Communication system

Abstract

This communication system comprises at least one terminal device, at least one base station that communicates with the at least one terminal device, and at least one sensing function node that manages sensing, wherein the sensing function node uses information relating to the position of an Uncrewed Aerial Vehicle (UAV) to determine, from among the at least one terminal device and the at least one base station, a first node that transmits sensing signals and a second node that receives the sensing signals.

Description

Communication System

[0001] The present disclosure relates to wireless communication technology.

[0002] In 3GPP (3rd Generation Partnership Project), a standardization organization for mobile communication systems, a fifth-generation (hereinafter sometimes referred to as "5G") radio access system is being studied as a successor to Long Term Evolution (LTE) and Long Term Evolution Advanced (LTE-A), which is one of the fourth-generation radio access systems (see Non-Patent Document 1) (for example, Non-Patent Document 2). The 5G radio link technology is called "New Radio Access Technology" ("New Radio" is abbreviated as "NR"). Research on NR systems is proceeding based on LTE systems and LTE-A systems.

[0003] For example, in Europe, an organization called METIS has summarized the requirements for 5G (see Non-Patent Document 3). For 5G radio access systems, it is required that compared with LTE systems, the system capacity is 1000 times, the data transmission rate is 100 times, the data processing delay is one fifth (1 / 5), the number of simultaneous connections of communication terminals is 100 times, and further lower power consumption and lower device cost are realized (see Non-Patent Document 3).

[0004] In order to meet such requirements, 3GPP is proceeding with the study of 5G standards (see Non-Patent Documents 4 to 23).

[0005] As for NR access schemes, OFDM (Orthogonal Frequency Division Multiplexing) is used in the downlink direction, and OFDM and DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) are used in the uplink direction. In addition, similar to LTE and LTE-A, the 5G system does not include circuit switching and only adopts the packet communication scheme.

[0006] NR allows for the use of higher frequencies compared to LTE, in order to improve transmission speed and reduce processing delay.

[0007] In noise reduction (NR), which sometimes uses higher frequencies than LTE, cell coverage is ensured by forming a narrow beam-shaped transmission and reception range (beamforming) and changing the direction of the beam (beam sweeping).

[0008] The decisions regarding the frame configuration in the NR system under 3GPP, as described in Non-Patent Document 1 (Chapter 5), will be explained using Figure 1. Figure 1 is an explanatory diagram showing the configuration of a radio frame used in an NR communication system. In Figure 1, one radio frame is 10 ms. The radio frame is divided into 10 subframes of equal size. In the NR frame configuration, one or more numerologies, i.e., one or more subcarrier spacings (SCS), are supported. In NR, regardless of the subcarrier spacing, one subframe is 1 ms, and one slot consists of 14 symbols. Furthermore, the number of slots contained in one subframe is one for a subcarrier spacing of 15 kHz, and the number of slots for other subcarrier spacings increases proportionally to the subcarrier spacing (see Non-Patent Document 11 (3GPP TS38.211)).

[0009] The decisions regarding the channel configuration in the NR system at 3GPP are described in Non-Patent Document 2 (Chapter 5) and Non-Patent Document 11.

[0010] A Physical Broadcast Channel (PBCH) is a channel used for downlink transmission from a base station (hereinafter sometimes simply referred to as "base station") to a communication terminal (hereinafter sometimes simply referred to as "communication terminal" or "terminal") such as a mobile terminal (hereinafter sometimes simply referred to as "mobile terminal"). The PBCH is transmitted together with a Downlink Synchronization Signal.

[0011] In NR, the downlink synchronization signal consists of a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS). The synchronization signal is transmitted from the base station as a synchronization signal burst (Synchronization Signal Burst; hereinafter sometimes referred to as SS burst) at a predetermined period and for a predetermined duration. The SS burst is composed of a synchronization signal block (Synchronization Signal Block; hereinafter sometimes referred to as SS block) for each beam of the base station.

[0012] The base station transmits SS blocks of each beam, switching beams, during the duration of the SS burst. The SS blocks consist of P-SS, S-SS, and PBCH.

[0013] The Physical Downlink Control Channel (PDCCH) is the channel used for downlink transmission from the base station to the communication terminal. The PDCCH carries Downlink Control Information (DCI). DCI includes resource allocation information for the Downlink Shared Channel (DL-SCH), one of the transport channels described later, resource allocation information for the Paging Channel (PCH), another transport channel described later, and HARQ (Hybrid Automatic Repeat reQuest) information related to the DL-SCH. In addition, DCI may include Uplink Scheduling Grant. DCI may also include Ack (Acknowledgement) / Nack (Negative Acknowledgement), which are response signals to uplink transmissions. Furthermore, to allow for flexible switching between DL / UL within a slot, DCI may include a Slot Format Indication (SFI). PDCCH, or DCI, is also called an L1 / L2 control signal.

[0014] In NR, a time and frequency range is defined as a candidate range for PDCCH. This range is called the Control Resource Set (CORESET). The communication terminal monitors the CORESET and acquires PDCCH.

[0015] The Physical Downlink Shared Channel (PDSCH) is a channel used for downlink transmission from a base station to a communication terminal. The PDSCH is mapped to the Downlink Shared Channel (DL-SCH), which is a transport channel, and the PCH, which is also a transport channel.

[0016] The Physical Uplink Control Channel (PUCCH) is the channel used for uplink transmission from the communication terminal to the base station. The PUCCH carries Uplink Control Information (UCI). UCI includes Ack / Nack, which are response signals to downlink transmissions, Channel State Information (CSI), and Scheduling Request (SR). CSI consists of the Rank Indicator (RI), Precoding Matrix Indicator (PMI), and Channel Quality Indicator (CQI) reports. RI is the rank information of the channel matrix in MIMO (Multiple Input Multiple Output). PMI is the information of the precoding weight matrix used in MIMO. CQI is quality information indicating the quality of the received data or the quality of the communication channel. UCI may be carried by the PUCCH, which will be described later. PUCCH, or UCI, is also called an L1 / L2 control signal.

[0017] The Physical Uplink Shared Channel (PUSCH) is a channel used for uplink transmission from a communication terminal to a base station. The Uplink Shared Channel (UL-SCH), which is one of the transport channels, is mapped to the PUSCH.

[0018] A Physical Random Access Channel (PRACH) is a channel used for uplink transmission from a communication terminal to a base station. The PRACH carries a random access preamble.

[0019] The downlink reference signal (RS) is a well-known symbol in NR (Noise Reduction) communication systems. The following four types of downlink reference signals are defined: UE-specific reference signals: Demodulation Reference Signal (DM-RS), Phase Tracking Reference Signal (PT-RS), Positioning Reference Signal (PRS), and Channel State Information Reference Signal (CSI-RS). Measurements at the physical layer of the communication terminal include Reference Signal Received Power (RSRP) measurement and Reference Signal Received Quality (RSRQ) measurement.

[0020] Similarly, the uplink reference signals are also known symbols in NR (Noise Reduction) communication systems. The following three types of uplink reference signals are defined: Data Demodulation Reference Signal (DM-RS), Phase Tracking Reference Signal (PT-RS), and Sounding Reference Signal (SRS).

[0021] This section explains the transport channel described in Non-Patent Document 2 (Chapter 5). Of the downlink transport channels, the broadcast channel (BCH) broadcasts to the entire coverage of the base station (cell). The BCH is mapped to the physical broadcast channel (PBCH).

[0022] Downlink Shared Channels (DL-SCH) are subject to HARQ-based retransmission control. DL-SCH can broadcast to the entire coverage of a base station (cell). DL-SCH supports dynamic or semi-static resource allocation. Semi-static resource allocation is also called semi-persistent scheduling. DL-SCH supports discontinuous reception (DRX) for communication terminals to reduce power consumption. DL-SCH is mapped to the physical downlink shared channel (PDSCH).

[0023] Paging Channels (PCHs) support DRX for communication terminals to enable low power consumption for those terminals. PCHs are required to broadcast across the entire coverage of a base station (cell). PCHs are mapped to physical resources, such as Physical Downlink Shared Channels (PDSCHs), which are dynamically available for traffic.

[0024] Among the uplink transport channels, the Uplink Shared Channel (UL-SCH) is subject to retransmission control by HARQ. UL-SCH supports dynamic or quasi-static resource allocation. Quasi-static resource allocation is also called configured grant. UL-SCH is mapped to the physical uplink shared channel (PUSCH).

[0025] Random Access Channels (RACHs) are limited to control information. RACHs carry a risk of collisions. RACHs are mapped to Physical Random Access Channels (PRACHs).

[0026] This section explains HARQ. HARQ is a technology that improves the communication quality of a transmission line by combining Automatic Repeat Request (ARQ) and Forward Error Correction. HARQ has the advantage that error correction through retransmission works effectively even for transmission lines where the communication quality changes. In particular, it is possible to further improve quality by combining the reception result of the initial transmission and the reception result of the retransmission during retransmission.

[0027] Here is an example of how to retransmit data. If the receiving side is unable to correctly decode the received data, in other words, if a CRC (Cyclic Redundancy Check) error occurs (CRC = NG), the receiving side sends "Nack" to the sending side. Upon receiving "Nack," the sending side retransmits the data. If the receiving side is able to correctly decode the received data, in other words, if no CRC error occurs (CRC = OK), the receiving side sends "Ack" to the sending side. Upon receiving "Ack," the sending side sends the next data.

[0028] Here are some other examples of retransmission methods. If a CRC error occurs at the receiving end, the receiving end requests retransmission from the sending end. This request is made by toggling the NDI (New Data Indicator). Upon receiving the retransmission request, the sending end retransmits the data. If no CRC error occurs at the receiving end, no retransmission request is made. If the sending end does not receive a retransmission request within a specified time, it is assumed that no CRC error occurred at the receiving end.

[0029] This section explains the logical channel described in Non-Patent Document 1 (Chapter 6). The Broadcast Control Channel (BCCH) is a downstream channel for broadcasting system control information. The BCCH, being a logical channel, is mapped to the broadcast channel (BCH), which is a transport channel, or to the downstream shared channel (DL-SCH).

[0030] The Paging Control Channel (PCCH) is a downstream channel for transmitting changes to paging information and system information. The PCCH, being a logical channel, is mapped to the Paging Channel (PCH), which is a transport channel.

[0031] The Common Control Channel (CCCH) is a channel used to transmit control information between a communication terminal and a base station. The CCCH is used when a communication terminal does not have an RRC connection with the network. In the downlink direction, the CCCH is mapped to the downlink common channel (DL-SCH), which is a transport channel. In the uplink direction, the CCCH is mapped to the uplink common channel (UL-SCH), which is a transport channel.

[0032] A Dedicated Control Channel (DCCH) is a channel that transmits individual control information between a communication terminal and the network on a one-to-one basis. DCCH is used when a communication terminal has an RRC connection with the network. DCCH is mapped to the Uplink Shared Channel (UL-SCH) for uplink traffic and to the Downlink Shared Channel (DL-SCH) for downlink traffic.

[0033] A Dedicated Traffic Channel (DTCH) is a one-to-one communication channel to a communication terminal for transmitting user information. DTCHs exist for both uplink and downlink traffic. Uplink DTCHs are mapped to the Uplink Shared Channel (UL-SCH), and downlink DTCHs are mapped to the Downlink Shared Channel (DL-SCH).

[0034] Location tracking of communication terminals is performed in units of areas consisting of one or more cells. Location tracking is performed to track the location of communication terminals even when they are in standby mode, and to enable them to be called, in other words, to enable them to receive calls. This area used for location tracking of communication terminals is called a Tracking Area (TA).

[0035] In NR, calling communication terminals within a range smaller than the tracking area is supported. This range is called the RAN Notification Area (RNA). Paging of communication terminals in the RRC_INACTIVE state, as described later, is performed within this range.

[0036] In NR (Noise Reduction), carrier aggregation (CA), which involves aggregating two or more component carriers (CCs), is being considered to support wide frequency bandwidths. CA is described in Non-Patent Document 1.

[0037] When a CA (Carrier Acquisition) is configured, the UE (User Equipment) which is a communication terminal has a single RRC (Rapid Relay Control) connection to the network (NW). In the RRC connection, one serving cell provides NAS (Non-Access Stratum) mobility information and security input. This cell is called the primary cell (PCell). Depending on the capabilities of the UE, secondary cells (SCells) are configured together with the PCell to form a set of serving cells. A set of serving cells consisting of one PCell and one or more SCells is configured for one UE.

[0038] Furthermore, in 3GPP, in order to further increase communication capacity, there is dual connectivity (DC), in which a UE connects to two base stations for communication. DC is described in Non-Patent Documents 1 and 22.

[0039] In dual connectivity (DC) base stations, one is sometimes called the "Master Node (MN)" and the other the "Secondary Node (SN)". The serving cells composed of the master base station are sometimes collectively called the Master Cell Group (MCG), and the serving cells composed of the secondary base station are sometimes collectively called the Secondary Cell Group (SCG). In a DC, the primary cell within the MCG or SCG is called a Special Cell (SpCell or SPCell). A Special Cell in an MCG is called a PCell, and a Special Cell in an SCG is called a Primary SCG Cell (PSCell).

[0040] Furthermore, in NR, the base station pre-configures a portion of the carrier frequency band (hereinafter sometimes referred to as the Bandwidth Part (BWP)) for the UE, and the UE performs transmission and reception with the base station in the BWP, thereby reducing power consumption in the UE.

[0041] Furthermore, 3GPP is considering supporting services (or applications) using side-link (SL) communication (also called PC5 communication) in both the Evolved Packet System (EPS) described later and the 5G core system (see Non-Patent Documents 1, 2, 26-28). SL communication takes place between terminals. Examples of services using SL communication include V2X (Vehicle-to-everything) services and proximity services. In SL communication, not only direct communication between terminals but also communication between the UE and NW via relay has been proposed (see Non-Patent Documents 26, 28).

[0042] A physical channel used for SL (see Non-Patent Literatures 2 and 11) will be described. A Physical Sidelink Broadcast Channel (PSBCH) carries information related to system and synchronization, and is transmitted from a UE.

[0043] A Physical Sidelink Control Channel (PSCCH) carries control information from a UE for sidelink communication and V2X sidelink communication.

[0044] A Physical Sidelink Shared Channel (PSSCH) carries data from a UE for sidelink communication and V2X sidelink communication.

[0045] A Physical Sidelink Feedback Channel (PSFCH) carries HARQ feedback on a sidelink, from a UE that has received PSSCH transmission to a UE that has transmitted the PSSCH.

[0046] A transport channel used for SL (see Non-Patent Literature 1) will be described. A Sidelink Broadcast Channel (SL-BCH) has a predetermined transport format, and is mapped to the PSBCH, which is a physical channel.

[0047] A sidelink shared channel (SL-SCH: Sidelink shared channel) supports broadcast transmission. SL-SCH supports both UE autonomous resource selection and resource allocation scheduled by a base station. There is a collision risk in UE autonomous resource selection, while no collision occurs when a UE is allocated individual resources by a base station. In addition, SL-SCH supports dynamic link adaptation by changing transmission power, modulation and coding. SL-SCH is mapped to PSSCH, which is a physical channel.

[0048] A logical channel used for SL (see Non-Patent Document 2) will be described. A sidelink broadcast control channel (SBCCH: Sidelink Broadcast Control Channel) is a sidelink channel for broadcasting sidelink system information from one UE to other UEs. SBCCH is mapped to SL-BCH, which is a transport channel.

[0049] A sidelink traffic channel (STCH: Sidelink Traffic Channel) is a one-to-many sidelink traffic channel for transmitting user information from one UE to other UEs. STCH is only used by UEs having sidelink communication capability and UEs having V2X sidelink communication capability. One-to-one communication between two UEs having sidelink communication capability is also implemented by STCH. STCH is mapped to SL-SCH, which is a transport channel.

[0050] A sidelink control channel (SCCH: Sidelink Control Channel) is a sidelink control channel for transmitting control information from one UE to other UEs. SCCH is mapped to SL-SCH, which is a transport channel.

[0051] In LTE, SL communication was limited to broadcast only. In NR, support for unicast and groupcast in addition to broadcast is being considered for SL communication (see Non-Patent Document 27 (3GPP TS23.287)).

[0052] In SL, unicast and groupcast communications support HARQ feedback (Ack / Nack), CSI reporting, and other features.

[0053] Furthermore, 3GPP is considering Integrated Access and Backhaul (IAB), which involves wirelessly conducting both the access link between the UE and the base station, and the backhaul link between base stations (see Non-Patent Documents 2, 20, and 29).

[0054] 3GPP is considering supporting uncrewed aerial systems (UAS) in mobile communication systems (see Non-Patent Document 30). For example, methods for communicating with terminals mounted on uncrewed aerial vehicles (UAVs) are being considered (see Non-Patent Document 39).

[0055] 3GPP TS36.300 V18.4.03GPP TS38.300 V18.4.0“Scenarios, requirements and KPIs for 5G mobile and wireless system”、ICT-317669-METIS / D1.13GPP TR23.799 V14.0.03GPP TR38.801 V14.0.03GPP TR38.802 V14.2.03GPP TR38.804 V14.0.03GPP TR38.912 V16.0.03GPP RP-1721153GPP TS23.501 V19.2.13GPP TS38.211 V18.5.03GPP TS38.212 V18.5.03GPP TS38.213 V18.5.03GPP TS38.214 V18.5.03GPP TS38.321 V18.4.03GPP TS38.322 V18.2.03GPP TS38.323 V18.4.03GPP TS37.324 V18.0.03GPP TS38.331 V18.4.03GPP TS38.401 V18.4.03GPP TS38.413 V18.4.03GPP TS37.340 V18.4.03GPP TS38.423 V18.4.03GPP TS38.305 V18.4.03GPP TS23.273 V19.1.03GPP TR23.703 V12.0.03GPP TS23.287 V18.4.03GPP TS23.303 V18.0.03GPP TS38.340 V18.2.03GPP TR22.870 V0.1.13GPP RP-2423483GPP RP-2425083GPP RP-2425273GPP RP-2425463GPP RP-2431513GPP RWS-230250ITU, “The ITU-R Framework for IMT-2030”, July 2023,インターネット<https: / / www.itu.int / en / ITU-R / study-groups / rsg5 / rwp5d / imt-2030 / Documents / IMT-2030%20Framework_WP%205D%20Management%20Team.pdf>3GPP TS37.355 V18.4.03GPP TS22.125 V19.2.03GPP TS23.256 V19.1.0.

[0056] In 3GPP's mobile communication systems, it has been proposed to track the trajectory of unmanned aerial vehicles (UAVs) using sensing (see Non-Patent Documents 30 and 40). However, the aforementioned Non-Patent Documents do not disclose the specific procedures for sensing. As a result, problems may arise where sensing cannot be performed.

[0057] In view of the above issues, one of the objectives of this disclosure is to provide a communication system that enables trajectory tracking of UAVs using sensing.

[0058] The communication system of this disclosure comprises at least one terminal device, at least one base station that communicates with the at least one terminal device, and at least one sensing function node that manages sensing. The sensing function node is configured to determine, using information regarding the position of an unmanned aerial vehicle (UAV), at least one of the at least one terminal device and the at least one base station, which is a first node that is a source node that transmits a sensing signal and a second node that is a destination node that receives the sensing signal.

[0059] With the above configuration, it becomes possible to track the trajectory of a UAV using sensing.

[0060] The purpose, features, aspects, and advantages of this disclosure will become clearer from the following detailed description and accompanying drawings.

