Communication method and control terminal

Abstract

In the present invention, a control terminal that controls a relay device relaying a wireless signal between a base station and a user device establishes a wireless connection with a network belonging to a first operator (PLMN) and a wireless connection with a network belonging to a second operator (PLMN). The control terminal controls the relay device on the basis of control accepted by the control terminal from the networks.

Description

[Technical Field]

[0001] The present disclosure relates to a communication method and a control terminal for use in a mobile communication system. [Background technology]

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

[0003] Radio signals (radio waves) in high frequency bands such as millimeter waves or terahertz waves have a tendency to propagate in a highly directional manner, which poses a problem of reducing the coverage of base stations. To solve this problem, repeater devices, which are a type of relay device that relays radio signals between base stations and user devices and can be controlled from a network, have attracted attention (see, for example, Non-Patent Document 1). Such repeater devices can expand the coverage of base stations while suppressing interference, for example, by amplifying radio signals received from base stations and transmitting them directionally. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP contribution: RP-213700, “New SI: Study on NR Network-controlled Repeaters” Summary of the Invention

[0005] A communication method according to a first aspect is a communication method executed by a control terminal that controls a relay device that relays radio signals between a base station and a user device, and includes the steps of establishing a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator, and controlling the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network.

[0006] A control terminal according to a second aspect is a control terminal that controls a relay device that relays radio signals between a base station and a user device, and includes a communication unit that establishes a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator, and a control unit that controls the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating a configuration of a mobile communication system according to an embodiment. [Figure 2] FIG. 10 is a diagram showing the configuration of a protocol stack of a radio interface of a user plane that handles data. [Figure 3] FIG. 1 is a diagram showing the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals). [Figure 4] FIG. 2 is a diagram for explaining a repeater (NCR device) according to the first embodiment. [Figure 5] FIG. 2 is a diagram for explaining a relay device and a control terminal (NCR-UE) according to the first embodiment. [Figure 6] FIG. 3 is a diagram illustrating a control method of the NCR device according to the first embodiment. [Figure 7]FIG. 2 is a diagram illustrating an example of the configuration of a protocol stack in a mobile communication system having an NCR device and an NCR-UE according to a first embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of the configuration of an NCR-UE and an NCR device according to the first embodiment. [Figure 9] FIG. 10 is a diagram for explaining a relay device (RIS device) according to a second embodiment. [Figure 10] FIG. 10 is a diagram for explaining a relay device (RIS device) according to a second embodiment. [Figure 11] FIG. 10 is a diagram for explaining a relay device and a control terminal (RIS-UE) according to a second embodiment. [Figure 12] FIG. 10 is a diagram illustrating the configuration of a RIS-UE and a RIS device according to a second embodiment. [Figure 13] A diagram showing an example configuration of a gNB according to an embodiment. [Figure 14] A figure showing an example of downlink signaling from a gNB to an NCR-UE according to an embodiment. [Figure 15] FIG. 2 is a diagram illustrating an example of an operation of the mobile communication system according to the embodiment. [Figure 16] FIG. 1 is a diagram for explaining multi-PLMN operation according to an embodiment. [Figure 17] FIG. 10 is a diagram illustrating an example of a multiple PLMN connection procedure according to an embodiment. [Figure 18] FIG. 10 is a diagram illustrating an example of a multi-PLMN cooperation procedure according to an embodiment. [Figure 19] FIG. 10 is a diagram illustrating an example of a control terminal-driven time-sharing control procedure according to the embodiment. [Figure 20] FIG. 10 is a diagram illustrating an example of a network-driven time-sharing control procedure according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] When controlling relay devices such as repeater devices from a network, the control technology for specifically controlling the relay devices has not yet been established, and it is currently difficult to efficiently extend coverage using relay devices.

[0009] Therefore, an object of the present disclosure is to enable appropriate control of a relay device that performs relay transmission between a base station and a user device.

[0010] 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.

[0011] (1) Overview of the embodiment A first aspect of the communication method is a communication method executed by a control terminal that controls a relay device that relays radio signals between a base station and a user device, and includes the steps of establishing a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator, and controlling the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network.

[0012] A second aspect of the communication method is the communication method of the first aspect, wherein the establishing step includes a step of transmitting first notification information regarding the second network to the first network after establishing a wireless connection with the first network.

[0013] A third aspect of the communication method is the communication method of the second aspect, wherein the establishing step further includes a step of receiving information from the first network that allows or instructs the establishment of a wireless connection with the second network after transmitting the first notification information.

[0014] A fourth aspect of the communication method is the communication method of the second or third aspect, wherein the first notification information is information indicating whether the control terminal has the capability or setting to establish wireless connections with a plurality of networks.

[0015] A fifth aspect of the communication method is a communication method of any one of the second to fourth aspects, wherein the first notification information includes at least one of an identifier of the second network, information indicating whether the control terminal has the ability to communicate simultaneously with the first network and the second network, and frequency information indicating a frequency related to the second network.

[0016] A sixth aspect of the communication method is a communication method of any one of the first to fifth aspects, further comprising a step of transmitting second notification information regarding control specified for the control terminal from the first network to the second network.

[0017] A seventh aspect of the communication method is the sixth aspect of the communication method, further comprising the step of receiving, from the first network, control information specifying an operation state to be prohibited as an operation state of the relay device or control information specifying an operation state of the relay device, wherein the transmitting step includes the step of transferring the control information received from the first network to the second network as the second notification information.

[0018] An eighth aspect of the communication method is the sixth aspect of the communication method, wherein the second notification information includes information indicating the timing when the control terminal is controlled from the first network or the timing when the control terminal is not controlled from the first network.

[0019] A ninth aspect of the communication method is a communication method of any one of the first to eighth aspects, wherein the controlling step includes a step of time-divisionally executing control of the relay device in accordance with control from the first network and control of the relay device in accordance with control from the second network.

[0020] A communication method of a tenth aspect is the communication method of the ninth aspect, further comprising the steps of the control terminal determining the time division pattern and notifying the first network and the second network of the determined pattern.

[0021] The communication method of an 11th aspect is the communication method of the 9th aspect, further comprising the steps of receiving information from the first network indicating the time division pattern determined by the first network, and notifying the second network of the pattern.

[0022] A twelfth aspect of the communication method is a communication method of any one of the ninth to eleventh aspects, further comprising the steps of acquiring information indicating the throughput in the first network and / or the throughput in the second network, and changing the time division ratio based on the throughput.

[0023] of the thirteenth aspect Control terminal is a control terminal that controls a relay device that relays radio signals between a base station and a user device, and includes: a communication unit that establishes a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator; and a control unit that controls the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network.

[0024] (2) Overview of mobile communication systems FIG. 1 is a diagram showing the configuration of a mobile communication system according to an embodiment. 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). In the following description, 5GS is used as an example, but the mobile communication system may also be at least partially based on an LTE (Long Term Evolution) system. Alternatively, the mobile communication system may also be at least partially based on a sixth generation (6G) system.

[0025] The mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. The 5GC 20 may be simply referred to as the core network (CN) 20.

[0026] 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 is a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided 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).

[0027] The NG-RAN 10 includes a base station (called "gNB" in the 5G system) 200. The gNBs 200 are connected to each other via an Xn interface, which is an interface between base stations. 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 that performs wireless communication with a UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0028] In addition, gNBs can also connect to the Evolved Packet Core (EPC), which is the LTE core network. LTE base stations can also connect to 5GC. LTE base stations and gNBs can also be connected via a base station-to-base station interface.

