C2 communication management method

Abstract

One disclosure of the present specification provides a method performed by a UE. The method comprises the steps of: performing C2 communication with the second UE through a command and control (C2) connection via the PC5; measuring the signal strength of the C2 connection via the PC5; an unmanned aerial system (UAS) layer of the first UE transmitting C2 connection status information to an application layer of the first UE, the C2 connection status information including information related to the measured signal strength of the C2 connection via the PC5; and determining whether i) to switch the C2 connection via the PC5 to the C2 connection via the network or ii) to release the C2 connection via the PC5 based on a request for an application layer of the first UE based on the C2 connection status information.

Description

Technical Field

[0001] This specification relates to mobile communications. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE goal, including those aimed at reducing user and provider costs, improving service quality, and expanding and improving coverage and system capacity. As upper layer requirements, 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of frequency bands, simple structure, open interfaces, and sufficient power consumption of terminals.

[0003] Development of requirements and specifications for New Radio (NR) systems has begun in the International Telecommunication Union (ITU) and 3GPP. 3GPP must identify and develop technical components for successful standardization of new RATs that will meet both immediate market needs and longer-term requirements set forth by the ITU Radiocommunication Sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process in a timely manner. In addition, NR should be able to use any spectrum band in the range of at least up to 100 GHz that can be used for wireless communications even in the more distant future.

[0004] The goal of NR is a single technology framework that addresses all use cases, requirements and deployment scenarios, including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. NR should be inherently forward compatible.

[0005] When C2 communication is performed between UEs, a method of switching between a C2 connection via the PC 5 and a C2 connection via a network is required. Summary of the invention

[0006] Technical Solution

[0007] The first UE may measure the signal strength of the C2 connection via PC5 with the second UE and decide based thereon whether to disconnect the C2 connection or switch to the C2 connection via the network. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An example of a communication system to which an implementation of the present disclosure is applied is shown.

[0009] Figure 2 An example of a wireless device to which an implementation of the present disclosure is applied is shown.

[0010] Figure 3 An example of a UE to which an implementation of the present disclosure is applied is shown.

[0011] Figure 4An example 5G system structure is illustrated to which implementations of the present specification may be applied.

[0012] Figure 5a and Figure 5b The layer 2 link establishment process is illustrated.

[0013] Figure 6 A scenario is shown in which a direct communication path is switched between the PC 5 and the Uu.

[0014] Figure 7 The disclosed embodiments according to the present specification are illustrated.

[0015] Figure 8 A process of a first UE according to the disclosure of this specification is shown.

[0016] Fig. 9 The process of the base station according to the disclosure of this specification is shown. DETAILED DESCRIPTION

[0017] The following techniques, devices and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data Rate for GSM Evolution (EDGE). OFDMA can be implemented by radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE adopts OFDMA in DL and SC-FDMA in UL. The evolutions of 3GPP LTE include LTE-A (Advanced), LTE-A Pro and / or 5G NR (New Radio).

[0018] For the convenience of description, the implementation of the present disclosure is mainly described with respect to a 3GPP-based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP-based wireless communication system, various aspects of the present disclosure that are not limited to a 3GPP-based wireless communication system are applicable to other mobile communication systems.

[0019] For terms and techniques not specifically described among the terms and techniques used in the present disclosure, reference may be made to wireless communication standard documents published prior to the present disclosure.

[0020] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and / or B". For example, "A, B, or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B, and C".

[0021] In the present disclosure, a slash ( / ) or a comma may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0022] In the present disclosure, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted as being the same as "at least one of A and B".

[0023] Additionally, in the disclosure, “at least one of A, B, and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.” Additionally, “at least one of A, B, or C” or “at least one of A, B, and / or C” may mean “at least one of A, B, and C.”

[0024] In addition, the brackets used in the present disclosure may mean "for example". In detail, when it is shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, the "control information" in the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of "control information". In addition, even when it is shown as "control information (ie, PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0025] The technical features described separately in one drawing in the present disclosure may be implemented separately or simultaneously.

[0026] Although not limited thereto, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein may be applied to various fields requiring wireless communication and / or connection between devices (e.g., 5G).

[0027] Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings. Unless otherwise indicated, the same reference numerals in the following drawings and / or descriptions may represent the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0028] Figure 1 An example of a communication system to which an implementation of the present disclosure is applied is shown.