[0061] This is an explanatory diagram showing the configuration of a wireless frame used in an NR communication system. This is a block diagram showing the overall configuration of an NR communication system 210 as discussed in 3GPP. This is a configuration diagram of a DC by a base station connected to an NG core. This is a block diagram showing the configuration of a mobile terminal 202 shown in Figure 2. This is a block diagram showing the configuration of a base station 213 shown in Figure 2. This is a block diagram showing the configuration of the 5GC section. This is a flowchart outlining the process from cell search to standby operation performed by a communication terminal (UE) in an NR communication system. This is a diagram showing an example of a cell configuration in an NR system. This is a connection configuration diagram showing an example of a terminal connection configuration in SL communication. This is a connection configuration diagram showing an example of a base station connection configuration that supports access backhaul integration. This is a diagram showing an example of UAV sensing in Embodiment 1. This is a diagram showing another example of UAV sensing in Embodiment 1. This is a diagram showing another example of UAV sensing in Embodiment 1. This is a diagram showing another example of UAV sensing in Embodiment 1. This is a sequence diagram showing an example of UAV sensing operation in Embodiment 1. This is a sequence diagram showing another example of UAV sensing operation in Embodiment 1. This is a sequence diagram showing another example of the sensing operation of the UAV in Embodiment 1. This is a sequence diagram showing another example of the sensing operation of the UAV in Embodiment 1. This is a sequence diagram showing an example of the source base station / UE switching operation in UAV sensing in Modification 1 of Embodiment 1. This is a sequence diagram continuing from Figure 19. This is a sequence diagram showing an example of the destination base station / UE switching operation in UAV sensing in Modification 1 of Embodiment 1. This is a sequence diagram continuing from Figure 21. This is a sequence diagram showing an example of the switching operation between the source base station / UE and the destination base station / UE in UAV sensing in Modification 1 of Embodiment 1. This is a sequence diagram continuing from Figure 23. This is a sequence diagram showing an example of the operation of UAV trajectory deviation detection using sensing in Modification 2 of Embodiment 1. This is a sequence diagram continuing from Figure 25. This is a sequence diagram showing an example of the operation of illegal object detection using sensing in Embodiment 2. This is a sequence diagram continuing from Figure 27.This is a sequence diagram showing another example of the operation of illegal object detection using sensing for Modification 1 of Embodiment 2. This is a sequence diagram showing another example of the operation of illegal object detection using sensing for Modification 1 of Embodiment 2. This is a sequence diagram continuing from Figure 30. This is a sequence diagram showing another example of the operation of illegal object detection using sensing for Modification 1 of Embodiment 2. This is a sequence diagram continuing from Figure 32. This is a sequence diagram showing another example of the operation of illegal object detection using sensing for Modification 1 of Embodiment 2. This is a sequence diagram continuing from Figure 34. This is a sequence diagram showing another example of the operation of illegal object detection using sensing for Modification 1 of Embodiment 2. This is a sequence diagram continuing from Figure 36. This is a sequence diagram showing an example of the operation in which sensing is performed across multiple SFs for Embodiment 3. This is a sequence diagram continuing from Figure 38. This is a sequence diagram showing another example of the operation in which sensing is performed across multiple SFs for Embodiment 3. This is a sequence diagram continuing from Figure 40.

[0062] Embodiment 1. Figure 2 is a block diagram showing the overall configuration of the NR communication system 210 discussed in 3GPP. Figure 2 will be explained. The radio access network is called NG-RAN (Next Generation Radio Access Network) 211. A mobile terminal device (hereinafter referred to as "Mobile Terminal (User Equipment: UE)") 202, which is a communication terminal device, can communicate wirelessly with a base station device (hereinafter referred to as "NR base station (NG-RAN NodeB: gNB)") 213 and transmits and receives signals wirelessly. The NG-RAN 211 is composed of one or more NR base stations 213.

[0063] Here, "communication terminal equipment" includes not only mobile terminal equipment such as portable mobile phone terminals, but also stationary devices such as sensors. In the following explanation, "communication terminal equipment" may sometimes be simply referred to as "communication terminal."

[0064] The Access Stratum (AS) protocol is terminated between UE202 and NG-RAN211. Examples of AS protocols used include RRC (Radio Resource Control), SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer). RRC is used in the control plane (hereinafter sometimes referred to as C-plane, C-Plane, or CP), SDAP is used in the user plane (hereinafter sometimes referred to as U-plane, U-Plane, or UP), and PDCP, MAC, RLC, and PHY are used in both the C-plane and U-plane.

[0065] The control protocol RRC (Radio Resource Control) between UE202 and NR base station 213 performs functions such as broadcasting, paging, and RRC connection management. The states of NR base station 213 and UE202 in RRC are RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVE.

[0066] In RRC_IDLE mode, functions such as PLMN (Public Land Mobile Network) selection, System Information (SI) broadcasting, paging, cell re-selection, and mobility are performed. In RRC_CONNECTED mode, the mobile terminal has an RRC connection and can send and receive data with the network. In RRC_CONNECTED mode, functions such as handover (HO) and neighbor cell measurement are performed. In RRC_INACTIVE mode, while the connection between the 5G core unit 214 and the NR base station 213 is maintained, functions such as System Information (SI) broadcasting, paging, cell re-selection, and mobility are performed.

[0067] The gNB 213 is connected via an NG interface to a 5G core unit (hereinafter sometimes referred to as the "5GC unit") 214, which includes an Access and Mobility Management Function (AMF), a Session Management Function (SMF), or a User Plane Function (UPF). Control information and / or user data are communicated between the gNB 213 and the 5GC unit 214. The NG interface is a collective term for the N2 interface between the gNB 213 and the AMF 220, the N3 interface between the gNB 213 and the UPF 221, the N11 interface between the AMF 220 and the SMF 222, and the N4 interface between the UPF 221 and the SMF 222. Multiple 5GC units 214 may be connected to a single gNB 213. The gNB213 units are connected via an Xn interface, and control information and / or user data are communicated between them.

[0068] The 5GC unit 214 is a higher-level device, specifically a higher-level node, and controls the connection between the NR base station 213 and the mobile terminal (UE) 202, and distributes paging signals to one or more NR base stations (gNB) 213 and / or LTE base stations (E-UTRAN NodeB: eNB). The 5GC unit 214 also performs mobility control in the idle state. The 5GC unit 214 manages the tracking area list when the mobile terminal 202 is in the idle state, in the inactive state, and in the active state. The 5GC unit 214 initiates the paging protocol by sending a paging message to a cell belonging to the tracking area where the mobile terminal 202 is registered.

[0069] The gNB213 may constitute one or more cells. If one gNB213 constitutes multiple cells, each cell is configured to communicate with the UE202.

[0070] The gNB213 may be divided into a Central Unit (CU) 215 and a Distributed Unit (DU) 216. One CU 215 is configured within the gNB213. One or more DU 216 are configured within the gNB213. One DU 216 constitutes one or more cells. The CU 215 is connected to the DU 216 by an F1 interface, and control information and / or user data are communicated between the CU 215 and the DU 216. The F1 interface consists of an F1-C interface and an F1-U interface. The CU 215 is responsible for the functions of the RRC, SDAP, and PDCP protocols, and the DU 216 is responsible for the functions of the RLC, MAC, and PHY protocols. One or more TRPs (Transmission Reception Points) 219 may be connected to the DU 216. The TRP219 transmits and receives wireless signals to and from the UE.

[0071] CU215 may be divided into a C-plane CU (CU-C) 217 ​​and a U-plane CU (CU-U) 218. One CU-C 217 is configured within CU215. One or more CU-U 218s are configured within CU215. CU-C 217 is connected to CU-U 218 by an E1 interface, and control information is communicated between CU-C 217 and CU-U 218. CU-C 217 is connected to DU216 by an F1-C interface, and control information is communicated between CU-C 217 and DU216. CU-U 218 is connected to DU216 by an F1-U interface, and user data is communicated between CU-U 218 and DU216.

[0072] In a 5G communication system, the Unified Data Management (UDM) function and Policy Control Function (PCF) described in Non-Patent Document 10 (3GPP TS23.501) may be included. The UDM and / or PCF may be included in the 5GC unit 214 in Figure 2.

[0073] In a 5G communication system, a Location Management Function (LMF) as described in Non-Patent Document 24 (3GPP TS38.305) may be provided. The LMF may be connected to a base station via an AMF, as disclosed in Non-Patent Document 25 (3GPP TS23.273).

[0074] In a 5G communication system, the Non-3GPP Interworking Function (N3IWF) described in Non-Patent Document 10 (3GPP TS23.501) may be included. In non-3GPP access with a UE, the N3IWF may terminate the Access Network (AN) with the UE.

[0075] Figure 3 shows the configuration of a DC (Dual Connectivity) connected to the NG core. In Figure 3, solid lines indicate U-Plane connections, and dashed lines indicate C-Plane connections. In Figure 3, the master base station 240-1 may be a gNB or an eNB. Similarly, the secondary base station 240-2 may be a gNB or an eNB. For example, in Figure 3, a DC configuration in which the master base station 240-1 is a gNB and the secondary base station 240-2 is an eNB may be called NG-EN-DC. Figure 3 shows an example in which the U-Plane connection between the 5GC unit 214 and the secondary base station 240-2 is performed via the master base station 240-1, but it may also be performed directly between the 5GC unit 214 and the secondary base station 240-2. Furthermore, in Figure 3, instead of the 5GC unit 214, an EPC (Evolved Packet Core), which is a core network connected to the LTE system and the LTE-A system, may be connected to the master base station 240-1. A U-Plane connection may also be directly established between the EPC and the secondary base station 240-2.

[0076] Figure 4 is a block diagram showing the configuration of the mobile terminal 202 shown in Figure 2. The transmission process of the mobile terminal 202 shown in Figure 4 will now be explained. First, control data from the control unit 310 and user data from the application unit 302 are sent to the protocol processing unit 301. Buffering of the control data and user data may be performed. The buffers for the control data and user data may be provided in the control unit 310, the application unit 302, or the protocol processing unit 301. The protocol processing unit 301 performs protocol processing such as SDAP, PDCP, RLC, MAC, etc., for example, determining the destination base station in DC, etc., and adding headers in each protocol. The data that has undergone protocol processing is passed to the encoder unit 304, where encoding processing such as error correction is performed. There may be data that is output directly from the protocol processing unit 301 to the modulation unit 305 without undergoing encoding processing. The data encoded by the encoder unit 304 is then modulated by the modulation unit 305. Precoding in MIMO may be performed in the modulation unit 305. The modulated data is converted into a baseband signal, then output to the frequency conversion unit 306, where it is converted to a wireless transmission frequency. The transmission signal is then sent from antennas 307-1 to 307-4 to the base station 213. Figure 4 illustrates the case with four antennas, but the number of antennas is not limited to four.

[0077] Furthermore, the reception processing of the mobile terminal 202 is performed as follows: A radio signal from the base station 213 is received by antennas 307-1 to 307-4. The received signal is converted from the radio reception frequency to a baseband signal by the frequency conversion unit 306, and demodulation processing is performed by the demodulation unit 308. Weight calculation and multiplication processing may also be performed in the demodulation unit 308. The demodulated data is passed to the decoder unit 309, where decoding processing such as error correction is performed. The decoded data is passed to the protocol processing unit 301, where protocol processing such as MAC, RLC, PDCP, and SDAP is performed, for example, operations such as header removal in each protocol. Of the data that has undergone protocol processing, control data is passed to the control unit 310, and user data is passed to the application unit 302.

[0078] The series of processes performed by the mobile terminal 202 are controlled by the control unit 310. Therefore, although the control unit 310 is omitted in Figure 4, it is connected to each of the units 302, 304 to 309.

[0079] Each part of the mobile terminal 202, for example, the control unit 310, the protocol processing unit 301, the encoder unit 304, and the decoder unit 309, are implemented by a processing circuit that includes, for example, a processor and memory. For example, the control unit 310 is implemented by the processor executing a program that describes a series of processes for the mobile terminal 202. The program that describes a series of processes for the mobile terminal 202 is stored in memory. Examples of memory include non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), and flash memory. Each part of the mobile terminal 202, for example, the control unit 310, the protocol processing unit 301, the encoder unit 304, and the decoder unit 309, may also be implemented by a dedicated processing circuit such as an FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), or DSP (Digital Signal Processor). In Figure 4, the number of antennas used by the mobile terminal 202 for transmission and the number of antennas used for reception may be the same or different.

[0080] Figure 5 is a block diagram showing the configuration of the base station 213 shown in Figure 2. The transmission process of the base station 213 shown in Figure 5 will now be explained. The EPC communication unit 401 transmits and receives data between the base station 213 and the EPC. The 5GC communication unit 412 transmits and receives data between the base station 213 and the 5GC (5GC unit 214, etc.). The other base station communication unit 402 transmits and receives data with other base stations. The EPC communication unit 401, the 5GC communication unit 412, and the other base station communication unit 402 each exchange information with the protocol processing unit 403. Control data from the control unit 411, as well as user data and control data from the EPC communication unit 401, the 5GC communication unit 412, and the other base station communication unit 402, are sent to the protocol processing unit 403. Buffering of control data and user data may be performed. A buffer for control data and user data may be provided in the control unit 411, the EPC communication unit 401, the 5GC communication unit 412, or the other base station communication unit 402.

[0081] The protocol processing unit 403 performs protocol processing such as SDAP, PDCP, RLC, and MAC, for example, routing of transmission data in DCs, and adding headers for each protocol. The processed data is passed to the encoder unit 405, where it undergoes encoding processing such as error correction. There may be data that is output directly from the protocol processing unit 403 to the modulation unit 406 without undergoing encoding processing. Data may also be sent from the protocol processing unit 403 to the other base station communication unit 402. For example, in a DC, data sent from the 5GC communication unit 412 or the EPC communication unit 401 may be sent to another base station, such as a secondary base station, via the other base station communication unit 402. The encoded data is then modulated in the modulation unit 406. Precoding in MIMO may be performed in the modulation unit 406. The modulated data is converted into a baseband signal and then output to the frequency conversion unit 407, where it is converted to a wireless transmission frequency. Subsequently, a transmission signal is sent from antennas 408-1 to 408-4 to one or more mobile terminals 202. Figure 5 illustrates the case where there are four antennas, but the number of antennas is not limited to four.

[0082] Furthermore, the reception processing at base station 213 is performed as follows: A radio signal from one or more mobile terminals 202 is received by antennas 408-1 to 408-4. The received signal is converted from the radio reception frequency to a baseband signal by the frequency conversion unit 407, and demodulation processing is performed by the demodulation unit 409. The demodulated data is passed to the decoder unit 410, where decoding processing such as error correction is performed. The decoded data is passed to the protocol processing unit 403, where protocol processing such as MAC, RLC, PDCP, and SDAP is performed, for example, operations such as header removal in each protocol. Of the data that has undergone protocol processing, control data is passed to the control unit 411, the 5GC communication unit 412, the EPC communication unit 401, or the other base station communication unit 402, and user data is passed to the 5GC communication unit 412, the EPC communication unit 401, or the other base station communication unit 402. Data sent from another base station communication unit 402 may be sent to the 5GC communication unit 412 or the EPC communication unit 401. This data may be, for example, uplink data sent to the 5GC communication unit 412 or the EPC communication unit 401 via another base station in a DC.

[0083] The series of processes performed by the base station 213 are controlled by the control unit 411. Therefore, although the control unit 411 is omitted in Figure 5, it is connected to each of the units 401, 402, 405-410, and 412.

[0084] Each part of the base station 213, for example, the control unit 411, the protocol processing unit 403, the 5GC communication unit 412, the EPC communication unit 401, the other base station communication unit 402, the encoder unit 405, and the decoder unit 410, are implemented as processing circuits including a processor and memory, similar to the mobile terminal 202 described above, or as dedicated processing circuits such as FPGA, ASIC, and DSP. In Figure 5, the number of antennas used by the base station 213 for transmission and the number of antennas used for reception may be the same or different.

[0085] As an example of the configuration of the CU215 shown in Figure 2, a configuration may be used in which a DU communication unit is added, excluding the encoder unit 405, modulation unit 406, frequency conversion unit 407, antennas 408-1 to 408-4, demodulation unit 409, and decoder unit 410 shown in Figure 5. The DU communication unit is connected to the protocol processing unit 403. The protocol processing unit 403 in the CU215 performs protocol processing such as PDCP and SDAP.

[0086] As an example of the DU216 configuration shown in Figure 2, a configuration may be used in which a CU communication unit is provided, excluding the EPC communication unit 401, other base station communication unit 402, and 5GC communication unit 412 shown in Figure 5. The CU communication unit is connected to the protocol processing unit 403. The protocol processing unit 403 in the DU216 performs protocol processing such as PHY, MAC, and RLC.

[0087] Figure 6 is a block diagram showing the configuration of the 5GC unit. Figure 6 shows the configuration of the 5GC unit 214 shown in Figure 2. Figure 6 shows the case where the 5GC unit 214 shown in Figure 2 includes the configuration of the AMF, SMF, and UPF. In the example shown in Figure 6, the AMF may have the function of the control plane control unit 525, the SMF may have the function of the session management unit 527, and the UPF may have the functions of the user plane communication unit 523 and the Data Network communication unit 521. The Data Network communication unit 521 transmits and receives data between the 5GC unit 214 and the Data Network. The base station communication unit 522 transmits and receives data between the 5GC unit 214 and the base station 213 via the NG interface. User data sent from the Data Network is passed from the Data Network communication unit 521 to the base station communication unit 522 via the user-plane communication unit 523, and then transmitted to one or more base stations 213. User data sent from the base station 213 is passed from the base station communication unit 522 to the Data Network communication unit 521 via the user-plane communication unit 523, and then transmitted to the Data Network.

[0088] Control data sent from base station 213 is passed from base station communication unit 522 to control plane control unit 525. The control plane control unit 525 may pass the control data to session management unit 527. Control data may also be sent from Data Network. Control data sent from Data Network may be sent from Data Network communication unit 521 to session management unit 527 via user plane communication unit 523. The session management unit 527 may also send the control data to control plane control unit 525.

[0089] The user-plane communication unit 523 includes the PDU processing unit 523-1 and the mobility anchoring unit 523-2, and performs all processing for the user-plane (hereinafter sometimes referred to as U-Plane). The PDU processing unit 523-1 processes data packets, for example, sending and receiving packets with the Data Network communication unit 521 and sending and receiving packets with the base station communication unit 522. The mobility anchoring unit 523-2 is responsible for maintaining the data path when the UE is in mobility.

[0090] The session management unit 527 manages the PDU session established between the UE and the UPF. The session management unit 527 includes the PDU session control unit 527-1 and the UE IP address assignment unit 527-2. The PDU session control unit 527-1 manages the PDU session between the mobile terminal 202 and the 5GC unit 214. The UE IP address assignment unit 527-2 assigns an IP address to the mobile terminal 202.

[0091] The control plane control unit 525 includes the NAS security unit 525-1 and the idle state mobility management unit 525-2, and performs all processing for the control plane (hereinafter sometimes referred to as C-Plane). The NAS security unit 525-1 performs security for NAS (Non-Access Stratum) messages, etc. The idle state mobility management unit 525-2 performs mobility management in the standby state (also referred to as RRC_IDLE state or simply idle), generation and control of paging signals in the standby state, addition, deletion, updating, searching, and tracking area management for one or more mobile terminals 202 under its umbrella.

[0092] The series of processes in the 5GC unit 214 are controlled by the control unit 526. Therefore, although the control unit 526 is omitted in Figure 6, it is connected to each of the units 521 to 523, 525, and 527. Each of the units in the 5GC unit 214 is implemented by a processing circuit consisting of, for example, a processor and memory, or by a dedicated processing circuit such as an FPGA, ASIC, or DSP, similar to the control unit 310 of the mobile terminal 202 described above.

[0093] Next, an example of a cell search method in a communication system is shown. Figure 7 is a flowchart illustrating the process from cell search to standby operation performed by a communication terminal (UE) in an NR-type communication system. When the communication terminal starts a cell search, in step ST601, it synchronizes the slot timing and frame timing using the first synchronization signal (P-SS) and the second synchronization signal (S-SS) transmitted from the surrounding base station.

[0094] P-SS and S-SS together are called the Synchronization Signal (SS). Each cell is assigned a synchronization code that corresponds one-to-one with its assigned PCI (Physical Cell Identifier). 1008 different PCI combinations are being considered. The communication terminal uses these 1008 PCI combinations to synchronize and also detects (identifies) the PCI of the synchronized cell.

[0095] The communication terminal then receives the PBCH in step ST602 for the next synchronized cell. The BCCH on the PBCH is mapped to the MIB (Master Information Block), which contains cell configuration information. Therefore, by receiving the PBCH and obtaining the BCCH, the MIB can be obtained. The information in the MIB includes, for example, the SFN (System Frame Number), scheduling information for SIB (System Information Block) 1, subcarrier spacing for SIB1 etc., and DM-RS position information.

[0096] Furthermore, the communication terminal obtains the SS block identifier from the PBCH. Part of the bit sequence of the SS block identifier is included in the MIB. The remaining bit sequence is included in the identifier used for sequence generation of the DM-RS associated with the PBCH. The communication terminal obtains the SS block identifier using the MIB included in the PBCH and the sequence of the DM-RS associated with the PBCH.

[0097] Next, in step ST603, the communication terminal measures the received power of the SS block.

[0098] Next, in step ST604, the communication terminal selects the cell with the best reception quality from among the one or more cells detected up to step ST603, for example, the cell with the highest received power, i.e., the best cell. The communication terminal also selects the beam with the best reception quality, for example, the beam with the highest received power of the SS block, i.e., the best beam. For example, the received power of the SS block for each SS block identifier is used to select the best beam.

