Communication control method and network node

Abstract

A communication control method according to an aspect is one in a radio communication system. The communication control method has a step in which a base station transmits, to user equipment, a first radio resource used for the communication between the user equipment and a radio tag. The communication control method also has a step in which the user equipment uses the first radio resource to communicate with the radio tag. The first radio resource here is a radio resource that is different from a second radio resource used for the communication between the base station and the user equipment.

Description

Technical Field

[0001] The present disclosure relates to a communication control method and a network node in a wireless communication system.

Background Art

[0002] In the 3GPP (The Third Generation Partnership Project), which is a standardization project for mobile communication systems, discussions on Passive IoT are being held (see, for example, Non-Patent Documents 1 to 3).

[0003] Passive IoT is a technology that supports, for example, ultra-low cost and ultra-low power devices.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

[0005] The communication control method according to the first aspect is a communication control method in a wireless communication system. The communication control method includes a step in which a base station transmits a first radio resource used for communication between a user device and a radio tag to the user device. Further, the communication control method includes a step in which the user device communicates with the radio tag using the first radio resource. Here, the first radio resource is a radio resource different from a second radio resource used for communication between the base station and the user device.

[0006] The second aspect of the communication control method is a communication control method in a wireless communication system. The communication control method includes the step of a base station transmitting passive link support information to a user device indicating whether or not the base station supports passive links. The communication control method also includes the step of the user device re-selecting a cell prioritizing cells that support passive links, provided that the base station supports passive links and in a predetermined case. Here, the predetermined case is one of the following: the user device has a wireless tag under its control; the user device is interested in communicating with a wireless tag using a passive link; or the user device is communicating with a wireless tag using a passive link. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a diagram showing an example configuration of a wireless communication system according to the first embodiment. [Figure 2] Figure 2 is a diagram showing an example configuration of a UE (User Equipment) according to the first embodiment. [Figure 3] Figure 3 is a diagram showing an example configuration of a gNB (base station) according to the first embodiment. [Figure 4] Figure 4 is a diagram showing an example of the configuration of a wireless tag according to the first embodiment. [Figure 5] Figure 5 is a diagram showing an example of the configuration of a protocol stack related to the user plane according to the first embodiment. [Figure 6] Figure 6 is a diagram showing an example of the configuration of a protocol stack related to the control plane according to the first embodiment. [Figure 7] Figure 7 is a diagram illustrating the challenges of the passive IoT according to the first embodiment. [Figure 8] Figures 8(A) and 8(B) are diagrams illustrating scenario a according to the first embodiment. [Figure 9] Figures 9(A) to 9(C) are diagrams illustrating scenario b according to the first embodiment. [Figure 10] Figure 10 is a diagram illustrating scenario c according to the first embodiment. [Figure 11] Figure 11 is a diagram illustrating an example of operation according to the first embodiment. [Figure 12] Figure 12 is a diagram illustrating an example of operation according to the second embodiment. [Figure 13] Figure 13 is a diagram illustrating an example of operation according to the third embodiment. [Figure 14] Figure 14 is a diagram illustrating an example of operation according to the fourth embodiment. [Modes for carrying out the invention]

[0008] One embodiment aims to suppress the occurrence of interference. Another embodiment aims to enable a base station to control communication between a user device and a wireless tag.

[0009] The wireless communication system according to the embodiment will be described with reference to the drawings. In the drawings, identical or similar parts are denoted by the same or similar reference numerals.

[0010] [First Embodiment] (Example of a wireless communication system configuration) Figure 1 is a diagram showing an example configuration of a wireless communication system according to the first embodiment. Wireless communication system 1 includes a mobile communication system that is a 5th Generation System (5GS) according to the 3GPP standard. In the following description, 5GS will be used as an example of the mobile communication system, but an LTE (Long Term Evolution) system may be applied at least partially. Furthermore, a 6th Generation (6G) system or later may be applied at least partially as the mobile communication system. Note that wireless communication system 1 may also be a mobile communication system.

[0011] The wireless communication system 1 includes a user equipment (UE: User Equipment) 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 RF (Radio Frequency) tag 300. Hereinafter, the 5GC 20 may sometimes be simply referred to as the core network (CN) 20.

[0012] The UE 100 is a movable wireless communication device. The UE 100 may be any device as long as it is used by a user. The UE 100 is, for example, a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), an aircraft or a device provided in an aircraft (Aerial UE).

[0013] The NG-RAN 10 includes base stations (referred to as "gNB" in the 5G system) 200. The gNBs 200 are interconnected 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 the UE 100 that has established a connection with its cell. The gNB 200 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), a measurement control function for mobility control and scheduling, etc. Note that "cell" is used as a term indicating the smallest unit of a wireless communication area. "Cell" is also used as a term indicating a function or resource for performing wireless communication with the UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0014] Note that the gNB can also be connected to the EPC (Evolved Packet Core), which is the core network of LTE. The base station of LTE can also be connected to the 5GC. The base station of LTE and the gNB can also be connected via an interface between base stations.

[0015] The 5GC 20 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 performs data transfer control. The AMF 30 and the UPF are connected to the gNB 200 via the NG interface, which is an interface between the base station and the core network.

[0016] The RF tag (or wireless tag. Hereinafter, it may be referred to as a "wireless tag") 300 is a wireless communication device capable of wireless communication with the UE 100 or the gNB 200. The wireless tag 300 is also an information medium that writes data, etc. into the built-in memory or reads data, etc. from the memory using radio waves or an electromagnetic field. The wireless tag 300 is, for example, an extremely small, thin, lightweight, and low-complexity IoT (Internet of Things) device.