[0029] Figure 1 The 5G usage scenarios shown are only exemplary. The technical features of the present disclosure can be applied to Figure 1 Other 5G usage scenarios not shown.

[0030] The three main requirement categories for 5G include (1) enhanced mobile broadband (eMBB) category, (2) massive machine type communications (mMTC) category, and (3) ultra-reliable and low latency communications (URLLC) category.

[0031] Reference Figure 1 , the communication system 1 includes wireless devices 100a to 100f, a base station (BS) 200, and a network 300. Figure 1 A 5G network is shown as an example of a network of the communication system 1 , but implementations of the present disclosure are not limited to the 5G system and may be applied to future communication systems other than the 5G system.

[0032] BS 200 and network 300 may be implemented as wireless devices, and certain wireless devices may operate as BSs / network nodes relative to other wireless devices.

[0033] The wireless devices 100a to 100f represent devices that perform communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or LTE), and may be referred to as communication / radio / 5G devices. The wireless devices 100a to 100f may include, but are not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an IoT device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. A vehicle may include an unmanned vehicle (UAV) (e.g., a drone). An XR device may include an AR / VR / mixed reality (MR) device, and may be implemented in the form of a head mounted device (HMD), a head up display (HUD) installed in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart pads, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include televisions, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0034] In the present disclosure, the wireless devices 100a to 100f may be referred to as user equipment (UE). For example, the UE may include a cellular phone, a smart phone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle with an autonomous driving function, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a holographic device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a weather / environmental device, a device related to 5G services, or a device related to the field of the fourth industrial revolution.

[0035] For example, a UAV may be an aerial vehicle that is flown without humans aboard and is controlled by wireless signals.

[0036] For example, a VR device may include a device for realizing an object or background of a virtual world. For example, an AR device may include a device realized by connecting an object or background of a virtual world to an object or background of a real world. For example, an MR device may include a device realized by merging an object or background of a virtual world into an object or background of a real world. For example, a holographic device may include a device for realizing a 360-degree stereoscopic image by recording and reproducing stereoscopic information using a light interference phenomenon generated when two lasers meet, called holography.

[0037] For example, a public safety device may include an image relay device or an image device that may be wearable on a user's body.

[0038] For example, MTC devices and IoT devices may be devices that do not require direct human intervention or manipulation. For example, MTC devices and IoT devices may include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors.

[0039] For example, a medical device may be a device for the purpose of diagnosing, curing, alleviating, treating or preventing a disease. For example, a medical device may be a device for the purpose of diagnosing, curing, alleviating or correcting an injury or trauma. For example, a medical device may be a device for the purpose of inspecting, replacing or modifying a structure or function. For example, a medical device may be a device for regulating pregnancy. For example, a medical device may include a device for treatment, a device for operation, a device for (in vitro) diagnosis, a hearing aid or a device for surgery.

[0040] For example, the safety device may be a device installed to prevent possible danger and maintain safety. For example, the safety device may be a camera, a closed-circuit TV (CCTV), a recorder or a black box.

[0041] For example, a fintech device may be a device that is capable of providing financial services such as mobile payments. For example, a fintech device may include a payment device or a point of sale (POS) system.

[0042] For example, weather / environmental devices may include devices for monitoring or predicting weather / environmental conditions.

[0043] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. The AI ​​technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a super 5G network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0044] Wireless communication / connection 150a, 150b, and 150c may be established between wireless devices 100a to 100f and / or between wireless devices 100a to 100f and BS200 and / or between BS200. In this document, wireless communication / connection may be established through various RATs (e.g., 5G NR), such as uplink / downlink communication 150a, sidelink communication or device-to-device (D2D) communication 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc. Wireless devices 100a to 100f and BS200 / wireless devices 100a to 100f may send / receive radio signals to each other through wireless communication / connection 150a, 150b, and 150c. For example, wireless communication / connection 150a, 150b, and 150c may send / receive signals through various physical channels. To this end, at least a portion of various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and resource allocation processes may be performed based on various proposals of the present disclosure.

[0045] AI refers to the field that studies artificial intelligence or the methods that can create it, while machine learning refers to the field that defines the various problems solved in the field of AI and the methods to solve them. Machine learning is also defined as algorithms that increase the performance of a task through steady experience with the task.