[0099] Next, in step ST605, the communication terminal receives DL-SCH based on the scheduling information of SIB1 included in MIB and obtains SIB (System Information Block) 1 in the broadcast information BCCH. SIB1 contains information regarding access to the cell, cell configuration information, and scheduling information for other SIBs (SIBk: an integer k ≥ 2). SIB1 also contains the Tracking Area Code (TAC).

[0100] Next, in step ST606, the communication terminal compares the TAC of SIB1 received in step ST605 with the TAC portion of the Tracking Area Identity (TAI) in the Tracking Area List already held by the communication terminal. The Tracking Area List is also called the TAI list. TAI is identification information for identifying a tracking area and consists of MCC (Mobile Country Code), MNC (Mobile Network Code), and TAC (Tracking Area Code). MCC is the country code. MNC is the network code. TAC is the code number of the tracking area.

[0101] If, as a result of the comparison in step ST606, the TAC received in step ST605 is the same as a TAC included in the tracking area list, the communication terminal enters standby mode in that cell. If, after comparison, the TAC received in step ST605 is not included in the tracking area list, the communication terminal requests a change in the tracking area through that cell to the Core Network (EPC), which includes the MME, etc., in order to perform a Tracking Area Update (TAU).

[0102] The devices constituting the core network (hereinafter sometimes referred to as "core network devices") update the tracking area list based on the identification number (UE-ID, etc.) of the communication terminal sent from the communication terminal along with the TAU request signal. The core network devices transmit the updated tracking area list to the communication terminal. The communication terminal rewrites (updates) its TAC list based on the received tracking area list. After that, the communication terminal enters a waiting state in that cell.

[0103] Next, we will show examples of random access methods in communication systems. In random access, four-step random access and two-step random access are used. Furthermore, for both four-step and two-step random access, there are contention-based random access, that is, random access where timing collisions with other mobile terminals may occur, and contention-free random access.

[0104] An example of a collision-based four-step random access method is shown. In the first step, the mobile terminal transmits a random access preamble to the base station. The random access preamble may be selected by the mobile terminal from a predetermined range, or it may be individually assigned to the mobile terminal and notified by the base station.

[0105] In the second step, the base station sends a random access response to the mobile terminal. The random access response includes uplink scheduling information used in the third step, and a terminal identifier used in the uplink transmission of the third step.

[0106] In the third step, the mobile terminal transmits data uplink to the base station. The mobile terminal uses the information obtained in the second step for the uplink transmission. In the fourth step, the base station notifies the mobile terminal whether or not a collision has been resolved. If the mobile terminal is notified that there is no collision, it terminates the random access process. If the mobile terminal is notified that there is a collision, it restarts the process from the first step.

[0107] The collision-free four-step random access method differs from the collision-based four-step random access method in the following ways: Prior to the first step, the base station pre-assigns a random access preamble and uplink scheduling to the mobile terminal. Furthermore, notification of collision resolution status is unnecessary in the fourth step.

[0108] An example of a collision-based two-step random access method is shown below. In the first step, the mobile terminal sends a random access preamble and an uplink transmission to the base station. In the second step, the base station notifies the mobile terminal whether a collision occurred. If the mobile terminal is notified that there was no collision, it terminates the random access process. If the mobile terminal is notified that there was a collision, it restarts the process from the first step.

[0109] The collision-free two-step random access method differs from the collision-based two-step random access method in the following ways: Prior to the first step, the base station pre-assigns a random access preamble and uplink scheduling to the mobile terminal. In the second step, the base station transmits a random access response to the mobile terminal.

[0110] Figure 8 shows an example of a cell configuration in NR. In an NR cell, a narrow beam is formed and transmitted by changing its direction. In the example shown in Figure 8, the base station 750 uses beam 751-1 to transmit and receive data with a mobile terminal at a certain time. At other times, the base station 750 uses beam 751-2 to transmit and receive data with a mobile terminal. Similarly, the base station 750 uses one or more of beams 751-3 to 751-8 to transmit and receive data with a mobile terminal. In this way, the base station 750 configures a wide-area cell 752.

[0111] Figure 8 shows an example where the base station 750 uses eight beams, but the number of beams may be different from eight. Also, in the example shown in Figure 8, the base station 750 uses one beam simultaneously, but it may use multiple beams.

[0112] The concept of Quasi-Colocation (QCL) is used for beam identification (see Non-Patent Document 14 (3GPP TS38.214)). That is, the beam is identified by information indicating which reference signal (e.g., SS block, CSI-RS) beam it can be considered identical to. This information may include information about the aspects of the beams that can be considered identical, such as Doppler shift, Doppler shift diffusion, mean delay, mean delay diffusion, and spatial Rx parameters (see Non-Patent Document 14 (3GPP TS38.214)).

[0113] In 3GPP, Side Link (SL) is supported for D2D (Device to Device) and V2V (Vehicle to Vehicle) communication (see Non-Patent Documents 1 and 16). SL is defined by the PC5 interface.

[0114] In SL communication, in addition to broadcast, support for unicast and groupcast is being considered, and therefore support for PC5-S signaling is being explored (see Non-Patent Document 27 (3GPP TS23.287)). For example, PC5-S signaling is implemented to establish a link for SL, i.e., PC5 communication. This link is implemented at the V2X layer and is also referred to as a Layer 2 link.

[0115] Furthermore, support for RRC signaling in SL communication is being considered (see Non-Patent Document 27 (3GPP TS23.287)). RRC signaling in SL communication is also referred to as PC5 RRC signaling. For example, it has been proposed to notify UEs of their capabilities between UEs performing PC5 communication, and to notify AS layer settings for performing V2X communication using PC5 communication.

[0116] Figure 9 shows an example of a mobile terminal connection configuration in SL communication. In the example shown in Figure 9, UE805 and UE806 are located within the coverage 803 of base station 801. UL / DL communication 807 is performed between base station 801 and UE805. UL / DL communication 808 is performed between base station 801 and UE806. SL communication 810 is performed between UE805 and UE806. UE811 and UE812 are located outside the coverage 803. SL communication 814 is performed between UE805 and UE811. Additionally, SL communication 816 is performed between UE811 and UE812.

[0117] As an example of communication between a UE and a NW via a relay in SL communication, UE805, shown in Figure 9, relays communication between UE811 and base station 801.

[0118] A UE performing relay may use a configuration similar to that shown in Figure 4. The relay processing in the UE will be explained using Figure 4. The relay processing by UE 805 in communication from UE 811 to base station 801 will be explained. The radio signal from UE 811 is received by antennas 307-1 to 307-4. The received signal is converted from the radio reception frequency to a baseband signal by the frequency conversion unit 306, and demodulation processing is performed in the demodulation unit 308. Weight calculation and multiplication processing may also be performed in the demodulation unit 308. The demodulated data is passed to the decoder unit 309, where decoding processing such as error correction is performed. The decoded data is passed to the protocol processing unit 301, where protocol processing such as MAC and RLC used for communication with UE 811 is performed, for example, operations such as header removal in each protocol. Protocol processing such as RLC and MAC used for communication with base station 801 is also performed, for example, operations such as header addition in each protocol. In the protocol processing unit 301 of the UE811, PDCP and SDAP protocol processing may also be performed. The processed data is passed to the encoder unit 304, where encoding processing such as error correction is performed. There may also be data that is output directly from the protocol processing unit 301 to the modulation unit 305 without encoding processing. The data encoded by the encoder unit 304 is then modulated by the modulation unit 305. Precoding in MIMO may be performed in the modulation unit 305. The modulated data is converted into a baseband signal and then output to the frequency conversion unit 306, where it is converted to a wireless transmission frequency. After that, the transmission signal is sent from antennas 307-1 to 307-4 to the base station 801.

[0119] As described above, an example of relaying by UE805 in communication from UE811 to base station 801 was shown, but the same process is used in relaying communication from base station 801 to UE811.

[0120] 5G base stations can support Integrated Access and Backhaul (IAB) (see Non-Patent Documents 2 and 20). A base station that supports IAB (hereinafter sometimes referred to as an IAB base station) consists of an IAB donor CU, which is a CU of the base station that operates as an IAB donor providing IAB functionality; an IAB donor DU, which is a DU of the base station that operates as an IAB donor; and an IAB node that is connected to the IAB donor DU and to the UE using a wireless interface. An F1 interface is provided between the IAB node and the IAB donor CU (see Non-Patent Document 2).

[0121] Figure 10 shows an example of IAB base station connections. IAB donor CU901 is connected to IAB donor DU902. IAB node 903 is connected to IAB donor DU902 using a wireless interface. IAB node 903 is connected to IAB node 904 using a wireless interface. In other words, multi-stage connections of IAB nodes may occur. UE905 is connected to IAB node 904 using a wireless interface. UE906 may be connected to IAB node 903 using a wireless interface, and UE907 may be connected to IAB donor DU902 using a wireless interface. Multiple IAB donor DU902 may be connected to IAB donor CU901, multiple IAB node 903 may be connected to IAB donor DU902, and multiple IAB node 904 may be connected to IAB node 903.

[0122] A BAP (Backhaul Adaptation Protocol) layer is provided in the connection between IAB donor DUs and IAB nodes, and in the connection between IAB nodes (see Non-Patent Document 29). The BAP layer performs operations such as routing received data to IAB donor DUs and / or IAB nodes, and mapping to RLC channels (see Non-Patent Document 29).

[0123] As an example of the configuration of an IAB donor CU, a configuration similar to that of CU215 is used.

[0124] As an example of the IAB donor DU configuration, a configuration similar to that of DU216 is used. In the protocol processing section of the IAB donor DU, BAP layer processing is performed, such as adding a BAP header to downlink data, routing to IAB nodes, and removing the BAP header from uplink data.

[0125] As an example of an IAB node configuration, a configuration excluding the EPC communication unit 401, other base station communication unit 402, and 5GC communication unit 412 shown in Figure 5 may be used.

[0126] The transmission and reception processing at the IAB node will be explained using Figures 5 and 10. The transmission and reception processing of the IAB node 903 in communication between the IAB donor CU 901 and UE 905 will be explained. In uplink communication from UE 905 to IAB donor CU 901, the radio signal from the IAB node 904 is received by the antenna 408 (part or all of antennas 408-1 to 408-4). The received signal is converted from the radio reception frequency to a baseband signal by the frequency conversion unit 407, and demodulation processing is performed by the demodulation unit 409. The demodulated data is passed to the decoder unit 410, where decoding processing such as error correction is performed. The decoded data is passed to the protocol processing unit 403, where protocol processing such as MAC and RLC used for communication with the IAB node 904 is performed, for example, operations such as header removal in each protocol. Furthermore, routing to the IAB donor DU902 is performed using a BAP header, and protocol processing such as RLC and MAC used for communication with the IAB donor DU902 is performed, such as adding headers for each protocol. The processed data is passed to the encoder unit 405, where encoding processing such as error correction is performed. There may be data that is output directly from the protocol processing unit 403 to the modulation unit 406 without encoding processing. The encoded data is then modulated in the modulation unit 406. Precoding in MIMO may be performed in the modulation unit 406. The modulated data is converted into a baseband signal, then output to the frequency conversion unit 407, where it is converted to a wireless transmission frequency. After that, a transmission signal is sent from antennas 408-1 to 408-4 to the IAB donor DU902. Similar processing is performed in downlink communication from the IAB donor CU901 to UE905.

[0127] The same transmission and reception processing is performed at IAB node 904 as at IAB node 903. In the protocol processing unit 403 of IAB node 903, as part of the BAP layer processing, for example, the addition of a BAP header and routing to IAB node 904 in uplink communication, and the removal of a BAP header in downlink communication are performed.

[0128] Hereafter, expressions using the slash symbol ( / ) will mean that the expression includes at least one of the two elements before and after the slash.

[0129] In 3GPP, the integration of communication and sensing (ISAC: Integrated Sensing And Communication) is being considered (see Non-Patent Documents 31-36). ISAC is also listed as a use case in IMT-2030 (see Non-Patent Document 37). In 3GPP, a specific use case for ISAC has been proposed: tracking the trajectory of uncrewed aerial vehicles (UAVs) using sensing (see Non-Patent Document 30).

[0130] In UAV sensing, radio waves from the transmitting base station / UE can be reflected, potentially allowing them to reach base stations / UEs further than usual. As a result, it is possible that the transmitting base station / UE and the receiving base station / UE belong to different base stations.

[0131] However, the aforementioned non-patent literature does not disclose the specific procedures for sensing in the case described above. For example, the aforementioned non-patent literature does not disclose how to determine the source base station / UE and the destination base station / UE. As a result, problems arise such as being unable to perform sensing in the case described above.

[0132] This embodiment discloses a method for solving these problems.

[0133] The planned location of the UAV is used to determine the transmitting base station / UE and / or the receiving base station / UE. The planned location of the UAV may be, for example, a pre-configured UAV flight path (see Non-Patent Document 2). The flight path may include the position coordinates of waypoints that the UAV is scheduled to pass through. Note that the planned location of the UAV is not limited to position coordinates, but may also be a geographical area or zone that the UAV is scheduled to pass through. The flight path may include altitude information. The flight path may include time information. This time information may include information about the time at which the UAV will pass through the planned location. The transmitting base station / UE is a node that transmits radio waves for sensing the UAV, and may be called a transmitting source node. The receiving base station / UE is a node that receives radio waves for sensing the UAV, and may be called a receiving destination node. The source base station / UE and the destination base station / UE may be collectively referred to as sensing operation nodes.

[0134] Multiple sensing operation nodes may be configured. For example, sensing may be performed in which one source node transmits radio waves to multiple destination nodes. Sensing may be performed in which multiple source nodes transmit radio waves to one destination node. Sensing may be performed in which each of multiple source nodes transmits radio waves to multiple destination nodes. This makes it possible to improve the accuracy of sensing, for example.

[0135] Sensing may be carried out in a manner in which a base station transmits radio waves and a UE receives radio waves, or in a manner in which a base station transmits radio waves and another base station receives radio waves, or in a manner in which a UE transmits radio waves and a base station receives radio waves, or in a manner in which a UE transmits radio waves and another UE receives radio waves. The combination of the transmitting base station / UE and the receiving base station / UE may be a combination of different base stations, or a combination of a base station and a UE connected to a different base station, or a combination of UEs connected to different base stations.

[0136] The source node transmits sensing radio waves to the UAV. The sensing radio waves may be modulated using a predetermined modulation scheme (e.g., pulse modulation or FMCW (Frequency Modulated Continuous Wave)). The source node may transmit the sensing radio waves using resources used for sensing. These resources may be frequency-time resources. For example, a frequency band, BWP, or subband dedicated to sensing may be provided. As another example, these resources may be spatial resources. These spatial resources may include, for example, beams. As yet another example, these resources may be signals provided for sensing. Hereafter, signals provided for sensing may be referred to as sensing signals. Sensing signals may include signals having a known sequence. Sensing signals may be downlink signals. For example, sensing signals may be transmitted in a downlink slot or on a downlink frequency. The receiving base station may perform the receiving operation of sensing signals using downlink resources for communication. For example, the receiving base station may receive sensing signals transmitted in a downlink slot or on a downlink frequency. The source UE may use downlink resources for communication to transmit the sensing signal. For example, the source UE may transmit the sensing signal using a downlink slot or a downlink frequency. This can improve the flexibility of sensing, for example.

[0137] As another example, the sensing signal may be an uplink signal. For example, the sensing signal may be transmitted in an uplink slot or at an uplink frequency. The receiving UE may use its uplink resources for communication to receive the sensing signal. For example, the receiving UE may receive the sensing signal transmitted in an uplink slot or at an uplink frequency. The transmitting base station may use its uplink resources for communication to transmit the sensing signal. For example, the transmitting base station may transmit the sensing signal in an uplink slot or at an uplink frequency. This can achieve, for example, the same effects as described above.

[0138] For downlink sensing signals, the sensing signal may be RS, PRS, CSI-RS, SSB (Synchronization Signal Block), SS, MIB, or MIB DM-RS, etc., which are provided for sensing. For uplink sensing signals, the sensing signal may be RS, SRS, or DM-RS, etc., which are provided for sensing. When sensing signals are transmitted and received between UEs, the sensing signal may use RS, or SL-CSI-RS, etc., which are provided for sensing in SL communication.

[0139] Figure 11 shows an example of sensing by the UAV 1101. In the example shown in Figure 11, base station 1102 transmits a sensing signal, and UE 1103 receives the sensing signal. The receiving UE 1103 may be connected to a different base station 1104 than the transmitting base station 1102.

[0140] Figure 12 shows another example of sensing by the UAV 1101. In the example shown in Figure 12, base station 1102 transmits a sensing signal, and another base station 1104 receives the sensing signal.

[0141] Figure 13 shows another example of sensing by the UAV 1101. In the example shown in Figure 13, the UE 1105 transmits a sensing signal and the base station 1104 receives the sensing signal. The transmitting UE 1105 may be connected to a different base station 1102 than the receiving base station 1104.

[0142] Figure 14 shows another example of sensing by the UAV 1101. In the example shown in Figure 14, UE 1105 transmits a sensing signal, and another UE 1103 receives the sensing signal. The source UE 1105 and the receiving UE 1103 may be connected to different base stations. For example, the source UE 1105 may be connected to base station 1102, and the receiving UE 1103 may be connected to base station 1104.

[0143] A sensing function (SF) may be provided to manage the sensing of objects. The SF may manage the sensing of the UAV. The SF may obtain flight path information from the USS (UAS Service Supplier) / UTM (UAS Traffic Management). Here, the USS / UTM may be a function unit that provides UAS services and policies, and manages the operation of the UAV. The SF may request the information from the USS / UTM. The USS / UTM may notify the SF of the information. The USS / UTM may notify the SF of the information in response to the request from the SF.

[0144] The functional unit or node of the network to which the source base station / UE and the destination base station / UE are connected may determine the SF on which sensing will be performed. For example, the AMF may determine the SF. For example, the AMF may determine the SF using information about the location of the UAV.

[0145] The SF may reside within the NW. The SF may be provided separately from other functions within the NW. This can reduce the complexity of processing and minimize malfunctions. Alternatively, the SF may be included in other functions or nodes within the NW. This can facilitate coordination with other functions or nodes and reduce the amount of signaling. Therefore, from now on, operations centered on the SF may be interpreted as operations of other functions or nodes within the NW. The SF may reside outside the NW. Signaling between the SF and each functional unit / node of the NW may be performed through the NEF (Network Exposure Function). For example, if the SF resides outside the NW, the SF may send and receive signals with each functional unit / node of the NW through the NEF.

[0146] The SF may obtain information about base stations / UEs around the UAV. The SF may obtain information about base stations / UEs around the planned location of the UAV. This information may include, for example, information about the location of the base stations / UEs, or information about the time related to that location. The SF may obtain this information from the LMF. The SF may request this information from the LMF. This request may include information about the UAV's flight path, or information about the UAV's planned location.

[0147] The LMF may notify the SF of information regarding base stations / UEs around the UAV. The LMF may notify the SF of information regarding base stations / UEs around the planned location of the UAV. The LMF may notify the SF of information regarding all base stations / UEs present around the planned location of the UAV. The SF may decide which base stations / UEs to use for sensing from this information. The SF may make this decision, for example, using information regarding the location of the base stations / UEs.

[0148] As another example, the LMF may inform the SF of some or specific base stations / UEs located around the planned location of the UAV. The LMF may determine the aforementioned some or specific base stations / UEs. The LMF may use the information about the planned location of the UAV included in the request from the SF to make this determination.

[0149] The notification from the LMF to the SF may be triggered by the request from the SF to the LMF. The LMF may, for example, use information about the UAV's flight path to derive information about base stations / UEs around the UAV's planned location. This allows the LMF to derive base stations / UEs suitable for sensing the UAV. As a result, the efficiency of sensing resources can be improved.

[0150] Information regarding multiple base stations / UEs may be notified. The LMF may notify the SF. The SF may acquire information regarding multiple base stations / UEs. This allows the SF to select the appropriate source base station / UE and destination base station / UE from among multiple base stations / UEs. As a result, the reliability of sensing can be improved.

[0151] The Service Firm (SF) may determine the base station / UE (i.e., sensing operation node) to be used for sensing. This determination may use information about the UAV's flight path or information about the base station / UE's location. As another example, the SF may use information about the UAV's location (e.g., past sensing results of the UAV) to determine the sensing operation node.

[0152] The base station / UE (i.e., sensing operation node) used for sensing may be determined using the altitude of the UAV. Different base stations / UEs may be configured as sensing operation nodes based on the altitude of the UAV. A configuration may be made in which the base station / UE used for sensing is determined using the altitude of the UAV. This can, for example, improve the flexibility of sensing.

[0153] The SF may obtain altitude information from the flight path, from past sensing results, or from the USS / UTM. The USS / UTM may obtain altitude information for the UAV from, for example, the UAV-C (UAV Controller).