[0017] (Configuration example of UE) FIG. 2 is a diagram showing a configuration example 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 UE 100 may include a reader / writer 140. The receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200.

[0018] 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 the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130.

[0019] The transmitting unit 120 performs various types of transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 130 into a wireless signal and transmits it from the antenna.

[0020] The control unit 130 performs various control and processing in the UE100. Such processing includes processing in each layer described later. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation, demodulation, encoding, and decoding of baseband signals. The CPU executes programs stored in memory and performs various processing. In the example shown below, the operation or processing in the UE100 may be performed by the control unit 130.

[0021] The reader / writer 140 includes an RFID (Radio Frequency Identifier) ​​antenna 141. The reader / writer 140 communicates with the wireless tag 300 via the RFID antenna 141 under the control unit 130. The reader / writer 140 communicates with the wireless tag 300 using RFID technology. RFID technology is a technology that uses radio waves or electromagnetic fields to write data to or read data from the wireless tag 300 contactlessly. The reader / writer 140 can also generate power for the wireless tag 300 using the radio waves or electromagnetic fields transmitted from the RFID antenna 141. The UE 100 can communicate wirelessly with the wireless tag 300 via the reader / writer 140. Note that the reader / writer 140 may have only a reader function and no writer function.

[0022] Furthermore, the reader / writer 140 can also communicate wirelessly with the wireless tag 300 using the 3GPP communication protocol. In this case, instead of the RFID antenna 141, the reader / writer 140 may include an antenna capable of transmitting and receiving wireless signals at frequencies used by 3GPP. In addition, the reader / writer 140 can also communicate wirelessly with the wireless tag 300 using backscattering. In this case, the reader / writer 140 may include an antenna capable of transmitting and receiving frequency signals used for backscattering. Details of backscattering will be described later.

[0023] (Example of gNB configuration) Figure 3 is a diagram showing an example configuration of a gNB200 (base station) according to the first embodiment. The gNB200 comprises a transmitter 210, a receiver 220, a control unit 230, and a backhaul communication unit 240. The gNB200 may also include a reader / writer 250. The transmitter 210 and receiver 220 constitute a wireless communication unit that performs wireless communication with the UE100. The backhaul communication unit 240 constitutes a network communication unit that communicates with the CN20.

[0024] The transmitting unit 210 performs various types of transmissions under the control of the control unit 230. The transmitting unit 210 includes an antenna and a transmitter. The transmitter converts the baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0025] 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 the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 230.

[0026] The control unit 230 performs various control and processing in the gNB200. Such processing includes processing in each layer described later. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used for processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation, demodulation, encoding, and decoding of baseband signals. The CPU executes programs stored in memory and performs various processing. In the example shown below, the operation or processing in the gNB200 may be performed by the control unit 230.

[0027] The backhaul communication unit 240 is connected to an adjacent base station via the Xn interface, which is an inter-base station interface. The backhaul communication unit 240 is connected to the AMF30 / UPF via the NG interface, which is an inter-base station-core network interface. The gNB200 may consist of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally separated), and the two units may be connected by the F1 interface, which is a fronthaul interface.

[0028] The reader / writer 250 includes an RFID antenna 251. Under the control unit 230, the reader / writer 250 communicates with the wireless tag 300 via the RFID antenna 251. The reader / writer 250 uses radio waves or electromagnetic fields transmitted from the RFID antenna 251 to write data to and read data from the wireless tag 300 contactlessly. The reader / writer 250 can also generate power for the wireless tag 300 using radio waves or electromagnetic fields transmitted from the RFID antenna 251. The gNB200 can communicate wirelessly with the wireless tag 300 via the reader / writer 250. Note that the reader / writer 250 may have only a reader function and no writer function.

[0029] Furthermore, the reader / writer 250 can also communicate wirelessly with the wireless tag 300 using the 3GPP communication protocol. In this case, instead of the RFID antenna 251, the reader / writer 250 may include an antenna capable of transmitting and receiving wireless signals at frequencies used by 3GPP. Additionally, the reader / writer 250 can communicate wirelessly with the wireless tag 300 using backscattering. In this case, the reader / writer 250 may include an antenna capable of transmitting and receiving frequencies used in backscattering.

[0030] (Example of wireless tag configuration) Figure 4 is a diagram showing an example configuration of a wireless tag 300 according to the first embodiment. The wireless tag 300 includes an RFID antenna 310, a control unit 320, and a memory 330. The wireless tag 300 may also include a power supply 340.

[0031] The RFID antenna 310 uses RFID technology to communicate wirelessly with the UE100 or gNB200. As mentioned above, RFID technology includes both radio wave and electromagnetic induction methods.

[0032] The radio wave method is a method of transmitting energy and signals using radio waves. In this case, the RFID antenna 310 receives radio waves transmitted from the UE100 or gNB200, and a rectifier circuit provided in the RFID antenna 310 outputs a portion of the radio waves as a DC power supply to the control unit 320. This causes the control unit 320 to operate. The RFID antenna 310 also converts the received radio waves into a received signal using a demodulation circuit or the like, and outputs the received signal to the control unit 320. The RFID antenna 310 also converts the transmission signal received from the control unit 320 into a radio signal in the radio band using a modulation circuit or the like, and transmits the radio signal to the UE100 or gNB200. At this time, the RFID antenna 310 may also transmit the radio signal using the reflected waves of the received radio waves received from the UE100 or gNB200.

