Communication control method, communication node, wireless communication system, program, and chipset

Abstract

A communication control method according to one aspect of the present invention is used in a wireless communication system. The communication control method includes a step in which an IoT device receives, from a communication node, at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission, as a received signal. In addition, the communication control method includes a step in which the IoT device uses the received signal to perform backscattering transmission on a second unmodulated signal transmitted from the communication node.

Description

Communication control method and IoT device

[0001] The present disclosure relates to a communication control method and an IoT device.

[0002] In recent years, the Internet of Things (IoT) has been attracting attention as a wireless communication technology. As more and more "things" are interconnected, it is expected that production efficiency will improve and life will become more comfortable than ever before.

[0003] Technologies used in IoT include barcodes and radio frequency identifiers (RFIDs), for example. However, barcodes and RFIDs lack interference management schemes, making it difficult for them to support large-scale networks.

[0004] Therefore, the Third Generation Partnership Project (3GPP) (registered trademark; the same applies hereinafter), a standardization project for mobile communication systems, is studying the feasibility of new IoT technologies. This IoT technology is expected to have a greater number of connections and a higher device density than existing 3GPP IoT technologies. Furthermore, this IoT technology is expected to have lower complexity and power consumption than existing 3GPP LPWA (Low Power Wide Area) technologies such as NB-IoT (Narrow Band-IoT) or LTE-MTC (Long Term Evolution-Machine Type Communication). IoT devices used in this IoT technology are called ambient IoT devices.

[0005] 3GPP TR 38.848 V18.0.0 (2023-09)

[0006] A communication control method according to a first aspect is a communication control method in a wireless communication system. The communication control method includes a step of receiving, from a communication node, at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission as a received signal. The communication control method also includes a step of performing backscattering transmission by the IoT device using the received signal in response to a second unmodulated signal transmitted from the communication node.

[0007] An IoT device according to a second aspect is an IoT device in a wireless communication system. The IoT device has a control unit that receives, as a received signal from a communication node, at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission. The control unit uses the received signal to perform backscattering transmission in response to a second unmodulated signal transmitted from the communication node.

[0008] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system according to the first embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a UE (user equipment) according to the first embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a gNB according to the first embodiment. FIG. 4 is a diagram illustrating an example of the configuration of an ambient IoT device according to the first embodiment. FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack related to a user plane according to the first embodiment. FIG. 6 is a diagram illustrating an example of the configuration of a protocol stack related to a control plane according to the first embodiment. FIG. 7 is a diagram illustrating an example of communication according to the first embodiment. FIGS. 8(A) and 8(B) are diagrams illustrating an example of a topology configuration according to the first embodiment. FIGS. 9(A) and 9(B) are diagrams illustrating an example of a topology configuration according to the first embodiment. FIG. 10 is a diagram illustrating an example of a topology configuration according to the first embodiment. FIGS. 11(A) and 11(B) are diagrams illustrating an example of a multiple access scheme according to the first embodiment. FIG. 12 is a diagram illustrating an example of the configuration of a protocol stack related to ambient IoT according to the first embodiment. FIGS. 13(A) to 13(D) are diagrams illustrating examples of signal formats of DL commands according to the first embodiment. Fig. 14 is a diagram illustrating an example of operation according to the first embodiment. Fig. 15 is a diagram illustrating an example of operation according to the second embodiment. Fig. 16 is a diagram illustrating an example of communication according to the third embodiment. Fig. 17 is a diagram illustrating an example of operation according to the third embodiment.

[0009] One aspect aims to enable proper control of communications in ambient IoT devices.

[0010] Most existing wireless communication devices use batteries that need to be manually replaced and manually charged. However, powering all IoT devices with batteries would be difficult because it would require not only the cost of the IoT devices themselves but also the maintenance costs for the IoT devices.

[0011] First, the ambient IoT devices described above are envisioned to function as battery-less devices with no energy storage capabilities, in which case the ambient IoT devices function as pure battery-less devices that have no power storage capabilities whatsoever and are completely dependent on the availability of an external energy source.

[0012] Second, ambient IoT devices are envisioned to function as battery devices with limited energy storage, e.g., energy storage that does not require manual replacement and does not require manual charging.

[0013] Specific examples of ambient IoT devices will be described later. As described above, technology using ambient IoT devices is expected to have a higher number of connections, lower complexity, and lower power consumption than existing 3GPP technology. The use of such ambient IoT devices is expected to lead to automation and digitalization in various industries, as well as the development of new markets.

[0014] Hereinafter, a wireless 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. An ambient IoT device is used in the wireless communication system according to the embodiment.

[0015] [First embodiment]

[0016] (Configuration example of wireless communication system) FIG. 1 is a diagram showing a configuration example of a wireless communication system according to the first embodiment. The wireless communication system 1 includes a mobile communication system that is a 5th Generation System (5GS) of the 3GPP standard. In the following, the mobile communication system will be described using 5GS as an example, but an LTE (Long Term Evolution) system may also be applied at least in part. A sixth generation (6G) system or later system may also be applied at least in part as the mobile communication system. Note that the wireless communication system 1 may be a mobile communication system.

[0017] The wireless communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN: Next Generation Radio Access Network) 10, a 5G core network (5GC: 5G Core Network) 20, and an ambient IoT device 300. Hereinafter, the 5GC 20 may be simply referred to as the core network (CN) 20. Note that a node other than the UE 100 may exist between the gNB 200 and the ambient IoT device 300. Such a node may be referred to as an assisting node or an intermediate node. Details of the assisting node and the intermediate node will be described later.

[0018] The UE 100 is a mobile wireless communication device. The UE 100 may be any device that is used by a user. The UE 100 may be, for example, a mobile phone terminal (including a smartphone) and / or 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).

[0019] The NG-RAN 10 includes a base station (called a "gNB" in a 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, and the like. Note that the term "cell" is used to indicate the smallest unit of a wireless communication area. The term "cell" is also used to indicate a function or resource for wireless communication with the UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0020] In addition, gNBs can also be connected to the Evolved Packet Core (EPC), which is the core network of LTE. LTE base stations can also be connected to 5GC. LTE base stations and gNBs can also be connected via an inter-base station interface.

[0021] The 5GC20 includes an Access and Mobility Management Function (AMF) 30 and a User Plane Function (UPF). The AMF 30 performs various mobility controls for the UE 100. The AMF 30 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 30 and the UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0022] The ambient IoT device 300 is a wireless communication device capable of wireless communication with the UE 100 and / or the gNB 200. The ambient IoT device 300 may also perform wireless communication with an assist node or an intermediate node, as described below.

[0023] First, the ambient IoT device 300 can transmit information within the ambient IoT device 300 by reflecting radio waves transmitted from the UE 100 or the gNB 200 and modulating the reflected waves. Generally, the technology of reflecting unmodulated radio waves and modulating the reflected waves to transmit information is called backscattering communication. The ambient IoT device 300 has a backscattering communication function. The ambient IoT device 300 may be an information medium capable of reading information from an internal memory using the backscattering communication function. The ambient IoT device 300 may be an information medium capable of writing information to an internal memory. In this case, the ambient IoT device 300 can receive transmitted radio waves modulated with information and extract the information by demodulating the received radio waves.

[0024] Second, the ambient IoT device 300 may be a battery-less IoT device. In this case, the ambient IoT device 300 converts received radio waves into energy (specifically, power) and operates using the energy. The ambient IoT device 300 may use an energy source other than radio waves, such as light, heat, magnetism, vibration, or sound, to convert energy. Generally, such energy conversion is called energy harvesting. A known method for energy harvesting may be used. In this manner, the ambient IoT device may have an energy harvesting function. Alternatively, the ambient IoT device 300 may have a limited battery function. As described above, a "limited battery" refers to a battery that does not require manual replacement or manual charging. The ambient IoT device 300 may have a battery function that charges power obtained by the energy harvesting function. The ambient IoT device 300 may be a wireless tag.