[0029] The 5GC20 includes an Access and Mobility Management Function (AMF) and a User Plane Function (UPF) 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 UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0030] FIG. 2 is a diagram showing the configuration of a protocol stack of a radio interface of a user plane that handles data.

[0031] 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.

[0032] 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 parity bits scrambled by the RNTI added.

[0033] 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 UE100 and the MAC layer of gNB200 via transport channels. The MAC layer of gNB200 includes a scheduler, which determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to UE100.

[0034] The RLC layer transmits data to the RLC layer on the receiving side 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 logical channels.

[0035] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0036] The SDAP layer maps IP flows, which are the units for Quality of Service (QoS) control by the core network, to radio bearers, which are the units for QoS control by the Access Stratum (AS). Note that if the RAN is connected to the EPC, SDAP is not necessary.

[0037] 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).

[0038] The protocol stack of the radio interface of the control plane has a Radio Resource Control (RRC) layer and a Non-Access Stratum (NAS) layer instead of the SDAP layer shown in FIG.

[0039] 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.

[0040] 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 300. Note that the UE 100 has an application layer and the like in addition to the radio interface protocol. The layer below the NAS layer is called the AS layer.

[0041] (3) Relay device and control terminal An embodiment of the relay device and the control terminal will now be described.

[0042] (3.1) First Example The relay device according to the first embodiment is a repeater device that can be controlled from a network. Compared to 4G / LTE, 5G / NR enables wideband transmission using higher frequency bands. Radio signals in high frequency bands such as the millimeter wave band or the terahertz wave band have high linearity, which makes it difficult to reduce the coverage of the gNB 200. In FIG. 4, the UE 100A may be located outside the coverage area of ​​the gNB 200, for example, outside an area where a radio signal can be received directly from the gNB 200. There may be an obstruction between the gNB 200 and the UE 100A, preventing the UE 100A from communicating with the gNB 200 within line of sight.

[0043] In the first embodiment, a repeater device (500A), which is a type of relay device that relays radio signals between a gNB 200 and a UE 100A and can be controlled from a network, is introduced into a mobile communication system 1. Hereinafter, such a repeater device is referred to as an NCR (Network-Controlled Repeater) device. Such a repeater device may also be referred to as a smart repeater device.

[0044] 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. Then, the NCR device 500A 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 directivity (beam). Alternatively, the NCR device 500A may transmit the radio signal with a variable (adaptive) directional beam. This enables efficient expansion of the coverage of the gNB 200. In the first embodiment, it is mainly assumed that the NCR device 500A is applied to downlink communication from the gNB 200 to the UE 100A, but the NCR device 500A can also be applied to uplink communication from the UE 100A to the gNB 200.

[0045] Also, as shown in FIG. 5, a new UE (hereinafter referred to as "NCR-UE") 100B, which is a type of control terminal for controlling the NCR device 500A, is introduced. The NCR-UE 100B establishes a wireless connection with the gNB 200 and performs wireless communication with the gNB 200, thereby controlling the NCR device 500A in cooperation with the gNB 200. This enables efficient coverage expansion using the NCR device 500A. The NCR-UE 100B controls the NCR device 500A under control from the gNB 200.

[0046] The NCR-UE 100B may be configured separately from the NCR device 500A. For example, the NCR-UE 100B may be located near the NCR device 500A and electrically connected to the NCR device 500A. The NCR-UE 100B may be connected to the NCR device 500A by wire or wirelessly. Alternatively, the NCR-UE 100B may be configured integrally with the NCR device 500A. The NCR-UE 100B and the NCR device 500A may be fixedly installed, for example, at the coverage edge (cell edge) of the base station 200 or on a wall or window of a building. The NCR-UE 100B and the NCR device 500A may be mobile, installed in a vehicle, for example. Furthermore, one NCR-UE 100B may control multiple NCR devices 500A.

[0047] In the example shown in FIG. 5, the NCR device 500A dynamically or quasi-statically changes a beam to be transmitted or received. For example, the NCR device 500A forms a beam toward each of the UE 100A1 and the UE 100A2. The NCR device 500A may also form a beam toward the gNB 200. For example, in a communication resource between the gNB 200 and the UE 100A1, the NCR device 500A transmits a radio signal received from the gNB 200 toward the UE 100A1 by beamforming and / or transmits a radio signal received from the UE 100A1 by beamforming toward the gNB 200. In a communication resource between the gNB 200 and the UE 100A2, the NCR device 500A transmits a radio signal received from the gNB 200 toward the UE 100A2 by beamforming and / or transmits a radio signal received from the UE 100A2 by beamforming toward the gNB 200. Instead of or in addition to forming a beam, the NCR device 500A may form a null (so-called null steering) toward a non-communicating UE 100 (not shown) and / or a neighboring gNB 200 (not shown) for interference suppression.

[0048] Fig. 6 is a diagram illustrating a control method of the NCR device 500A according to the first embodiment. As shown in Fig. 6, the NCR device 500A relays radio signals (referred to as "UE signals") between the gNB 200 and the UE 100A. The UE signals include uplink signals (referred to as "UE-UL signals") transmitted from the UE 100A to the gNB 200 and downlink signals (referred to as "UE-DL signals") transmitted from the gNB 200 to the UE 100A. The NCR device 500A relays the UE-UL signals from the UE 100A to the gNB 200, and also relays the UE-DL signals from the gNB 200 to the UE 100A.

[0049] The NCR-UE 100B transmits and receives radio signals (herein referred to as "NCR-UE signals") to and from the gNB 200. The NCR-UE signals include uplink signals (herein referred to as "NCR-UE-UL signals") transmitted from the NCR-UE 100B to the gNB 200, and downlink signals (herein referred to as "NCR-UE-DL signals") transmitted from the gNB 200 to the NCR-UE 100B. The NCR-UE-UL signals include signaling for controlling the NCR device 500A.

[0050] The gNB200 directs a beam toward the NCR-UE100B based on the NCR-UE-UL signal from the NCR-UE100B. Because the NCR device 500A is co-located with the NCR-UE100B, when the gNB200 directs a beam toward the NCR-UE100B, the beam is ultimately directed toward both the NCR-UE100B and the NCR device 500A. The gNB200 uses the beam to transmit an NCR-UE-DL signal and a UE-DL signal. The NCR-UE100B receives the NCR-UE-DL signal. Note that the NCR device 500A and the NCR-UE100B may be at least partially integrated. For example, the NCR device 500A and the NCR-UE100B may have integrated functions (e.g., antennas) for transmitting, receiving, or relaying UE signals and / or NCR-UE signals. Note that the beam includes a transmission beam and / or a reception beam. A beam is a general term for transmission and / or reception controlled to maximize the power of transmitted and / or received waves in a specific direction by adjusting / adapting antenna weights, etc.

[0051] 7 is a diagram illustrating an example of the configuration of a protocol stack in a mobile communication system 1 having an NCR device 500A and an NCR-UE 100B according to the first embodiment. The NCR device 500A relays wireless signals transmitted and received between the gNB 200 and the UE 100A. The NCR device 500A has an RF (Radio Frequency) function for amplifying and relaying received wireless signals, and performs directional transmission using beamforming (e.g., analog beamforming).

[0052] The NCR-UE 100B has at least one layer (entity) of PHY, MAC, RRC, and F1-AP (Application Protocol). The F1-AP is a type of fronthaul interface. The NCR-UE 100B exchanges downlink signaling and / or uplink signaling (described below) with the gNB 200 via at least one of PHY, MAC, RRC, and F1-AP. If the NCR-UE 100B is a type or part of a base station, the NCR-UE 100B may exchange with the gNB 200 via an Xn AP (Xn-AP), which is an inter-base station interface.