[0033] The electromagnetic induction method is a method of transmitting energy and signals by generating an electromagnetic field in an antenna coil through electromagnetic induction. In the case of the electromagnetic induction method, the RFID antenna 310 is a loop coil antenna. Both the RFID antenna 141 of the UE100 and the RFID antenna 251 of the gNB200 are loop coil antennas. Even in the electromagnetic induction method, power to the control unit 320 can be obtained by a rectifier circuit, the received signal can be obtained by a demodulation circuit, and reflected waves may be used, just as in the radio wave method.

[0034] The control unit 320 receives a received signal from the RFID antenna 310. The control unit 320 writes the data contained in the received signal to the memory 330, for example, according to the instruction information contained in the received signal. The control unit 320 also reads data from the memory 330, for example, according to the instruction information contained in the received signal. The control unit 320 outputs a transmission signal containing the read data to the RFID antenna 310. In the example shown below, the operation or processing in the wireless tag 300 may be performed by the control unit 320.

[0035] Memory 330 stores the identifier of the wireless tag 300 (or identification information of the wireless tag 300; hereinafter, "identifier" and "identification information" may be used interchangeably), and data. The memory 330 of the wireless tag 300 may adopt the EPC GEN2 (EPC (Electronic Product Code) Class 1 Generation 2) standard compliant with ISO / IEC 18000-63. Memory 330 conforming to the EPC GEN2 standard has four memory areas: USER memory, TID (Tag ID) memory, EPC memory, and RESERVED memory. USER memory is an area that users of the wireless tag 300 can freely write to and read from. TID memory is an area where the manufacturer and model information of the wireless tag 300 is written. TID memory is a read-only, non-write area. EPC memory is an area where the identifier of the wireless tag 300 is written. RESERVED memory is an area where the password information of the wireless tag 300 is written. The password information includes password information used to lock writing to the wireless tag 300 and password information used to disable (kill) the wireless tag 300.

[0036] Power source 340 is, for example, a power source that utilizes energy harvesting. The environment includes heat, vibration, motion, light, wind power, radio waves, biotechnology, etc. Energy harvesting is a power generation method that obtains electromotive force from the surrounding environment. Energy harvesting is different from power generation methods that use batteries such as secondary batteries. However, the wireless tag 300 may be equipped with a battery and generate its own power, like an active tag. Therefore, power source 340 may use a battery power source.

[0037] Furthermore, the wireless tag 300 may not have a writer function to write data to the memory 330, but only a reader function to read data from the memory 330.

[0038] Furthermore, the wireless tag 300 can also communicate wirelessly with the UE100 or gNB200 using the 3GPP communication protocol. In this case, instead of the RFID antenna 310, the wireless tag 300 may include an antenna capable of transmitting and receiving wireless signals at frequencies used by 3GPP.

[0039] In the following description, the communication method of the wireless tag 300 will be explained as utilizing RFID technology, but it is not limited to this. For example, the communication method of the wireless tag 300 may utilize a 3GPP-compliant communication protocol. Furthermore, the wireless tag 300 may communicate using backscattering.

[0040] (Protocol stack) Next, we will describe an example of a protocol stack configuration. Here, we will describe an example of a protocol stack configuration for the UE100, gNB200, and AMF30, excluding the wireless tag 300.

[0041] Figure 5 shows an example of the protocol stack configuration for a user-plane wireless interface that handles data.

[0042] The user plane radio interface protocol consists of a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an SDAP (Service Data Adaptation Protocol) layer.

[0043] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the UE100's PHY layer and the gNB200's PHY layer via a physical channel. The UE100's PHY layer receives downlink control information (DCI) transmitted from the gNB200 over the physical downlink control channel (PDCCH). Specifically, the UE100 performs blind decoding of the PDCCH using a Radio Network Temporary Identifier (RNTI) and acquires the successfully decoded DCI as the DCI addressed to its own UE. The DCI transmitted from the gNB200 has a CRC parity bit added, which is scrambled by the RNTI.

[0044] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat request (HARQ), and random access procedures. Data and control information are transmitted between the MAC layer of the UE100 and the MAC layer of the gNB200 via the transport channel. The MAC layer of the gNB200 includes a scheduler. The scheduler determines the transport format for the up and down links (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to the UE100.

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

[0046] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

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

[0048] Figure 6 shows an example of the protocol stack configuration for a wireless interface of a control plane that handles signaling (control signals).

[0049] The protocol stack for the control plane's wireless interface is shown in the diagram. 5 Instead of the SDAP layer shown, use the RRC (Radio Resource Control) layer and NAS (Non-Access Stratum). layer It holds.

[0050] RRC signaling for various settings is transmitted between the RRC layer of the UE100 and the RRC layer of the gNB200. The RRC layer controls the logical channel, transport channel, and physical channel in response to the establishment, re-establishment, and release of the radio bearer. If there is a connection (RRC connection) between the RRC of the UE100 and the RRC of the gNB200, the UE100 is in the RRC connected state. If there is no connection (RRC connection) between the RRC of the UE100 and the RRC of the gNB200, the UE100 is in the RRC idle state. If the connection between the RRC of the UE100 and the RRC of the gNB200 is suspended, the UE100 is in the RRC inactive state.

[0051] The NAS, located above the RRC layer, handles session management and mobility management, among other things. NAS signaling is transmitted between the UE100's NAS and the AMF30's NAS. The UE100 also has application layers in addition to its wireless interface protocol. Furthermore, layers below the NAS are called AS (Access Stratum).

[0052] (Passive IoT) Passive IoT is a technology that supports devices that are, for example, ultra-low cost and ultra-low power. Hereafter, devices that support passive IoT may be referred to as "passive IoT devices." The Wireless Tag 300 is an example of a passive IoT device.