[0025] (Example of UE configuration) Figure 2 is a diagram showing an example of the configuration of the UE 100 (user equipment) according to the first embodiment. The UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit 130. The receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200. The receiving unit 110 and the transmitting unit 120 are capable of wireless communication with the ambient IoT device 300.

[0026] The receiving unit 110 performs various types of reception under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130. The receiving unit 110 may receive a reflected wave reflected by the ambient IoT device 300 under the control of the control unit 130. The receiving unit 110 receives the received reflected wave as a radio signal, converts it into a baseband signal, and outputs it to the control unit 130.

[0027] The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna. Alternatively, the transmitting unit 120 (or the transmitter) may transmit an unmodulated carrier wave under the control of the control unit 130. The carrier wave is reflected by the ambient IoT device 300.

[0028] The control unit 130 performs various controls and processes in the UE 100. Such processes include processes of each layer described below. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processes by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. In the example shown below, the operation or processing in the UE 100 may be performed by the control unit 130.

[0029] (Example of gNB configuration) Figure 3 is a diagram showing an example of the configuration of a gNB200 (base station) 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. The transmitting unit 210 and the receiving unit 220 constitute a wireless communication unit that performs wireless communication with the UE100. The transmitting unit 210 and the receiving unit 220 are capable of wireless communication with the ambient IoT device 300. The backhaul communication unit 240 constitutes a network communication unit that communicates with the CN20.

[0030] 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. Alternatively, the transmitting unit 210 (or the transmitter) may transmit an unmodulated carrier wave under the control of the control unit 230. The carrier wave is reflected by the ambient IoT device 300.

[0031] The receiving unit 220 performs various types of reception 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 (received signal) and outputs the signal to the control unit 230. The receiving unit 220 may receive a reflected wave reflected by the ambient IoT device 300 under the control of the control unit 230. The receiving unit 220 receives the reflected wave as a radio signal, converts the received signal into a baseband signal, and outputs the baseband signal to the control unit 230.

[0032] The control unit 230 performs various controls and processes in the gNB 200. Such processes include processes for each layer described below. 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 the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. In the example shown below, the operation or processing in the gNB 200 may be performed by the control unit 230.

[0033] The backhaul communication unit 240 is connected to adjacent base stations via an Xn interface, which is an interface between base stations. The backhaul communication unit 240 is connected to the AMF 30 / UPF via an NG interface, which is an interface between a base station and a core network. The gNB 200 is composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally divided), and the two units may be connected by an F1 interface, which is a fronthaul interface.

[0034] 4 is a diagram illustrating an example of the configuration of the ambient IoT device 300 according to the first embodiment. The ambient IoT device 300 according to the first embodiment includes an antenna 310, a modulator 320, a control unit 330, and a memory 340.

[0035] The antenna 310 receives an unmodulated carrier wave. Hereinafter, this unmodulated carrier wave will be referred to as a CW (Continuous Wave). The antenna 310 converts the received CW into a received signal and outputs this received signal to the modulator 320. The antenna 310 also reflects the CW in accordance with the transmission signal output from the modulator 320 and transmits a reflected wave. Hereinafter, this reflected wave will be referred to as a BS (Back Scattering or Back Scatter). The antenna 310 performs BS transmission.

[0036] The modulator 320 may generate a transmission signal by modulating data read from the memory 340 under the control of the control unit 330. The modulator 320 outputs the modulated signal to the antenna 310. The modulator 320 may also acquire data by demodulating a signal received from the antenna 310 under the control of the control unit 330. The modulator 320 outputs the acquired data to the control unit 330. In the ambient IoT device 300, the modulator 320 may specifically be a switch. When the switch receives a reception signal from the antenna 310, the switch turns on and outputs the reception signal to the control unit 330. The switch is controlled to be on or off under the control of the control unit 330, and outputs a transmission signal corresponding to the on or off state to the antenna 310. The switch may be an RF (Radio Frequency) switch. The switch may be configured with a transistor. Alternatively, the switch may be a mechanical switch that can be physically switched on or off.

[0037] The control unit 330 has an energy harvesting function that converts the received signal received from the modulator 320 into power. The control unit 330 controls the modulator 320 and the memory 340 using the converted power as driving power for the ambient IoT device 300. The control unit 330 also reads information stored in the memory 340 and controls the modulator 320 to transmit a transmission signal corresponding to the information. For example, the control unit 330 controls the on / off of the modulator 320 to control the reflectivity of the reflected wave (BS) (e.g., whether the reflectivity is 100% or 0%) and output a transmission signal corresponding to information (e.g., 1 bit) stored in the memory 340 from the modulator 320 to the antenna 310. For example, the control unit 330 controls the timing of turning the modulator 320 on or off to output a transmission signal corresponding to multiple bits from the modulator 320 to the antenna 310. In this way, the control unit 330 controls the reflectivity of the reflected wave (BS) by controlling the on / off of the modulator 320, and is able to transmit a modulated reflected wave corresponding to the information stored in the memory 340 from the antenna 310.

[0038] The memory 340 stores various types of information. The information stored in the memory 340 may be information acquired when the ambient IoT device 300 functions as a sensor. Alternatively, the information stored in the memory 340 may be information specific to the ambient IoT device 300 that has been stored in advance in the memory 340. Examples of the specific information include identification information for the ambient IoT device 300 (or the group to which the ambient IoT device 300 belongs). The memory 340 can read the stored information under the control of the control unit 330. Information may be written to the memory 340 under the control of the control unit 330. In this case, the control unit 330 (or the modulator 320) converts the signal received from the antenna 310 into a baseband signal in the baseband band, reads information from the baseband signal, and writes the read information to the memory 340.

[0039] The ambient IoT device 300 may have a limited battery. As described above, limited battery means a battery that does not need to be manually replaced or manually charged. Furthermore, the ambient IoT device 300 may have the energy harvesting function described above.

[0040] (Protocol Stack) Next, a configuration example of a protocol stack will be described. Here, a configuration example of a protocol stack in the UE 100, the gNB 200, and the AMF 30 will be described.

[0041] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a user plane that handles data.

[0042] 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.

[0043] 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 a CRC (Cyclic Redundancy Code) parity bit scrambled by the RNTI added.

[0044] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to the UE 100.

[0045] The RLC layer transmits data to the receiving RLC layer using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0046] The PDCP layer performs header compression / decompression, encryption / decryption, and the like.

[0047] The SDAP layer maps IP flows, which are units for Quality of Service (QoS) control by the core network, to radio bearers, which are units for QoS control by the Access Stratum (AS). Note that if the RAN is connected to the EPC, SDAP may not be required.

[0048] FIG. 6 is a diagram showing an example of the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals).

[0049] The protocol stack of the radio interface of the control plane has a Radio Resource Control (RRC) layer and a Non-Access Stratum (NAS) instead of the SDAP layer shown in FIG.

[0050] 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.

[0051] The NAS, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS of the UE 100 and the NAS of the AMF 30. Note that the UE 100 has an application layer and the like in addition to the radio interface protocol. The layer below the NAS is called an Access Stratum (AS).

[0052] (Communication Example of Ambient IoT Device) Next, a communication example of the ambient IoT device 300 according to the first embodiment will be described.

[0053] FIG. 7 is a diagram illustrating an example of communication of the ambient IoT device 300 according to the first embodiment.

[0054] As shown in FIG. 7 , a node (or device) capable of directly communicating with the ambient IoT device 300 is referred to as a communication node 400. The communication node 400 may be the UE 100 or the gNB 200. Alternatively, the communication node 400 may be a relay device. Alternatively, the communication node 400 may be referred to as an assist node. Alternatively, the communication node 400 may be referred to as an intermediate node. Assist nodes and intermediate nodes will be described later. Alternatively, the communication node 400 may be an IAB (Integrated Access and Backhaul) node. The IAB node is, for example, a relay node interposed between the UE 100 and the gNB 200, and is a node in which a backhaul link (a communication link between the IAB node and the gNB 200) is mainly connected by wire. Alternatively, the communication node 400 may be an NCR (Network-Controlled Repeater). The NCR is, for example, a relay node interposed between the UE 100 and the gNB 200, and is a node connected mainly by wireless connection between the gNB 200 and the NCR. Alternatively, the communication node 400 may be an eNB, which is an LTE base station. The communication node 400 may be a network node that functions as a base station in 6G or later.