[0046] A robot means a machine that automatically processes or operates a given task through its own capabilities. In particular, a robot that has the ability to recognize the environment and determine the actions to be performed by itself can be called an intelligent robot. According to the purpose or field of use, robots can be classified as industrial, medical, household, military, etc. Robots can perform various physical operations, such as moving robot joints using actuators or motors. Mobile robots also include driven wheels, brakes, propellers, etc., allowing them to travel on the ground or fly in the air.

[0047] Autonomous driving means the technology of self-driving, and autonomous vehicles mean vehicles that are driven without user control or with minimal user control. For example, autonomous driving may include maintaining a lane while in motion, automatically adjusting speed (e.g., adaptive cruise control), automatically driving along a set route, and automatically setting a route when a destination is set. Vehicles cover vehicles equipped with an internal combustion engine, hybrid vehicles equipped with an internal combustion engine and an electric motor, and electric vehicles equipped with an electric motor, and may include trains, motorcycles, etc. as well as cars. Autonomous vehicles may be considered robots with autonomous driving capabilities.

[0048] Extended reality is collectively referred to as VR, AR, and MR. VR technology provides real-world objects and backgrounds only through computer graphics (CG) images. AR technology provides virtual CG images on top of real object images. MR technology is a CG technology that combines virtual objects into the real world. MR technology is similar to AR technology in that they display real objects and virtual objects together. However, the difference is that in AR technology, virtual objects are used as a supplementary form of real objects, while in MR technology, virtual objects and real objects are used as equal individuals.

[0049] NR supports multiple parameter sets (and / or multiple subcarrier spacing (SCS)) to support various 5G services. For example, if the SCS is 15kHz, wide areas can be supported in traditional cellular bands, and if the SCS is 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. If the SCS is 60kHz or higher, bandwidths greater than 24.25GHz can be supported to overcome phase noise.

[0050] The NR frequency band may be defined as two types of frequency ranges, namely, FR1 and FR2. The numerical values ​​of the frequency ranges may vary. For example, the two types of frequency ranges (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency range used in the NR system, FR1 may mean "range below 6 GHz", FR2 may mean "range above 6 GHz" and may be referred to as millimeter wave (mmW).

[0051] [Table 1]

[0052] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz-6000MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0053] As described above, the numerical value of the frequency range of the NR system may be changed. For example, as shown in Table 2 below, FR1 may include a frequency band of 410 MHz to 7125 MHz. That is, FR1 may include a frequency band of 6 GHz (or 5850 MHz, 5900 MHz, 5925 MHz, etc.) or higher. For example, a frequency band of 6 GHz (or 5850 MHz, 5900 MHz, 5925 MHz, etc.) or higher included in FR1 may include an unlicensed frequency band. The unlicensed frequency band may be used for various purposes, such as for communication of vehicles (e.g., autonomous driving).

[0054] [Table 2]

[0055] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0056] Here, the radio communication technology implemented in the wireless device in the present disclosure may include narrowband Internet of Things (NB-IoT) technology for low power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of low power wide area network (LPWAN) technology, which may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the above names. Additionally and / or alternatively, the radio communication technology implemented in the wireless device in the present disclosure may be based on LTE-M technology communication. For example, LTE-M technology may be an example of LPWAN technology and is referred to as various names such as enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in at least one of various specifications such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication and / or 7) LTE M, and may not be limited to the above names. Additionally and / or alternatively, the radio communication technology implemented in the wireless device in the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN considering low power communication, and may not be limited to the above names. For example, ZigBee technology may generate a personal area network (PAN) associated with small / low power digital communication based on various specifications such as IEEE 802.15.4, and may be referred to as various names.

[0057] Figure 2 An example of a wireless device to which an implementation of the present disclosure is applied is shown.

[0058] exist Figure 2 In the embodiment, the first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to the usage / service. For example, {the first wireless device 100 and the second wireless device 200} may correspond to Figure 1 At least one of {wireless devices 100a to 100f and BS200}, {wireless devices 100a to 100f and wireless devices 100a to 100f} and / or {BS200 and BS200}. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / components and / or modules.

[0059] The first wireless device 100 may include at least one transceiver (eg, transceiver 106 ), at least one processing chip (eg, processing chip 101 ), and / or one or more antennas 108 .