[0053] Passive IoT devices support ultra-low power devices. The low power consumption of passive IoT devices means that they may not need batteries, or they may even be able to utilize energy harvesting.

[0054] Even passive IoT devices may have a built-in power supply. However, even in such cases, they can be powered by small-capacity batteries and / or energy harvesting, assuming low power consumption, thus achieving lower costs compared to devices that use large-capacity batteries.

[0055] On the other hand, passive IoT devices communicate at lower power than UE100 devices in 5G systems, resulting in a narrower coverage range. Furthermore, communication time is limited, and the amount of data that can be sent and received at one time is small. Additionally, with passive IoT, interference can occur if multiple passive IoT devices communicate simultaneously. Therefore, communication with passive IoT can be unstable and irregular.

[0056] One example of a target for passive IoT is RFID. RFID tags are classified into passive tags, active tags, and semi-passive tags (or semi-active tags). Passive tags are wireless tags that use radio waves from a reader as their power source. Passive IoT primarily utilizes passive tags. Active tags are wireless tags that use a battery built into the tag as their power source. Semi-passive tags operate as passive tags under normal circumstances and become active tags upon request from a reader. Passive IoT may target, for example, semi-passive tags or active tags.

[0057] Another target for passive IoT is, for example, backscattering. Backscattering refers to the reflection of radio waves, particles, or signals in the direction from which they came. In passive IoT, backscattering is used in communication methods that utilize reflected waves, as mentioned above. The wireless tag 300 can transmit data using reflected waves by modulating them.

[0058] Furthermore, energy harvesting is one example of a target for passive IoT. As mentioned above, energy harvesting is a method of generating electricity from the environment. For example, energy harvesting generates electricity by converting energy such as vibration or heat into electrical energy. Energy harvesting may include solar panels or wind turbines. The low power consumption of passive IoT makes it possible to use energy harvesting as a power source. Since energy harvesting does not require charging or replacement like batteries, it can operate for long periods without maintenance.

[0059] (Challenges of Passive IoT) If passive IoT can be integrated into a 3GPP-compliant mobile communication system, then, for example, passive IoT devices can be managed using NG-RAN10 or CN20.

[0060] However, there are several challenges to consider when integrating passive IoT into mobile communication systems.

[0061] Figure 7 is a diagram illustrating the challenges of the passive IoT according to the first embodiment. In Figure 7, the network 500 and the communication node 400 are included in a mobile communication system compliant with 3GPP. The communication node 400 is a node that has a reader / writer function and communicates with the wireless tag 300. The communication node 400 is either UE100 or gNB200. On the other hand, the network 500 includes a device that communicates with the communication node 400. The network 500 is either CN20 or gNB200.

[0062] From the perspective of network 500 (CN20 or gNB200), there is an issue of whether to manage the wireless tag 300 as a wireless tag or as a UE100. If the wireless tag 300 can be managed as a UE100 in network 500, it will also be possible to treat the wireless tag 300 in the same way as a UE100.

[0063] Another issue is whether the reader function (and / or writer function) will be handled by the UE100 or the gNB200. Both the UE100 and the gNB200 can communicate directly with the wireless tag 300.

[0064] Furthermore, there is the question of whether the link between the communication node 400 and the wireless tag 300 will utilize existing specifications such as RFID, or whether a 3GPP-compliant communication protocol will be used. Alternatively, there is the question of whether the link will utilize a 3GPP-compliant communication band, or an RFID-specific communication band (such as the 13.56MHz band or 900MHz band).

[0065] Thus, several challenges exist in integrating passive IoT into mobile communication systems. It will be understood that all or part of the above-mentioned challenges can be solved in the embodiments shown below.

[0066] (Passive IoT scenario) Three scenarios (scenario a, scenario b, and scenario c) are assumed as scenarios in which passive IoT is used. In all three scenarios, a communication node 400 exists, but the communication node 400 may be, for example, a UE100 with a reader / writer 140, or a gNB200 with a reader / writer 250.

[0067] Figures 8(A) and 8(B) illustrate scenario a according to the first embodiment. Scenario a is, for example, a scenario in which passive IoT is used locally.

[0068] As shown in Figure 8(A), the communication node 400 detects the wireless tag 300 when it passes through the gate, which is loaded onto a moving object such as a truck T (or pallet). The wireless tag 300 may be attached to each product. Alternatively, the wireless tag 300 may be attached to each pallet containing products. For example, if the communication node 400 is installed at the main gate of a factory and the communication node 400 detects the wireless tag 300, it becomes possible to manage products being shipped out of the factory or parts entering the factory.

[0069] The example in Figure 8(B) shows how a moving object (e.g., a person H or a moving vehicle) moves over a communication node 400 to detect a wireless tag 300 loaded on a fixed object (e.g., a pallet). The wireless tag 300 may be attached to each product. Alternatively, the wireless tag 300 may be attached to each pallet. By detecting the wireless tag 300, for example, products loaded on a pallet can be managed.

[0070] Figures 9(A) to 9(C) illustrate scenario b according to the first embodiment. Scenario b is a scenario for managing wireless tags 300 located in a certain location. This location may be a factory (or warehouse) (Figure 9(A)), a specific area (Figure 9(B)), or the cargo on a truck T (Figure 9(C)). By managing the wireless tags 300 located in this location, the communication node 400 can perform tasks such as inventory management of products or parts within a factory, or management of products or parts loaded on a truck T.