[0055] The communication node 400 transmits an unmodulated carrier wave (CW). That is, the communication node 400 performs CW transmission. The ambient IoT device 300 reflects the unmodulated carrier wave and transmits a reflected wave. The reflected wave is modulated according to the data transmitted from the ambient IoT device 300. That is, the ambient IoT device 300 performs BS transmission. The communication node 400 performs BS reception.

[0056] In addition, the communication node 400 may be a communication node that performs CW transmission and a communication node that performs BS reception.

[0057] As described above, various connection configurations between the ambient IoT devices 300 and the communication nodes 400 are assumed depending on the type of the communication node 400. Alternatively, various connection configurations of the ambient IoT devices 300 within the wireless communication system 1 are assumed. In 3GPP, such connection configurations are referred to as topologies, and four topologies are discussed. The four topologies (Topology 1, Topology 2, Topology 3, and Topology 4) will be described below.

[0058] (Topology of Ambient IoT Device 300)

[0059] (A1) Topology 1 FIG. 8A is a diagram illustrating an example of the configuration of topology 1 according to the first embodiment.

[0060] 8A, in topology 1, the ambient IoT device 300 communicates directly and bidirectionally with a base station (BS) 410. Data related to the ambient IoT device 300 and / or signaling related to the ambient IoT device 300 are transferred between the ambient IoT device 300 and the base station 410. In topology 1, the base station 410 that performs CW transmission to the ambient IoT device 300 may be different from the base station 410 that performs BS reception from the ambient IoT device 300. Topology 1 illustrates an example in which the communication node 400 is the base station 410.

[0061] (A2) Topology 2 FIG. 8B is a diagram illustrating an example of the configuration of topology 2 according to the first embodiment.

[0062] As shown in FIG. 8(B), in topology 2, an intermediate node 420 exists between the ambient IoT device 300 and the base station 410. That is, in topology 2, the ambient IoT device 300 communicates bidirectionally with the intermediate node 420. The intermediate node 420 may be a communication node 400. That is, the intermediate node 420 may be any of the gNB 200, the UE 100, a relay node, an IAB node, and an NCR. The intermediate node 420 transfers data related to the ambient IoT device 300 and / or signaling related to the ambient IoT device 300 between the base station 410 and the ambient IoT device 300. Topology 2 illustrates an example in which the communication node 400 serves as the intermediate node 420.

[0063] (A3) Topology 3 Figures 9(A) and 9(B) are diagrams showing an example configuration of topology 3 according to the first embodiment. In topology 3, communication is performed via a node called an assisting node 430. That is, as shown in Figure 9(A), the ambient IoT device 300 transmits data and / or signaling to a base station 410 and receives data and / or signaling from the assisting node 430. In Figure 9(A), the assisting node 430 may perform CW transmission, and the base station 410 may perform BS reception. Figure 9(A) shows communication in the downstream direction.

[0064] 9(B), the ambient IoT device 300 receives data and / or signaling from the base station 410 and transmits the data and / or signaling to the assist node 430. In FIG. 9(B), the base station 410 may perform CW transmission, and the assist node 430 may perform BS reception. FIG. 9(B) shows communication in the uplink stream direction.

[0065] Thus, in topology 3, the assist node 430 may be a node that performs CW transmission but does not perform BS reception (FIG. 9(A)). The assist node 430 may be a node that does not perform CW transmission but performs BS reception (FIG. 9(B)). In other words, the assist node 430 may be a node that performs either CW transmission or BS reception. Topology 3 shows an example in which the assist node 430 is the communication node 400. The assist node 430 may be any of the gNB 200, UE 100, relay node, IAB node, and NCR.

[0066] (A4) Topology 4 Fig. 10 is a diagram illustrating a configuration example of topology 4 according to the first embodiment. In topology 4, the ambient IoT device 300 communicates bidirectionally with the UE 100. Data and / or signaling is transferred between the UE 100 and the ambient IoT device 300. Topology 4 illustrates an example in which the communication node 400 is the UE 100.

[0067] (Multiple Access Method for Ambient IoT Devices) In a wireless communication system 1 including ambient IoT devices 300, it is assumed that a large number of ambient IoT devices 300 will be connected to the wireless communication system 1. In this case, if the ambient IoT devices 300 all simultaneously transmit BS signals using the same frequency, interference will occur. As a result, the receiving communication node 400 may not be able to properly receive the reflected waves transmitted from the ambient IoT devices 300.

[0068] 11A and 11B are diagrams illustrating an example of a multiple access method according to the first embodiment.

[0069] As shown in FIG. 11A , BS transmission may use a single-sideband (SSB) transmission method. SSB is a method of amplitude modulation in which one sideband is removed and the remaining sideband is used for transmission. In amplitude modulation, frequency components are composed of two sidebands (a low sideband (LSB) and an upper sideband (USB)) symmetrical about the carrier used in CW transmission. In contrast, in SSB, only one sideband (in FIG. 11A , the lower sideband is removed and the upper sideband is used) is used. Therefore, compared to double-sideband transmission, SSB can reduce the transmission power of the ambient IoT device 300 and improve frequency efficiency. The receiving communication node 400 can estimate the missing sideband from the position of the carrier used in CW transmission, enabling processing similar to that in double-sideband transmission. SSB may be implemented, for example, by a known configuration. For example, a carrier wave and a signal wave are input to a balanced modulator, and the carrier wave is balanced-modulated with the signal wave. After that, unnecessary sidebands are removed using a band pass filter (BPF), thereby enabling SSB transmission. Such a configuration may be provided, for example, within the control unit 330. Note that a transmission method using double sidebands is called DSB (Dual Sideband).

[0070] 11B, when BS transmission is performed simultaneously from multiple ambient IoT devices 300 using SSB, the BS transmission is performed using different frequencies. This makes it possible to avoid interference and to perform normal BS reception at the communication node 400 even when BS transmission is performed simultaneously from multiple ambient IoT devices 300 using SSB.

[0071] (Protocol Stack) FIG. 12 is a diagram showing an example of the configuration of a protocol stack in the wireless communication system 1 including an ambient IoT device.

[0072] In the example shown in FIG. 12, a requesting node (Requesting node) transmits settings and / or requests regarding communication with the ambient IoT device 300 to the intermediate node 420 (or assist node 430) using an RRC message. CW transmission and BS transmission are performed in the physical layer (PHY), and the receiving node (Receiver node) transmits data received in the BS transmission (or a response message) using an RRC message. In FIG. 13, the requesting node and receiving node are gNB200, and the intermediate node 420 (or assist node 430) is an example of UE100. Although communication with the ambient IoT device 300 is performed at the PHY layer, a protocol stack different from that in FIG. 13 may be used depending on the combination of the type of entity in the requesting node and receiving node and the type of entity in the intermediate node 420 or assist node 430.

[0073] (Communication control method according to the first embodiment) Communication in the ambient IoT device 300 is performed by the communication node 400 transmitting an unmodulated carrier wave to the ambient IoT device 300, and the ambient IoT device 300 transmitting a reflected wave of the carrier wave to the communication node 400.

[0074] On the other hand, the network-side device may wish to control communication in the ambient IoT device 300. For example, the network-side device may wish to individually control communication for a plurality of ambient IoT devices 300. Alternatively, the network-side device may wish to group the ambient IoT devices 300 and control each group. If the network-side device can control communication for the ambient IoT device 300, communication corresponding to various use cases may become possible.

[0075] Therefore, the first embodiment aims to enable a network-side device to appropriately control communication in the ambient IoT device 300.

