information includes the identifier of each group. The mobile communication system according to claim 1.

4. A control terminal for controlling a relay device that relays wireless signals between a network and one or more user devices and has multiple antennas used to form multiple beams, A receiving unit that receives an RRC message from the network containing setting information for grouping the multiple beams, The relay device comprises a control unit that controls the relay device to form beams according to the groups set in the setting information, based on the setting information. Control terminal.

5. A communication method performed by a control terminal that controls a relay device having a plurality of antennas used for relaying wireless signals between a network and one or more user devices and for forming a plurality of beams, Receiving an RRC message from the network containing configuration information for grouping the multiple beams, The system includes controlling the relay device to form beams according to the groups set in the configuration information based on the configuration information. Communication method.

6. A control terminal for controlling a relay device that relays wireless signals between a network and one or more user devices and has multiple antennas used to form multiple beams, The process of receiving an RRC message from the network that includes setting information for grouping the multiple beams, Based on the aforementioned setting information, the relay device is instructed to perform a process that controls it to form beams according to the groups set in the aforementioned setting information. program.

7. A chipset for a control terminal that controls a relay device having a plurality of antennas used for relaying wireless signals between a network and one or more user devices and for forming a plurality of beams, Receiving an RRC message from the network containing configuration information for grouping the multiple beams, Based on the aforementioned configuration information, the relay device is controlled to form a beam according to the group set in the configuration information. Chipset.

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