[0071] Figure 10 is a diagram illustrating scenario c according to the first embodiment. Scenario c is a scenario in which measurement values ​​are read continuously or periodically from a wireless tag 300 placed or present in a certain location. For example, a thermometer and a wireless tag 300 connected to the thermometer are placed on a site or pasture. The wireless tag 300 can obtain measurement values ​​(temperature information) from the thermometer. The communication node 400 then reads the measurement values ​​from the wireless tag 300 continuously or periodically, enabling temperature management on the site or pasture.

[0072] (Communication control method according to the first embodiment) Next, a communication control method according to the first embodiment will be described.

[0073] In the first embodiment, we will describe a case where the communication node 400 is UE100 and the network 500 is gNB200.

[0074] Figure 11 is a diagram showing an example configuration of the wireless communication system 1 according to the first embodiment. As shown in Figure 11, a passive link is established between the UE 100 and the wireless tag 300. The passive link is, for example, a communication link between the UE 100 and the wireless tag 300.

[0075] In this embodiment, the passive link is configured as follows.

[0076] Firstly, passive links utilize frequency bands (e.g., licensed bands) used in 3GPP-compliant mobile communication systems.

[0077] Secondly, the passive link may use a 3GPP communication protocol. Alternatively, the passive link may use a non-3GPP communication protocol, such as RFID.

[0078] Thirdly, in a passive link, the wireless tag 300 may be a passive tag, a semi-passive tag, or an active tag. In a passive link, not only passive communication with passive tags but also active communication with active tags may occur.

[0079] Under these circumstances, the wireless communication system 1, including the wireless tag 300, faces the following challenges.

[0080] In other words, the passive link uses the same frequency band as 3GPP-compliant mobile communication systems. Therefore, interference may occur between the communication in the passive link and the communication between the UE100 and the wireless tag 300. When such interference occurs, the UE100 may not be able to communicate properly with the wireless tag 300.

[0081] Furthermore, we want the gNB200 to be able to control passive link communication. By having the gNB200 take the lead in passive link communication, it will be possible to perform various controls, including control of communication to the UE100.

[0082] Therefore, the objective of the first embodiment is to suppress the occurrence of interference. Furthermore, the objective of the first embodiment is to enable the gNB200 to control passive link communication.

[0083] Therefore, in the first embodiment, the gNB200 notifies the UE100 of the radio resources for the passive link. Specifically, the base station (e.g., gNB200) transmits to the user device a first radio resource to be used for communication between the user device (e.g., UE100) and the radio tag (e.g., radio tag 300). Secondly, the user device uses the first radio resource to communicate with the radio tag. Here, the first radio resource is a different radio resource from the second radio resource used for communication between the base station and the user device.

[0084] Thus, since the radio resources for the passive link are different from the radio resources used for communication between the base station and user equipment, it is possible to suppress interference between passive link communication and communication between the base station and user equipment. Furthermore, the radio resources for the passive link are allocated by the gNB200 and transmitted to the UE100. Therefore, by transmitting the radio resources for the passive link, the gNB200 can take the lead in controlling communication on the passive link.

[0085] (Example of operation according to the first embodiment) Figure 12 shows an example of operation according to the first embodiment.

[0086] As shown in Figure 12, in step S10, the gNB200 transmits information about the wireless resources for the passive link to the UE100. There are two methods for this notification:

[0087] Firstly, the gNB200 may transmit (broadcast) information about the radio resource using a System Information Block (SIB). UE100s that do not communicate with the radio tag 300 may also receive information about the radio resource. The radio resource for passive links may be shared by multiple UE100s. For example, consider a case where there is a UE100 that communicates with the radio tag 300 and other UEs that communicate with other radio tags. In such a case, if the distance between the UE100 and the other UEs is greater than a threshold, the radio resource for passive links (e.g., the first radio resource) and the radio resource for other passive links between the other UEs and other radio tags (e.g., the third radio resource) may be the same (i.e., shared). In such cases, the gNB200 may broadcast a System Information Block containing information about the radio resource.

[0088] Secondly, the gNB200 may transmit information about the radio resource in the form of an RRC Reconfiguration message. For example, in the above case, if the distance between UE100 and other UEs is less than a threshold, the radio resource for the passive link (e.g., the first radio resource) may be a different radio resource from the radio resources for other passive links (e.g., the third radio resource). In this case, the gNB200 may send a first RRC Reconfiguration message to UE100 containing information about the radio resources for the passive link, and a second RRC Reconfiguration message to UE100 containing information about the radio resources for other passive links. The gNB200 may also transmit information about the radio resource in Downlink Control Information (DCI) or MAC Control Element (MAC CE).

[0089] Specific examples of information regarding wireless resources include the following:

[0090] Firstly, information regarding wireless resources includes the said wireless resources ofThe information includes time-direction information. This time-direction information may be represented by HFN (Hyper Frame Number), wireless frames, subframes, or slots. The time-direction information may also be represented by a start point and a period. In addition to the start point and period, the time-direction information may also include an end point. The information may also include a pattern. This pattern may consist of a bitmap, where each bit corresponds to a time unit (e.g., a subframe), and "0" may indicate unavailable, and "1" may indicate permitted. Alternatively, "0" may indicate permitted, and "1" may indicate unavailable.

[0091] Secondly, information regarding the radio resource includes frequency direction information of the radio resource. Frequency direction information may be represented by carrier frequency (or center frequency), BWP (Bandwidth Part), resource block (PRB: Physical Resource Block), or resource element (RE).

[0092] Thirdly, information regarding wireless resources may include wireless resources for passive links in adjacent cells. The wireless resources for passive links in adjacent cells may be associated with the identifier of that adjacent cell. Furthermore, information regarding wireless resources may include information about adjacent cells that support passive links. The information about adjacent cells that support passive links may also be associated with the identifier of that adjacent cell.