[0076] Therefore, in the first embodiment, first, a communication node (e.g., communication node 400) transmits at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of an IoT device (e.g., ambient IoT device 300), and a signal representing control information related to backscattering transmission as a transmission signal to the IoT device. Second, the IoT device receives the transmission signal. Third, the communication node transmits a second unmodulated signal. Fourth, the IoT device uses the transmission signal to perform backscattering transmission of the second unmodulated signal.

[0077] As described above, in the first embodiment, the communication node 400 transmits a transmission signal to the ambient IoT device 300, and the ambient IoT device 300 performs BS transmission using the transmission signal. This allows, for example, the communication node 400 to control communication of the ambient IoT device using control information. Therefore, it becomes possible for a network-side device to appropriately control communication in the ambient IoT device.

[0078] The communication node 400 is an example of a network-side device. That is, the network-side device may be any one of the UE 100, the gNB 200, an intermediate node, and an assist node.

[0079] Furthermore, the transmission signal transmitted by the communication node 400 may be referred to as a "DL (Down Link) command" hereinafter. After transmitting the DL command, the communication node 400 performs CW transmission and receives a BS transmission from the ambient IoT device 300. Alternatively, after transmitting the DL command, the communication node 400 may receive a BS transmission from the ambient IoT device 300 in response to a CW transmission by another communication node. The DL command may be a control command or a control signal.

[0080] (Signal Format of DL Command) As described above, the DL command is at least one of the first unmodulated signal, the preamble signal, the signal representing identifier information of the ambient IoT device 300, and the signal representing control information related to BS transmission.

[0081] Here, a specific example of a DL command according to the first embodiment will be described.

[0082] 13(A) to 13(D) are diagrams illustrating an example of a signal format of a DL command according to the first embodiment. The DL commands illustrated in Fig. 13(A) to 13(D) illustrate an example of a signal format when transmitting all of the first unmodulated signal, the preamble signal, the signal representing identifier information of the ambient IoT device 300, and the signal representing control information related to backscattering transmission.

[0083] As shown in FIG. 13(A), the DL command includes a CW portion for transmitting a first unmodulated signal, a preamble portion for transmitting a preamble signal, a device / group ID portion for transmitting a signal indicating identifier information of the ambient IoT device 300, and a BS control information portion for transmitting a signal indicating control information regarding BS transmission.

[0084] (A1) CW Section The first unmodulated signal transmitted in the CW section may be represented by a signal sequence in which a bit string of "1" is consecutively arranged. For example, in the case of OOK (On-Off-keying), a bit string of "1" indicates the presence of a carrier wave, and a bit string of "0" indicates the absence of a carrier wave. Therefore, the communication node 400 can transmit a carrier wave using an unmodulated signal by using a bit string of "1". Also, for example, in the case of ASK (Amplitude-Shift-Keying), a bit string of "1" indicates a large amplitude, and a bit string of "0" indicates a small amplitude. Therefore, in the communication node 400, by using a bit string of "1", it is possible to more reliably transmit a carrier wave using an unmodulated signal compared to the case of a bit string of "0". FIG. 13(C) shows an example of an output waveform in the case of OOK, for example.

[0085] The first unmodulated signal transmitted in the CW unit may be used to determine a reference power in the ambient IoT device 300. Specifically, the first unmodulated signal may be used to determine the received power of the CW (CW using the second unmodulated signal) used when transmitting a BS in the ambient IoT device 300. For example, the control unit 330 of the ambient IoT device 300 may perform the following processing.

[0086] That is, the control unit 330 stores the received power of the first unmodulated signal transmitted in the CW unit as a reference power in the memory 340. Then, when the received power of the received signal is equal to or greater than the reference power, the control unit 330 determines that the received signal is a signal received by CW transmission (CW transmission using the second unmodulated signal) and performs BS transmission. On the other hand, when the received power of the received signal is less than the reference power, the control unit 330 determines that the received signal is not a signal received by CW transmission and does not perform BS transmission. The reference power may be lower than the received power. For example, the reference power may be set to a value obtained by multiplying the received power by 1 / 2. The received power and reference power may be a received voltage and a reference voltage, respectively, a received current and a reference current, respectively, or a received electric field strength and a reference electric field strength, respectively.

[0087] In this way, the ambient IoT device 300 uses the first unmodulated signal as a reference power for the second unmodulated signal, and therefore can be said to use the first unmodulated signal for BS transmission.

[0088] Furthermore, the first unmodulated signal transmitted in the CW unit may be used for power storage (or charging) in the ambient IoT device 300. If the ambient IoT device 300 has a power storage function, the control unit 330 of the ambient IoT device 300 can convert the unmodulated signal into power using the above-described energy conversion function, and store (or charge) the power in the power storage unit (or charging unit).

[0089] (A2) Preamble Section The preamble signal transmitted in the preamble section is represented by a bit pattern that is known in the ambient IoT device 300, for example, as defined in a specification.

[0090] The preamble signal may be used for time synchronization in the ambient IoT device 300. For example, the control unit 330 of the ambient IoT device 300 can achieve time synchronization with the communication node 400 (or the network) by using the preamble signal to determine the timing of time synchronization. In this way, the ambient IoT device 300 achieves time synchronization with the communication node 400 using the preamble signal, and then, in a time-synchronized state, can perform BS transmission in response to CW transmission from the communication node 400. Therefore, it can be said that the BS transmission is performed using the preamble signal. Note that the time synchronization may be synchronization of the operating clock of the ambient IoT device 300 with the communication node 400 (or the network).

[0091] (A3) Device ID / Group ID Section The identifier information of the ambient IoT device 300 transmitted in the device ID / group ID section may be information for specifying the ambient IoT device 300 that performs BS transmission. This allows, for example, the communication node 400 (or a network device) to specify the execution of BS transmission to a specific ambient IoT device 300 among multiple ambient IoT devices 300.

[0092] The identifier information may represent a group of ambient IoT devices, allowing the communication node 400 (or a network device) to designate a specific group for BS transmission.

[0093] Furthermore, the identifier information may be used from the communication node 400 (or network) side to call a specific ambient IoT device 300. Note that the identifier information may be written in advance (for example, at the time of shipping from a factory) in the memory 340 of the ambient IoT device 300. The ambient IoT device 300 may determine whether or not the implementation of BS transmission has been specified by comparing the identifier information received from the communication node 400 (or network device) with the identifier information stored in the memory 340.

[0094] (A4) BS Control Information Section The control information transmitted in the BS control information section (hereinafter, sometimes referred to as "BS control information") may include at least one of transmission mode information, frequency information, communication timing information, and communication mode information.

[0095] (A4-1) Mode Information The mode information indicates either active transmission, which uses an internal power source for transmission, or passive transmission, which uses received waves as a power source for transmission. Active transmission corresponds to, for example, transmission by the UE 100 using an internal power source. On the other hand, passive transmission corresponds to, for example, BS transmission by the ambient IoT device 300.

[0096] (A4-2) Frequency Information The frequency information represents information related to the frequency used in BS transmission. The frequency information is specified by one of the bit patterns, which are previously associated with a bit pattern. For example, a bit pattern of "00" may represent frequency pattern A, a bit pattern of "01" may represent frequency pattern B, a bit pattern of "10" may represent frequency pattern C, and a bit pattern of "11" may represent frequency pattern D.

[0097] The frequency patterns may directly represent the transmission frequencies, for example, frequency pattern A is transmission frequency f1, frequency pattern B is transmission frequency f2, etc.