[0154] SF may determine candidates for base stations / UEs to be used for sensing. Hereafter, these candidates may be referred to as candidates for sensing operation nodes. SF may determine multiple base stations / UEs as candidates for sensing operation nodes. SF may determine a sensing operation node (source base station / UE and destination base station / UE) from the candidates for sensing operation nodes. SF may determine one source base station / UE and one destination base station / UE as the sensing operation node. This, for example, can improve resource efficiency in the communication system. As another example, SF may determine multiple source base stations / UEs and one destination base station / UE as the sensing operation node. This, for example, can avoid complexity in sensing result reporting. As yet another example, SF may determine multiple source base stations / UEs and multiple destination base stations / UEs as the sensing operation node. This, for example, can improve sensing accuracy.

[0155] When selecting a receiving base station / UE from among candidates, received signal strength may be used. This received signal strength may be measured using radio waves transmitted from the base station / UE or the sensing signals described above. This received signal strength may be, for example, RSSI (Received Signal Strength Indicator), RSRP, RSRQ, or SINR (Signal-to-Interference plus Noise Ratio). This makes it possible to improve resource utilization efficiency in the communication system, for example.

[0156] As another example, the sensing result used for position estimation may be determined from the sensing result reports transmitted from candidate receiving base stations / UEs. For example, the received signal strength may be used for this determination. The received signal strength may be, for example, RSSI, RSRP, RSRQ, or SINR. This allows for rapid sensing in, for example, a communication system.

[0157] Video information may be used to determine the base station / UE (i.e., sensing operation node) to be used for sensing. For example, imaging results from a UAV may be used. The UAV may notify the base station of the imaging results. The base station may be a serving base station for the UAV. The base station may transmit the imaging results to the LMF, to the SF, or to the DN (Data Network). As another example, the UAV may transmit the imaging results to the UAV-C. The UAV-C may notify the USS / UTM of the imaging results. The USS / UTM may notify the LMF of the imaging results or to the SF.

[0158] The imaging results may be compared with a map. This comparison may be performed by the LMF, SF, or DN. The position of the UAV may be derived through this comparison.

[0159] The SF may obtain information regarding the location of the UAV. The SF may obtain this information from the LMF, from the DN, or derive it itself.

[0160] The SF may instruct the source base station / UE to transmit a sensing signal. The SF may determine the resources to be used for sensing. Hereafter, these resources may be referred to as sensing resources. The SF may notify the base station of information regarding the sensing resources. The SF may notify the source node of information regarding the sensing resources.

[0161] As another example, a base station may determine the sensing resources. Multiple base stations may determine the sensing resources. One of the multiple base stations may determine the resources it will use for sensing, or it may determine the resources that a UE connected to it will use for sensing. The base station may notify the service provider (SF) of information regarding the sensing resources, or of information regarding the source UE. The SF may request information regarding the sensing resources from the base station. The base station may notify the SF of such information in response to such request.

[0162] Sensing resources may include resources related to time, resources related to frequency, or resources related to coding.

[0163] Sensing may be performed periodically. This allows for continuous sensing, for example, and as a result, improves the reliability of UAV trajectory tracking. In another example, sensing may be performed semi-persistently. Sensing may be activated / deactivated. This can improve the utilization efficiency of the communication system, for example. In yet another example, sensing may be performed aperiodicly. For example, sensing may be triggered on request. This can further improve the utilization efficiency of the communication system, for example. Information regarding sensing resources may include information indicating periodic sensing, semi-persistent sensing, or aperiodic sensing. If semi-persistent sensing is configured, the SF may transmit information to the source base station / UE indicating sensing activation or deactivation. In another example, the base station may transmit information to the source base station / UE indicating sensing activation or deactivation. A base station interface, such as an Xn interface, may be used to transmit the information from the base station to the source base station.

[0164] Information relating to coding resources may include the sensing signal information described above. For example, information relating to coding resources may include information about the SS block of the source base station, information about positioning signals transmitted from the source base station, information about the PCI of the source base station, information about the SRS of the source UE, and information about the SRS of the source UE.

[0165] Radio waves used for communication may be used for sensing. This can improve the utilization efficiency in communication systems, for example.

[0166] A sensing signal may be provided. This signal may be used for sensing. This allows for, for example, accurate sensing.

[0167] Sensing indicators may be provided. The SF may determine these indicators. The SF may determine the source base station / UE and / or the destination base station / UE using the sensing indicators.

[0168] The SF may query candidate base stations / UEs (i.e., candidate sensing operation nodes) that are potential source base stations / UEs and / or destination base stations / UEs for information regarding their ability to handle the index. The candidate sensing operation nodes may notify the SF of their ability to handle the index. The SF may use this notification to determine the source base station / UE and / or destination base station / UE.

[0169] As another example, the base station / UE may determine the index. The SF may use the index notified by the base station / UE to determine the source base station / UE and / or the destination base station / UE.

[0170] The SF may request information about the indicator from the candidate sensing operation node. The candidate sensing operation node may notify the SF of information about the indicator.

[0171] Sensing capabilities may be provided. These capabilities may be used to determine the source base station / UE and / or the destination base station / UE.

[0172] The SF may request information about the capability from the candidate sensing operation node. The candidate sensing operation node may notify the SF of the information about the capability.

[0173] As another example, the SF may notify the determined source base station / UE of the metrics required for sensing. The SF may also notify the determined destination base station / UE of the metrics required for sensing. The source base station / UE and / or the destination base station / UE may then perform sensing using these metrics. This can, for example, reduce signaling between the SF and the base stations / UE.

[0174] Examples of indicators / capabilities in sensing are disclosed below: (a1) Sensing resource transmission function. (a2) Sensing resource reception function. (a3) ​​Sensing measurement function. (a4) Supported sensing frequency information. (a5) Sensing window support information. (a6) Sensing signal resolution. (a7) Combinations of (a1) to (a6).

[0175] (a1) may not be limited to information on whether or not it has the capability to transmit sensing resources, but may also be information on which sensing resources (e.g., sensing signals) it can transmit. For example, (a1) may include information indicating whether a sensing operation node or a candidate thereof can transmit sensing signals such as an SRS or an RS provided for sensing. (a1) may also include information on sensing resources. Such sensing resources may include resources related to time, resources related to frequency, resources related to codes, or information on modulation schemes.

[0176] (a2) may not be limited to information on whether or not it has the ability to receive sensing resources, but may also be information on which sensing resources it can receive. For example, (a2) may include information indicating whether a sensing operation node or a candidate thereof can receive sensing signals such as PRS, CSI-RS, SSB, SRS, or RS provided for sensing. (a2) may also include information on sensing resources. Such sensing resources may include resources related to time, resources related to frequency, resources related to codes, or information on modulation schemes.

[0177] (a3) may be information not limited to whether or not it has a sensing measurement function, but may also be information about which sensing measurement indicators it supports. For example, examples of sensing measurement indicators include RSRP, RSRQ, SIR (Signal to Interference Ratio), SINR, Doppler shift, AOD (Angle of Departure), TDOA (Time Difference of Arrival), AOA (Angle of Arrival), CIR (Channel Impulse Response), and PDP (Power Delay Profile). (a3) ​​may also be information about whether or not it has a function to measure the time change of such information. (a3) ​​may also be information about sensing measurement using LOS (Line of Sight) or NLOS (Non-Line of Sight). For example, (a3) ​​may be information about whether or not it supports sensing measurement using LOS, information about whether or not it supports sensing measurement using NLOS, or information about whether or not it supports a function to derive whether the path to be sensed is LOS or NLOS. Information regarding LOS may be provided for each sensing path. Information regarding NLOS may be provided for each sensing path. For example, this information may be provided for the path from the source node to the sensing target, or for the path from the sensing target to the receiving node. Also, (a3) ​​may be information on whether or not it has a function to derive position, range, velocity, acceleration, or direction of movement. The velocity to be derived may include information on direction.

[0178] (a4) may be information such as frequency band, frequency layer, or BWP. (a4) may be information such as whether or not it has full-duplex functionality or subband full-duplex functionality. A frequency band, BWP, or subband dedicated to sensing may be provided.

[0179] A sensing window may be provided for sensing measurements. The sensing operation node performs sensing measurements in the sensing window. Communication is not required in the sensing window. (a5) is information on whether or not the system has the function to perform sensing measurements in such a sensing window.

[0180] (a6) may be, for example, the time resolution in receiving the sensing signal. This makes it possible to predict, for example, position errors. Another example is that (a6) may include frequency resolution. This makes it possible to predict, for example, velocity errors. Another example is that (a6) may include spatial resolution. This spatial resolution may include, for example, information about the beamwidth of the received beam. This makes it possible to predict, for example, position errors.

[0181] Upon receiving information about the sensing capabilities of such sensing operation nodes or their candidates, the SF can determine, for example, which UEs / base stations can be used for sensing, and what types of sensing are possible.

[0182] The SF may instruct the receiving base station / UE to receive the sensing signal. The SF may also notify the receiving base station / UE of information about the transmitting base station / UE. This information may include, for example, information about the sensing resource being transmitted. The information about the sensing resource may be, for example, the same as described above. The instruction may also include information about the sensing result report.

[0183] The source node may instruct the receiving node to receive the sensing signal. This instruction may be given using an inter-base station interface (e.g., Xn interface), an interface between a base station and a terminal (e.g., Uu interface), or an interface between terminals (e.g., PC5 interface). This allows the source node to quickly instruct the receiving node to receive the sensing signal.

[0184] The information relating to the sensing result report may include information about the trigger for the report. This trigger may be, for example, a periodic report, an event-triggered report, or a report triggered by a report request. The information relating to the sensing result report may include information about the periodicity or information about the event.

[0185] The aforementioned events may include the detection of radio waves from a predetermined base station / UE. An example of the criteria for detecting such radio waves may include the reception strength of the radio waves being equal to or greater than a predetermined threshold. The reception strength may be RSSI, RSRP, RSRQ, SINR, or a combination of the above. The radio waves may be radio waves for communication or radio waves for sensing (e.g., the sensing signals described above).

[0186] Another example of the event may include the failure to detect radio waves from a predetermined base station / UE. An example of the criterion for failure to detect such radio waves may include the reception strength of the radio waves being below or less than a predetermined threshold. The reception strength may be RSSI, RSRP, RSRQ, SINR, or a combination of the above. The radio waves may be radio waves for communication or radio waves for sensing (e.g., the sensing signals described above).

[0187] Another example of the event may include the detection of a base station / UE radio wave within a predetermined time range. Examples of such detection may be the same as those described above.

[0188] The source node may directly notify the receiving node of information regarding sensing resources. This notification may be made using an inter-base station interface (e.g., Xn interface), an interface between a base station and a terminal (e.g., Uu interface), or an interface between terminals (e.g., PC5 interface). This allows the source node to quickly notify information regarding sensing resources.

[0189] Sensing results may be reported periodically. This allows for continuous sensing reporting, for example, improving the reliability of UAV trajectory tracking. As another example, sensing reports may be semi-persistent. Sensing reports may be activated / deactivated. This can improve the efficiency of communication systems, for example. As yet another example, sensing reports may be aperiodic. For example, sensing reports may be triggered upon request. This can further improve the efficiency of communication systems, for example. Information regarding sensing result reports may include information indicating periodic reporting, semi-persistent reporting, or aperiodic reporting. If semi-persistent reporting is configured, the SF may transmit information to the receiving base station / UE indicating activation or deactivation of the report. In another example, the base station may transmit information to the receiving base station / UE indicating activation or deactivation of the report. A base station interface, such as an Xn interface, may be used to transmit the information from the base station to the receiving base station.

[0190] The transmitting base station / UE may transmit a sensing signal. The transmission of the sensing signal may be performed using the sensing resources described above. The receiving base station / UE may receive a sensing signal. The sensing resources described above may be used for receiving the sensing signal.

[0191] The receiving base station / UE may report the results of the sensing signal reception to the SF. This report may include information about the received sensing resource, information about the reception time, information about the delay amount, information about the received signal strength, information about the Doppler shift, information about the transmission / reception frequency difference over a predetermined time, and information about the multipath characteristics.

[0192] Information regarding the delay amount may also be the difference between the transmission time and reception time of the sensing signal. Information regarding the delay amount may be reported, for example, when the sensing radio wave is pulse-modulated.

[0193] Information regarding the difference between transmitted and received frequencies over a predetermined period of time may, for example, be the difference between the transmitted and received frequencies of the sensing radio wave over a predetermined period of time. This information may be reported, for example, when FMCW is used for sensing.

[0194] The information regarding the multipath characteristics may include the results described above for the second and subsequent paths, and may also include the amount of delay for the second and subsequent paths. This amount of delay may be the delay from the first path or the delay from the previous path.

[0195] The reporting of the sensing signal reception results from the receiving base station / UE to the SF may be performed using the aforementioned information regarding triggers. For example, the receiving UE may make periodic reports, or the receiving base station may make periodic reports. As another example, the receiving UE may make event trigger reports, or the receiving base station may make event trigger reports. The base station may or may not be an IAB node.

[0196] The report may include information about the event that triggered the report. The event may be similar to those described above. For example, the report may include information indicating that the received intensity of the sensing signal is above or above a predetermined threshold. This allows the SF to understand, for example, that the receiving base station / UE is receiving the sensing signal with sufficient intensity, and as a result, to appropriately control the sensing. As another example, the report may include information indicating that the radio waves from the transmitting base station / UE were detected within a predetermined time range. This allows the SF to quickly understand, for example, that the UAV has arrived at the scheduled location at the scheduled time.

[0197] The SF may use the received sensing signal to estimate the position of the UAV or the speed of the UAV. The estimated speed may include information about the orientation. The SF may notify the USS / UTM of the estimation result. The estimation result may include information about the time related to the estimation result.

[0198] The sequences in Figures 15 to 18 will be explained below. In these figures, if a UE and a base station are connected, they are assigned the same number. For example, UE#1 is connected to base station#1, and UE#2 is connected to base station#2.

[0199] Figure 15 is a sequence diagram showing an example of UAV sensing operation. In the example shown in Figure 15, the sensing signal transmitted from base station #1 is received by UE #2, which is connected to base station #2.

[0200] In step ST1301 shown in Figure 15, the SF requests information about the planned location of the UAV from the USS / UTM. Hereafter, this request may be referred to as the first request. The first request may include information about a time. This time may be, for example, the time related to the planned location of the UAV. The USS / UTM derives the planned location of the UAV in response to the first request. Information about the time may be used in this deriving process. In step ST1302, the USS / UTM notifies the SF of the information about the planned location of the UAV. Hereafter, this information may be referred to as the first location information.

[0201] In step ST1302A shown in Figure 15, the SF requests information from the LMF regarding the location of the base station / UE. Hereafter, this request may be referred to as the second request. The second request may include information regarding the planned location of the UAV, or it may include information regarding the time. The time may be, for example, the time related to the planned location of the UAV. The LMF may use this information to derive a base station / UE near the planned location of the UAV. In step ST1302B, the LMF notifies the SF of information regarding the location of the base station / UE. Hereafter, this information may be referred to as the second location information. The notification may include information used to identify the base station / UE. This allows the SF to quickly identify the base station / UE to be used for sensing, for example. The notification may include information regarding multiple base stations / UE. This allows the SF to select a source base station / UE and / or destination base station / UE from multiple base stations / UE. As a result, the reliability of sensing can be improved.

[0202] In step ST1303 shown in Figure 15, the SF determines the source base station / UE and / or destination base station / UE as sensing operation nodes. The information contained in step ST1302B may be used for this determination. In the example shown in Figure 15, the SF determines base station #1 as the source base station and UE #2 as the destination UE.

[0203] In step ST1305 shown in Figure 15, SF notifies base station #1 of the settings related to the transmission of sensing signals. Hereafter, these settings may be referred to as transmission settings. These transmission settings may include information about the sensing resources described above. This information about sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. Base station #1 uses these transmission settings to configure the settings related to the transmission of sensing signals. In step ST1307, base station #1 notifies SF that the settings related to the transmission of sensing signals have been completed. Hereafter, these notifications may be referred to as transmission setting completion notifications.

[0204] As another example, base station #1 may determine the sensing resource. In step ST1305, SF may instruct base station #1 to set the transmission settings. Base station #1 may determine the sensing resource in response to this instruction. The transmission setting completion notification in step ST1307 may include information about the sensing resource determined by base station #1. SF may use step ST1307 to obtain information about the sensing resource.

[0205] In steps ST1309 and ST1311 shown in Figure 15, the SF notifies UE#2 of the settings related to receiving the sensing signal. Hereafter, these settings may be referred to as reception settings. The notification may be made via base station #2. Step ST1309 shows the notification from the SF to base station #2, and step ST1311 shows the notification from base station #2 to UE#2. The reception settings may include information about the sensing resources described above. This information about sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. The reception settings may include information about the sensing result reports described above. For example, this information about sensing result reports may include information about triggers for sensing result reports. This information about triggers for sensing result reports may include information indicating periodic reports, information indicating event-triggered reports, or information indicating reports triggered by a report request. The information may include information about the reporting cycle or information about events. In the example shown in Figure 15, the reception settings include information indicating the reporting of event triggers. UE#2 may use step ST1311 to configure the reception settings for sensing signals or to configure the sensing result reporting settings.

[0206] In steps ST1313 and ST1315 shown in Figure 15, UE#2 notifies SF that the settings for receiving sensing signals have been completed. Hereafter, this notification may be referred to as a reception setting completion notification. The reception setting completion notification may include information regarding the completion of the setting of an event related to the reporting of an event trigger. The reception setting completion notification may be sent via base station #2. Step ST1313 shows the notification from UE#2 to base station #2, and step ST1315 shows the notification from base station #2 to SF.

[0207] In step ST1317 shown in Figure 15, base station #1 transmits a sensing signal. UE #2 receives the sensing signal in step ST1317. The sensing signal received by UE #2 may be a sensing signal reflected from the UAV. In step ST1319, UE #2 determines whether the reception result of the sensing signal satisfies a predetermined event. This predetermined event may be an event set using the reception settings in step ST1311. In the example shown in Figure 15, UE #2 determines that the predetermined event has been satisfied.

[0208] In steps ST1321 and ST1323 shown in Figure 15, UE#2 notifies SF of the sensing result. This notification may be made via base station #2. Step ST1321 shows the notification from UE#2 to base station #2, and step ST1323 shows the notification from base station #2 to SF. The notification may include information regarding the received intensity of the sensing signal, information regarding the time the sensing signal was received, or information regarding the resources of the sensing signal.

[0209] In step ST1325 shown in Figure 15, the SF estimates the position of the UAV using the sensing results. The SF may also estimate the velocity of the UAV. The estimated velocity may include information about the orientation. In step ST1327, the SF notifies the USS / UTM of the estimated UAV position. This notification may include information about the estimated velocity of the UAV, or it may include information about the time related to the estimated position.

[0210] In Figure 15, SF may notify the source base station / UE and / or the receiving base station / UE of the required indicators for sensing. The source base station / UE and / or the receiving base station / UE may notify SF of the ability to respond to the required indicators. SF may request sensing capabilities from the source base station / UE and / or the receiving base station / UE. The source base station / UE and / or the receiving base station / UE may notify SF of the capabilities of their own base station / UE. The aforementioned notifications and / or requests may be made after step ST1302, after step ST1302B, before step ST1303, before step ST1305, or simultaneously with step ST1305 and / or step ST1307. The same may apply in subsequent figures.

[0211] Figure 16 is a sequence diagram showing another example of UAV sensing operation. In the example shown in Figure 16, base station #2 receives the sensing signal transmitted from base station #1. In Figure 16, the same numbering is used for processes similar to those in Figure 15, and common explanations are omitted.

[0212] The procedure 1300 shown in Figure 16 is the same as in Figure 15. In step ST1303, SF decides that base station #1 transmits the sensing signal and base station #2 receives the sensing signal. That is, SF determines base station #1 as the source base station and base station #2 as the destination base station. Steps ST1305 to ST1307 shown in Figure 16 are the same as in Figure 15.

[0213] In step ST1359 shown in Figure 16, SF notifies base station #2 of the settings related to receiving the sensing signal (i.e., reception settings). The reception settings may include information about the sensing resources described above. This information about sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. The reception settings may also include information about the sensing result report described above. For example, this information about the sensing result report may include information about the trigger for the sensing result report. This information about the trigger for the sensing result report may include information indicating periodic reports, information indicating event-triggered reports, or information indicating reports triggered by a report request. Base station #2 may report an event trigger. This information may include information about the reporting cycle or information about the event. In the example shown in Figure 16, the reception settings may include information indicating an event-triggered report. Base station #2 may use step ST1359 to configure the reception of sensing signals or to configure the reporting of sensing results.