[0093] Fourth, the information regarding the wireless resource may include information specifying whether carrier sense (LBT: Listen-Before-Talk) is required for communication between the UE100 and the wireless tag 300. As mentioned above, when multiple UE100s share the wireless resource, communication between the UE100 and the wireless tag 300 and other UEs may be required. and Carrier sensing may be performed to prevent interference with communication with other wireless tags. The UE100 can perform carrier sensing or not, according to information specifying whether carrier sensing is necessary or not.

[0094] In step S11, the UE100, which has the wireless tag 300 under its control, communicates with the wireless tag 300 using the wireless resource for the passive link. Within the said wireless resource, the UE100 transmits to the wireless tag 300 and receives from the wireless tag 300. If carrier sense is specified, communication with the wireless tag 300 occurs when LBT is successful.

[0095] Furthermore, the wireless resources for passive links may reside within the wireless resources for DL ​​(Digital Link) used for communication between the gNB200 and the UE100. However, even if the wireless resources for passive links reside within the wireless resources for DL, they are not shared with the wireless resources for DL ​​(they are used separately). Also, the wireless resources for passive links may reside within the wireless resources for UL (Uninterruptible Link) used for communication between the gNB200 and the UE100. However, in this case as well, even if the wireless resources for passive links reside within the wireless resources for UL, they are not shared with the wireless resources for UL (they are used separately).

[0096] Furthermore, the wireless resources for passive links may reside within the wireless resources used for sidelinks, which are among the wireless resources used for communication between UE100s. However, even in this case, although the wireless resources for passive links reside within the wireless resources for sidelinks, they are not shared with the wireless resources for sidelinks (they are used separately).

[0097] Furthermore, a UE that does not have a wireless tag 300 under its control may stop monitoring DL (i.e., PDCCH (Physical Downlink Control Channel)) on the wireless resources for passive links. This is to suppress interference. Also, a UE that does not have a wireless tag 300 under its control may stop transmitting UL (i.e., PUCCH (Physical Uplink Control Channel)) on the wireless resources for passive links. The wireless resources for passive links may reside within the wireless resources for side links, which are used for communication between UEs 100. However, even in this case, the wireless resources for passive links, even if they reside within the wireless resources for side links, are not shared with the wireless resources for side links (they are used separately). This is also to suppress interference. Furthermore, a UE that does not have a wireless tag 300 under its control may stop transmitting or receiving (monitoring) side links (i.e., PSCCH (Physical Sidelink Control Channel) or PSSCH (Physical Sidelink Shared Channel)) on the wireless resources for passive links. In this case as well, the purpose is to suppress interference.

[0098] (Modified version of the first embodiment) While it has been explained that passive links use frequency bands used in 3GPP-compliant mobile communication systems, this is not limited to these. Other frequency bands may also be used in passive links. Other frequency bands may include, for example, unlicensed bands or frequency bands used by RFID for communication. In this case, interference between communication between gNB200 and UE100 will not occur, but interference between passive links may occur. Therefore, as in the first embodiment, interference can be suppressed by gNB200 controlling communication. gNB200 may set one or more of the following for UE100: the frequency band (band or frequency bandwidth) to be used for the passive link, the frequency channel within that frequency band, and time information indicating whether the use of that frequency band or frequency channel is permitted or not (e.g., wireless frame number, subframe number, slot number, bitmap showing permitted / not permitted patterns for each wireless frame, time information, etc.). UE100 performs passive link communication with the wireless tag 300 according to these settings.

[0099] [Second Embodiment] Next, a second embodiment will be described.

[0100] The second embodiment is one in which UE100 requests the gNB200 to allocate radio resources for a passive link. Specifically, firstly, the user device (e.g., UE100) requests the base station (e.g., gNB200) to allocate first radio resources to be used for communication between the user device and a radio tag (e.g., radio tag 300). Secondly, the base station transmits the first radio resources to the user device in response to the request.

[0101] This allows, for example, the gNB200 to allocate radio resources for the passive link in response to a request from the UE100. Thus, similar to the first embodiment, the gNB200 can take the lead in controlling communication on the passive link by transmitting radio resources for the passive link.

[0102] (Example of operation according to the second embodiment) Figure 13 is a diagram illustrating an example of operation according to the second embodiment.

[0103] As shown in Figure 13, in step S20, gNB200 may send information to UE100 indicating that it supports passive links. This information indicating that it supports passive links may be referred to as "passive link support information" below. Passive link support information may also be information indicating that gNB200 does not support passive links. Alternatively, passive link support information may also be information indicating whether or not gNB200 supports passive links. Passive link support information may be included in a System Information Block (SIB) and transmitted (notified).

[0104] Firstly, passive link support information may be included in RRC messages (individual signaling), such as RRC Reconfiguration messages. In this case, passive link support information may imply permission for passive linking. "Permission for passive linking" may mean that UE100 is permitted to communicate via passive linking. Alternatively, "permission for passive linking" may mean that requests for wireless resources to be used via passive linking are permitted. Alternatively, "permission for passive linking" may mean that both of these are permitted.

[0105] Secondly, passive link support information may also be information indicating that passive links are supported. Furthermore, such passive link support information may also be information indicating that passive links are permitted. Additionally, passive link support information may also be information indicating the protocol of the supported or permitted passive link. Information indicating the protocol may include, for example, information indicating that it is RFID, information indicating that it is NFC (Near Field Communication), or the name of the protocol standard.