[0098] Alternatively, the frequency pattern may be represented by a detuning frequency indicating how far the frequency used for BS transmission is from the frequency used for CW transmission. For example, in frequency pattern A, a frequency (or frequency band) that is detuning frequency "x" from the frequency used for CW transmission is used for BS transmission, and in frequency pattern B, a frequency (or frequency band) that is detuning frequency "y" from the frequency used for CW transmission is used for BS transmission (e.g., FIG. 11(B)). The detuning frequency may be determined by a combination of the frequency pattern and identifier information of the ambient IoT device 300. For example, a frequency (or frequency band) at detuning frequency "z" is used for BS transmission based on a combination of frequency pattern A (a frequency that is detuning frequency "x" from the transmission frequency of CW transmission) and identifier information of the ambient IoT device 300. In this way, the frequency used for BS transmission can be determined for each ambient IoT device 300 based on a combination of the detuning frequency and identifier information of the ambient IoT device 300. The combination may be determined using a table or a calculation formula.

[0099] (A4-3) Communication Timing Information The communication timing information indicates the communication timing of BS transmission. BS transmission in the ambient IoT device 300 is performed at the transmission timing of CW transmission (transmission of the second unmodulated signal) from the communication node 400. Therefore, it can be said that the communication timing of BS transmission indicates the timing of CW transmission in the communication node 400. In other words, the communication timing information may indicate the timing at which CW transmission is performed.

[0100] Regarding the communication timing information, a bit pattern representing the communication timing information and a transmission pattern are linked in advance, and the communication timing information is represented by one of these bit patterns. For example, the following linking may be used: The bit pattern "00" represents a transmission pattern in which CW transmission starts immediately after this DL command and is performed for one radio frame period. The bit pattern "01" represents a transmission pattern in which CW transmission starts immediately after this DL command and is performed for 10 radio frame periods. The bit pattern "10" represents a transmission pattern in which CW transmission starts one radio frame after this DL command and is performed for one radio frame period. The bit pattern "11" represents a transmission pattern in which CW transmission starts 10 radio frames after this DL command and is performed for 10 radio frame periods.

[0101] In the above example, instead of a "radio frame", a "subframe", a "slot", or a "symbol" may be used.

[0102] Furthermore, in the above example, "data reception" may be used instead of "CW transmission." The ambient IoT device 300 may also be able to write data. Therefore, data writing may be specified by a communication mode (to be described later), and the timing of "data reception" (i.e., the timing of data writing) may be indicated by communication timing information.

[0103] (A4-4) Communication Mode Information The communication mode information indicates the communication mode of the ambient IoT device 300. Specifically, the communication mode information may be information indicating a write mode for writing to the ambient IoT device 300. Alternatively, the communication mode information may be information indicating a specific type of BS transmission when BS transmission is performed in the ambient IoT device 300.

[0104] The bit pattern representing the communication mode information and the communication mode information are associated in advance, and the communication mode information may be represented by any of the bit patterns. For example, the communication mode information may be associated as follows.

[0105] That is, the bit pattern "000" represents a communication mode in which all data stored in the memory 340 of the ambient IoT device 300 is transmitted to the BS.

[0106] Furthermore, the bit pattern "001" represents a communication mode in which a portion of the data stored in the memory 340 of the ambient IoT device 300 is transmitted to the BS. The portion of the data may be the maximum amount of data that can be transmitted to the BS, starting with the newest data.

[0107] Furthermore, the bit pattern "010" represents a survival confirmation mode. The survival confirmation mode represents, for example, a communication mode in which the ambient IoT device 300 confirms whether it can perform BS transmission. In the survival confirmation mode, the ambient IoT device 300 may transmit its own identifier information stored in its own memory 340 to the BS.

[0108] Furthermore, the bit pattern "011" represents a device-originating (DO) data presence / absence confirmation mode. The DO data presence / absence confirmation mode represents, for example, a communication mode in which the ambient IoT device 300 confirms whether there is data to transmit by BS transmission. In the DO data presence / absence confirmation mode, the ambient IoT device 300 may indicate that there is data by BS transmission by transmitting its own identifier information by BS. The ambient IoT device 300 may indicate that there is no data to transmit by BS transmission by not transmitting its own identifier information by BS.

[0109] Furthermore, the bit pattern "100" represents a communication mode in which data is written to the memory 340 of the ambient IoT device 300. In this case, the communication node 400 may transmit the data to be written following this DL command.

[0110] The write mode can be considered to be a mode different from BS transmission. Therefore, it can be said that the ambient IoT device 300 performs BS transmission using part of the BS control information.

[0111] An example of the signal format of the DL command has been described above.

[0112] (Example of Operation According to First Embodiment) Next, an example of operation using a DL command will be described.

[0113] FIG. 14 is a diagram illustrating an example of operation according to the first embodiment.

[0114] As shown in FIG. 14 , in step S10, the transmitter of the communication node 400 transmits a DL command. When the communication node 400 is a UE 100, the transmitter 120 of the UE 100 transmits the DL command. When the communication node 400 is a gNB 200, the transmitter 210 of the gNB 200 transmits the DL command. The control unit 330 of the ambient IoT device 300 receives the DL command. The DL command may be transmitted by being included in DCI of the PHY layer. The DL command may be transmitted on a physical channel (or signal waveform) newly created for communication with the ambient IoT device 300 in the PHY layer. The DL command may be transmitted by being included in a message of a new layer newly created for communication with the ambient IoT device 300.

[0115] In step S11, the ambient IoT device 300 performs a predetermined operation. The predetermined operation may be a process performed by the ambient IoT device 300 in response to the DL command. Details of the predetermined operation will be described in a second embodiment.

[0116] In step S12, the transmitter of the communication node 400 performs CW transmission. If the communication node 400 is the UE 100, the transmitter 120 of the UE 100 performs CW transmission. If the communication node 400 is the gNB 200, the transmitter 210 of the gNB 200 performs CW transmission. The transmitter of the communication node 400 may perform CW transmission in accordance with the DL command.

[0117] In step S13, the ambient IoT device 300 performs BS transmission in response to the CW transmission. The control unit 330 of the ambient IoT device 300 performs BS transmission in accordance with the DL command. The BS transmission in step S13 will also be described in the second embodiment. The receiving unit of the communication node 400 receives the BS transmission from the ambient IoT device 300, and receives data transmitted by the BS transmission. When the communication node 400 is a UE 100, the receiving unit 110 of the UE 100 performs reception processing for the BS transmission. Also, when the communication node 400 is a gNB 200, the receiving unit 220 of the gNB 200 performs reception processing for the BS transmission.

[0118] (Another Operation Example 1 According to First Embodiment) In the first embodiment, an example has been described in which the CW section, preamble section, device / group ID section, and BS control information section are transmitted in this order for the signal format of the DL command shown in Fig. 13(A). In the DL command, the CW section, preamble section, device / group ID section, and BS control information section may be transmitted in any order. For example, the CW section may be transmitted first, followed by the preamble section, then the BS control information section, and finally the device / group ID section.

[0119] Second Embodiment Next, a second embodiment will be described, focusing on the differences from the first embodiment.

[0120] The first embodiment has described an example of a DL command transmission operation by the communication node 400. The second embodiment will describe an example of a DL command reception operation by the ambient IoT device 300.

[0121] Specifically, first, the IoT device (e.g., ambient IoT device 300) has a control unit (e.g., control unit 330) that receives at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission as a received signal (e.g., a DL command) from a communication node (e.g., communication node 400). Second, the control unit uses the received signal to perform backscattering transmission for the second unmodulated signal transmitted from the communication node.

[0122] As described above, in the second embodiment, the ambient IoT device 300 can perform BS transmission using the DL command. Therefore, the network-side device can use the DL command to control the BS transmission in the ambient IoT device 300. Therefore, in the second embodiment, the network-side device can also appropriately control the communication in the ambient IoT device 300.

[0123] (Example of Operation According to Second Embodiment) Next, an example of operation according to the second embodiment will be described.

[0124] FIG. 15 is a diagram illustrating an example of operation according to the second embodiment.

[0125] As shown in FIG. 15, in step S20, the control unit 330 of the ambient IoT device 300 enters a DL command waiting mode.

