Communication control method and communication node

Abstract

A communication control method according to an aspect of the present invention is used for a wireless communication system. This communication control method includes a step in which a communication node transmits a transmission signal, which comprises a non-modulated continuous wave and a modulated wave obtained by modulating a command, to an IoT device. Here, the command includes information indicating that the non-modulated continuous wave is used for a random access procedure, and randomization information indicating information for the random access procedure to be performed at random for each IoT device.

Description

Communication control method and communication node

[0001] The present disclosure relates to a communication control method and a communication node.

[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 higher number of connections and a higher device density than existing IoT technologies in 3GPP. Furthermore, this IoT technology is expected to have lower complexity and power consumption than existing 3GPP Low Power Wide Area (LPWA) technologies such as Narrow Band IoT (NB-IoT) or Long Term Evolution Machine Type Communication (LTE-MTC). 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 including a step of transmitting, from a communication node, a transmission signal composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave to an IoT device, wherein the command includes information indicating that the unmodulated continuous wave is to be used for a random access procedure, and randomization information indicating information for randomly performing the random access procedure for each IoT device.

[0007] A communication node according to a second aspect is a communication node in a wireless communication system. The communication node has a transmitter that transmits a transmission signal to an IoT device, the transmission signal being composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave. Here, the command includes information indicating that the unmodulated continuous wave is to be used for the random access procedure, and randomization information indicating information for randomly performing the random access procedure for each IoT device.

[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 the configuration of a topology according to the first embodiment. FIGS. 9(A) and 9(B) are diagrams illustrating an example of the configuration of a topology according to the first embodiment. FIG. 10 is a diagram illustrating an example of the configuration of a topology according to the first embodiment. FIG. 11 is a diagram illustrating an example of the configuration of "device 1" according to the first embodiment. FIG. 12 is a diagram illustrating an example of the configuration of "device 2a" according to the first embodiment. FIG. 13 is a diagram illustrating an example of operation according to the first embodiment.

[0009] One aspect is to mitigate collisions of D2R transmissions and to properly perform random access procedures.

[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 AMF (Access and Mobility Management Function) 30 and a UPF (User Plane Function). 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. The devices (or nodes) included in the 5GC20 may be referred to as core network devices (or core network nodes). The AMF 30 and the UPF are examples of core network devices.

[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. The communication node 400 may be called a reader.

[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] (Ambient IoT Device Types) In 3GPP, it has been agreed that there are the following three types of ambient IoT devices 300.

[0068] (B1) Device 1

[0069] (B2) Device 2a

[0070] (B3) Device 2b "Device 1" is, for example, a device with peak power consumption of "1 μW" or less, no amplification in either the DL or UL direction, and backscattering transmission using an externally provided carrier. "Device 2a" is, for example, a device with peak power consumption of "several hundred μW" or less, amplification in the DL and / or UL direction, and backscattering transmission using an externally provided carrier. "Device 2b" is, for example, a device with peak power consumption of "several hundred μW" or less, amplification in the DL and / or UL direction, and UL transmission generated internally. Note that both device types have an energy storage function.

[0071] In 3GPP, any of the above terms (B1) to (B3) is used to represent the type of the ambient IoT device 300. In the present embodiment, any of the above terms (B1) to (B3) may also be used to represent the type of the ambient IoT device 300.

[0072] (Example of Block Configuration of Each Device) The 3GPP also agreed on the block configuration of "Device 1" and "Device 2a." The configuration of each block will be described.

[0073] (C1) Example of Block Configuration of "Device 1" Fig. 11 is a diagram showing an example of the block configuration of "Device 1" (i.e., the ambient IoT device 300 whose type is "Device 1") according to the first embodiment. The same blocks as those in the example configuration of Fig. 4 described above are assigned the same reference numerals.

[0074] As shown in FIG. 11 , “device 1” includes at least an antenna 310, a matching network 350, an RF energy harvester 351, a PMU (Power Management Unit) 352, an energy storage unit 353, an RF BPF (Radio Frequency Band Pass Filter) 354, an RF envelope detector (or envelope detector) 355, a BB LPF (Base Band Low Pass Filter) 356, a comparator 357, baseband logic 358, a memory 359, a backscattering modulator 360, and a clock generator 361.

[0075] The matching network 350 matches the impedance between the antenna 310 and other blocks (including the RF energy harvester 351 and the RF BPF 354) and outputs the radio signal received by the antenna 310 to the other blocks.