[0053] 8 is a diagram showing an example of the configuration of an NCR-UE 100B and an NCR device 500A according to the first embodiment. The NCR-UE 100B includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140. The receiving unit 110 and the transmitting unit 120 configure a communication unit.

[0054] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal (wireless signal) received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130. The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmitted signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0055] The control unit 130 performs various controls in the NCR-UE 100B. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used 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. The control unit 130 also performs functions of at least one layer of PHY, MAC, RRC, and F1-AP.

[0056] The interface 140 is electrically connected to the NCR device 500A. The control unit 130 controls the NCR device 500A via the interface 140. When the NCR-UE 100B and the NCR device 500A are integrally configured, the NCR-UE 100B does not need to have the interface 140. Furthermore, the receiving unit 110 and the transmitting unit 120 of the NCR-UE 100B may be integrally configured with the wireless unit 510A of the NCR device 500A.

[0057] The NCR device 500A includes a radio unit 510A and an NCR control unit 520A. The radio unit 510A includes an antenna unit 510a including multiple antennas (multiple antenna elements), an RF circuit 510b including an amplifier, and a directivity control unit 510c that controls the directivity of the antenna unit 510a. The RF circuit 510b amplifies and relays (transmits) radio signals transmitted and received by the antenna unit 510a. The RF circuit 510b may convert analog radio signals into digital signals and reconvert them to analog signals after digital signal processing. The directivity control unit 510c may perform analog beamforming using analog signal processing, digital beamforming using digital signal processing, or hybrid analog and digital beamforming.

[0058] The NCR control unit 520A controls the wireless unit 510A in response to a control signal from the control unit 130 of the NCR-UE 100B. The NCR control unit 520A may include at least one processor. The NCR control unit 520A may output information related to the capabilities of the NCR device 500A to the NCR-UE 100B. When the NCR-UE 100B and the NCR device 500A are configured integrally, the control unit 130 of the NCR-UE 100B and the NCR control unit 520A of the NCR device 500A may also be configured integrally.

[0059] In the first embodiment, the receiver 110 of the NCR-UE 100B receives signaling (downlink signaling) used to control the NCR device 500A from the gNB 200 via wireless communication. The controller 130 of the NCR-UE 100B controls the NCR device 500A based on the signaling. This enables the gNB 200 to control the NCR device 500A via the NCR-UE 100B.

[0060] In the first embodiment, the control unit 130 of the NCR-UE 100B acquires NCR capability information indicating the capability of the NCR device 500A from the NCR device 500A (NCR control unit 520A). Alternatively, the control unit 130 may acquire the NCR capability information by reading out the NCR capability information that is pre-written in a memory unit of the control unit 130 itself. Then, the transmission unit 120 of the NCR-UE 100B transmits the acquired NCR capability information to the gNB 200 by wireless communication. The NCR capability information is an example of uplink signaling from the NCR-UE 100B to the gNB 200. This enables the gNB 200 to grasp the capability of the NCR device 500A.

[0061] (3.2) Second Example The repeater according to the second embodiment is a Reconfigurable Intelligent Surface (RIS) device that changes the propagation direction of incident radio waves (radio signals) by reflection or refraction. The "NCR" in the first embodiment described above can be read as "RIS." Similar to NCR, a RIS can perform beamforming (directivity control) by changing the characteristics of a metamaterial. In the case of a RIS, the range (distance) of the beam may be changed, similar to a lens, by controlling the reflection direction and / or refraction direction of each unit element. For example, the RIS may be configured to be able 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.

[0062] As shown in FIG. 9 , the RIS device 500B according to the second embodiment may be a reflection-type RIS device 500B. Such a RIS device 500B changes the propagation direction of an incident radio wave by reflecting the radio wave. Here, the reflection angle of the radio wave can be variably set. The RIS device 500B reflects the radio wave incident from the gNB 200 toward each of the UE 100A1 and the UE 100A2. The RIS device 500B may also reflect the radio waves incident from each of the UE 100A1 and the UE 100A2 toward the gNB 200. The RIS device 500B dynamically changes the reflection angle of the radio wave. For example, in the communication resource between the gNB 200 and the UE 100A1, the RIS device 500B reflects the radio wave incident from the gNB 200 toward the UE 100A1 and / or reflects the radio wave incident from the UE 100A1 toward the gNB 200. Here, the communication resources include resources in the time direction and / or resources in the frequency direction. In the communication resources between the gNB200 and the UE100A2, the RIS device 500B reflects radio waves incident from the gNB200 toward the UE100A2 and / or reflects radio waves incident from the UE100A2 toward the gNB200.

[0063] As shown in FIG. 10 , the RIS device 500B may be a transparent RIS device 500B. Such a RIS device 500B changes the propagation direction of the radio waves by refracting the incident radio waves. Here, the refraction angle of the radio waves is variably settable. The RIS device 500B refracts the radio waves incident from the gNB 200 toward each of the UE 100A1 and the UE 100A2. The RIS device 500B may also refract the radio waves incident from each of the UE 100A1 and the UE 100A2 toward the gNB 200. The RIS device 500B dynamically changes the refraction angle of the radio waves. For example, in the communication resource between the gNB 200 and the UE 100A1, the RIS device 500B refracts the radio waves incident from the gNB 200 toward the UE 100A1 and / or refracts the radio waves incident from the UE 100A1 toward the gNB 200. In the communication resources between gNB200 and UE100A2, RIS device 500B refracts radio waves incident from gNB200 toward UE100A2 and / or refracts radio waves incident from UE100A2 toward gNB200.

[0064] In the second embodiment, as shown in FIG. 11, a new UE (hereinafter referred to as "RIS-UE") 100C is introduced, which is a control terminal for controlling the RIS device 500B. The RIS-UE 100C establishes a wireless connection with the gNB 200 and performs wireless communication with the gNB 200, thereby controlling the RIS device 500B in cooperation with the gNB 200. This makes it possible to achieve efficient coverage expansion using the RIS device 500B while suppressing increases in installation costs and decreases in installation flexibility for the RIS device 500B. The RIS-UE 100C controls the RIS device 500B in accordance with RIS control information (relay device control information) from the gNB 200.

[0065] The RIS-UE 100C may be configured separately from the RIS device 500B. For example, the RIS-UE 100C may be located near the RIS device 500B and electrically connected to the RIS device 500B. The RIS-UE 100C may be connected to the RIS device 500B via a wired or wireless connection. Alternatively, the RIS-UE 100C may be configured integrally with the RIS device 500B. The RIS-UE 100C and the RIS device 500B may be fixedly installed, for example, on a wall or window. The RIS-UE 100C and the RIS device 500B may be mobile, installed, for example, in a vehicle. Furthermore, one RIS-UE 100C may control multiple RIS devices 500B.

[0066] FIG. 12 is a diagram showing the configuration of a RIS-UE 100C and a RIS device 500B according to the second embodiment. As shown in FIG. 12, the RIS-UE 100C includes a receiving unit 110, a transmitting unit 120, a control unit 130, and an interface 140. The receiving unit 110 and the transmitting unit 120 form a communication unit. This configuration is the same as that of the first embodiment described above.

[0067] The RIS device 500B includes a RIS 510B and a RIS control unit 520B. The RIS 510B is a metasurface made of metamaterial. For example, the RIS 510B is configured by arranging extremely small structures relative to the wavelength of radio waves in an array. By varying the shape of the structures depending on their location, it is possible to arbitrarily design the direction and / or beam shape of the reflected waves. The RIS 510B may be a transparent dynamic metasurface. The RIS 510B 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. By minutely 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 and reflects some of the radio waves, and a mode that reflects all of the radio waves.