[0126] First, the DL command standby mode may be a power-saving mode (or a no-power mode) that detects DL commands but does not detect other signals. The DL command standby mode may also be a state in which the modulator 320 is not operating. Alternatively, the DL command standby mode may be a state in which the control unit 330 (or the antenna 310) monitors the received power (or received voltage) without demodulating the DL command in the modulator 320.

[0127] Second, the DL command standby mode may be a state in which a specific DL command is awaited. For example, the DL command standby mode may be a state in which a DL command (a first unmodulated signal thereof) is awaited. Therefore, for example, the control unit 330 may monitor whether the received power (or received voltage) is equal to or greater than a threshold.

[0128] In step S21, the transmitter of the communication node 400 transmits a DL command. The control unit 330 of the ambient IoT device 300 receives the DL command.

[0129] In step S22, the control unit 330 of the ambient IoT device 300 performs a predetermined operation in response to receiving the DL command. A specific example of the predetermined operation will be described below.

[0130] (B1) When the DL command is a first unmodulated signal: When the control unit 330 of the ambient IoT device 300 detects (consecutively) "1" in the output from the modulator 320, the control unit 330 may determine that the first unmodulated signal in the DL command (or that the DL command is the first unmodulated signal) has been detected. When the control unit 330 detects the first unmodulated signal, the control unit 330 may perform at least one of the following predetermined operations.

[0131] First, when the control unit 330 detects the first unmodulated signal, the control unit 330 may determine the reference power (or reference voltage) using the first unmodulated signal. Specifically, the control unit 330 may determine the received power (or received voltage) of the first unmodulated signal as the reference power (or reference voltage) for determining whether or not the CW (second unmodulated signal) used in BS transmission has been received. Alternatively, the control unit 330 may specify a threshold for determining whether or not the symbol point corresponding to the CW (second unmodulated signal) has been received, based on the symbol point corresponding to the preamble signal.

[0132] Second, when the control unit 330 detects the first unmodulated signal, the control unit 330 may perform a power generation operation based on the first unmodulated signal. The control unit 330 may perform a power generation operation by utilizing a power generation function in the ambient IoT device 300. Alternatively, the control unit 330 may perform a charging operation (or a power storage operation) based on the first unmodulated signal as the predetermined operation. The control unit 330 may perform a power generation operation (or a power storage operation) by utilizing the charging function (or a power storage function) in the ambient IoT device 300.

[0133] Third, when the control unit 330 detects that the signal is the first unmodulated signal, the control unit 330 may start waiting for the next signal (for example, a preamble signal) after the first unmodulated signal.

[0134] (B2) When the DL Command is a Preamble Signal When the control unit 330 detects a preamble signal, the control unit 330 may perform at least one of the following predetermined operations.

[0135] First, the control unit 330 may perform time synchronization (or timing synchronization) using the preamble signal. The control unit 330 may perform clock synchronization using the preamble signal as a standard clock.

[0136] Second, the control unit 330 may use the preamble signal to determine the reference power (or reference voltage). As in the case where the DL command is the first unmodulated signal, the control unit 330 may use the preamble signal to determine the reference power for determining whether or not the CW (second unmodulated signal) used when transmitting from the BS has been received. The control unit 330 may also determine a threshold for determining whether or not a symbol point has been received.

[0137] Third, the control unit 330 may start listening for the next signal after the preamble signal (for example, a signal transmitted as the device ID / group ID portion).

[0138] (B3) When the DL command is a signal transmitted as a device ID / group ID section, the control unit 330 may perform at least one of the following as a predetermined operation when it detects a signal transmitted as a device ID / group ID section.

[0139] First, the control unit 330 may check whether the identifier information included in the signal matches the identifier information of the ambient IoT device 300 itself (or the identifier information of the group to which the ambient IoT device 300 belongs). The control unit 330 reads its own identifier information from the memory 340 and compares it with the identifier information included in the DL command. If the identifier information included in the DL command matches its own identifier information, the control unit 330 may perform the following operation. On the other hand, if the identifier information included in the DL command does not match its own identifier information, the control unit 330 may stop the following processing (or continue the DL command standby mode).

[0140] Second, the control unit 330 may start waiting for the next signal (for example, a signal transmitted as a BS control information section) following the signal transmitted as a device ID / group ID section.

[0141] (B4) When the DL command is a signal transmitted as a BS control information part, the control unit 330 may perform at least one of the following as a predetermined operation when it detects a signal transmitted as a BS control information part.

[0142] First, when the BS control information includes mode information ((A4-1) in the first embodiment), the control unit 330 determines whether to perform active transmission or passive transmission in accordance with the mode information. Then, the control unit 330 performs either active transmission or passive transmission at the transmission timing (step S25 in the following stage). Note that the following description will be continued assuming that the control unit 330 performs passive transmission (i.e., BS transmission).

[0143] Second, if the BS control information includes frequency information ((A4-2) in the first embodiment), the control unit 330 uses the frequency information to determine the frequency to be used for BS transmission. For example, detailed information on the frequency pattern (e.g., a frequency pattern corresponding to a bit pattern) is stored in the memory 340. Therefore, the control unit 330 may check the detailed information and identify a frequency pattern (e.g., frequency pattern B) that matches the bit pattern (e.g., "01") included in the frequency information, thereby determining the frequency to be used for BS transmission (e.g., the transmission frequency used in frequency pattern B is f2, or the frequency used in frequency pattern B is a frequency that is offset by the offset frequency "y" from the frequency used in CW transmission). The control unit 330 may identify the offset frequency from the frequency used in CW transmission based on a combination of its own identifier information and the frequency pattern, and use the identified frequency to determine the frequency to be used for BS transmission. The control unit 330 performs BS transmission using the determined frequency (step S25, later).

[0144] Third, when the BS control information includes communication timing information, the control unit 330 determines the time for BS transmission. For example, detailed information of the communication timing information (e.g., a transmission pattern corresponding to a bit pattern representing the communication timing information) is stored in the memory 340. Therefore, the control unit 330 may determine the time for BS transmission by identifying a transmission pattern (e.g., a transmission pattern in which CW transmission starts immediately after this DL command and in which CW transmission is performed in one radio frame period) corresponding to a bit pattern (e.g., "00") included in the communication timing information.

[0145] For example, if the bit pattern included in the communication timing information is "01", the control unit 330 may determine to perform BS transmission during a 10 radio frame period starting immediately after receiving the DL command.

[0146] Alternatively, if the bit pattern included in the communication timing information is "10", the control unit 330 may determine that BS transmission is to be performed starting one radio frame later, during one radio frame period.

[0147] Alternatively, if the bit pattern of the communication timing information is "11", the control unit 330 may determine that BS transmission will be performed for a period of 10 radio frames, starting one radio frame later. The control unit 330 performs BS transmission at the determined time (step S25 below).

[0148] Fourth, when the BS control information includes communication mode information, the control unit 330 may determine the content of the information to be transmitted by BS transmission based on the communication mode information. For example, detailed information of the communication mode information (e.g., a communication mode corresponding to a bit pattern representing the communication mode information) is stored in the memory 340. Therefore, the control unit 330 may identify a communication mode (e.g., a communication mode in which all data stored in the memory 340 is transmitted via the BS) corresponding to a bit pattern (e.g., "000") included in the communication mode information, and determine the content of the information to be transmitted by BS transmission according to the communication mode.

[0149] For example, if the bit pattern representing the communication mode information is "001", the control unit 330 may read from the memory 340 the maximum amount of data that can be transmitted via BS, starting with the most recent data among the data stored in the memory 340, and use that data as the content of the information to be transmitted via BS transmission.

[0150] Alternatively, if the bit pattern representing the communication mode information is "010", the control unit 330 may determine that the communication mode is survival confirmation mode, read its own identifier information from the memory 340, and use the identifier information as the content of the information to be transmitted via BS transmission.