[0106] In step S21, UE100 requests gNB200 to allocate radio resources for a passive link. The conditions for sending this request may be that gNB200 supports passive links, or that gNB200 authorizes UE100 to use a passive link (or a request for radio resources to be used for a passive link). UE100 sends the request in either case. The content of the request may be at least one of the following:

[0107] Firstly, the request may include information indicating that communication will be conducted using a passive link. This information may also indicate an interest in conducting communication using a passive link.

[0108] Secondly, the request may include information about the wireless resources to be used in the passive link. This information may be the same as the information about the wireless resources described in the first embodiment. This information may be determined by the UE100, taking into account the transmission and / or reception time for the passive link.

[0109] Thirdly, the request may include information indicating the protocol to be used for the passive link. This information may be the same as the protocol information included in the passive link support information.

[0110] Fourth, the request may include the amount of data transmitted and received over the passive link. The request may also be the number of wireless tags 300 communicating over the passive link.

[0111] Fifth, the request may include the location information of UE100 itself. As described above, gNB200 may share or dedicate wireless resources for passive links based on the distance between UE100 and other UEs. In this case, gNB200 may make the decision based on the location information of each UE.

[0112] Sixth, the requirement may include the transmit power of the passive link. In the gNB200, wireless resources for the passive link may be shared or dedicated based on the transmit power of the UE100 and other UEs, and this may be used as reference information.

[0113] In step S22, the gNB200 transmits information regarding the wireless resources for the passive link to the UE100 (or the entire cell) in response to the request. The method and content of transmitting the information regarding the wireless resources may be the same as in the first embodiment. Thereafter, as in the first embodiment, the UE100 communicates with the wireless tag 300 using the wireless resources for the passive link (step S23).

[0114] [Third Embodiment] Next, a third embodiment will be described.

[0115] The third embodiment is one in which, during cell reselection in UE100, cells that support passive links are given priority in the cell reselection process.

[0116] Cell reselection is a procedure performed by UE100, which is in an RRC idle or RRC inactive state, to move from its current serving cell to an adjacent cell as it moves. Specifically, UE100 identifies the adjacent cell to which it should camp on using the cell reselection procedure and reselects the identified adjacent cell. Cell reselection is performed, for example, as follows:

[0117] Firstly, the UE100 performs frequency prioritization based on the frequency-specific priority specified by the gNB200, for example, through a system information block or an RRC release message.

[0118] Secondly, the UE100 performs measurement processing to measure the wireless quality for both the serving cell and the adjacent cell. Specifically, the UE100 measures the received power and received quality of the reference signal (e.g., CD-SSB (Cell Defining-Synchronization Signal and PBCH block)) transmitted by both the serving cell and the adjacent cell.

[0119] Thirdly, UE100 performs a cell reselection process to re-select the cell to which it will camp on, based on the measurement results. Specifically, UE100 may re-select an adjacent cell if the frequency priority of the adjacent cell is higher than the priority of the current serving cell, and the adjacent cell meets a predetermined quality standard (i.e., the minimum required quality standard) for a predetermined period. Also, if the frequency priority of the adjacent cell is the same as the priority of the current serving cell, UE100 may rank the wireless quality and re-select an adjacent cell that has a higher rank than the current serving cell for a predetermined period. Furthermore, UE100 may re-select an adjacent cell if the frequency priority of the adjacent cell is lower than the priority of the current serving cell, and the wireless quality of the current serving cell remains below a certain threshold, while the wireless quality of the adjacent cell remains above another threshold for a predetermined period.

[0120] In the third embodiment, UE100 may set the priority of a cell that supports a passive link to the highest priority so as to prioritize cell reselection. Alternatively, UE100 may set the priority of a cell that supports a passive link to a higher priority than the priority of a serving cell.

[0121] Specifically, firstly, the base station (e.g., gNB200) transmits passive link support information to the user equipment (e.g., UE100) indicating whether or not the base station supports passive links. Secondly, the user equipment reselects a cell prioritizing cells that support passive links, provided that the base station supports passive links and under predetermined conditions. These predetermined conditions include the user equipment having a wireless tag (e.g., wireless tag 300) under its control, the user equipment being interested in communicating with a wireless tag using a passive link, or the user equipment communicating with a wireless tag using a passive link.

[0122] This allows, for example, the UE100 to camp on to a cell that supports passive linking and communicate properly with the wireless tag 300.

[0123] (Example of operation according to the third embodiment) Figure 14 is a diagram illustrating an example of operation according to the third embodiment. Note that UE100 is in the RRC idle state or RRC inactive state.

[0124] As shown in Figure 14, in step S30, UE100 starts processing.

[0125] In step S31, UE100 receives passive link support information from gNB200. Passive link support information may also be information indicating whether or not gNB200 supports passive linking. Passive link support information may also be the same as the passive link support information described in the second embodiment. Passive link support information may also be a setting of frequency priority that should be applied by UE100 performing passive linking. This setting links frequency and priority, and a different value is set than the frequency priority applied by a normal (non-passive linking) UE100.

[0126] In step S32, UE100 confirms that gNB200 supports passive linking based on passive linking support information, and then, in predetermined cases, re-selects a cell prioritizing passive linking. These predetermined cases are: when UE100 has a wireless tag 300, when UE100 is interested in communicating with the wireless tag 300 using passive linking, or when UE100 is communicating with the wireless tag 300 using passive linking. In such cases, UE100 re-selects a cell by setting the priority of the passive linking cell to the highest priority or by setting the priority of that cell to a higher priority than the serving cell. Passive linking support information may also be the frequency priority settings that should be applied by UE100 performing passive linking. In this setting, frequency and priority are linked, and different values ​​are set from the frequency priority applied by a normal (non-passive linking) UE100. Then, UE100 camps on to that cell.