[0068] The RIS control unit 520B controls the RIS 510B in accordance with RIS control information 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 information from the control unit 130 of the RIS-UE 100C and drives the actuator in accordance with the RIS control information. Note that when the RIS-UE 100C and the RIS device 500B are configured integrally, the control unit 130 of the RIS-UE 100C and the RIS control unit 520B of the RIS device 500B may also be configured integrally.

[0069] (4)Base station 13 is a diagram illustrating a configuration example of the gNB 200 according to the embodiment. The gNB 200 includes a transmitter 210, a receiver 220, a controller 230, and a backhaul communication unit 240.

[0070] 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.

[0071] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used 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.

[0072] The backhaul communication unit 240 is connected to neighboring 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. Note that the gNB is composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally divided), and both units may be connected via an F1 interface.

[0073] (5) Example of a communication sequence 14 is a diagram illustrating an example of downlink signaling from the gNB 200 to the NCR-UE 100B according to the embodiment. Here, an example in which the relay device is the NCR device 500A will be described, but the relay device may also be the RIS device 500B.

[0074] The gNB 200 (transmitter 210) transmits downlink signaling to the NCR-UE 100B. The downlink signaling may be an RRC message, which is signaling of the RRC layer (i.e., Layer 3). Alternatively, the downlink signaling may be a MAC CE (Control Element), which is signaling of the MAC layer (i.e., Layer 2). Alternatively, the downlink signaling may be downlink control information (DCI), which is signaling of the PHY layer (i.e., Layer 1). The downlink signaling may be UE-specific signaling or broadcast signaling. The downlink signaling may be a fronthaul message (e.g., an F1-AP message). If the NCR-UE 100B is a type or part of a base station, the NCR-UE 100B may communicate with the gNB 200 via an Xn AP (Xn-AP), which is an inter-base station interface.

[0075] For example, the gNB 200 (transmitter 210) transmits NCR control information specifying the operation state of the NCR device 500A as downlink signaling to the NCR-UE 100B that has established a wireless connection with the gNB 200 (step S1). The NCR control information specifying the operation state of the NCR device 500A may be MAC CE, which is signaling of the MAC layer (layer 2), or DCI, which is signaling of the PHY layer (layer 1). However, the NCR control information may be included in an RRC Reconfiguration message, which is a type of RRC message individual to a UE, and transmitted to the NCR-UE 100B. The downlink signaling may be a message of a layer higher than the RRC layer (for example, an NCR application). The downlink signaling may be a message of a layer higher than the RRC layer encapsulated in a message of a layer lower than the RRC layer and transmitted. The NCR-UE 100B (transmitter 120) may transmit, on the uplink, a response message in response to the downlink signaling from the gNB 200. The response message may be transmitted in response to the NCR device 500A completing the configuration specified in the downlink signaling or receiving the configuration.

[0076] The NCR control information may include frequency control information that specifies the center frequency of a radio signal (e.g., a component carrier) to be relayed by the NCR device 500A. When the NCR control information received from the gNB 200 includes frequency control information, the NCR-UE 100B (control unit 130) controls the NCR device 500A to relay a radio signal having a center frequency indicated by the frequency control information (step S2A). The NCR control information may include multiple pieces of frequency control information that specify different center frequencies. By including frequency control information in the NCR control information, the gNB 200 can specify, via the NCR-UE 100B, the center frequency of a radio signal to be relayed by the NCR device 500A.

[0077] The NCR control information may include mode control information that specifies an operation mode of the NCR device 500A. The mode control information may be associated with frequency control information (center frequency). The operation mode may be any of a mode in which the NCR device 500A performs omnidirectional transmission and / or reception, a mode in which the NCR device 500A performs fixed-directivity transmission and / or reception, a mode in which the NCR device 500A performs transmission and / or reception using a variable directional beam, and a mode in which the NCR device 500A performs MIMO (Multiple Input Multiple Output) relay transmission. The operation mode may be any of a beamforming mode (i.e., a mode that prioritizes improving a desired wave) and a null steering mode (i.e., a mode that prioritizes suppressing interference waves). When the NCR control information received from the gNB 200 includes mode control information, the NCR-UE 100B (control unit 130) controls the NCR device 500A to operate in the operation mode indicated by the mode control information (step S2). Since the NCR control information includes mode control information, the gNB200 can specify the operating mode of the NCR device 500A via the NCR-UE100B.

[0078] Here, the mode in which the NCR device 500A performs non-directional transmission and / or reception is a mode in which the NCR device 500A performs relaying in all directions and may be referred to as an omni-mode. The mode in which the NCR device 500A performs fixed-directivity 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) by the gNB 200 to the NCR-UE 100B. The mode in which the NCR device 500A performs transmission and / or reception using a variable directional beam may be a mode in which analog beamforming is performed, a mode in which digital beamforming is performed, or a mode in which hybrid beamforming is performed. This mode may also be a mode in which an adaptive beam specific to the UE 100A is formed. Any of these modes may be specified (set) by the gNB 200 to the NCR-UE 100B. In addition, in the operation mode in which beamforming is performed, beam control information, which will be described later, may be provided from the gNB 200 to the NCR-UE 100B. 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, a mode in which MU (Multi-User) spatial multiplexing is performed, or a mode in which transmit diversity is performed. Any of these modes may be specified (set) by the gNB 200 to the NCR-UE 100B. The operation mode may include a mode in which relay transmission by the NCR device 500A is turned on (activated) and a mode in which relay transmission by the NCR device 500A is turned off (deactivated). Any of these modes may be specified (set) by the gNB 200 to the NCR-UE 100B by NCR control information.

[0079] The NCR control information may include beam control information that specifies a transmission direction, transmission weight, or beam pattern when the NCR device 500A performs directional transmission. The beam control information may be associated with frequency control information (center frequency). The beam control information may include a PMI (Precoding Matrix Indicator). The beam control information may include beam formation angle information. When the NCR control information received from the gNB 200 includes beam control information, the NCR-UE 100B (control unit 130) controls the NCR device 500A to form the transmission directivity (beam) indicated by the beam control information (step S2). Since the NCR control information includes beam control information, the gNB 200 can control the transmission directivity of the NCR device 500A via the NCR-UE 100B.

[0080] The NCR control information may include output control information that specifies the degree to which the NCR device 500A amplifies a radio signal (amplification gain) or transmission power. The output control information may be information indicating a difference value (i.e., a relative value) between a current amplification gain or transmission power and a target amplification gain or transmission power. When the NCR control information received from the gNB 200 includes the output control information, the NCR-UE 100B (control unit 130) controls the NCR device 500A to change the amplification gain or transmission power to the amplification gain or transmission power indicated by the output control information (step S2). The output control information may be associated with frequency control information (center frequency). The output control information may be information that specifies any one of the amplifier gain, beamforming gain, and antenna gain of the NCR device 500A. The output control information may be information that specifies the transmission power of the NCR device 500A.

[0081] When one NCR-UE 100B controls multiple NCR devices 500A, the gNB 200 (transmission unit 210) may transmit NCR control information to the NCR-UE 100B for each NCR device 500A. In this case, the NCR control information may include an identifier (NCR identifier) ​​of the corresponding NCR device 500A. The NCR-UE 100B (control unit 130) that controls multiple NCR devices 500A determines the NCR device 500A to which the NCR control information applies, based on the NCR identifier included in the NCR control information received from the gNB 200. Note that the NCR identifier may be transmitted from the NCR-UE 100B to the gNB 200 together with the NCR control information, even when the NCR-UE 100B controls only one NCR device 500A.