[0076] The RF energy harvester 351 has an energy harvesting function and extracts energy from the radio signal. The RF energy harvester 351 may also have a rectifier that converts the radio signal from an AC component to a DC component.

[0077] The PMU 352 manages (or controls) the accumulation of energy from the RF energy harvester 351 and manages (or controls) the supply of power to the blocks that require it.

[0078] The energy storage unit 353 stores energy from the RF energy harvester 351 .

[0079] The RF BPF 354 outputs a radio signal in a specific frequency band. The RF BPF 354 is used to improve selectivity. Note that the RF BPF 354 may not be included in the "device 1" depending on the implementation.

[0080] The RF envelope detector 355 converts the radio signal in the radio band output from the RF BPF 354 into a baseband signal in the baseband band.

[0081] The BB LPF 356 removes high frequency components from the baseband signal output from the RF envelope detector 355 and improves the quality of the signal input to the comparator 357 .

[0082] The comparator 357 determines whether the input signal output from the BB LPF 356 is “high” or “low.”

[0083] The baseband logic 358 includes functional blocks such as an encoder, a decoder, and a controller.

[0084] The memory 359 stores device identification information (or device ID) and the like for identifying (or distinguishing) the ambient IoT device 300 from other ambient IoT devices. The memory 359 may be a non-volatile memory (e.g., an EEPROM (Electrically Erasable Programmable Read-Only Memory)) that permanently stores the device ID and the like. The memory 359 may also be a memory (register) that temporarily stores information required only while the energy stored in the energy storage unit 353 is available.

[0085] The backscattering modulator 360 switches impedance to modulate the output signal from the baseband logic 358 into a backscattering signal. Alternatively, the backscattering modulator 360 switches impedance (the impedance of the antenna or the transmission line) using the output signal (digital signal or digital data) from the baseband logic 358 to modulate the high-frequency signal (e.g., CW) input from the antenna 310 into a backscattering signal. For example, the backscattering modulator 360 can modulate and then reflect the high-frequency signal input from the antenna 310 by terminating (not reflecting) the high-frequency input signal for digital data "0" and opening (reflecting) the high-frequency input signal for digital data "1."

[0086] The clock generator 361 generates the clock signals required within the device.

[0087] The above is an example of the configuration of "device 1." In relation to the example of the configuration of the ambient IoT device 300 shown in FIG. 4 , for example, the following applies. That is, the matching network 350, the RF BPF 354, the RF envelope detector 355, the BB LPF 356, the comparator 357, and the backscattering modulator 360 may be included in the modulator 320 shown in FIG. 4 . Also, the PMU 352 and the baseband logic 358 may be included in the control unit 330 shown in FIG. 4 . Furthermore, the memory 359 may correspond to the memory 340 shown in FIG. 4 .

[0088] (C2) Example of block configuration of "device 2a" Fig. 12 is a diagram showing an example of the block configuration of "device 2a" (i.e., the ambient IoT device 300 whose type is "device 2a") according to the first embodiment. The same reference numerals are used to designate the same blocks as those in the example configurations of Figs. 4 and 11 described above.

[0089] The "device 2a" shown in FIG. 12 further includes at least an LNA (Low Noise Amplifier) ​​365, a baseband amplifier 366, a large frequency shifter 367, a reflection amplifier 368, and an energy harvester 369 in addition to the "device 1" shown in FIG. 11.

[0090] LNA365 amplifies the output signal from RF BPF354 (i.e., the signal from the reader (gNB200 or UE100)) to improve the signal strength and signal sensitivity at the receiving side.

[0091] The baseband amplifier 366 amplifies the baseband signal output from the RF envelope detector 355 to improve the signal strength.

[0092] The large frequency shifter 367 shifts the frequency of the backscattering signal from one frequency (eg, the FDD-DL frequency) to another frequency (eg, the FDD-UL frequency).

[0093] The energy harvester 369 generates energy from an environment using a source other than an RF signal. Specifically, energy harvesting sources include sunlight (solar panels), vibration (vibration power generation), and heat (thermal power generation), but are not limited to these.

[0094] The above describes an example configuration of the "device 2a." Of the blocks shown in Fig. 12, the LNA 365 and the large frequency shifter 367 are items for future study. In the example block configuration shown in Fig. 12, in relation to the example block configuration shown in Fig. 4, the LNA 365, the baseband amplifier 366, the large frequency shifter 367, and the reflection amplifier 368 may be further included in the modulator 320.

[0095] (PRDCH and PDRCH) In addition, the 3GPP has also agreed on the physical channels used by the ambient IoT device 300.