[0214] In step ST1365 shown in Figure 16, base station #2 notifies SF of the completion of reception settings. This notification of completion of reception settings may include information regarding the completion of setting up an event related to the reporting of an event trigger.

[0215] In step ST1367 shown in Figure 16, base station #1 transmits a sensing signal. Base station #2 receives the sensing signal in step ST1367. The sensing signal received by base station #2 may be a sensing signal reflected from the UAV. Base station #2 may determine whether the reception result of the sensing signal satisfies a predetermined event. If base station #2 determines that the predetermined event has been met, it may execute the processing from step ST1373 onward.

[0216] In step ST1373 shown in Figure 16, base station #2 notifies SF of the sensing result. This notification may include information regarding the received intensity of the sensing signal, information regarding the time the sensing signal was received, or information regarding the resources of the sensing signal.

[0217] Steps ST1325 and ST1327 shown in Figure 16 are the same as those in Figure 15.

[0218] Figure 17 is a sequence diagram showing another example of UAV sensing operation. In the example shown in Figure 17, base station #2 receives sensing radio waves transmitted from UE #1. In Figure 17, the same numbering is used for processes similar to those in Figures 15 and 16, and common explanations are omitted.

[0219] The procedure 1300 shown in Figure 17 is the same as in Figure 15. In step ST1303, SF determines that UE#1 transmits a sensing signal and base station#2 receives the sensing signal. That is, SF determines UE#1 as the source UE and base station#2 as the receiving base station.

[0220] In steps ST1305 and ST1405 shown in Figure 17, SF notifies UE#1 of the settings for transmitting sensing signals (i.e., transmission settings). This notification may be made via base station #1. Step ST1305 shows the notification from SF to base station #1, and step ST1405 shows the notification from base station #1 to UE#1. The transmission settings may include information about the sensing resources described above. This information about sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. UE#1 uses the transmission settings to configure the settings for transmitting sensing signals.

[0221] In steps ST1407 and ST1307 shown in Figure 17, UE#1 notifies SF of the completion of transmission settings. This notification of completion of transmission settings may be made via base station #1. Step ST1407 shows the notification from UE#1 to base station #1, and step ST1307 shows the notification from base station #1 to SF.

[0222] Steps ST1359 and ST1365 shown in Figure 17 are the same as those in Figure 16.

[0223] In step ST1417 shown in Figure 17, UE#1 transmits a sensing signal. Base station #2 receives the sensing signal in step ST1417. The sensing signal received by base station #2 may be a sensing signal reflected from the UAV. Base station #2 may determine whether the reception result of the sensing signal satisfies a predetermined event. If base station #2 determines that the predetermined event has been met, it may execute the processing from step ST1373 onward.

[0224] Step ST1373 shown in Figure 17 is the same as in Figure 16. Steps ST1325 and ST1327 are the same as in Figure 15.

[0225] Figure 18 is a sequence diagram showing another example of UAV sensing operation. In the example shown in Figure 18, UE#2 receives the sensing radio waves transmitted from UE#1. In Figure 18, the same numbering is used for processes similar to those in Figures 15, 16, and 17, and common explanations are omitted.

[0226] The procedure 1300 shown in Figure 18 is the same as in Figure 15. In step ST1303, SF determines that UE#1 transmits the sensing signal and UE#2 receives the sensing signal. That is, SF determines UE#1 as the source UE and UE#2 as the recipient UE.

[0227] Steps ST1305, ST1405, ST1407, and ST1307 shown in Figure 18 are the same as in Figure 17. Steps ST1309 to ST1315 are the same as in Figure 15.

[0228] In step ST1467 shown in Figure 18, UE#1 transmits a sensing signal. UE#2 receives the sensing signal in step ST1467. The sensing signal received by UE#2 may be a sensing signal reflected from the UAV.

[0229] Steps ST1319 to ST1327 shown in Figure 18 are the same as those in Figure 15.

[0230] Figures 15 to 18 illustrate a combination of one source base station / UE and one destination base station / UE, but the system is not limited to this example. Sensing may be performed using a combination of multiple source nodes and multiple destination nodes. This can improve the accuracy of position and / or velocity estimation in the SF, for example.

[0231] This embodiment 1 makes it possible to determine the source base station / UE and destination base station / UE to be used for sensing, and as a result, cross-base station sensing becomes possible. This enables high-precision sensing.

[0232] Modification 1 of Embodiment 1. The source base station / UE and / or destination base station / UE may switch due to the movement of the UAV. However, the above-mentioned non-patent literature does not disclose the detailed procedure for switching. Therefore, a problem arises in which the switching cannot be performed and sensing cannot be maintained.

[0233] This modified example discloses a method for solving the aforementioned problem.

[0234] The Signal Facility (SF) determines the switching between the source base station / UE and / or the destination base station / UE. This determination may use the estimated position and / or velocity of the UAV obtained by sensing, or it may use information about the planned position of the UAV. For example, the flight path may be used as information about the planned position of the UAV. The estimated position of the UAV may include information about altitude. The velocity may include information about orientation. This eliminates the need for the SF to query the LMF for the UAV's position as the UAV moves. As a result, the amount of signaling within the communication network can be reduced.

[0235] The switching may be determined using the received intensity of the sensing signal. For example, the switching may be determined using a report of the sensing signal reception results. This allows for a rapid switching, for example, when the received intensity of the sensing signal begins to decrease. As a result, it is possible to prevent the occurrence of a gap in sensing.

[0236] The switching may be determined using the planned position of the UAV. The planned position of the UAV may include altitude information. For example, the switching may be triggered when the planned position of the UAV is about to move out of the sensing area for both the source base station / UE and the destination base station / UE. This allows for rapid switching based on, for example, the movement of the UAV. As a result, it is possible to prevent the occurrence of a gap in sensing.

[0237] The switching may be determined using the reception result of the sensing signal at the receiving base station / UE. Specifically, the report of the reception result of the sensing signal may be used to determine the switching. The report may also be an event trigger report. The event may be, for example, any of the following (b1) to (b6): (b1) The received intensity of the sensing signal is below or equal to a predetermined threshold. (b2) The received intensity of the sensing signal has started to decrease. (b3) The received intensity of the sensing signal has weakened by a predetermined threshold or more from its past maximum value. (b4) The received intensity of the sensing signal has continued to decrease for a predetermined period of time. (b5) The received intensity of the sensing signal has continued to decrease for a predetermined period of time since it reached its past maximum value. (b6) A combination of two or more of (b1) to (b5).

[0238] (b5) may be a state in which the received intensity of the sensing signal continues to decrease monotonically for a predetermined period from the time the received intensity of the sensing signal reaches its past maximum value, or it may be a state in which the received intensity of the sensing signal remains at or below the value obtained by subtracting a predetermined value from the maximum value for a predetermined time from the time the received intensity of the sensing signal reaches its past maximum value.

[0239] The switching may be, for example, a switching of the source base station / UE. The switching of the source base station / UE may be, for example, a switching of the source base station to another base station, a switching of the source base station to a UE, a switching of the source UE to a base station, or a switching of the source UE to another UE.

[0240] As another example, the switching may be a switching of the receiving base station / UE. The switching of the receiving base station / UE may be, for example, a switching of the receiving base station to another base station, a switching of the receiving base station to a UE, a switching of the receiving UE to a base station, or a switching of the receiving UE to another UE.

[0241] As another example, the switching may involve switching both the source base station / UE and the destination base station / UE. The switching may also be a combination of the aforementioned switching of the source base station / UE and the switching of the destination base station / UE.

[0242] For example, the source base station and the receiving base station may each be switched to other base stations. The source base station may be switched to another base station and the receiving base station may be switched to a UE. The source base station may be switched to a UE and the receiving base station may be switched to another base station. The source base station may be switched to a UE and the receiving base station may be switched to a UE.

[0243] Other examples of switching both the source base station / UE and the destination base station / UE include the source base station being switched to another base station and the destination UE being switched to a base station. The source base station being switched to another base station and the destination UE being switched to another UE. The source base station being switched to a UE and the destination UE being switched to a base station. The source base station being switched to a UE and the destination UE being switched to another UE.

[0244] Other examples of switching both the source base station / UE and the destination base station / UE include the source UE switching to a base station and the destination base station switching to another base station. The source UE switching to a base station and the destination base station switching to a UE. The source UE switching to another UE and the destination base station switching to another base station. The source UE switching to another UE and the destination base station switching to a UE.

[0245] Other examples of switching both the source base station / UE and the destination base station / UE include the source UE being switched to a base station and the destination UE being switched to another base station; the source UE being switched to a base station and the destination UE being switched to another UE; the source UE being switched to another UE and the destination UE being switched to a base station; and both the source UE and the destination UE being switched to other UEs.

[0246] A priority order may be established for the combination of source base station / UE and destination base station / UE. For example, the combination of source base station and destination UE may have the highest priority. The combination of source base station and destination base station may have the second highest priority. The combination of source UE and destination UE may have the third highest priority. The combination of source UE and destination base station may have the fourth highest priority. This priority order may be changed. This can, for example, avoid complexity in the communication system and reduce the power consumption of the UE.

[0247] Some or all of the source nodes and / or destination nodes may be switched. For example, if multiple source nodes and / or multiple destination nodes are configured, some or all of the multiple source nodes and / or multiple destination nodes may be switched. This allows for flexible sensing, for example.

[0248] The sensor function (SF) may use the received signal strength of the sensing signal to make a switching decision.

[0249] Sensing may be performed by surrounding base stations / UEs. Surrounding base stations / UEs may be base stations / UEs capable of sensing the area surrounding the location of the UAV. Surrounding base stations / UEs may be base stations / UEs surrounding the source base station / UE and / or the destination base station / UE.

[0250] Sensing signals may be transmitted by surrounding base stations / UEs (hereinafter, a base station / UE that transmits sensing signals may be referred to as a surrounding source base station / UE). Sensing signals may be received by surrounding base stations / UEs (hereinafter, a base station / UE that receives sensing signals may be referred to as a surrounding receiving base station / UE). The received intensity of the sensing signal at the surrounding receiving base station / UE may be used to determine the switching.

[0251] The surrounding base stations / UEs may be determined using the UAV's altitude. Different base stations / UEs may be set as surrounding base stations / UEs based on the UAV's altitude. The surrounding base stations / UEs that transmit sensing signals may be configured to be determined using the UAV's altitude. This can, for example, improve flexibility in sensing.

[0252] As an example of switching using the received signal strength of the sensing signal at the receiving base station / UE, a decrease in the received signal strength may trigger the switching. The received signal strength may be the same as that disclosed in Embodiment 1. For example, when the received signal strength of the sensing signal at the receiving base station / UE falls below or below a predetermined threshold, the source base station / UE may be switched, or both the source base station / UE and the receiving base station / UE may be switched.

[0253] As an example of switching using the received signal strength of a sensing signal at a nearby receiving base station / UE, the switching may be triggered by an increase in the received signal strength. For example, the source base station / UE may be switched, the receiving base station / UE may be switched, or both the source base station / UE and the receiving base station / UE may be switched when the received signal strength of the sensing signal at a nearby receiving base station / UE exceeds a predetermined threshold.

[0254] Switching may be determined using the received signal strength of the sensing signal at the receiving base station / UE and the received signal strength of the sensing signal at a nearby receiving base station / UE. For example, the difference between the received signal strength of the sensing signal at the receiving base station / UE and the received signal strength of the sensing signal at a nearby receiving base station / UE may be used. For example, when this difference exceeds or is above a predetermined threshold, switching of the source base station / UE may occur, or switching of both the source base station / UE and the receiving base station / UE may occur.

[0255] Hereafter, the source base station / UE after switching may be referred to as the source base station / UE (AS) or source node (AS) by adding the code "AS" to indicate "After Switching". Similarly, the destination base station / UE after switching may be referred to as the destination base station / UE (AS) or destination node (AS).

[0256] The source base station / UE before switching may be referred to as the source base station / UE (BS) or source node (BS) by adding the code "BS" to indicate "Before Switching". Similarly, the destination base station / UE before switching may be referred to as the destination base station / UE (BS) or destination node (BS).

[0257] The SF may instruct the source base station / UE (AS) to begin transmitting a sensing signal. The SF may determine the sensing resources described above. The SF may notify the source base station / UE (AS) of information regarding the sensing resources. The source base station / UE (AS) may use the information contained in the notification to configure the transmission of the sensing signal. The source base station / UE (AS) may notify the SF that the configuration is complete.

[0258] As another example, the sensing resource may be determined by the source base station (AS), or by the base station to which the source UE (AS) is connected. The base station may notify the SF of information regarding the sensing resource, or of information regarding the source UE (AS). The SF may request information regarding the sensing resource from the base station. The base station may notify the SF of the information in response to the request from the SF. The sensing resource may be the same as that disclosed in Embodiment 1. The base station may use the request from the SF to determine the sensing resource or to set up the transmission of a sensing signal. This setting may be made to the source UE (AS). The source base station / UE (AS) may notify the SF of the completion of the setting. This notification may include information regarding the sensing resource.

[0259] The SF may instruct the source base station / UE(BS) to stop transmitting the sensing signal. The source base station / UE(BS) may stop transmitting the sensing signal upon receiving such instruction. This can, for example, improve the efficiency of the communication system. The source base station / UE(BS) may notify the SF that it has stopped transmitting the sensing signal.

[0260] As another example, the SF may not stop transmitting sensing signals from the source base station / UE(BS). The source base station / UE(BS) may continue transmitting sensing signals. For example, the SF may decide to continue transmitting sensing signals. This may, for example, improve the accuracy of sensing and enable the detection of other objects.

[0261] The SF may instruct the receiving base station / UE(AS) to begin receiving the sensing signal. The SF may notify the receiving base station / UE(AS) of information regarding the transmitting base station / UE(AS). This information may include, for example, information regarding sensing resources. This information regarding sensing resources may be, for example, the same as that disclosed in Embodiment 1. The instruction may also include information regarding the sensing result report. This information regarding the sensing result report may include, for example, the information disclosed in Embodiment 1. The receiving base station / UE(AS) may use this information to begin receiving the sensing signal. The receiving base station / UE(AS) may notify the SF that the sensing signal reception setup is complete.

[0262] The SF may instruct the receiving base station / UE(BS) to stop receiving the sensing signal. The receiving base station / UE(BS) may stop receiving the sensing signal upon receiving this instruction. This can improve the efficiency of the communication system, for example. The receiving base station / UE(BS) may notify the SF that it has stopped transmitting the sensing signal.

[0263] As another example, the SF may not stop the receiving operation of the sensing signal by the receiving base station / UE(BS). The receiving base station / UE(BS) may continue the receiving operation of the sensing signal. For example, the SF may decide to continue the receiving operation of the sensing signal. This may, for example, improve the accuracy of sensing and enable the detection of other objects.

[0264] As another example, the SF may instruct the source base station / UE(BS) to switch the source node and / or the destination node. This instruction may include information about the source base station / UE(AS) and information about the destination base station / UE(AS).

[0265] This instruction may be given from the SF to the receiving base station / UE (BS).

[0266] A source base station / UE(BS) may notify the source base station / UE(AS) of the setting of sensing resources. This notification may be triggered, for example, by a switching instruction from SF to source base station / UE(BS). A base station interface (e.g., Xn interface) may be used for this notification, an interface between a base station and a terminal (e.g., Uu interface) may be used, or an interface between terminals (e.g., PC5 interface) may be used. This allows for, for example, rapid notification of sensing resources.

[0267] A notification of sensing resource settings may be sent from the receiving base station / UE(BS) to the receiving base station / UE(AS). This notification may be triggered, for example, by the instruction from the SF to the receiving base station / UE(BS). This notification from the receiving base station / UE(BS) to the receiving base station / UE(AS) may be sent in the same manner as the notification from the transmitting base station / UE(BS) to the transmitting base station / UE(AS). This will, for example, produce the same effect as described above.

[0268] The source base station / UE(BS) may notify the receiving base station / UE(AS) of the sensing resource settings. This notification may be triggered, for example, by the instruction from SF to the source base station / UE(BS). The notification from the source base station / UE(BS) to the receiving base station / UE(AS) may be made in the same manner as the notification from the source base station / UE(BS) to the source base station / UE(AS). This will, for example, produce the same effect as described above.

[0269] Figures 19 and 20 are sequence diagrams illustrating an example of the switching operation between the source base station and the UE in UAV sensing. In the example shown in Figures 19 and 20, the source UE is UE#1, and the destination UE is switched from UE#2 to UE#3. UE#1, UE#2, and UE#3 are connected to base stations #1, #2, and #3, respectively. In Figures 19 and 20, the same numbering is used for processes similar to those in Figures 15, 17, and 18, and common explanations are omitted.

[0270] Step ST1467 shown in Figure 19 is the same as in Figure 18. Steps ST1319 to ST1327 are the same as in Figure 15. In step ST1319 shown in Figure 19, UE#2 may detect that the received intensity of the sensing signal from UE#1 is below or less than a predetermined threshold. In steps ST1321 and ST1323 shown in Figure 19, the information regarding the sensing result may include information regarding the detected event. In the example in Figure 19, the event may indicate that the received intensity of the sensing signal from UE#1 is below or less than a predetermined threshold. This allows, for example, SF to quickly grasp that the received intensity of the sensing signal at UE#2 has weakened.

[0271] Steps ST1302A and ST1302B shown in Figure 19 are the same as in Figure 15. SF may use the information about the detected event included in step ST1323 to perform the processing in step ST1302A. The event may be, for example, that the received intensity of the sensing signal is below or less than a predetermined threshold.

[0272] In step ST1903 shown in Figure 19, the SF decides to switch the source base station / UE. The information contained in step ST1302B may be used in this decision. In the example shown in Figure 19, the SF decides to switch the source UE from UE#1 to UE#3.

[0273] In steps ST1905 and ST1906 shown in Figure 19, the SF notifies UE#3 of the settings related to the transmission of the sensing signal (i.e., the transmission settings). Thereafter, the transmission settings after the switching of the source base station / UE may be referred to as the transmission settings (AS). The transmission settings (AS) may be the same as the transmission settings disclosed in Embodiment 1. The notification may be made via base station #3. Step ST1905 shows the notification from the SF to base station #3, and step ST1906 shows the notification from base station #3 to UE#3. Steps ST1905 and ST1906 shown in Figure 19 may be performed, for example, in the same way as steps ST1305 and ST1405 in Figure 17.

[0274] In steps ST1907 and ST1908 shown in Figure 19, UE#3 notifies SF that the settings for transmitting the sensing signal have been completed. This notification may be called a transmission setting completion notification, as in Embodiment 1. This transmission setting completion notification may be made via base station #3. Step ST1907 shows the notification from UE#3 to base station #3, and step ST1908 shows the notification from base station #3 to SF. Steps ST1907 and ST1908 shown in Figure 19 may be performed, for example, in the same way as steps ST1407 and ST1307 in Figure 17.

[0275] In steps ST1909 and ST1911 shown in Figure 20, the SF notifies UE#2 of a change in the settings related to receiving the sensing signal. Thereafter, the receiving settings used after switching between the source base station / UE or the destination base station / UE may be referred to as the receiving settings (AS). This notification may be made via base station #2. Step ST1909 shows the notification from the SF to base station #2, and step ST1911 shows the notification from base station #2 to UE#2. The receiving settings (AS) may include information about the changed sensing resources. This information about the changed sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. The receiving settings (AS) may also include information about sensing result reporting. For example, this information about sensing result reporting may include information about the trigger for sensing result reporting. The information regarding the trigger for the sensing result report may include information indicating periodic reporting, information indicating event-triggered reporting, or information indicating reporting triggered by a reporting request. The information may include information regarding the reporting cycle or information regarding events. In the example shown in Figure 19, the reception setting (AS) includes information indicating event-triggered reporting. UE#2 may change the reception setting for the sensing signal or set the sensing result report using step ST1911.

[0276] In steps ST1913 and ST1915 shown in Figure 20, UE#2 notifies SF that the change in settings related to receiving sensing signals has been completed. Hereafter, this notification may be referred to as a setting change completion notification. This setting change completion notification may be sent via base station #2. Step ST1913 shows the notification from UE#2 to base station #2, and step ST1915 shows the notification from base station #2 to SF.

[0277] In step ST1917 shown in Figure 20, UE#3 transmits a sensing signal. UE#2 receives the sensing signal in step ST1917. The sensing signal received by UE#2 may be a sensing signal reflected from the UAV. In step ST1919, UE#2 determines whether the reception result of the sensing signal satisfies a predetermined event. This predetermined event may be an event set using the reception setting (AS) in step ST1911. In the example shown in Figure 20, UE#2 determines that the predetermined event has been satisfied.