[0082] In this way, the NCR-UE 100B (control unit 130) controls the NCR device 500A based on the NCR control information from the gNB 200. This enables the gNB 200 to control the NCR device 500A via the NCR-UE 100B.

[0083] Fig. 15 is a diagram showing an example of the operation of the mobile communication system 1 according to the embodiment. In Fig. 15, non-essential steps are indicated by dashed lines. "NCR" in Fig. 15 may be read as "RIS".

[0084] In step S11, the gNB 200 (transmitter 210) broadcasts NCR support information indicating that the gNB 200 supports the NCR-UE 100B (and / or supports the above-described grouping). For example, the gNB 200 (transmitter 210) broadcasts a system information block (SIB) including the NCR support information. The NCR support information may be information indicating that the NCR-UE 100B is accessible. Alternatively, the gNB 200 (transmitter 210) may broadcast NCR non-support information indicating that the gNB 200 does not support the NCR-UE 100B. The NCR non-support information may be information indicating that the NCR-UE 100B is not accessible.

[0085] At this stage, the NCR-UE 100B may be in an RRC idle state or an RRC inactive state. The NCR-UE 100B (control unit 130), which has not established a radio connection with the gNB 200, may determine, in response to receiving NCR support information from the gNB 200, that access to the gNB 200 is permitted, and may perform an access operation to establish a radio connection with the gNB 200. The NCR-UE 100B (control unit 130) may perform cell reselection by regarding the gNB 200 (cell) to which access is permitted as having the highest priority.

[0086] On the other hand, if the gNB 200 does not broadcast NCR support information (or broadcasts NCR non-support information), the NCR-UE 100B (control unit 130) that has not established a wireless connection with the gNB 200 may determine that it is unable to access (establish a connection with) the gNB 200. This allows the NCR-UE 100B to establish a wireless connection only with a gNB 200 that can handle the NCR-UE 100B.

[0087] Note that, when the gNB 200 is congested, the gNB 200 may broadcast access restriction information that restricts access from the UE 100. However, unlike a normal UE 100, the NCR-UE 100B can be considered a network-side entity. Therefore, the NCR-UE 100B may ignore the access restriction information from the gNB 200. For example, when the NCR-UE 100B (control unit 130) receives NCR support information from the gNB 200, it may perform an operation to establish a wireless connection with the gNB 200 even if the gNB 200 is broadcasting access restriction information. For example, the NCR-UE 100B (control unit 130) may not execute (or may ignore) UAC (Unified Access Control). Alternatively, a special value indicating that the access is from an NCR-UE may be used as either or both of AC / AI (Access Category / Access Identity) used in UAC.

[0088] In step S12, the NCR-UE 100B (control unit 130) starts a random access procedure for the gNB 200. In the random access procedure, the NCR-UE 100B (transmitting unit 120) transmits a random access preamble (Msg1) and an RRC message (Msg3) to the gNB 200. Also in the random access procedure, the NCR-UE 100B (receiving unit 110) receives a random access response (Msg2) and an RRC message (Msg4) from the gNB 200.

[0089] In step S13, when establishing a radio connection with the gNB200, the NCR-UE100B (transmitting unit 120) may transmit NCR-UE information indicating that its own UE is an NCR-UE to the gNB200. For example, during a random access procedure with the gNB200, the NCR-UE100B (transmitting unit 120) includes the NCR-UE information in a message for the random access procedure (e.g., Msg1, Msg3, Msg5) and transmits the message to the gNB200. Based on the NCR-UE information received from the NCR-UE100B, the gNB200 (control unit 230) recognizes that the accessing UE100 is the NCR-UE100B, and can, for example, remove the NCR-UE100B from the access restriction target (i.e., accept the access). When the random access procedure is completed, the NCR-UE100B transitions from an RRC idle state or an RRC inactive state to an RRC connected state.

[0090] In step S14, the gNB 200 (transmitter 120) transmits a capability inquiry message to the NCR-UE 100B to inquire about the capability of the NCR-UE 100B. The NCR-UE 100B (receiver 110) receives the capability inquiry message.

[0091] In step S15, the NCR-UE 100B (transmitter 120) transmits a capability information message including NCR capability information to the gNB 200. The capability information message may be an RRC message, for example, a UE Capability message. The gNB 200 (receiver 220) receives the capability information message. The gNB 200 (controller 230) determines the capabilities of the NCR device 500A based on the received capability information message.

[0092] In step S16, the gNB 200 (transmitter 120) transmits a configuration message including various settings related to the NCR device 500A to the NCR-UE 100B. The NCR-UE 100B (receiver 110) receives the configuration message. The configuration message is a type of the above-mentioned downlink signaling. The configuration message may be an RRC message, for example, an RRC Reconfiguration message.

[0093] In step S17, the gNB 200 (transmitter 120) transmits a control instruction specifying the operation state of the NCR device 500A to the NCR-UE 100B. The control instruction may be the above-mentioned NCR control information (e.g., L1 / L2 signaling). The NCR-UE 100B (receiver 110) receives the control instruction. The NCR-UE 100B (controller 130) controls the NCR device 500A in accordance with the control instruction.

[0094] In step S18, the NCR-UE 100B controls the NCR device 500A in accordance with the above setting (and control instruction). Note that the NCR-UE 100B may autonomously control the NCR device 500A for at least one group 511A without relying on a control instruction from the gNB 200. For example, the NCR-UE 100B may autonomously control the NCR device 500A based on the location of the UE 100A and / or information that the NCR-UE 100B receives from the UE 100A.

[0095] (6) Multi-PLMN operation 16 is a diagram for explaining the operation of multiple PLMNs (Public Land Mobile Networks) according to an embodiment. A PLMN is a terrestrial wireless communication network (hereinafter simply referred to as a "network") provided to subscribers by a communication carrier (hereinafter referred to as an "operator"). A PLMN identifier is assigned to the network. The PLMN identifier is an identification number of the network and can also be considered as an operator identifier.

[0096] As shown in FIG. 16, a network 50a (first PLMN) belonging to a first operator is assigned PLMN#1 as its PLMN identifier. The network 50a has at least one gNB 200a and at least one AMF 300a. A network 50b (second PLMN) belonging to a second operator is assigned PLMN#2 as its PLMN identifier. The network 50b has at least one gNB 200b and at least one AMF 300b. Hereinafter, when there is no need to distinguish between the networks 50a and 50b, they will be simply referred to as networks 50. Although an example will be described using two networks 50 (i.e., two PLMNs), the number of networks 50 (PLMNs) may be three or more. However, it is assumed that there is no communication interface between the networks 50.

[0097] The relay device 500 is the above-mentioned NCR device 500A or RIS device 500B. The control terminal 400 is the above-mentioned NCR-UE 100B or RIS-UE 100C. The control terminal 400 controls the relay device 500. As described above, the control terminal 400 is co-located with the relay device 500, and for example, at least a part of the control terminal 400 may be integrated with the relay device 500. The relay device 500 relays radio signals transmitted and received between the gNB 200a and the UE 100a in the network 50a. The relay device 500 also relays radio signals transmitted and received between the gNB 200b and the UE 100b in the network 50b.