[0096] For example, as shown in FIG. 7, the physical channel used for transmission from the communication node 400 to the ambient IoT device 300 (hereinafter, sometimes referred to as "R2D (Reader to Device) transmission") is called the PRDCH (Physical Reader to Device channel).

[0097] On the other hand, the physical channel used for transmission from the ambient IoT device 300 to the communication node 400 (hereinafter, sometimes referred to as "D2R (Device to Reader) transmission") is called a PDRCH (Physical Device to Reader channel).

[0098] For example, in topology 1 shown in Figure 8 (A), the physical channel used for R2D transmission from BS410 (or gNB200) to ambient IoT device 300 is PRDCH, and the physical channel used for D2R transmission from ambient IoT device 300 to BS410 is PDRCH.

[0099] In topology 2 shown in FIG. 8(B), the physical channel used for R2D transmission from the intermediate node 420 to the ambient IoT device 300 is PRDCH, and the physical channel used for D2R transmission from the ambient IoT device 300 to the intermediate node 420 is PDRCH.

[0100] In the following, a communication link using a PRDCH may be referred to as an R2D link, and a communication link using a PDRCH may be referred to as a D2R link. In the following, the PRDCH and the R2D link may be used without distinction. In the following, the PDRCH and the D2R link may be used without distinction.

[0101] (Communication control method according to the first embodiment) Generally, after powering on, the UE 100 camps on a suitable cell and then performs a random access procedure with the network (gNB 200). Specifically, the UE 100 transmits a random access preamble (Msg1) to the gNB 200 using the configuration information received through the system information (SIB1). The UE 100 receives a random access response (Msg2) including an uplink grant and a timing advance (TA) value from the gNB 200. Then, the UE 100 transmits a request message (Msg3) (such as an RRC setup request message) for establishing an RRC connection using the uplink grant, and establishes the RRC connection. At this time, the UE 100 adjusts the transmission timing using the TA value. As a result, for example, UE 100 establishes synchronization in the uplink direction with the network (gNB 200). In other words, the random access procedure can be said to be a procedure for establishing synchronization of the uplink of UE 100 by determining the TA value.

[0102] On the other hand, there is a problem of how to consider the random access procedure in the ambient IoT device 300. For example, it is possible for the ambient IoT device 300 to determine a TA value by performing a random access procedure. Although it is assumed that the ambient IoT device 300 communicates with the communication node 400 (or reader) within a limited distance, determining the TA value and adjusting the transmission timing from the ambient IoT device 300 enables appropriate communication between the communication node 400 and the ambient IoT device 300.

[0103] In the first embodiment, attention is focused on one assumed scenario of the random access procedure, in which D2R transmission is performed using different timing and frequency for each ambient IoT device 300.

[0104] In such a scenario, if multiple ambient IoT devices 300 simultaneously perform D2R transmissions, the D2R transmissions collide, preventing the random access procedure from being properly performed. In other words, in such a scenario, the challenge is to mitigate D2R transmission collisions. By suppressing D2R transmission collisions, the random access procedure can be properly performed.

[0105] Therefore, the first embodiment aims to suppress collisions of D2R transmissions and to enable the random access procedure to be performed appropriately.

[0106] Therefore, in the first embodiment, a communication node (e.g., communication node 400) transmits a transmission signal composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave (e.g., CW) to an IoT device (e.g., ambient IoT device 300). Here, the command includes information indicating that the unmodulated continuous wave is used for the random access procedure, and randomization information indicating information for randomly performing the random access procedure for each IoT device.

[0107] In this way, the random access procedure is performed by the communication node 400 transmitting a command including information indicating that a CW is to be used for the random access procedure to the ambient IoT device 300, and the ambient IoT device 300 performing D2R transmission using a CW in response to the command. For example, the ambient IoT device 300 may start the random access procedure by transmitting a random access preamble (Msg1) in the D2R transmission.

[0108] Then, by using the randomization information, the ambient IoT device 300 can randomly perform the D2R transmission for each ambient IoT device 300. Therefore, it is possible to suppress collisions of D2R transmissions, and it is possible to appropriately perform a random access procedure for the ambient IoT device 300.

[0109] (Example of Operation According to First Embodiment) Next, an example of operation according to the first embodiment will be described.

[0110] Fig. 13 is a diagram illustrating an example of operation according to the first embodiment. In Fig. 13, a communication node 400 is described, but the communication node 400 may be a reader as described above.