[0278] In steps ST1921 and ST1923 shown in Figure 20, UE#2 notifies SF of the sensing result. This notification may be made via base station #2. Step ST1921 shows the notification from UE#2 to base station #2, and step ST1923 shows the notification from base station #2 to SF. Steps ST1921 and ST1923 shown in Figure 20 may be the same as steps ST1321 and ST1323 shown in Figure 15.

[0279] In step ST1925 shown in Figure 20, the SF estimates the position of the UAV using the sensing results. Step ST1925 may be the same as step ST1325 shown in Figure 15. In step ST1927, the SF notifies the USS / UTM of the information regarding the estimated UAV position. Step ST1927 may be the same as step ST1327 shown in Figure 15.

[0280] In steps ST1931 and ST1935 shown in Figure 20, SF instructs UE#1 to stop transmitting the sensing signal. This instruction may be given via base station #1. Step ST1931 shows the instruction from SF to base station #1, and step ST1935 shows the instruction from base station #1 to UE#1. The instruction may include a setting for stopping the transmission of the sensing signal. Hereafter, this setting may be referred to as the transmission stop setting. The transmission stop setting may include information indicating that the transmission setting of UE#1 is being released. UE#1 stops transmitting the sensing signal in response to this instruction.

[0281] In steps ST1937 and ST1939 shown in Figure 20, UE#1 notifies SF that the transmission of sensing signals has been stopped. Hereafter, this notification may be referred to as a transmission stop completion notification. This transmission stop completion notification may be sent via base station #1. Step ST1937 shows the notification from UE#1 to base station #1, and step ST1939 shows the notification from base station #1 to SF. SF may then recognize the cessation of the sensing signal transmission operation as a result of this notification.

[0282] Figures 19 and 20 show an example where the source base station / UE(BS) is UE#1, but the process is not limited to this example. The source base station / UE(BS) may also be base station #1. For example, instead of step ST1467, base station #1 may transmit the sensing signal. Base station #1 may stop transmitting the sensing signal at step ST1931. Steps ST1935 and ST1937 may be omitted. This makes it possible, for example, to switch the source node from a base station to a UE, or from one base station to another base station.

[0283] Figures 19 and 20 show an example where the source base station / UE(AS) is UE#3, but the process is not limited to this example. The source base station / UE(AS) may also be base station #3. For example, base station #3 may perform the settings related to the transmission of the sensing signal triggered by step ST1905. Steps ST1906 and ST1907 may be omitted. Instead of step ST1917, base station #3 may transmit the sensing signal. This makes it possible, for example, to switch the source node from UE to base station.

[0284] Figures 19 and 20 show an example where the receiving base station / UE is UE#2, but the system is not limited to this example. The receiving base station / UE may also be base station #2. For example, base station #2 may receive the sensing signal in step ST1467. Base station #2 may perform event detection in ST1319. Step ST1321 may be omitted. Base station #2 may change the receiving settings for the sensing signal. Steps ST1911 and ST1913 may be omitted. Base station #2 may receive the sensing signal in step ST1917. Base station #2 may perform event detection in ST1919. Step ST1921 may be omitted. This makes it possible to switch the source base station / UE even when the receiving node is a base station.

[0285] Figures 21 and 22 are sequence diagrams illustrating an example of the switching operation between the receiving base station and UE in UAV sensing. In the example shown in Figures 21 and 22, the source UE is UE#1, and the receiving UE is switched from UE#2 to UE#3. UE#1, UE#2, and UE#3 are connected to base stations #1, #2, and #3, respectively. In Figures 21 and 22, the same numbering is used for processes similar to those in Figures 15, 17, 18, 19, and 20, and common explanations are omitted.

[0286] Step ST1467 shown in Figure 21 is the same as in Figure 18. Steps ST1319 to ST1327 are the same as in Figure 15. In step ST1319 shown in Figure 21, UE#2 may detect that the received intensity of the sensing signal from UE#1 is below or less than a predetermined threshold. In steps ST1321 and ST1323 shown in Figure 21, the information regarding the sensing result may include information regarding the detected event. In the example in Figure 21, the event may indicate that the received intensity of the sensing signal from UE#1 is below or less than a predetermined threshold. This allows, for example, SF to quickly grasp that the received intensity of the sensing signal at UE#2 has weakened.

[0287] Steps ST1302A and ST1302B shown in Figure 21 are the same as in Figure 15. SF may use the information about the detected event included in step ST1323 to perform the processing in step ST1302A. The event may be, for example, that the received intensity of the sensing signal is below or less than a predetermined threshold.

[0288] In step ST2003 shown in Figure 21, the SF decides to switch the receiving base station / UE. Information included in step ST1302B may be used in this decision. In the example shown in Figure 21, the SF decides to switch the receiving UE from UE#2 to UE#3.

[0289] In steps ST2009 and ST2011 shown in Figure 21, the SF notifies UE#3 of the settings related to receiving the sensing signal (i.e., the reception settings). As described above, the reception settings after switching between the receiving base station / UE may be called the reception settings (AS). This notification may be made via base station #3. Step ST2009 shows the notification from the SF to base station #3, and step ST2011 shows the notification from base station #3 to UE#3. The reception settings (AS) may include information about sensing resources. This information about sensing resources may include resources related to time, resources related to frequency, resources related to space (e.g., resources related to beams), or resources related to codes. The reception settings (AS) may also include information about sensing result reporting. For example, this information about sensing result reporting may include information about the trigger for sensing result reporting. The information regarding the trigger for the sensing result report may include information indicating periodic reporting, information indicating event-triggered reporting, or information indicating reporting triggered by a reporting request. The information may include information regarding the reporting cycle or information regarding events. In the example shown in Figure 21, the reception setting (AS) includes information indicating event-triggered reporting. UE#3 may use step ST2011 to configure the reception of sensing signals or to configure the sensing result report.

[0290] In steps ST2013 and ST2015 shown in Figure 21, UE#3 notifies SF that the settings for receiving the sensing signal have been completed. This notification may be called a reception setting completion notification, as in Embodiment 1. This reception setting completion notification may be sent via base station #3. Step ST2013 shows the notification from UE#3 to base station #3, and step ST2015 shows the notification from base station #3 to SF.

[0291] In step ST2017 shown in Figure 22, UE#1 transmits a sensing signal. UE#3 receives the sensing signal in step ST2017. The sensing signal received by UE#3 may be a sensing signal reflected from the UAV. In step ST2019, UE#3 determines whether the reception result of the sensing signal satisfies a predetermined event. This predetermined event may be an event set using the reception setting (AS) in step ST2011. In the example shown in Figure 22, UE#3 determines that the predetermined event has been satisfied.

[0292] In steps ST2021 and ST2023 shown in Figure 22, UE#3 notifies SF of the sensing result. This notification may be made via base station #3. Step ST2021 shows the notification from UE#3 to base station #3, and step ST2023 shows the notification from base station #3 to SF. Steps ST2021 and ST2023 shown in Figure 22 may be the same as steps ST1321 and ST1323 shown in Figure 15.

[0293] Steps ST1925 and ST1927 shown in Figure 22 are the same as those in Figure 20.

[0294] In steps ST2031 and ST2035 shown in Figure 22, SF instructs UE#1 to stop receiving the sensing signal. This instruction may be given via base station #2. Step ST2031 shows the instruction from SF to base station #2, and step ST2035 shows the instruction from base station #2 to UE#2. The instruction may include a setting for stopping the reception of the sensing signal. Hereafter, this setting may be referred to as the reception stop setting. The reception stop setting may include information indicating that the reception setting of UE#2 is being released. UE#2 stops receiving the sensing signal in response to this instruction.

[0295] In steps ST2037 and ST2039 shown in Figure 22, UE#2 notifies SF that the cessation of sensing signal reception is complete. Hereafter, this notification may be referred to as a reception cessation completion notification. This reception cessation completion notification may be sent via base station #2. Step ST2037 shows the notification from UE#2 to base station #2, and step ST2039 shows the notification from base station #2 to SF. SF may recognize the cessation of sensing signal reception operation as a result of this notification.

[0296] Figures 21 and 22 show an example where the source base station / UE is UE#1, but the system is not limited to this example. The source base station / UE may also be base station #1. For example, instead of steps ST1467 and ST2017, base station #1 may transmit the sensing signal. This makes it possible to switch the receiving base station / UE even when the source node is a base station.

[0297] Figures 21 and 22 show an example where the receiving base station / UE(AS) is UE#3, but the system is not limited to this example. The receiving base station / UE(AS) may also be base station #3. For example, base station #3 may start receiving the sensing signal triggered by step ST2009. Steps ST2011 and ST2013 may not be performed. Base station #3 may receive the sensing signal in step ST2017. Base station #3 may perform event detection in step ST2019. Step ST2021 may not be performed. This makes it possible, for example, to switch the receiving node from a UE to a base station, or from one base station to another base station.

[0298] Figures 21 and 22 show an example where the receiving base station / UE(BS) is UE#2, but the system is not limited to this example. The receiving base station / UE(BS) may also be base station #2. For example, base station #2 may receive the sensing signal in step ST1467. Base station #2 may perform event detection in ST1319. ST1321 may not be performed. Base station #2 may stop receiving the sensing signal. Steps ST2035 and ST2037 may not be performed. This makes it possible, for example, to switch the receiving node from a base station to a UE, or from a base station to another base station.

[0299] Multiple combinations of source base stations / UEs and destination base stations / UEs may be configured. These multiple combinations may be pre-configured according to the planned location of the UAV. For example, these multiple combinations may be configured before the switching of the destination base station / UE and / or before the switching of the destination base station / UE. These multiple combinations may include a first combination of source base stations / UEs and destination base stations / UEs, and a second combination of source base stations / UEs. For example, the first and second combinations are configured according to the planned location of the UAV. For example, the first combination senses the UAV. If the UAV moves in this situation, the system may switch from the first combination to the second combination. The switch from the first combination to the second combination may be based on the received signal strength of the sensing signal. For example, the system may switch from the first combination to the second combination when the received signal strength at the destination base station / UE of the first combination falls below a predetermined threshold. When the received signal strength at the receiving base station / UE for the second combination exceeds a predetermined threshold, the system may switch from the first combination to the second combination. This prevents, for example, interruptions in the reception of sensing signals due to the movement of the UAV, thereby improving the reliability of sensing.

[0300] Another example of sensing using multiple combinations is that sensing may be performed in both the first and second combinations. For each of the first and second combinations, a receiving node that meets predetermined conditions may notify the SF of the sensing results. The SF may use this notification to decide to stop sensing in one of the combinations. This can, for example, achieve the same effect as described above.

[0301] These multiple combinations may be set, for example, after the switching of the destination base station / UE and / or the switching of the destination base station / UE. This allows, for example, the detection of multiple UAVs or other objects.

[0302] Figures 23 and 24 are sequence diagrams showing an example of the switching operation between the source base station / UE and the receiving base station / UE in UAV sensing. In the example shown in Figures 23 and 24, UE#1 is the source UE (BS) and UE#3 is the receiving UE (BS). UE#2 is the source UE (AS) and UE#4 is the receiving UE (AS). In the example shown in Figures 23 and 24, both UE#1 and UE#2 transmit the sensing signal, and both UE#3 and UE#4 receive the sensing signal. UE#1, UE#2, UE#3, and UE#4 are connected to base stations #1, #2, #3, and #4, respectively. In Figures 23 and 24, the same numbering is used for processes similar to those in Figures 15, 17, 18, 19, 20, 21, and 22, and common explanations are omitted.

[0303] Steps ST1467 and ST1319-ST1327 shown in Figure 23 are the same as in Figure 18. Steps ST1302A and ST1302B are the same as in Figure 15.

[0304] In step ST2103 shown in Figure 23, the SF decides to switch between the source base station / UE and / or the destination base station / UE. Information contained in step ST1302B may be used in this decision. In the example shown in Figure 23, the SF decides UE#3 as the source UE(AS) and UE#4 as the destination UE(AS).

[0305] Steps ST1905 to ST1908 shown in Figure 23 are the same as in Figure 19. Steps ST2009 to ST2015 are the same as in Figure 21. In steps ST2009 to ST2015, UE#3 performs reception settings related to the sensing signal transmitted from UE#2.

[0306] In steps ST2109 to ST2115 shown in Figure 24, the same processing as in steps ST2009 to ST2015 is performed on UE#4. In steps ST2109 to ST2105, reception settings for sensing signals transmitted from UE#1 and / or UE#2 may be performed.

[0307] In step ST2117 shown in Figure 24, UE#1 transmits a sensing signal. UE#3 and UE#4 receive the sensing signal in step ST2117. In step ST2118, UE#2 transmits a sensing signal. UE#3 and UE#4 receive the sensing signal in step ST2118.

[0308] In step ST2119 shown in Figure 24, UE#4 detects an event. In the example in Figure 24, UE#4 detects an event related to the sensing signal from UE#2.

[0309] In steps ST2121 and ST2123 shown in Figure 24, UE#4 reports the result of receiving the sensing signal (i.e., the sensing result) to SF. This report may be made via base station #4. Step ST2121 shows the report from UE#4 to base station #4, and step ST2123 shows the report from base station #4 to SF.

[0310] In step ST2125 shown in Figure 24, the SF performs a position estimation of the UAV. The velocity of the UAV may be estimated, or the time related to the position and / or velocity of the UAV may be estimated. The velocity may include information about orientation. In step ST2127, the SF notifies the USS / UTM of the estimation results.

[0311] Steps ST1931 to ST1939 shown in Figure 24 are the same as in Figure 20. Steps ST2031 to ST2039 are the same as in Figure 22.

[0312] This modified example 1 makes it possible to track the source base station / UE and the destination base station / UE even when the UAV moves, and as a result, sensing can be performed continuously.

[0313] Modification 2 of Embodiment 1. UAV trajectory tracking may be performed using sensing. UAV trajectory deviation detection may be performed using sensing.

[0314] However, the aforementioned non-patent literature does not disclose specific methods for trajectory tracking, such as detecting trajectory deviations. As a result, problems arise such as the inability to detect trajectory deviations.

[0315] This modified example 2 discloses a method for solving the aforementioned problems.

[0316] The base stations / UEs surrounding the sensing operation node (i.e., the source base station / UE and / or the destination base station / UE) determined using the flight path are used for sensing the UAV's orbit tracking. The surrounding base stations / UE disclosed in Modification 1 of Embodiment 1 may be used as the source base station / UE. The surrounding base stations / UE may be used as the destination base station / UE. One surrounding base station / UE may be used as the source base station / UE, and another surrounding base station / UE may be used as the destination base station / UE.

[0317] Orbital deviation may be detected by transmitting and receiving sensing radio waves using the source base station / UE and destination base station / UE determined using the flight path, triggered by any of the following (c1) to (c4): (c1) No radio waves were detected. (c2) No radio waves were detected at a predetermined time. (c3) No radio waves were detected within a predetermined time range. (c4) Radio waves were detected outside a predetermined time range.

[0318] For example, the failure to detect radio waves may mean that the received signal strength is below or less than a predetermined threshold.

[0319] Orbital deviation may be detected when a sensing radio wave is detected during transmission and reception of sensing radio waves using surrounding base stations. For example, the detection of a radio wave may be triggered by the reception strength being above or greater than a predetermined threshold.

[0320] RSSI, RSRP, RSRQ, SINR, or any combination thereof may be used for the received signal strength. The aforementioned triggers may be set up as events.

[0321] The receiving base station / UE may report the results of the sensing signal reception to the SF. This report may include, for example, information indicating that the radio waves from the source base station / UE were not received, or information indicating that radio waves from a nearby base station / UE were received. The nearby base station / UE may report the results of the sensing signal reception to the SF. This report may include, for example, information indicating that the radio waves from the source base station / UE were received, or information indicating that the radio waves from the source base station / UE were not received, or information indicating that radio waves from other nearby base stations / UE were received. The SF may use this information to estimate the position of the UAV.

[0322] The SF may notify the USS / UTM of the estimated location of the UAV. The USS / UTM may use this information to determine whether the UAV has deviated from its orbit.

[0323] Figures 25 and 26 are sequence diagrams illustrating an example of the operation of trajectory deviation detection of a UAV using sensing. In the example shown in Figures 25 and 26, UE#1 is the source UE and UE#3 is the destination UE. UE#2 is a nearby source UE and UE#4 is a nearby destination UE. UE#1, UE#2, UE#3, and UE#4 are connected to base stations #1, #2, #3, and #4, respectively. In Figures 25 and 26, the same numbering is used for processes similar to those in Figures 15 and 17-24, and common explanations are omitted.

[0324] Steps ST1467 and ST1319-ST1327 shown in Figure 25 are the same as in Figure 18. Steps ST1302A and ST1302B are the same as in Figure 15.

[0325] In step ST2203 shown in Figure 25, SF decides to add a source base station / UE and / or a destination base station / UE. Information contained in step ST1302B may be used in this decision. In the example shown in Figure 25, SF decides to add UE#2 as a peripheral source UE and UE#4 as a peripheral destination UE.

[0326] Steps ST1905 to ST1908 shown in Figure 25 are the same as in Figure 19. Steps ST2009 to ST2015 are the same as in Figure 21. In steps ST2009 to ST2015, reception settings are made for the sensing signal transmitted from UE#2.

[0327] Steps ST2109 to ST2119 shown in Figure 26 are the same as in Figure 24. In the example in Figure 26, UE#4 may detect an event related to the sensing signal from UE#1 or an event related to the sensing signal from UE#2 in step ST2119.

[0328] Steps ST2121 to ST2127 shown in Figure 26 are the same as those in Figure 24.

[0329] In step ST2229 shown in Figure 26, the USS / UTM detects a deviation in the UAV's trajectory. The information contained in step ST2127 may be used for this detection. In step ST2230, the USS / UTM notifies UAV-C of information regarding the UAV's trajectory deviation. This information may include information regarding the estimated position of the UAV, information regarding the estimated velocity of the UAV, and information regarding the time of the estimation. The velocity may also include information regarding the direction. UAV-C uses the information notified in step ST2230 to correct the UAV's trajectory.

[0330] Other solutions are disclosed. The UAV performs its own positioning. This positioning may include, for example, positioning using a GNSS (Global Navigation Satellite System), positioning using an altimeter, or positioning in UE-based mode (see Non-Patent Document 24). The UAV reports information regarding the positioning results to the USS / UTM. This report may be made, for example, via the UAV's serving base station. Alternatively, the information may be reported from the UAV to the LMF. This report may be made, for example, in UE-assisted mode positioning (see Non-Patent Document 24). The LMF may report information regarding the positioning results to the USS / UTM.

[0331] As another example, the positioning may be performed by an LMF (Local Mobile Facility). The UAV may report the results of receiving the positioning signal to the LMF. This report may be made via a serving base station. The LMF may use the results of receiving the positioning signal to derive the UAV's position. The LMF may notify the USS / UTM of the information regarding the derived UAV's position.

[0332] The UAV may perform collision avoidance maneuvers. These collision avoidance maneuvers may not be detected as trajectory deviations. For example, after UAV-C transmits a trajectory correction instruction to the UAV, the USS / UTM may not consider the change in the UAV's position as a trajectory deviation. The UAV's collision avoidance maneuvers may include, for example, collision avoidance using an imaging device mounted on the UAV.

[0333] As another example, the collision avoidance maneuver may be detected as a trajectory deviation. For instance, after the UAV-C transmits a trajectory correction instruction to the UAV, the USS / UTM may consider the change in the UAV's position as a trajectory deviation. This can, for example, avoid complexity in the UAS.

[0334] The UAV may notify the serving base station of information regarding collision avoidance. This information may include information indicating that collision avoidance was performed, information regarding the time of collision avoidance, and information regarding the change in position due to collision avoidance. The serving base station may notify the USS / UTM of the information regarding collision avoidance. The USS / UTM may then be aware that the UAV has performed collision avoidance based on this notification. This allows the USS / UTM to prevent unnecessary detection of trajectory deviations, for example.

[0335] Positioning by a UAV may take precedence over sensing results from a UAV. For example, if both UAV positioning results and sensing results are available, the UAV positioning results may be given priority. This prevents malfunctions in trajectory tracking that could occur due to discrepancies between multiple position derivation results.

[0336] The sensing results from the UAV may take precedence over positioning results from the UAV. For example, if both positioning results from the UAV and sensing results are available, the sensing results from the UAV may be given priority. This can achieve the same effect as described above.

[0337] The network (NW) may decide on a case-by-case basis whether to prioritize UAV positioning or UAV sensing results. For example, the USS / UTM may decide whether to prioritize UAV positioning or UAV sensing results. For example, the SF may decide whether to prioritize UAV positioning or UAV sensing results. This can improve flexibility in, for example, orbit tracking.