[0098] Here, when the relay device 500 relays a radio signal transmitted and received between the gNB 200a and the UE 100a in the first PLMN (PLMN#1), a problem is expected in which the radio signal may cause interference to another PLMN (PLMN#2 in FIG. 16). Similarly, when the relay device 500 relays a radio signal transmitted and received between the gNB 200b and the UE 100b in the second PLMN (PLMN#2), a problem is expected in which the radio signal may cause interference to another PLMN (PLMN#1 in FIG. 16). Therefore, in the embodiment, the control terminal 400 accepts control from both the network 50a and the network 50b to control the relay device 500, thereby making it possible to mitigate the above-mentioned interference problem.

[0099] That is, a control terminal 400 that controls a relay device 500 that relays radio signals between a gNB 200 and a UE 100 establishes a wireless connection with a network 50a that belongs to a first operator and a wireless connection with a network 50b that belongs to a second operator different from the first operator. The control terminal 400 then controls the relay device 500 based on the control received by the control terminal 400 from the network 50a and the control received by the control terminal 400 from the network 50b. This enables the networks 50a and 50b to share the relay device 500 while suppressing the occurrence of interference between networks (between PLMNs).

[0100] (6.1) Multi-PLMN Attachment Procedures A multi-PLMN connection procedure according to an embodiment will now be described. The term "network" used below may refer to the gNB 200 and / or AMF 300 in the network.

[0101] After establishing a wireless connection with the network 50a, the control terminal 400 transmits first notification information regarding the network 50b to the network 50a. As a result, even if the network 50a does not have a communication interface with the network 50b, information regarding the network 50b can be obtained from the control terminal 400. For example, the first notification information includes at least one of an identifier (PLMN identifier) ​​of the network 50b, information indicating whether the control terminal 400 is capable of communicating simultaneously with the network 50a and the network 50b, and frequency information indicating a frequency related to the network 50b.

[0102] After transmitting the first notification information, the control terminal 400 may receive information from the network 50a permitting or instructing the establishment of a wireless connection with the network 50b, thereby enabling the control terminal 400 to establish a wireless connection with the network 50b under the management of the network 50a.

[0103] The first notification information may be information indicating whether the control terminal 400 has the capability or the setting to establish wireless connections with multiple networks, which allows the network 50a to appropriately determine whether to give permission or an instruction to the control terminal 400 to establish a wireless connection with the network 50b.

[0104] 17 is a diagram illustrating an example of a multi-PLMN connection procedure according to an embodiment, in which non-essential steps are indicated by dashed lines.

[0105] In step S101, the control terminal 400 establishes a wireless connection (e.g., an RRC connection) with the network 50a of PLMN#1. Here, PLMN#1 may be a primary PLMN. The primary PLMN may be pre-configured in a subscriber identity module (SIM) or the like of the control terminal 400. Similarly, PLMN#2 may be pre-configured in the SIM or the like as a secondary PLMN.

[0106] In step S102, the control terminal 400 discovers a network 50b of another connectable PLMN#2 (for example, a secondary PLMN). The control terminal 400 may discover the network 50b based on a PLMN identifier included in broadcast information transmitted by the gNB 200b of the network 50b.

[0107] In step S103, the control terminal 400 transmits first notification information to the network 50a. The network 50a receives the first notification information. The first notification information may be information (message) indicating that the control terminal 400 supports multiple PLMNs. The first notification information may be information (message) indicating that multiple PLMNs (e.g., a primary PLMN and a secondary PLMN) are pre-configured in a SIM or the like. The control terminal 400 may transmit the first notification information in response to discovering another connectable PLMN (e.g., a secondary PLMN). The control terminal 400 may transmit the first notification information in response to establishing a wireless connection with the network 50b. The first notification information may include at least one information element (information field) of the following A1) to A3).

[0108] A1) PLMN identifier of other PLMN For example, the control terminal 400 includes the PLMN identifier set as the secondary PLMN in the first notification information.

[0109] A2) Information element indicating whether communication with PLMN#1 can be performed simultaneously when communicating with other PLMNs The information element may be an information element indicating the number of radio units (transmitters and / or receivers) that the control terminal 400 has.

[0110] A3) Frequency information of other PLMNs For example, the control terminal 400 includes in the first notification information the operating frequency of the secondary PLMN. Here, the operating frequency may be a frequency included in the operating frequency band of the relay device 500. The operating frequency may be the operating frequency of the relay device 500 set by the network 50a, or may be a supported frequency as a hardware capability.

[0111] In step S104, the network 50a transmits a connection permission to the control terminal 400 that permits connection to the network 50b. The control terminal 400 receives the connection permission. The network 50a may permit the control terminal 400 to connect to the network 50b based on contract information between PLMN#1 and PLMN#2. Note that, if the first notification information is transmitted when the control terminal 400 connects to the network 50b, in step S104 the network 50a may transmit a connection permission that permits the control terminal 400 to maintain the connection to the network 50b (or a disconnection instruction that instructs the control terminal 400 to disconnect from the network 50b) to the control terminal 400.

[0112] In step S105, the control terminal 400 establishes a wireless connection (for example, an RRC connection) with the network 50b of PLMN#2.

[0113] In step S106, the control terminal 400 may notify the network 50b that it is connected to the network 50a. The control terminal 400 may notify the network 50b that the network 50b is a secondary PLMN. The notification may include information such as a PLMN identifier, whether simultaneous communication is possible, and frequency, similar to the first notification information described above.

[0114] When the control terminal 400 establishes a wireless connection with the networks 50a and 50b in this way, the network 50a and / or the network 50b sets and / or instructs the control terminal 400 to control the relay device 500. Details of such operations will be described later.

[0115] (6.2) Multi-PLMN Interaction Procedure A multi-PLMN cooperation procedure according to the embodiment will now be described. The multi-PLMN cooperation procedure is an example of a procedure that is performed after the control terminal 400 establishes wireless connections with the networks 50a and 50b.

[0116] The control terminal 400 transmits, to the network 50b, second notification information relating to the control specified by the network 50a to the control terminal 400. This allows the network 50b to grasp the content of the control specified by the network 50a to the control terminal 400.

[0117] The control terminal 400 may receive, from the network 50a, control information specifying an operation state (referred to as a "prohibited operation state") that is to be prohibited as an operation state of the relay device 500 or control information specifying an operation state of the relay device 500. The control terminal 400 may transfer the control information received from the network 50a to the network 50b as second notification information. This makes it easier for the network 50b to appropriately control the relay device 500 by the network 50b, taking into account the operation state or prohibited operation state of the relay device 500 specified by the network 50a.

[0118] The second notification information may include information indicating the timing when the control terminal 400 is controlled from the network 50a or the timing when the control terminal 400 is not controlled from the network 50a. This makes it easier for the network 50b to appropriately determine the timing when the network 50b controls the relay device 500, taking into consideration the timing.

[0119] 18 is a diagram illustrating an example of a multiple PLMN cooperation procedure according to the embodiment. In FIG. 18, non-essential steps are indicated by dashed lines.

[0120] In step S201, the network 50a transmits relay device control information to the control terminal 400. The control terminal 400 receives the relay device control information. The relay device control information may be the above-mentioned downlink signaling. The relay device control information may be an RRC message, a MAC CE, or a DCI, or a combination of these. The relay device control information may include at least one information element (information field) of the following B1) to B3).

[0121] B1) Control information indicating the operating state of the relay device 500 This information element indicates the operation state of the relay device 500 designated by the network 50a, and is used to set the beam direction for beamforming, for example. The information element may be transmitted together with timing information indicating the timing (cycle, slot, etc.) at which the operation state is applied.

[0122] B2) Control information indicating the prohibited operation state of the relay device 500 This is an information element indicating the prohibited operation state of the relay device 500 designated by the network 50a, and for example, regarding beam forming, it sets (designates) the beam direction that is prohibited from being used.