[0111] In step S10, the control unit of the communication node 400 (the control unit 130 of the UE 100 or the control unit 230 of the gNB 200) sets the following information in the command. The transmitting unit of the communication node 400 (the transmitting unit 120 of the UE 100 or the transmitting unit 210 of the gNB 200) transmits a transmission signal (D2R signal) consisting of a modulated wave obtained by modulating the command and an unmodulated continuous wave (CW).

[0112] First, the control unit of the communication node 400 sets information indicating that the CW is for a random access procedure in the command. The information may be information indicating that the CW is used for a random access procedure.

[0113] Second, the control unit of the communication node 400 sets randomization information indicating information for randomly performing the random access procedure for each ambient IoT device 300 in the command. Specifically, the randomization information includes integers n and m. When the ambient IoT device 300 receives the integers n and m, the ambient IoT device 300 performs D2R transmission using a CW if its own identification information (device ID) satisfies the following formula (1):

[0114] (Device ID mod n)+m=0 (1) Instead of equation (1), the following equation (2) may be used.

[0115] (Device ID mod n)=m (2) The control unit of the communication node 400 may set the integers n and m according to any of the following conditions.

[0116] That is, the control unit may set the integer n when the number of ambient IoT devices 300 that execute the random access procedure is to be limited to a predetermined number. For example, the control unit sets n=4 when the number of ambient IoT devices 300 that execute the random access procedure is to be limited to 25% (1 / 4).

[0117] Furthermore, regarding the integer n, the control unit may use the number of CWs for the random access procedure within a certain period as the integer n. For example, if the number of CWs for the random access procedure is to be transmitted "five times" per second, n = 5 is set. This makes it possible to reduce the number of ambient IoT devices 300 per CW transmission to 20% (1 / 5), for example. This enables randomization in the time direction in D2R transmission.

[0118] On the other hand, with regard to the integer m, the control unit may set an incremented value to the integer m according to the number of transmissions of the CW for the random access procedure. For example, when m = 0 for the current transmission of the CW, the control unit sets m = 1 for the next transmission of the CW. In formula (1) (or formula (2)), the device ID is divided by the integer n, but by using the integer m, it is possible to permit D2R transmission for ambient IoT devices 300 whose device ID ends with a digit that is not a multiple of n (i.e., there is a remainder when the device ID is divided by the integer n).

[0119] Furthermore, the control unit may set a different integer m for each transmission of a CW for the random access procedure within a certain period. For example, if the communication node 400 transmits the CW five times per second, the control unit sets m = 0, 1, 2, 3, 4 for each of the five CWs. For example, if CW transmission is performed at a different frequency (multi-tone) for each CW, it is also possible to distribute the ambient IoT devices 300 in the frequency direction. This enables randomization of D2R transmission in the frequency direction.

[0120] Note that with respect to integers n and m, m can take a range from "0" to "n-1" ([0, n-1]), because integer m represents the remainder when the device ID is divided by integer n.

[0121] In this way, the integer n is used, for example, to limit the number of ambient IoT devices 300 that execute the random access procedure. The integer n represents limitation information that limits the number of ambient IoT devices 300 that execute the random access procedure. Furthermore, the integer m represents, for example, increment information that is incremented each time the communication node 400 transmits the CW. In this way, the randomization information includes limitation information (integer n) and increment information (integer m). Note that equation (1) (or equation (2)) using the integers n, m, and the device ID represents an example of a predetermined condition. Furthermore, as shown in equation (1) (or equation (2)), the device ID is used, so it is also possible to control whether or not to perform D2R transmission for each ambient IoT device 300. In this case, by using the integers n and m as shown in equation (1) (or equation (2)), randomization is performed so that an ambient IoT device 300 having a specific device ID is not fixed and does not perform D2R transmission.

[0122] In step S11, the transmitting unit of the communication node 400 (the transmitting unit 120 of the UE 100 and the transmitting unit 210 of the gNB 200) transmits a transmission signal (D2R signal) consisting of a modulated wave modulated with a command and a CW.