[0338] As another example, the priority given to UAV positioning and UAV sensing results may be determined using the reliability (integrity) of the positioning results and / or sensing results. The UAV may transmit information regarding its positioning results and reliability to the SF or USS / UTM. The receiving base station / UE may transmit information regarding the sensing results and reliability to the SF or USS / UTM. The SF or USS / UTM may derive the reliability of the UAV's positioning results and the reliability of its sensing results. This can, for example, improve the reliability of UAV position estimation.

[0339] As another example, the priority given to UAV positioning and UAV sensing results may be determined using the accuracy of the positioning results and / or sensing results. This accuracy may be, for example, that disclosed in Non-Patent Document 38. The UAV may transmit information regarding its positioning results and accuracy to the SF or USS / UTM. The receiving base station / UE may transmit information regarding the sensing results and accuracy to the SF or USS / UTM. The SF or USS / UTM may derive the accuracy of the UAV's positioning results and the accuracy of its sensing results. This can, for example, improve the accuracy of UAV position estimation.

[0340] This modified version 2 makes it possible to detect trajectory deviations of the UAV, and as a result, collisions with the UAV can be prevented.

[0341] Embodiment 2. It has been proposed to detect illegal objects using sensing (see Non-Patent Document 30). Illegal objects may be objects other than the UAV being detected (for example, birds). However, the above-mentioned non-patent document does not disclose a specific method for detecting illegal objects. As a result, illegal objects may not be detected, and there is a possibility that the UAV may collide with an illegal object.

[0342] This second embodiment discloses a method for solving the aforementioned problems.

[0343] Illegal objects are detected using surrounding base stations / UEs. The detection of illegal objects may be performed in conjunction with UAV sensing. The surrounding base stations / UEs may be the same as in Modification 1 of Embodiment 1. Hereafter, the node that detects illegal objects may be referred to as an object detection node. The object detection node may determine that an illegal object has been detected when a sensing signal is detected at a surrounding base station / UE. The object detection node may also determine that an illegal object has been detected when a sensing signal is detected at a source base station / UE and / or a destination base station / UE.

[0344] For example, an object detection node may determine that it has detected an illegal object based on (d1) and at least one of (d2) to (d4) below: (d1) The receiving base station / UE receives sensing radio waves from the transmitting base station / UE. (d2) The surrounding base station / UE receives sensing radio waves from other surrounding base stations / UE. (d3) The surrounding base station / UE receives sensing radio waves from the transmitting base station / UE. (d4) The receiving base station / UE receives sensing radio waves from surrounding base stations / UE. This makes it possible to distinguish between a UAV and an illegal object, for example.

[0345] Another example is the use of changes in the reception characteristics of sensing radio waves. For example, an illegal object may be detected at a receiving base station / UE in response to a change in the reception characteristics of sensing radio waves from a transmitting base station / UE. This change in reception characteristics may be, for example, a change in channel characteristics (e.g., a change in CSI) or a change in multipath characteristics. This makes it possible to detect, for example, an illegal object located near a UAV.

[0346] The multipath characteristics may include the number of paths, information about the delay in each path, and information about the Doppler shift in each path. This makes it possible, for example, to detect the positions and / or velocities of multiple illegal objects.

[0347] As another example, beams may be used. For example, the reception characteristics of multiple beams may be used. Transmission of multiple beams may be, for example, transmission of multiple beams from one base station / UE, or transmission of one or more beams from multiple base stations / UEs. The TRP may perform the transmission. For example, an object detection node may determine that an illegal object has been detected when it receives sensing radio waves from multiple beams. This can reduce the number of base stations / UEs used for sensing, and as a result, improve the efficiency of the communication system.

[0348] Illegal object detection may be performed using both the UAV's positioning and sensing results. For example, an object detection node may detect an illegal object when it detects sensing radio waves at a location different from the UAV's positioning result.

[0349] An event trigger may be used to report the sensing results. This makes it possible to prevent unnecessary reporting of sensing results, and as a result, improve the efficiency of the communication system. The event may be the same as the event disclosed in Embodiment 1 and its modifications 1 and 2.

[0350] The following describes a specific example of an object detection node. The SF may detect illegal objects. The SF may detect illegal objects using sensing results, or it may detect illegal objects using sensing results and UAV positioning results. The SF may notify the USS / UTM of information indicating that an illegal object has been detected. This notification may include information about the location of the illegal object, or information about its velocity. The velocity may also include information about its orientation. This can, for example, reduce the processing load on the USS / UTM.

[0351] As another example, the LMF may perform illegal object detection. The LMF may use the UAV's positioning and sensing results to detect illegal objects. The LMF may notify the USS / UTM of information indicating that an illegal object has been detected. This notification may include information about the illegal object's location and / or velocity. The velocity may also include information about its orientation. This can, for example, reduce the processing load on the USS / UTM.

[0352] As another example, the USS / UTM may perform illegal object detection. The USS / UTM may perform illegal object detection using sensing results, or using sensing results and UAV positioning results. The SF may notify the USS / UTM of sensing results. The LMF may notify the USS / UTM of UAV positioning results. This can, for example, reduce the processing load on the SF and / or LMF.

[0353] The sensing may be performed when the UAV approaches the source base station / UE or the destination base station / UE. The SF may instruct the source base station / UE and / or the destination base station / UE to perform sensing. This eliminates the need for sensing at locations far from the UAV, for example, and as a result, sensing can be performed efficiently.

[0354] Different frequencies may be used for UAV sensing and illegal object sensing. For example, the transmit settings may include information about the frequency used for UAV sensing and information about the frequency used for illegal object sensing. The receive settings may include information about the frequency used for UAV sensing and information about the frequency used for illegal object sensing. For example, a higher frequency may be used for illegal object sensing than for UAV sensing. This makes it possible to detect illegal objects smaller than the UAV, for example.

[0355] Figures 27 and 28 are sequence diagrams showing an example of the operation of illegal object detection using sensing. In the example shown in Figures 27 and 28, UE#1 is the source UE and UE#3 is the destination UE. UE#2 is a nearby source UE and UE#4 is a nearby destination UE. UE#1, UE#2, UE#3, and UE#4 are connected to base stations #1, #2, #3, and #4, respectively. In Figures 27 and 28, the same numbers are used for processes similar to those in Figures 15 and 17-26, and common explanations are omitted.

[0356] Steps ST1467 and ST1319-ST1327 shown in Figure 27 are the same as in Figure 18. Steps ST1302A and ST1302B are the same as in Figure 15. Step ST2203 is the same as in Figure 25. In step ST2203, SF decides to add UE#2 as a peripheral source UE and UE#4 as a peripheral receiver UE.

[0357] Steps ST1905 to ST1908 shown in Figure 27 are the same as in Figure 19. Steps ST2009 to ST2015 are the same as in Figure 21. In steps ST2009 to ST2015, reception settings are made for the sensing signal transmitted from UE#2.

[0358] Steps ST2109 to ST2119 shown in Figure 28 are the same as in Figure 24. In the example in Figure 28, UE#4 may detect an event related to the sensing signal from UE#1 in step ST2119, or it may detect an event related to the sensing signal from UE#2. Steps ST2121 and ST2123 are the same as in Figure 24.

[0359] In step ST2319 shown in Figure 28, UE#3 detects an event related to the sensing signal from UE#1. In steps ST2321 and ST2123, the same processing as in ST1321 and ST1323 in Figure 15 is performed.

[0360] Steps ST2125 and ST2127 shown in Figure 28 are the same as in Figure 24. In the example in Figure 28, SF uses the sensing results of step ST2123 and ST2323 to estimate the positions of two objects. SF may estimate the position of the first object using the sensing results of step ST2123 and the position of the second object using the sensing results of ST2323.

[0361] In step ST2329 shown in Figure 28, the USS / UTM detects an illegal object. The information contained in step ST2127 may be used for this detection. For example, since the first object was detected by the sensing results of the surrounding receiving UE (UE#4), the position of the first object is outside the current position on the UAV's flight path. The USS / UTM may consider the first object to be an illegal object. On the other hand, since the second object was detected by the sensing results of the receiving UE (UE#3), the USS / UTM may consider the second object to be a UAV. In step ST2330, the USS / UTM notifies UAV-C that an illegal object has been detected. The information may include information regarding the estimated position of the UAV, information regarding the estimated speed of the UAV, information regarding the time of the estimation of the UAV, information regarding the estimated position of the illegal object, information regarding the estimated speed of the illegal object, and information regarding the time of the estimation of the illegal object. The speed of the UAV and / or the illegal object may include information regarding orientation. UAV-C may use the information from step ST2330 to instruct the UAV to take evasive action.

[0362] Tracking of multiple UAVs may be performed. Tracking of multiple UAVs may be performed using multiple combinations of source base stations / UEs and destination base stations / UEs. Tracking of multiple UAVs may be performed using the multipath characteristics of the sensed received radio waves. Tracking of multiple UAVs may be performed using other positioning methods, such as GNSS and / or altimeters.

[0363] This second embodiment makes it possible to detect illegal objects, and as a result, collisions with UAVs can be prevented.

[0364] Modification 1 of Embodiment 2. This Modification 1 discloses another method for detecting illegal objects.

[0365] The UAV itself may perform sensing.

[0366] For example, sensing may be performed in which the UAV transmits radio waves and the UAV receives reflected waves. The Service Facility (SF) may decide to perform the sensing. The SF may notify the UAV of information regarding the sensing settings. Hereafter, information regarding the sensing settings may be referred to as sensing settings. This notification may be made via the UAV's serving base station.

[0367] The sensing configuration may include information about the source node and / or destination node. For example, the sensing configuration may include information indicating that both the source node and the destination node are the UAV itself. This allows the UAV to quickly recognize that it is both transmitting and receiving sensing signals.

[0368] The sensing configuration may include information about resources used for sensing. These resources may be, for example, the same as the sensing resources disclosed in Embodiment 1. The sensing configuration may also include information about sensing result reporting. Examples of information about sensing result reporting include information about periodic reports, information about semi-persistent reports, information about non-periodic reports, and information about event-triggered reports. Information about periodic reports and / or information about event-triggered reports may be, for example, the same as those disclosed in Embodiment 1.

[0369] The event may include the detection of a predetermined radio wave. The event may also include the reception strength of the radio wave received by the UAV being above or above a predetermined threshold. As another example, the event may include the reception delay being below or below a predetermined threshold. The event relating to the reception delay allows, for example, the UAV to detect an object in its vicinity.

[0370] The UAV may perform sensing using the sensing settings described above. The UAV may transmit sensing radio waves (e.g., sensing signals). The UAV may receive sensing signals reflected by objects.

[0371] The UAV may notify the SF of the results of receiving the sensing signal. This notification may be made via the serving base station. This notification may be made periodically, semi-persistently, aperiodically, or triggered by an event.

[0372] The SF may estimate the position of an object, estimate its velocity, estimate its size, or estimate its shape. The SF may derive the reliability of the estimation results. The SF may notify the USS / UTM of the estimation results. The USS / UTM may use the notification to determine the presence or absence of an illegal object.

[0373] The USS / UTM may notify the UAV-C of information regarding an illegal object. This notification may include information regarding the location of the illegal object, information regarding its velocity, information regarding its size, or information regarding its shape. The UAV-C may use this information to instruct the UAV to take evasive action.

[0374] As another example, the Service Firm (SF) may notify the UAV of information regarding the object estimation results. This notification may be made via the UAV's serving base station. The UAV may then use this information to take evasive action. This would, for example, allow the UAV to quickly avoid illegal objects.

[0375] Figure 29 is a sequence diagram illustrating another example of the operation of illegal object detection using sensing. In the example shown in Figure 29, the UE mounted on the UAV is indicated as UAV-UE. The UAV-UE transmits a sensing signal and receives the sensing signal reflected by an object. In Figure 29, the UAV-UE is connected to a base station. In Figure 29, the same numbering is used for processes similar to those in Figure 28, and common explanations are omitted.

[0376] In steps ST2405 and ST2407 shown in Figure 29, the SF notifies the UAV-UE of the sensing settings. This notification may be made via the base station. Step ST2405 shows the notification from the SF to the base station, and step ST2407 shows the notification from the base station to the UAV-UE.

[0377] The sensing settings may include settings for reporting the results of receiving sensing signals. The sensing settings may include information indicating that the UAV-UE will transmit and receive sensing signals, information indicating that the UAV-UE will receive sensing signals that it has transmitted, and information regarding sensing signal resources (i.e., sensing resources). The UAV-UE uses step ST2407 to configure the transmission and reception of sensing signals.

[0378] In steps ST2409 and ST2411 shown in Figure 29, the UAV-UE notifies the SF that the settings for the sensing signal have been completed. Hereafter, this notification may be referred to as a sensing setting completion notification. This sensing setting completion notification may be sent via the base station. Step ST2409 shows the notification from the UAV-UE to the base station, and step ST2411 shows the notification from the base station to the SF.

[0379] In step ST2416 shown in Figure 29, the UAV-UE transmits a sensing signal. In ST2417, the UAV-UE receives a sensing signal reflected from an object.

[0380] In step ST2419 shown in Figure 29, the UAV-UE detects an event. This event may be the reception of a sensing signal transmitted by the UAV-UE. As an example of receiving such a sensing signal, the received intensity of the sensing signal may be equal to or greater than a predetermined threshold.

[0381] In steps ST2421 and ST2423 shown in Figure 29, the UAV-UE reports the reception result of the sensing signal (i.e., the sensing result) to the SF. This report may be made via the base station. Step ST2421 shows the report from the UAV-UE to the base station, and step ST2423 shows the report from the base station to the SF.

[0382] In step ST2425 shown in Figure 29, the SF estimates the position of the object. The size of the object may also be estimated, or the velocity of the object may be estimated. In step ST2427, the SF notifies the USS / UTM of the estimation results regarding the object.

[0383] Steps ST2329 and ST2330 shown in Figure 29 are the same as in Figure 28. The USS / UTM may use the estimation result from step ST2427 to determine the illegal object. The USS / UTM may notify the UAV-C of information regarding the illegal object.

[0384] In step ST2433 shown in Figure 29, UAV-C instructs UAV-UE to take evasive action. In step ST2435, UAV-UE performs evasive action.

[0385] Another solution is to perform sensing in which the source base station / UE transmits a sensing signal and the UAV receives the reflected wave.

[0386] The SF notifies the source base station / UE of the settings related to the transmission of the sensing signal. These settings may be the same as, for example, the transmission settings disclosed in Embodiment 1.

[0387] The SF notifies the UAV-UE of the settings related to the reception of sensing signals. This notification may be made via the UAV-UE's serving base station. These settings may be the same as, for example, the reception settings disclosed in Embodiment 1.

[0388] Figures 30 and 31 are sequence diagrams illustrating another example of illegal object detection using sensing. In the example shown in Figures 30 and 31, a base station transmits a sensing signal, and a UAV-UE receives the sensing signal reflected from an object. In Figures 30 and 31, the UAV-UE is connected to a serving base station. In Figures 30 and 31, the same numbering is used for processes similar to those in Figures 15 and 27-29, and common explanations are omitted.

[0389] Steps ST1301 to ST1307 shown in Figure 30 are the same as those in Figure 15.

[0390] In steps ST2509 and ST2511 shown in Figure 30, the SF notifies the UAV-UE of the settings related to receiving the sensing signal (i.e., reception settings). This notification may be made via the serving base station. Step ST2509 shows the notification from the SF to the serving base station, and step ST2511 shows the notification from the serving base station to the UAV-UE.

[0391] The reception settings may include settings for reporting the results of receiving the sensing signal. The reception settings may include information indicating that the sensing signal transmitted by the base station will be received, or information regarding the sensing signal resource (i.e., sensing resource). The UAV-UE uses step ST2511 to configure the sensing signal reception settings.

[0392] In steps ST2513 and ST2515 shown in Figure 30, the UAV-UE sends a reception setup completion notification to the SF. This reception setup completion notification may be sent via the serving base station. Step ST2513 shows the notification from the UAV-UE to the serving base station, and step ST2515 shows the notification from the serving base station to the SF.

[0393] In step ST2516 shown in Figure 31, the base station transmits a sensing signal. In ST2517, the UAV-UE receives the sensing signal reflected from the object.

[0394] Steps ST2419 to ST2427 shown in Figure 31 are the same as in Figure 29. Steps ST2329 and ST2330 are the same as in Figure 28. The USS / UTM may use the estimation result of step ST2427 to determine the illegal object. The USS / UTM may notify the UAV-C of information regarding the illegal object. Steps ST2433 and ST2435 are the same as in Figure 29.

[0395] Figures 32 and 33 are sequence diagrams illustrating another example of the operation of illegal object detection using sensing. In the example shown in Figures 32 and 33, the UE transmits a sensing signal, and the UAV-UE receives the sensing signal reflected from the object. In Figures 32 and 33, the UAV-UE is connected to a serving base station, and the UE is connected to a base station. In Figures 32 and 33, the same numbering is used for processes similar to those in Figures 15, 17, and 27-31, and common explanations are omitted.

[0396] Steps ST1301 to ST1305 shown in Figure 32 are the same as in Figure 15. Steps ST1405 and ST1407 are the same as in Figure 17. Step ST1307 is the same as in Figure 15.

[0397] Steps ST2509 to ST2515 shown in Figure 32 are the same as those in Figure 30.

[0398] In step ST2616 shown in Figure 33, the UE transmits a sensing signal. In ST2617, the UAV-UE receives the sensing signal reflected from the object.

[0399] Steps ST2419 to ST2427 shown in Figure 33 are the same as in Figure 29. Steps ST2329 and ST2330 are the same as in Figure 28. The USS / UTM may use the estimation result of step ST2427 to determine the illegal object. The USS / UTM may notify the UAV-C of information regarding the illegal object. Steps ST2433 and ST2435 are the same as in Figure 29.

[0400] Another solution is to perform sensing in which the UAV transmits a sensing signal and the receiving base station / UE receives the reflected wave.

[0401] The SF notifies the receiving base station / UE of the settings related to the reception of the sensing signal. These settings may be the same as, for example, the reception settings disclosed in Embodiment 1.

[0402] The service provider (SF) notifies the UAV-UE of the settings related to the transmission of sensing signals. This notification may be made via the UAV-UE's serving base station. These settings may be the same as, for example, the transmission settings disclosed in Embodiment 1.

[0403] Figures 34 and 35 are sequence diagrams illustrating another example of illegal object detection using sensing. In the example shown in Figures 34 and 35, the UAV-UE transmits a sensing signal, and the base station receives the sensing signal reflected from the object. In Figures 34 and 35, the UAV-UE is connected to a serving base station. In Figures 34 and 35, the same numbering is used for processes similar to those in Figures 15, 16, and 27-29, and common explanations are omitted.

[0404] Steps ST1301 to ST1303 shown in Figure 34 are the same as in Figure 15. Steps ST1359 and ST1365 are the same as in Figure 16.

[0405] In steps ST2709 and ST2711 shown in Figure 34, the SF notifies the UAV-UE of the settings related to the transmission of sensing signals (i.e., transmission settings). This notification may be made via the serving base station. Step ST2709 shows the notification from the SF to the serving base station, and step ST2711 shows the notification from the serving base station to the UAV-UE.

[0406] In steps ST2713 and ST2715 shown in Figure 34, the UAV-UE sends a transmission setup completion notification to the SF. This transmission setup completion notification may be sent via the serving base station. Step ST2713 shows the notification from the UAV-UE to the serving base station, and step ST2715 shows the notification from the serving base station to the SF.

[0407] In step ST2716 shown in Figure 35, the UAV-UE transmits a sensing signal. In ST2717, the base station receives the sensing signal reflected from the object.

[0408] Step ST1373 shown in Figure 35 is the same as in Figure 16. Steps ST2425 and ST2427 are the same as in Figure 29. Steps ST2329 and ST2330 are the same as in Figure 28. Steps ST2433 and ST2435 are the same as in Figure 29.

[0409] Figures 36 and 37 are sequence diagrams illustrating another example of illegal object detection using sensing. In the example shown in Figures 36 and 37, the UAV-UE transmits a sensing signal, and the UE receives the sensing signal reflected from the object. In Figures 36 and 37, the UAV-UE is connected to a serving base station. In Figures 36 and 37, the same numbering is used for processes similar to those in Figures 15, 16, and 27-29, and common explanations are omitted.

[0410] Steps ST1301 to ST1315 shown in Figure 36 are the same as in Figure 15. Steps ST2709 to ST2715 are the same as in Figure 34.

[0411] In step ST2816 shown in Figure 37, the UAV-UE transmits a sensing signal. In ST2817, the UE receives the sensing signal reflected from the object.