[0123] B3) Information element requesting (or permitting) the notification of the control information of B1) and / or B2) above to the network 50b The control terminal 400 determines whether to transmit the second notification information to the network 50b based on the information element. Alternatively, the control terminal 400 may be configured by the network 50b to transmit (report) the control information of the network 50a.

[0124] In step S202, the control terminal 400 transmits the control information received from the network 50a to the network 50b as second notification information. The network 50b receives the second notification information. As described above, the second notification information includes the operation status of the relay device 500 and / or the prohibited operation status of the relay device 500 set by the network 50a.

[0125] For example, the network 50b may control the relay device 500 via the control terminal 400 without using the operation state of the relay device 500 that is prohibited by the network 50a. The network 50b may perform communication with the UE 100b that is optimal in the operation state of the relay device 500 controlled by the network 50a. The network 50b may control the relay device 500 via the control terminal 400 at a timing when the operation state is not specified by the network 50a.

[0126] Steps S203 and S204 are operations in the reverse direction of steps S201 and S202. That is, in step S203, network 50b transmits relay device control information to control terminal 400. Control terminal 400 receives the relay device control information. In step S204, control terminal 400 may transfer the relay device control information to network 50a.

[0127] Note that each network 50 may only configure the control terminal 400 to control the relay device 500, and the control terminal 400 may autonomously control the specific relay device 500. For example, the control terminal 400 may autonomously control the relay device 500 based on the position of each UE 100 or a radio signal received from each UE 100.

[0128] (6.3) Time-sharing control procedure A time-division control procedure according to the embodiment will be described.

[0129] The control terminal 400 controls the relay device 500 in accordance with control from the network 50a and in accordance with control from the network 50b in a time-division manner. This allows the control right of the relay device 500 to be given to the networks 50a and 50b in a time-division manner, making it easy for the networks 50a and 50b to share the relay device 500.

[0130] The control terminal 400 may acquire information indicating the throughput in the network 50a and / or the throughput in the network 50b, and change the time-division ratio based on the acquired throughput. This makes it easier to ensure fairness between the networks 50a and 50b, assuming that the networks 50a and 50b share the relay device 500.

[0131] (6.3.1) Control terminal-initiated time-sharing control procedure In the control terminal-driven time-division control procedure, the time-division pattern is determined by the control terminal 400. The control terminal 400 notifies the determined pattern to the networks 50a and 50b.

[0132] 19 is a diagram showing an example of a control terminal-led time-sharing control procedure according to the embodiment. It is assumed that the control terminal 400 is connected to the networks 50a and 50b.

[0133] In step S301, the control terminal 400 divides resources in the time direction into n parts (two parts in the example of FIG. 19 ) and allocates them to each of the networks 50 to which the control terminal 400 is connected. Here, “n” indicates the number of networks 50 to which the control terminal 400 is connected. For example, the control terminal 400 divides one radio frame (i.e., 10 subframes) into two parts of five subframes each, and allocates the first five subframes to PLMN #1 and the last five subframes to PLMN #2. In this example, the five subframes are grouped together, but any allocation method may be used, such as alternate allocation (even subframes and odd subframes, etc.). The control terminal 400 then specifies the allocation pattern (a time division pattern such as a bitmap). The pattern may be expressed, for example, by a bitmap. Alternatively, the pattern may be expressed by a start timing and a period. The control terminal 400 may perform the process of step S301 according to the content (e.g., the allocation period) previously set by the network 50.

[0134] In steps S302 and S303, the control terminal 400 notifies each of the networks 50a and 50b of the time division pattern determined in step S301. Each network 50 transmits control information to the control terminal 400 during the time allocated to itself 50 based on the notified time division pattern (steps S304 and S306). Alternatively, each network 50 transmits control information to the control terminal 400 for setting the operating state of the relay device 500 during the time allocated to itself 50 based on the notified time division pattern. Then, the control terminal 400 controls the relay device 500 during the time allocated to it in accordance with the control information from the allocated network 50 (steps S305 and S307).

[0135] The network 50 may transmit to the control terminal 400 a request to change the time allocated to the network 50 (for example, a request to change to a different time timing or a request to change the period).

[0136] The control terminal 400 may change the ratio of time-sharing control depending on the system throughput when the relay device 500 is in use and when it is not in use. While controlling the relay device 500 according to the time allocation, each network 50 notifies the control terminal 400 of its throughput at the timing when the relay device 500 is controlled and / or its throughput at timings other than the control timing. The throughput may be the total throughput of the system. The throughput may also be the (total) throughput of a specific user (e.g., a user connected via the relay device 500). The throughput may be expressed using some kind of index. For example, the actual throughput may be expressed as a percentage of the theoretical system throughput. The control terminal 400 adjusts the time ratio so that the throughput is balanced between the networks over the long term or on average. For example, the control terminal 400 reallocates a larger portion of time to a network whose throughput is deteriorating when the relay device 500 cannot be controlled.

[0137] (6.3.2) Network-driven time-sharing control procedure In the network-driven time-division control procedure, the control terminal 400 receives information indicating the time-division pattern determined by the network 50a from the network 50a, and notifies the network 50b of the pattern.

[0138] 20 is a diagram showing an example of a network-driven time-division control procedure according to the embodiment. It is assumed that the control terminal 400 is connected to the networks 50a and 50b.

[0139] In step S351, the control terminal 400 notifies the network 50a of the number of networks 50 to which it is connected (and / or the PLMN identifier of each network 50 to which it is connected). The network 50a may be the primary PLMN of the control terminal 400. The control terminal 400 may notify the network 50a of at least one of the number of UEs 100 being served, the traffic volume, and the radio resource usage rate for the other PLMNs.

[0140] In step S352, based on the notification content in step S351, the network 50a divides the time direction resources into n parts (two parts in the example of FIG. 20) and allocates them to each network 50. The method for determining the time division pattern is the same as the control terminal-driven time division control procedure described above.

[0141] In step S353, the network 50a notifies the control terminal 400 of the time division pattern determined in step S352. The pattern may be expressed, for example, as a bitmap. Alternatively, the pattern may be expressed by a start timing and a period. The pattern may be transmitted together with network information. For example, if the network 50a is notified of the number of connected networks by the control terminal 400 in step S351, the network 50a associates its own network and other networks with the time division pattern. As a specific example, the network 50a associates subframes #0 to #3 with its own PLMN, subframes #4 to #6 with other PLMN 1, and subframes #7 to #9 with other PLMN 2. Furthermore, if the network 50a is notified of a PLMN identifier by the control terminal 400 in step S351, the network 50a associates the PLMN identifier with the time division pattern. For example, network 50a associates subframes #0 to #4 with PLMN #1 and subframes #5 to #9 with PLMN #2.

[0142] In step S354, the control terminal 400 notifies the network 50b of the time division pattern allocated to the network 50b. The network 50b may be a secondary PLMN of the control terminal 400. If a time division pattern is associated with each network 50 or PLMN identifier in step S352, the control terminal 400 notifies the network 50b of the time division pattern in accordance with the association. The subsequent operations (steps S355 to S358) are the same as those in the control terminal-initiated time division control procedure described above.

[0143] The network 50a may change the ratio of time-division control depending on the system throughput when the relay device 500 is in use and when it is not in use. The network 50b notifies the control terminal 400 of the throughput at the control timing of the relay device 500 and / or the throughput at the timing other than the control timing, and the control terminal 400 notifies the network 50a of the throughput. The throughput may be transmitted together with the PLMN identifier. The network 50a adjusts the time ratio so that the throughput is balanced between the networks over the long term or on average.