[0123] In step S12, the receiving unit (modulator 320) of the ambient IoT device 300 receives the transmission signal and extracts a demodulated signal from the transmission signal. Then, in step S12, the control unit 330 of the ambient IoT device 300 decodes the demodulated signal to obtain a command. The control unit 330 sets the integers n and m extracted from the command to equation (1) (or equation (2)), and determines whether its own device ID read from the memory 340 satisfies equation (1) (or equation (2)) (i.e., satisfies a predetermined condition). If its own device ID satisfies equation (1) (or equation (2)) (i.e., satisfies the predetermined condition), the control unit 330 performs D2R transmission during the CW period after the command. The D2R transmission may be performed by backscattering transmission by operating the backscattering modulator 360 (FIGS. 11 and 12) (or modulator 320) during the CW period. Alternatively, a D2R signal (PDRCH) may be generated and transmitted during the CW period. The control unit 330 may start the random access procedure by transmitting a D2R signal including a random access preamble (Msg1) of the random access procedure during the CW period. On the other hand, the control unit 330 does not perform D2R transmission when its own device ID does not satisfy formula (1) (or formula (2)) (i.e., when the predetermined condition is not satisfied). This limits D2R transmissions from multiple ambient IoT devices 300, making it possible to suppress collisions of D2R transmissions.

[0124] [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.

[0125] In the above-described embodiments and examples, an example in which the base station is an NR base station (gNB) has been described, but the base station may be an LTE base station (eNB) or a 6G base station. The base station may also be a relay node such as an IAB (Integrated Access and Backhaul) node. The base station may also be a DU of the IAB node. The UE 100 may also be an MT (Mobile Termination) of the IAB node.

[0126] 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.

[0127] 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.

[0128] 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).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] This application claims priority from Japanese Patent Application No. 2024-060186 (filed April 3, 2024), the entire contents of which are incorporated herein by reference.

[0133] (Addendum) The above can be summarized as follows.

[0134] (Supplementary Note 1) A communication control method in a wireless communication system, comprising: a step in which a communication node transmits, to an IoT device, a transmission signal composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave, wherein the command includes information indicating that the unmodulated continuous wave is used for a random access procedure, and randomization information indicating information for randomly performing the random access procedure for each IoT device.

[0135] (Supplementary Note 2) The communication control method according to Supplementary Note 1, wherein the randomization information includes limiting information for limiting the number of the IoT devices and increment information that is incremented each time the unmodulated continuous wave is transmitted.

[0136] (Supplementary Note 3) The communication control method according to Supplementary Note 1 or Supplementary Note 2, further comprising the steps of: the IoT device receiving the command; and the IoT device executing the random access procedure using identification information of the IoT device.

[0137] (Supplementary Note 4) The communication control method according to any one of Supplementary Note 1 to Supplementary Note 3, comprising: a step of receiving the command by the IoT device; and a step of executing the random access procedure by the IoT device when a predetermined condition using the restriction information, the increment information, and identification information of the IoT device is satisfied.

[0138] (Supplementary Note 5) A communication node in a wireless communication system, comprising: a transmitter that transmits a transmission signal composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave to an IoT device, wherein the command includes information indicating that the unmodulated continuous wave is used for a random access procedure, and randomization information indicating information for the random access procedure to be performed randomly for each IoT device.

[0139] 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 240: Backhaul communication unit 300: Ambient IoT device 310: Antenna 320: Modulator 330: Controller 340: Memory 350: Matching network 351: RF energy harvester 352: PMU 353: Energy storage unit 354: RF BPF 355: RF envelope detector 356: BB LPF 357: Comparator 358: Baseband logic 359: Memory 360: Backscattering modulator 361: Clock generator 365: LNA 366: Baseband amplifier 367: Large frequency shifter 368: Reflection amplifier 369: Energy harvester 400: Communication node 410: Base station 420: Intermediate node 430: Assist node

Claims

1. A communication control method in a wireless communication system, comprising: a communication node transmitting a transmission signal composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave to an IoT device; wherein the command includes information indicating that the unmodulated continuous wave is to be used for a random access procedure, and randomization information indicating information for randomly performing the random access procedure for each IoT device.

2. The communication control method according to claim 1, wherein the randomization information includes restriction information for restricting the number of IoT devices and increment information that is incremented each time the unmodulated continuous wave is transmitted.

3. The communication control method according to claim 1, further comprising: the IoT device receiving the command; and the IoT device executing the random access procedure using identification information of the IoT device.

4. The communication control method according to claim 2, comprising: the IoT device receiving the command; and the IoT device executing the random access procedure if a predetermined condition is met using the restriction information, the increment information, and the identification information of the IoT device.

5. A communication node in a wireless communication system, comprising: a transmitting unit that transmits a transmission signal to an IoT device, the transmission signal being composed of a modulated wave obtained by modulating a command and an unmodulated continuous wave, wherein the command includes information indicating that the unmodulated continuous wave is to be used for a random access procedure, and randomization information indicating information for the random access procedure to be performed randomly for each IoT device.

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