[0412] Steps ST1319 to ST1323 shown in Figure 37 are the same as in Figure 15. Steps ST2425 and ST2427 are the same as in Figure 29. Steps ST2329 and ST2330 are the same as in Figure 28. Steps ST2433 and ST2435 are the same as in Figure 29.

[0413] Sidelinks may be used for communication between the UAV-UE and the UE. For example, when the UAV-UE is outside the coverage range of the base station, illegal object detection may be performed using the transmission and reception of signals via sidelinks. This makes it possible, for example, to detect illegal objects over a wide area.

[0414] As another example, the UAV-UE may have SF (Sensing Firmware) functionality. This would enable, for example, wide-area illegal object detection. The UE may also have SF functionality. Sensing signal transmission and reception settings may be transmitted between the UAV-UE and the UE using a sidelink.

[0415] UAV trajectory deviation detection and illegal object detection may be performed in parallel. The USS / UTM may use the results of UAV trajectory tracking to distinguish between the UAV and the illegal object.

[0416] This modified version 1 enables highly efficient detection of illegal objects.

[0417] Embodiment 3. When tracking the trajectory of a UAV, the UAV may move beyond the range of the base station / UE to which the first SF is connected and into the range of the base station / UE to which the second SF is connected. In this case, a switch from the first SF to the second SF is required.

[0418] However, the aforementioned non-patent literature does not disclose any sensing procedures in such cases. As a result, problems arise such as the inability to perform wide-area orbital tracking in the communication system, or the inability to perform sensing near the boundaries of the range of the base station / UE to which the SF is connected.

[0419] This third embodiment discloses a method for solving the aforementioned problems.

[0420] The source service platform (SF) detects mobility to the destination SF. This detection may be triggered, for example, when the predicted position of the UAV enters the coverage area of ​​the base station to which the destination SF is connected. The predicted position of the UAV may be, for example, a position predicted by the flight path, or a position derived from sensing estimation results.

[0421] If the predicted location of the UAV falls within the coverage of a certain base station, the source SF may determine the SF connected to that base station as the destination SF.

[0422] Another example of mobility detection is when a sensing operation node (base station / UE) used for sensing is connected to a different SF than the source SF. The sensing operation node may be a source node, a destination node, or both.

[0423] The source service box (SF) may determine the destination SF to be the SF to which the sensing operation node (base station / UE) used for sensing is connected.

[0424] The SF that performs sensing is disclosed. The source SF may use the sensing results to estimate information related to the UAV (such as position and velocity).

[0425] The source service provider (SF) may request information about base stations / UEs under the control of the destination SF from the destination SF. This request may include information about the predicted location of the UAV.

[0426] The destination SF may notify the source SF of information regarding the base stations / UEs connected to the destination SF. This notification may include information regarding the resources of the base stations / UEs connected to the destination SF, or it may include information regarding their capabilities. The source SF may use this notification to determine the source base station / UE or the destination base station / UE.

[0427] The source SF may instruct a sensing operation node (base station / UE) connected to the destination SF to perform sensing, or may instruct a sensing operation node (base station / UE) connected to the source SF to perform sensing. This instruction may be an instruction to transmit a sensing signal, an instruction to receive a sensing signal, or both. This instruction to the base station / UE connected to the destination SF may be given via the destination SF. As another example, this instruction to the base station / UE connected to the destination SF may be given directly from the source SF. The transmitting base station / UE and the receiving base station / UE may perform sensing in response to this instruction.

[0428] The receiving base station / UE may report the sensing results to the switching source SF. This report may be made via the switching source SF. For example, if the receiving base station / UE connects to the switching source SF, the report may be made via the switching source SF. As another example, the report may be made directly to the switching source SF. The switching source SF may use the report to estimate the UAV's position, estimate its speed, or estimate the time related to the position and / or speed. The switching source SF may notify the USS / UTM of the estimation results.

[0429] Figures 38 and 39 are sequence diagrams illustrating an example of an operation in which sensing is performed across multiple service windows (SFs). In the example shown in Figures 38 and 39, SF#1 is the source SF and SF#2 is the destination SF. Base station #1 is connected to SF#1, and base station #2 is connected to SF#2. UE#1 is connected to base station #1, and UE#2 is connected to base station #2. In the example shown in Figures 38 and 39, SF#1 performs sensing. UE#1 is the source UE, and UE#2 is the destination UE. In Figures 38 and 39, the same numbering is used for processes similar to those in Figures 15, 17, and 18, and common explanations are omitted.

[0430] Steps ST1301 to ST1303 shown in Figure 38 are the same as in Figure 15. In step ST1303 shown in Figure 38, SF#1 determines UE#1 as the source UE and determines UE#2, which is under the control of base station #2 connected to SF#2, as the destination UE. Steps ST1305, ST1405, ST1407, and ST1307 are the same as in Figure 17.

[0431] In steps ST2908, ST2909, and ST1311 shown in Figure 39, SF#1 notifies UE#2 of the settings related to receiving sensing signals (i.e., reception settings). This notification may be made via SF#2 and base station #2. Step ST2908 shows the notification from SF#1 to SF#2, ST2909 shows the notification from SF#2 to base station #2, and step ST1311 shows the notification from base station #2 to UE#2. This notification may include reception settings similar to those in steps ST1309 and ST1311 in Figure 15. UE#2 may use step ST1311 to configure the sensing signal reception settings or to configure the sensing report settings.

[0432] In steps ST1313, ST2915, and ST2916 shown in Figure 39, UE#2 notifies SF#1 that the settings related to receiving the sensing signal are complete. This notification may be called a reception setting completion notification, as in Embodiment 1. This reception setting completion notification may be sent via base station #2 and SF#2. Step ST1313 shows the notification from UE#2 to base station #2, step ST2915 shows the notification from base station #2 to SF#2, and step ST2916 shows the notification from SF#2 to SF#1.

[0433] Step ST1467 shown in Figure 39 is the same as in Figure 18. UE#1 transmits a sensing signal. Step ST1319 is the same as in Figure 15. UE#2 receives the sensing signal from UE#1 and detects an event.

[0434] In steps ST1321, ST2923, and ST2924 shown in Figure 39, UE#2 notifies SF#1 of the sensing results. This notification may be made via base station #2 and SF#2. Step ST1321 shows the notification from UE#2 to base station #2, step ST2923 shows the notification from base station #2 to SF#2, and ST2924 shows the notification from SF#2 to SF#1. This notification may include information similar to that shown in steps ST1321 and ST1323 in Figure 15.

[0435] Steps ST1325 and ST1327 shown in Figure 39 are the same as those in Figure 15.

[0436] Figures 38 and 39 show the case where both the source node and the destination node are UEs, but the example is not limited to this. At least one of the source node and the destination node may be a base station.

[0437] For example, the source node may be base station #1. Steps ST1405 and ST1407 shown in Figure 38 may be omitted. Instead of step ST1467, base station #1 may transmit the sensing signal.

[0438] The receiving node may be base station #2. Steps ST1311 and ST1313 shown in Figure 39 may be omitted. Base station #2 may receive the sensing signal in step ST1467. Base station #2 may perform the processing in step ST1319. Step ST1321 may be omitted.

[0439] Figures 38 and 39 show the case where the source UE (UE#1) is connected to SF#1, but the example is not limited to this. The source UE may be connected to SF#2. Base station #1 may be connected to SF#2. Steps ST1305 and ST1307 in Figure 38 may be performed via SF#2.

[0440] Figures 38 and 39 show the case where the receiving UE (UE#2) is connected to SF#2, but the example is not limited to this. The receiving UE may be connected to SF#1. Base station #2 may be connected to SF#1. Steps ST2908 and ST2916 in Figure 39 may be omitted. Step ST2909 may be performed directly from SF#1 to base station #2, and step ST2915 may be performed directly from base station #2 to SF#1. Step ST2923 may be performed directly from base station #2 to SF#1. Step ST2924 may be omitted.

[0441] The aforementioned combinations may also be performed. For example, the source UE and base station #1 may be connected to SF #2 (the switching destination SF), and the receiving UE and base station #2 may be connected to SF #1 (the switching source SF).

[0442] Another example of a sensor function (SF) that performs sensing is that the target SF may use the sensing results to estimate information related to the UAV (such as position and velocity).

[0443] The source SF may request the destination SF to perform sensing. Hereafter, this request may be referred to as a sensing request. The sensing request may include information about base stations / UEs connected to the source SF, or information about the predicted location of a UAV. The information about base stations / UEs may include information used to identify base stations / UEs connected to the source SF, information about the resources of the base stations / UEs, or information about the capabilities of the base stations / UEs.

[0444] The switching destination SF may determine the source base station / UE or the receiving base station / UE. Information included in the sensing request from the switching source SF may be used in this determination.

[0445] The switching destination SF may instruct the sensing operation node (base station / UE) connected to the switching source SF to perform sensing, or may instruct the sensing operation node (base station / UE) connected to the switching destination SF to perform sensing. This instruction may be an instruction to transmit a sensing signal, an instruction to receive a sensing signal, or both. This instruction to the base station / UE connected to the switching source SF may be given via the switching source SF. As another example, this instruction to the base station / UE connected to the switching source SF may be given directly from the switching destination SF. The transmitting base station / UE and the receiving base station / UE may perform sensing in response to this instruction.

[0446] The receiving base station / UE may report the sensing results to the switching destination SF. This report may be made via the switching source SF. For example, if the receiving base station / UE connects to the switching source SF, the report may be made via the switching source SF. As another example, the report may be made directly to the switching destination SF. The switching destination SF may use the report to estimate the UAV's position, estimate its speed, or estimate the time related to the position and / or speed. The switching destination SF may notify the USS / UTM of the estimation results. The switching destination SF may notify the switching source SF of the completion of sensing.

[0447] FIGS. 40 and 41 are sequence diagrams illustrating an example of an operation in which sensing is performed across a plurality of SFs. In the examples illustrated in FIGS. 40 and 41, SF#1 is a switching-source SF, and SF#2 is a switching-destination SF. Base station #1 is connected to SF#1, and base station #2 is connected to SF#2. UE#1 is connected to base station #1, and UE#2 is connected to base station #2. In the examples illustrated in FIGS. 40 and 41, sensing is performed by SF#2. UE#1 is a transmission-source UE, and UE#2 is a reception-destination UE. In FIGS. 40 and 41, the same processes as those in FIGS. 15, 17, 18, 38 and 39 are denoted by the same reference numerals, and a common description is omitted.

[0448] Steps ST1301 to ST1302B illustrated in FIG. 40 are the same as those in FIG. 15.

[0449] In step ST3002 illustrated in FIG. 40, SF#1 transmits a sensing request to SF#2. The sensing request may include information related to a base station / UE connected to SF#1, or may include information related to a predicted position of a UAV. The information related to the base station / UE may include, for example, information used for identifying the base station / UE, may include information related to resources, or may include information related to capabilities.

[0450] In step ST3003 illustrated in FIG. 40, SF#2 determines a transmission-source base station / UE and / or a reception-destination base station / UE. The information included in ST3002 may be used for the determination. In the example illustrated in FIG. 40, SF#2 determines UE#1 as the transmission-source UE, and determines UE#2 as the reception-destination UE.

[0451] In step ST3004 shown in FIG. 40, SF#2 requests SF#1 for settings related to transmission of a sensing signal. Hereinafter, the request may be referred to as a sensing configuration request. The sensing configuration request may include information related to a source UE. The sensing configuration request may include information used for identifying the source UE, and may also include information related to sensing resources. The information related to sensing resources may include time resources, frequency resources, spatial resources (e.g., beam-related resources), and code resources.

[0452] In response to the sensing configuration request, SF#1 transmits transmission configuration to UE#1. Steps ST1305, ST1405, ST1407 and ST1307 shown in FIG. 40 are the same as those in FIG. 17.

[0453] In step ST3007 shown in FIG. 40, SF#1 notifies SF#2 that the settings related to the transmission of the sensing signal have been completed.

[0454] Steps ST1309 to ST1315 shown in FIG. 41 are the same as those in FIG. 15.

[0455] Step ST1467 shown in FIG. 41 is the same as that in FIG. 18. UE#1 transmits the sensing signal. UE#2 receives the sensing signal. Steps ST1319 to ST1323 are the same as those in FIG. 15.

[0456] In steps ST3025 and ST3027 shown in FIG. 41, SF#2 performs the same processing as steps ST1325 and ST1327 shown in FIG. 15.

[0457] In step ST3029 shown in FIG. 41, SF#2 notifies SF#1 of the completion of sensing.

[0458] In FIG. 40 and FIG. 41, the case where both the source node and the destination node are UEs is shown, but the disclosure is not limited to this example. At least one of the source node and the destination node may be a base station.

[0459] For example, the source node may be base station #1. Steps ST1405 and ST1407 shown in Figure 40 may be omitted. Instead of step ST1467, base station #1 may transmit the sensing signal.

[0460] The receiving node may be base station #2. Steps ST1311 and ST1313 shown in Figure 41 may be omitted. Base station #2 may receive the sensing signal in step ST1467. Base station #2 may perform the processing in step ST1319. Step ST1321 may be omitted.

[0461] Figures 40 and 41 show the case where the source UE (UE#1) is connected to SF#1, but the example is not limited to this. The source UE may be connected to SF#2. Base station #1 may be connected to SF#2. Steps ST1305 and ST1307 in Figure 40 may be performed directly between SF#2 and base station #1. Steps ST3004 and ST3007A may be omitted.

[0462] Figures 40 and 41 show the case where the receiving UE (UE#2) is connected to SF#2, but the example is not limited to this. The receiving UE may be connected to SF#1. Base station #2 may be connected to SF#1. Steps ST1309, ST1315, and ST1323 in Figure 41 may be performed via SF#1.

[0463] The aforementioned combinations may also be performed. For example, the source UE and base station #1 may be connected to SF #2 (the destination SF), and the destination UE and base station #2 may be connected to SF #1 (the source SF).

[0464] This third embodiment enables sensing even when a UAV moves across SF (Surface Field), thereby preventing gaps in sensing.

[0465] Although UAVs are disclosed in this specification, the UE may be an aircraft-borne UE with a crew present, or an UE located in the air.

[0466] In this specification, UE, UAV, and UAV-C may be referred to as nodes. Furthermore, network elements that communicate with UE, UAV, and UAV-C may also be referred to as nodes. For example, base stations that communicate with UE, UAV, and UAV-C may be referred to as nodes (RAN nodes, NW nodes, etc.). Furthermore, in this specification, nodes may also be functions. For example, functions in a core network may be referred to as nodes. Functions related to UAV sensing, such as SF, may also be referred to as nodes.

[0467] In this specification, elements in a UAS system may be referred to as nodes. For example, elements such as USS / UTM may be referred to as nodes. USS / UTM may be referred to as a UAV management function node.

[0468] In the communication system described herein, one or more cells are configured in a single gNB. In this disclosure, the terms gNB and cell are used, but unless otherwise specified, they may refer to either a gNB or a cell.

[0469] In this disclosure, gNB may be MCG or SCG.

[0470] The embodiments and their variations described above are merely illustrative, and these embodiments and their variations can be freely combined. Furthermore, any component of each embodiment and its variations can be modified or omitted as appropriate.

[0471] For example, in the embodiments and their modifications described above, a slot is an example of a time unit for communication in a fifth-generation communication system. A slot may also be a scheduling unit. The scheduling units described in the embodiments and their modifications described above may be TTI (Transmission Time Interval) units, subframe units, slot units, subslot units, minislot units, or symbol units.

[0472] For example, the methods disclosed in each of the embodiments and their modifications described above may be applied to an IAB. They may be applied to communication between an IAB donor and an IAB node. They may be applied to processing that uses Uu in an IAB.

[0473] 202 Communication terminal equipment (mobile terminal), 210 Communication system, 213, 240-1, 240-2, 750 Base station equipment (NR base station, base station), 214 5G core unit, 215 Central unit, 216 Distributed unit, 217 Central unit for control plane, 218 Central unit for user plane, 219 TRP, 301, 403 Protocol processing unit, 302 Application unit, 304, 405 Encoder unit, 305, 406 Modulation unit, 306, 407 Frequency conversion unit, 307-1 to 307-4, 408-1 to 408-4 Antenna, 308, 409 Demodulation unit, 309, 410 Decoder unit, 310, 411, 526 Control unit, 401 EPC communication unit, 402 Other base station communication unit, 412 5GC communication unit, 521 Data Network communication unit, 522 Base station communication unit, 523 User plane communication unit, 523-1 PDU processing unit, 523-2 Mobility anchoring unit, 525 Control plane control unit, 525-1 NAS security unit, 525-2 Idle state mobility management unit, 527 Session management unit, 527-1 PDU session control unit, 527-2 UE IP address assignment unit, 751-1 to 751-8 Beams, 752 Cells.

Claims

1. A communication system comprising at least one terminal device, at least one base station that communicates with the at least one terminal device, and at least one sensing function node that manages sensing, wherein the sensing function node is configured to determine at least one of the at least one of the at least one terminal device and the at least one base station, which is a first node that is a source node that transmits a sensing signal and which is a second node that is a destination node that receives the sensing signal, using information regarding the position of an unmanned aerial vehicle (UAV).

2. The communication system according to claim 1, wherein the information relating to the location of the UAV includes at least one of the planned location or geographical area of ​​the UAV and the positioning result of the UAV.

3. The communication system according to claim 1 or 2, wherein the sensing function node is configured to determine at least one of the first node and the second node using further information relating to the location of the at least one terminal device and information relating to the location of the at least one base station.

4. The communication system according to any one of claims 1 to 3, wherein the sensing function node is configured to determine at least one of the first node and the second node using an index or capability in the sensing.

5. The communication system according to any one of claims 1 to 4, wherein the sensing function node is configured to transmit a transmission setting for transmitting the sensing signal to the first node and to transmit a reception setting for receiving the sensing signal to the second node, the reception setting includes a setting for reporting the sensing result.

6. The communication system according to claim 5, wherein the second node is configured to transmit the sensing results to the sensing function node using the settings relating to the report.

7. The communication system according to claim 6, further comprising a UAV management function node for managing the operation of the UAV, wherein the sensing function node is configured to estimate information relating to the UAV using the sensing results, and to transmit the estimated information to the UAV management function node.

8. The communication system according to any one of claims 1 to 7, wherein the sensing function node is configured to determine the switching of at least one of the first node and the second node using at least one of the following: the planned location or geographical area of ​​the UAV, information about the UAV estimated using the sensing results, the received intensity of the sensing signal at the second node, and the signal reception results at the terminal device or base station located around the UAV, the first node, or the second node.

9. The communication system according to any one of claims 1 to 8, further comprising a UAV management function node for managing the operation of the UAV, wherein the UAV management function node is configured to detect a deviation from the trajectory of the UAV based on at least one of the following: the result of receiving the sensing signal at the second node, the result of receiving signals at the terminal device or base station located around the UAV, the first node or the second node, and the positioning result of the UAV.

10. The communication system according to any one of claims 1 to 9, further comprising an object detection node for detecting an object, wherein the object detection node is configured to detect the object based on at least one of the following: the result of receiving the sensing signal at the second node, and the result of receiving signals at the terminal device or base station located around the UAV, the first node, or the second node.

11. The communication system according to any one of claims 1 to 9, further comprising an object detection node for detecting objects, wherein the terminal device mounted on the UAV operates as the first node and the second node, and the object detection node is configured to detect objects based on the result of receiving the sensing signal at the terminal device mounted on the UAV.

12. The communication system according to any one of claims 1 to 9, further comprising an object detection node for detecting an object, wherein the terminal device mounted on the UAV operates as the second node, and the object detection node is configured to detect the object based on the result of receiving the sensing signal at the terminal device mounted on the UAV.

13. The communication system according to any one of claims 1 to 9, further comprising an object detection node for detecting illegal objects, wherein the terminal device mounted on the UAV operates as the first node, and the object detection node is configured to detect the object based on the result of receiving the sensing signal at the second node.

14. The communication system according to any one of claims 1 to 9, wherein the at least one sensing function node includes a first sensing function node connected to the first node and the second node, and a second sensing function node connected to a third node which is the switching destination of the first node and a fourth node which is the switching destination of the second node, the first sensing function node is configured to determine the third node and the fourth node, receive sensing results at the fourth node, and estimate information relating to the UAV using the sensing results.

15. The communication system according to any one of claims 1 to 9, wherein the at least one sensing function node includes a first sensing function node connected to the first node and the second node, and a second sensing function node connected to a third node which is the switching destination of the first node and a fourth node which is the switching destination of the second node, the second sensing function node is configured to determine the third node and the fourth node, receive sensing results at the fourth node, and estimate information relating to the UAV using the sensing results.

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