[0151] Alternatively, if the bit pattern representing the communication mode information is "011", the control unit 330 determines that the communication mode is the DO data presence / absence check mode and checks whether data to be transmitted by BS transmission exists in the memory 340. If data to be transmitted by BS transmission exists in the memory 340, the device's own identifier information stored in the memory 340 may be used as the content of the information to be transmitted by BS transmission. On the other hand, if data to be transmitted by BS transmission does not exist in the memory 340, there may be no information to be transmitted by BS transmission. The control unit 330 transmits the determined information content by BS transmission (step S25 below).

[0152] As explained in the first embodiment, the communication mode information includes not only BS transmission but also write mode. When the write mode (e.g., "100") is specified as the communication mode, the control unit 330 transitions to the write mode without performing BS transmission (without transitioning to the "BS processing standby mode" described later), and waits to receive data to be written transmitted from the communication node 400.

[0153] Fifth, the control unit 330 may start waiting for the next signal (for example, a second unmodulated signal (CW) or a signal for write data) following the signal transmitted as the BS control information unit. In the following, the control unit 330 will be described as waiting for a CW for BS transmission in accordance with the communication mode information, that is, transitioning to a mode for BS transmission. The mode for BS transmission will be referred to as a "BS processing standby mode" below.

[0154] In step S23, the control unit 330 of the ambient IoT device 300 transitions to a BS processing standby processing mode. Specifically, the control unit 330 waits for a CW (second unmodulated signal) for BS transmission (reflection of a CW transmission).

[0155] In step S24, the communication node 400 performs CW transmission.

[0156] First, the signal transmitted from the communication node 400 for BS transmission may be composed of a preamble signal and a CW (second unmodulated signal). In this case, the control unit 330 of the ambient IoT device 300 may perform time synchronization using the preamble signal. Also, the operation of the modulator 320 may be started at the timing of the CW after the preamble signal. The signal composed of the preamble signal and the CW may be a DL command.

[0157] Second, the signal transmitted from the communication node 400 for BS transmission may be only a CW (second unmodulated signal). The operation of the modulator 320 in the ambient IoT device 300 may be started at the timing of transmitting the CW.

[0158] In step S25, the ambient IoT device 300 performs BS transmission. The control unit 330 of the ambient IoT device 300 performs BS transmission in accordance with the BS control information. Specifically, the control unit 330 performs BS transmission in accordance with frequency information and / or communication timing information included in the BS control information. The control unit 330 also performs BS transmission in accordance with communication mode information included in the BS control information. Specifically, in a communication mode in which all data is transmitted via BS, the control unit 330 transmits all data stored in the memory 340 via BS transmission. In addition, in a communication mode in which only a portion of data is transmitted via BS, the control unit 330 transmits the maximum amount of data that can be transmitted via BS, starting with the most recent data stored in the memory 340. Furthermore, in a communication mode in which the survival confirmation mode is set, the control unit 330 transmits its own identifier information stored in the memory 340 via BS transmission after confirming its own survival. Furthermore, in the case of a communication mode of the DO data presence / absence checking mode, if data transmitted by BS exists in memory 340, control unit 330 transmits its own identifier information stored in memory 340 by BS transmission. On the other hand, in the case of a communication mode of the DO data presence / absence checking mode, if data transmitted by BS does not exist in memory 340, control unit 330 does not transmit its own identifier information by BS transmission, and does not need to perform any special processing for CW transmission.

[0159] In step S26, the control unit 330 of the ambient IoT device 300 transitions again to the DL command standby mode. The control unit 330 may transition to the DL command standby mode when the BS transmission (step S25) is completed. After transitioning to the DL command standby mode, the ambient IoT device 300 may repeat the processes from step S21 onward.

[0160] Third Embodiment Next, a third embodiment will be described.

[0161] In the first embodiment, an example was described in which the communication node 400 transmits a DL command. In the third embodiment, an example will be described in which a network device (for example, the gNB 200) controls what kind of DL command the communication node 400 transmits and at what timing.

[0162] Specifically, first, a network device (e.g., gNB 200) transmits configuration information to a communication node (e.g., communication node 400). Second, the communication node transmits a transmission signal (e.g., a DL command) to an IoT device (e.g., ambient IoT device 300) based on the configuration information. Here, as in the first embodiment, the transmission signal represents at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission.

[0163] This allows the network device to use the setting information to control the content of the DL command transmitted by the communication node 400 and the timing of transmitting the DL command, for example. This allows the network device to appropriately control communication in the ambient IoT device 300.

[0164] (Example of Operation According to Third Embodiment) Next, an example of operation according to the third embodiment will be described.

[0165] 16 is a diagram illustrating an example of communication in the third embodiment. As shown in FIG. 16, the network device 500 transmits setting information to the communication node 400.

[0166] The network device 500 may be a gNB 200. The network device 500 may be a device or entity connected to the core network 20 (hereinafter, sometimes referred to as a "core network device"). Examples of the core network device include an AMF 30 or an SMF. In the following, the network device 500 will be described using a gNB 200 as an example.

[0167] FIG. 17 is a diagram illustrating an example of operation according to the third embodiment.

[0168] As shown in FIG. 17, in step S30, the transmitter 210 of the gNB 200 transmits configuration information regarding the DL command to the communication node 400.

[0169] First, the configuration information basically includes information included in the DL command. Specifically, the configuration information may include at least one of identifier information of the ambient IoT device 300 and control information related to BS transmission. Alternatively, the configuration information may include information indicating which of the first unmodulated signal, the preamble signal, the signal representing the identifier information of the IoT device, and the signal representing control information related to backscattering transmission is to be transmitted as the DL command.

[0170] Second, the setting information may be represented in a list format as a plurality of pieces of setting information. Each of the plurality of pieces of setting information may have a setting ID. Alternatively, an index may be indicated in the order of entries of the plurality of pieces of setting information represented in list format, and each piece of setting information may be identified by the index.

[0171] Third, the setting information may include information specifying the timing at which the communication node 400 transmits a DL command. For example, the information may include the radio frame number of the starting radio frame at which transmission of the DL command starts. The information may include the period (cycle) at which the DL command is repeatedly transmitted. Alternatively, the setting information may include information indicating whether the DL command is to be transmitted periodically (periodic transmission) or aperiodically (aperiodic transmission).

[0172] When a DL command is transmitted periodically, the configuration information may include an instruction (or notification) to activate one or more pieces of configuration information among the plurality of pieces of configuration information. The instruction may be indicated by the above-mentioned setting ID. The instruction may be indicated by the above-mentioned index. The communication node 400 transmits a DL command including the activated configuration information at a timing specified in the configuration information. Furthermore, when a DL command is transmitted periodically, the configuration information may include an instruction (or notification) to deactivate one or more pieces of configuration information among the plurality of pieces of configuration information. The instruction may also be indicated by a setting ID or an index. The communication node 400 will stop transmitting DL commands including the deactivated configuration information.

[0173] Furthermore, when a DL command is transmitted aperiodically, the configuration information may include instruction information instructing the communication node 400 to transmit the DL command in accordance with the configuration information. The instruction information may include a setting ID of the configuration information to be instructed. The instruction information may include the above-mentioned index of the configuration information to be instructed. Upon receiving the configuration information including the instruction information, the communication node 400 may immediately transmit the DL command to the ambient IoT device 300 only once. The configuration information may include information indicating the timing of transmitting the DL command, and in that case, the communication node 400 will transmit the DL command only once at that timing. The information indicating the timing may indicate a waiting time for the communication node 400 after receiving the configuration information.

[0174] Fourth, when the communication node 400 is UE100, the transmitter 210 of the gNB 200 may transmit the configuration information by transmitting an RRC message including the configuration information. Also, when the communication node 400 is a gNB (in this case, for example, the gNB 200 becomes gNB #1, and the gNB that is the communication node 400 becomes gNB #2), the transmitter 210 of the gNB 200 (gNB #1) may transmit the configuration information by transmitting an Xn-AP message including the configuration information to the gNB (gNB #2). Furthermore, when the communication node 400 is an IAB node, the transmitter 210 of the gNB 200 may transmit the configuration information by transmitting an F1-AP message including the configuration information to the IAB node. Furthermore, when the communication node 400 is an NCR, the transmitter 210 of the gNB 200 may transmit the configuration information by transmitting an RRC message including the configuration information.