[0144] (7) Other embodiments The NCR / RIS control information transmitted from the gNB 200 to the NCR-UE 100B or the RIS-UE 100C may be information for controlling the direction and / or focal length of the beam relayed (output) by the NCR device 500A or the RIS device 500B. Information for controlling the direction is, for example, the antenna weight, as described above. Information for controlling the focal length is information for the NCR device 500A or the RIS device 500B to focus the beam depending on the distance between the NCR device 500A or the RIS device 500B and the UE 100A. Such information may be information indicating the distance between the NCR device 500A or the RIS device 500B and the UE 100A. Alternatively, such information may be information indicating the focal length (e.g., a focal range such as near or far). The NCR device 500A or the RIS device 500B adjusts the focal length of the beam based on the information. In the case of the RIS device 500B, the reflection (or refraction) angle of the outer elements of the metasurface surface and the reflection (or refraction) angle of the inner elements are controlled (made different) at different angles, thereby adjusting the focal length of the beam like a lens.

[0145] In the above-described embodiment, the frequency control information may include a cell ID that identifies a cell and / or a BWP ID that identifies a bandwidth portion (BWP). A BWP refers to a frequency band that is part of a cell.

[0146] 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.

[0147] 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 also be an LTE base station (eNB). The base station may also be a relay node such as an IAB (Integrated Access and Backhaul) node. The base station may also be a DU (Distributed Unit) of the IAB node.

[0148] A program may be provided that causes a computer to execute each process performed by UE100 (NCR-UE100B, RIS-UE100C) or gNB200. The program may be recorded on a computer-readable medium. Using the 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 UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

[0149] As used in this disclosure, the terms "based on" and "depending on" do not mean "based only on" or "depending only on," unless otherwise specified. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "based only on" and "at least in part on." Furthermore, "obtain / acquire" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating the information. "Transmit" may mean performing processing at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or via a wired connection. Alternatively, "transmit" may mean a combination of performing processing at least one layer and physically transmitting a signal wirelessly or via a wired connection. Similarly, "receive" may mean processing at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or via a wired connection. Alternatively, "receiving" may refer to a combination of performing at least one of the above-described layer processes and physically receiving a signal wirelessly or via a wire. The terms "include," "comprise," and variations thereof do not mean including only the listed items, but may mean including only the listed items or including additional items in addition to the listed items. Also, 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.

[0150] 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.

[0151] This application claims priority from Japanese Patent Application No. 2022-075441 (filed April 28, 2022), the entire contents of which are incorporated herein by reference.

[0152] (Addendum) The following additional notes are about the features of the above-described embodiment.

[0153] (1) A communication method executed by a control terminal that controls a relay device that relays radio signals between a base station and a user device, comprising: establishing a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator; and controlling the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network. Communication method.

[0154] (2) The establishing includes transmitting first notification information about the second network to the first network after establishing a wireless connection with the first network. The communication method described in (1) above.

[0155] (3) The establishing further includes receiving, after transmitting the first notification information, information from the first network that permits or instructs establishment of a wireless connection with the second network. The communication method described in (2) above.

[0156] (4) The first notification information is information indicating whether the control terminal has the capability or setting to establish wireless connections with multiple networks. The communication method according to (2) or (3) above.

[0157] (5) The first notification information includes at least one of an identifier of the second network, information indicating whether the control terminal has the ability to communicate with the first network and the second network simultaneously, and frequency information indicating a frequency related to the second network. A communication method according to any one of (2) to (4) above.

[0158] (6) and transmitting second notification information regarding control designated to the control terminal from the first network to the second network. A communication method according to any one of (2) to (5) above.

[0159] (7) receiving control information specifying an operation state to be prohibited as an operation state of the relay device or control information specifying an operation state of the relay device from the first network; The transmitting includes forwarding the control information received from the first network to the second network as the second notification information. The communication method described in (6) above.

[0160] (8) The second notification information includes information indicating a timing when the control terminal is controlled from the first network or a timing when the control terminal is not controlled from the first network. The communication method according to (6) or (7) above.

[0161] (9) The controlling includes controlling the relay device in accordance with control from the first network and controlling the relay device in accordance with control from the second network in a time-division manner. A communication method according to any one of (1) to (8) above.

[0162] (10) The control terminal determines the time division pattern; and notifying the first network and the second network of the determined pattern. The communication method according to (9) above.

[0163] (11) receiving information from the first network indicating the time division pattern determined by the first network; and reporting the pattern to the second network. The communication method according to (9) or (10) above.

[0164] (12) obtaining information indicative of a throughput in the first network and / or a throughput in the second network; and changing the ratio of the time division based on the throughput. A communication method according to any one of (9) to (11) above.

[0165] (13) A control terminal that controls a relay device that relays radio signals between a base station and a user device, a communication unit that establishes a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator; a control unit that controls the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network. Control terminal. [Explanation of symbols]

[0166] 1: Mobile communication system 100:UE 100B: NCR-UE 100C:RIS-UE 110: Receiving unit 120: Transmitter 130: Control unit 140: Interface 200 :gNB 210: Transmission unit 220: Receiving unit 230: Control unit 240: Backhaul communication unit 300:AMF 400: Control terminal 500: Relay device 500A:NCR device 500B :RIS device 510A: Wireless unit 510a: Antenna part 510b :RF circuit 510c: Directivity control section 520A: NCR control section 520B: RIS control unit

Claims

1. A communication method executed by a control terminal that controls a relay device that relays radio signals between a base station and a user device, comprising: establishing a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator; controlling the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network; the establishing includes transmitting first notification information about the second network to the first network after establishing a wireless connection with the first network; The first notification information includes information indicating whether the control terminal has the capability to communicate simultaneously with the first network and the second network. Communication method.

2. The establishing further includes receiving, after transmitting the first notification information, information from the first network that permits or instructs establishment of a wireless connection with the second network. The communication method according to claim 1 .

3. The first notification information is information indicating whether the control terminal has the capability or setting to establish wireless connections with a plurality of networks. The communication method according to claim 1 or 2.

4. and transmitting second notification information regarding control designated to the control terminal from the first network to the second network. The communication method according to claim 1 .

5. receiving control information specifying an operation state to be prohibited as an operation state of the relay device or control information specifying an operation state of the relay device from the first network; The transmitting includes transferring the control information received from the first network to the second network as the second notification information. The communication method according to claim 4.

6. The second notification information includes information indicating a timing when the control terminal is controlled from the first network or a timing when the control terminal is not controlled from the first network. The communication method according to claim 4.

7. The controlling includes controlling the relay device in accordance with control from the first network and controlling the relay device in accordance with control from the second network in a time-division manner. The communication method according to claim 1 .

8. The control terminal determines the time division pattern; and notifying the first network and the second network of the determined pattern. The communication method according to claim 7.

9. receiving information from the first network indicating the time division pattern determined by the first network; and advertising the pattern to the second network. The communication method according to claim 7.

10. obtaining information indicative of throughput in the first network and / or throughput in the second network; and changing the ratio of the time division based on the throughput. The communication method according to claim 7.

11. A control terminal that controls a relay device that relays radio signals between a base station and a user device, a communication unit for establishing a wireless connection with a first network belonging to a first operator and a wireless connection with a second network belonging to a second operator different from the first operator; a control unit that controls the relay device based on control received by the control terminal from the first network and control received by the control terminal from the second network, the communication unit transmits first notification information regarding the second network to the first network after establishing a wireless connection with the first network; The first notification information includes information indicating whether the control terminal has the capability to communicate simultaneously with the first network and the second network. Control terminal.

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