[0127] In addition, in the specified cases, either the UE100 intends to perform communication with the wireless tag 300 using a passive link, or the UE100 is authorized to communicate with the wireless tag 300 using a passive link.

[0128] In step S33, UE100 terminates the series of processes.

[0129] [Other embodiments] A program may be provided that causes a computer to perform each of the processes that UE100 or gNB200 performs. The program may be recorded on a computer-readable medium. Using a computer-readable medium, it is possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, but may be a recording medium such as a CD-ROM or DVD-ROM.

[0130] Alternatively, the circuits that perform each process carried out by UE100 or gNB200 may be integrated, and at least a portion of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chipset, SoC: System on a chip).

[0131] The terms “based on” and “depending on” used in this disclosure do not mean “based solely on” or “depending solely on” unless otherwise specified. “Based on” means both “based solely on” and “at least partially on.” Similarly, “depending on” means both “at least partially on” and “at least partially on.” Furthermore, the terms “include,” “comprise,” and variations thereof do not mean that only the listed items are included; they may include only the listed items, or they may include additional items in addition to the listed items. Also, the term “or” used in this disclosure is not intended to mean exclusive OR. Moreover, any reference to elements using designations such as “first,” “second,” etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient way to distinguish between two or more elements. Therefore, references to the first and second elements do not imply that only two elements may be adopted therein, or that the first element must precede the second element in any way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall be plural unless it is clearly indicated by the context that they are not.

[0132] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to that described above, and various design changes can be made without departing from the gist of the work. Furthermore, it is possible to combine all or part of each embodiment, each operation, each process, and each step, as long as they do not contradict each other.

[0133] This application claims priority to Japanese Patent Application No. 2022-032194 (filed March 2, 2022), and all of its contents are incorporated into the specification of this application.

[0134] (Note) The features of the above-described embodiment are noted below.

[0135] (1) A communication control method in a wireless communication system, The base station transmits a first radio resource, which is used for communication between the user device and the radio tag, to the user device. The user device has the step of using the first wireless resource to communicate with the wireless tag, The first radio resource is a different radio resource from the second radio resource used for communication between the base station and the user device. Communication control method.

[0136] (2) The transmission step includes the step of the base station transmitting information specifying whether carrier sensing is required for the communication between the user device and the radio tag. The communication control method described in (1) above.

[0137] (3) The transmission step involves the base station transmitting the first radio resource to the user device if the distance between the user device and another user device is greater than or equal to a threshold, and transmitting the first radio resource to the user device if the distance between the user device and the other user device is less than the threshold, and transmitting the first radio resource to the user device if the first radio resource is a different radio resource from the third radio resource. The communication control method described in (1) or (2) above.

[0138] (4) Furthermore, the user device has the step of requesting the allocation of the first radio resource from the base station, The transmission step includes the base station transmitting the first radio resource to the user device in response to the request. A communication control method as described in any of (1) to (3) above.

[0139] (5) A communication control method in a wireless communication system, The base station transmits passive link support information to the user equipment indicating whether or not the base station supports passive links. The user device includes the step of performing cell reselection prioritizing cells that support the passive link when the base station supports the passive link and in a predetermined case, The aforementioned predetermined cases are any of the following: when the user device has a wireless tag under its control; when the user device is interested in communicating with the wireless tag using the passive link; or when the user device is performing the communication with the wireless tag using the passive link. Communication control method. [Explanation of Symbols]

[0140] 1: Wireless communication system 10: NG-RAN 20:5GC(CN) 30: AMF 100 :UE 110: Receiving unit 120: Transmitter 130: Control Unit 140: Reader / Writer 141: RFID antenna 200 :gNB 210: Transmitter 220: Receiving unit 230: Control Unit 250: Reader / Writer 251: RFID antenna 300: Wireless Tag 310: RFID antenna 320: Control Unit 330: Memory 340 :Power supply

Claims

1. A communication control method in a wireless communication system, The network node transmits to the user device information regarding a first radio resource used for communication between the user device and the radio tag. The first wireless resource included in the information relating to the first wireless resource is a different wireless resource from the second wireless resource used for the communication between the network node and the user device. The aforementioned transmission includes, when the distance between the user device and another user device is greater than or equal to a threshold, the network node transmitting to the user device information regarding the first radio resource, including the first radio resource which is the same radio resource as the third radio resource used by the other user device for communication with other radio tags; and when the distance between the user device and another user device is less than a threshold, the network node transmitting to the user device information regarding the first radio resource, including the first radio resource which is a different radio resource from the third radio resource. Communication control method.

2. The aforementioned transmission includes the network node transmitting information specifying whether carrier sensing is required for the communication between the user device and the wireless tag. The communication control method according to claim 1.

3. Furthermore, the network node receives the allocation request for the first wireless resource from the user device, The network node, upon receiving the allocation request, transmits the first wireless resource to the user device, The communication control method according to claim 1.

4. A network node in a wireless communication system, It has a transmitting unit that transmits information about a first wireless resource used for communication between the user device and the wireless tag to the user device, The first wireless resource included in the information relating to the first wireless resource is a different wireless resource from the second wireless resource used for the communication between the network node and the user device. When the distance between the user device and another user device is greater than or equal to a threshold, the transmitting unit transmits to the user device information regarding the first radio resource, including the first radio resource which is the same radio resource as the third radio resource used by the other user device for communication with other radio tags; when the distance between the user device and another user device is less than the threshold, the transmitting unit transmits to the user device information regarding the first radio resource, including the first radio resource which is a different radio resource from the third radio resource. Network node.

Images