[0175] Thereafter, the communication node 400 transmits a DL command in accordance with the setting information (step S10). The subsequent steps (steps S12 and S13) are the same as those in the first and second embodiments.

[0176] (Another Operation Example 1 According to the Third Embodiment) In the third embodiment, an example in which the gNB 200 transmits the configuration information has been described, but the entity that transmits the configuration information is not limited to the gNB 200. For example, the AMF 30 may transmit the configuration information to the communication node 400. In this case, if the communication node 400 is the gNB 200, the transmission unit of the AMF 30 may transmit the configuration information by transmitting an NG-AP message including the configuration information to the gNB 200. Furthermore, if the communication node 400 is the UE 100, the transmission unit of the AMF 30 may transmit the configuration information by transmitting an NAS message including the configuration information to the UE 100. If the communication node 400 is an IAB node or an NCR, the transmission unit of the AMF 30 may transmit the configuration information by transmitting an NG-AP message including the configuration information.

[0177] (Another Operation Example 2 According to the Third Embodiment) The setting information (step S30 of FIG. 17) described in the third embodiment may include information indicating the communication frequency of the communication node 400 with the ambient IoT device 300. The communication frequency may be, for example, a 10 ms cycle or one-shot (only once). By combining the communication frequency with the identifier information of the ambient IoT device 300 (or the identifier information of the group to which the ambient IoT device 300 belongs), the gNB 200 can instruct the communication node 400 to acquire data at 10 ms cycles or acquire data in one BS transmission from a specific ambient IoT device 300. When the communication frequency is used, the BS control information of the DL command does not need to include frequency information and / or communication timing information.

[0178] [Other Embodiments] The above-described operational flows are not limited to being implemented independently, but can 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.

[0179] In the above-described embodiments and examples, an example in which the base station is an NR base station (gNB) is described, but the base station may also be an LTE base station (eNB) or a 6G base station.

[0180] That is, the UE 100 may be a terminal function unit (a type of communication module) for a base station to control a repeater that relays signals. Such a terminal function unit is referred to as an MT. Examples of the MT include, in addition to the IAB-MT, an NCR (Network Controlled Repeater)-MT and a RIS (Reconfigurable Intelligent Surface)-MT.

[0181] The term "network node" primarily refers to a base station, but may also refer to a core network device or a part of a base station (CU, DU, or RU). A network node may also be configured by a combination of at least a part of a core network device and at least a part of a base station.

[0182] A program may be provided that causes a computer to execute each process performed by the UE 100, the gNB 200, the communication node 400, or the core network device. The program may be recorded on a computer-readable medium. The computer-readable medium can be used to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM and / or a DVD-ROM. Furthermore, circuits that execute each process performed by the UE 100, the gNB 200, the communication node 400, or the core network device may be integrated, and at least a portion of the UE 100, the gNB 200, the communication node 400, or the core network device may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

[0183] The functions performed by the UE 100, the gNB 200, the communication node 400, or the core network device may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered to be circuitry or processing circuitry. A processor may also be a programmed processor that executes a program stored in memory. In this specification, circuitry, unit, or means refers to hardware that is programmed to perform the described functions or hardware that executes them. The hardware may be any hardware disclosed herein or any hardware known to be programmed or capable of performing the described functions. If the hardware is a processor, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0184] As used in this disclosure, the terms "based on" and "depending on / in response to" do not mean "based only on" or "depending only on," unless expressly stated otherwise. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "depending only on" and "depending at least in part on." The terms "include," "comprise," and variations thereof do not mean including only the listed items, but may mean including only the listed items or may include additional items in addition to the listed items. Additionally, the term "or," as used in this disclosure, is not intended to mean an exclusive or. Furthermore, any reference to elements using designations such as "first," "second," etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall include the plural unless the context clearly indicates otherwise.

[0185] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes can be made within the scope of the gist. Furthermore, the embodiments, operation examples, and processes can be appropriately combined within the scope of not being inconsistent.

[0186] This application claims priority from Japanese Patent Application No. 2023-193832 (filed November 14, 2023), the entire contents of which are incorporated herein by reference.

[0187] (Supplementary Note) (Supplementary Note 1) A communication control method in a wireless communication system, comprising: a step in which an IoT device receives, as a received signal from a communication node, at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission; and a step in which the IoT device uses the received signal to perform the backscattering transmission in response to a second unmodulated signal transmitted from the communication node.

[0188] (Supplementary Note 2) The communication control method according to Supplementary Note 1, further comprising a step in which the IoT device performs a predetermined operation in response to receiving the reception signal, wherein the predetermined operation includes at least one of the IoT device generating or storing electricity using the first unmodulated signal, determining a reference power, and starting to wait for the next signal.

[0189] (Supplementary Note 3) The communication control method according to Supplementary Note 1 or Supplementary Note 2, further comprising a step of the IoT device performing a predetermined operation in response to receiving the reception signal, wherein the predetermined operation is at least one of the IoT device performing time synchronization, determining a reference power, and starting to wait for a next signal using the preamble signal.

[0190] (Supplementary Note 4) The communication control method according to any one of Supplementary Note 1 to Supplementary Note 3, further comprising a step in which the IoT device performs a predetermined operation in response to receiving the received signal, wherein the predetermined operation is at least one of the IoT device using the identifier information to check whether it matches its own identifier information, to check whether it matches identifier information of a group to which the IoT device belongs, and to start waiting for the next signal.

[0191] (Supplementary Note 5) The communication control method according to any one of Supplementary Note 1 to Supplementary Note 4, further comprising a step in which the IoT device performs a predetermined operation in response to receiving the reception signal, wherein the predetermined operation is any one of determining a time of the backscattering transmission and / or determining a frequency to be used in the backscattering transmission using the control information, determining content of information to be transmitted in the backscattering transmission, waiting for the second unmodulated signal, and waiting for write data.

[0192] (Supplementary Note 6) An IoT device in a wireless communication system, comprising: a control unit that receives, from a communication node, at least one of a first unmodulated signal, a preamble signal, a signal representing identifier information of the IoT device, and a signal representing control information related to backscattering transmission as a received signal; and the control unit uses the received signal to perform the backscattering transmission for a second unmodulated signal transmitted from the communication node.

[0193] 1: Wireless communication system 10: NG-RAN 20: 5GC (CN) 30: AMF 100: UE 110: Receiver 120: Transmitter 130: Controller 200: gNB 210: Transmitter 220: Receiver 230: Controller 300: Ambient IoT device 310: Antenna 320: Switch 330: Controller 340: Memory 400: Communication node 410: Base station 420: Intermediate node 430: Assist node

Claims

1. A communication control method in a wireless communication system, The communication node receives configuration information from the network device, The communication node transmits a message to an IoT (Internet of Things) device based on the configuration information. The configuration information includes information regarding the time interval at which the communication node transmits the message. Communication control method.

2. A communication node in a wireless communication system, A receiving unit that receives configuration information from a network device, It includes a transmission unit that sends a message to an IoT device based on the aforementioned setting information, The configuration information includes information regarding the time interval at which the communication node transmits the message. Communication node.

3. A wireless communication system having a communication node and an IoT device, The aforementioned communication node receives configuration information from the network device. The communication node sends a message to the IoT device based on the configuration information. The configuration information includes information regarding the time interval at which the communication node transmits the message. Wireless communication system.

4. A communication node in a wireless communication system, The process of receiving configuration information from a network device, Based on the aforementioned configuration information, the process of sending a message to the IoT device is executed. The configuration information includes information regarding the time interval at which the communication node transmits the message. program.

5. A chipset for a communication node in a wireless communication system, Receiving configuration information from network devices, Based on the aforementioned configuration information, the system sends a message to an IoT device. The configuration information includes information regarding the time interval at which the communication node transmits the message. Chipset.