[0060] The processing chip 101 may include at least one processor (eg, the processor 102 ) and at least one memory (eg, the memory 104 ). Additionally and / or alternatively, the memory 104 may be located outside the processing chip 101 .

[0061] The processor 102 may control the memory 104 and / or the transceiver 106, and may be adapted to implement the descriptions, functions, processes, suggestions, methods, and / or operational flow charts described in the present disclosure. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then send a radio signal including the first information / signals through the transceiver 106. The processor 102 may receive a radio signal including second information / signals through the transceiver 106, and then store information obtained by processing the second information / signals in the memory 104.

[0062] The memory 104 may be operably connected to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store firmware and / or software code 105 that implements codes, commands, and / or command sets that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 105 may control the processor 102 to execute one or more protocols. For example, the firmware and / or software code 105 may control the processor 102 to execute one or more layers of a radio interface protocol.

[0063] In this document, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0064] The second wireless device 200 may include at least one transceiver (eg, transceiver 206 ), at least one processing chip (eg, processing chip 201 ), and / or one or more antennas 208 .

[0065] The processing chip 201 may include at least one processor (eg, the processor 202 ) and at least one memory (eg, the memory 204 ). Additionally and / or alternatively, the memory 204 may be located outside the processing chip 201 .

[0066] The processor 202 may control the memory 204 and / or the transceiver 206, and may be adapted to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts described in the present disclosure. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then send a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 106, and then store the information obtained by processing the fourth information / signals in the memory 204.

[0067] The memory 204 may be operably connected to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store firmware and / or software code 205 that implements codes, commands, and / or command sets that, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 205 may control the processor 202 to execute one or more protocols. For example, the firmware and / or software code 205 may control the processor 202 to execute one or more layers of a radio interface protocol.

[0068] In this document, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0069] In the following, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by one or more processors 102 and 202, but are not limited thereto. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP) layer). The one or more processors 102 and 202 may generate one or more protocol data units (PDUs), one or more service data units (SDUs), messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. The one or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, function, procedure, suggestion, method, and / or operational flowchart disclosed in the present disclosure, and provide the generated signal to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from the one or more transceivers 106 and 206, and obtain the PDU, SDU, message, control information, data, or information according to the description, function, procedure, suggestion, method, and / or operational flowchart disclosed in the present disclosure.

[0070] The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs) or one or more field programmable gate arrays (FPGAs) may be included in the one or more processors 102 and 202. For example, the one or more processors 102 and 202 may be configured by a collection of a communication control processor, an application processor (AP), an electronic control unit (ECU), a central processing unit (CPU), a graphics processing unit (GPU) and a memory control processor.

[0071] The one or more memories 104, 204 may be associated with the one or more processors 102, 202 and may store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The one or more memories 104, 204 may include random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), erasable programmable ROM (EPROM), flash memory, volatile memory, non-volatile memory, hard drive, register, cache memory, computer-readable storage medium and / or a combination thereof. The one or more memories 104, 204 may be located inside and / or outside the one or more processors 102, 202. In addition, the one or more memories 104, 204 may be connected to the one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0072] The one or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the description, features, processes, suggestions, methods, and / or operation flow charts disclosed herein to one or more other devices. The one or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, features, processes, suggestions, methods, and / or operation flow charts disclosed herein from one or more other devices. For example, the one or more transceivers 106, 206 may be associated with the one or more processors 102, 202 and may send and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to send user data, control information, wireless signals, etc. to one or more other devices. In addition, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, wireless signals, etc. from one or more other devices.

[0073] The one or more transceivers 106, 206 may be coupled to one or more antennas 108, 208. Additionally and / or alternatively, the one or more transceivers 106, 206 may include one or more antennas 108, 208. The one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, features, processes, suggestions, methods, and / or operational flow charts disclosed herein via the one or more antennas 108, 208. As used herein, the one or more antennas 108, 208 may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0074] The one or more transceivers 106, 206 may convert received user data, control information, radio signals / channels, etc. from RF band signals to baseband signals so as to process the received user data, control information, radio signals / channels, etc. using the one or more processors 102, 202. The one or more transceivers 106, 206 may convert the processed user data, control information, radio signals / channels, etc. from baseband signals to RF band signals using the one or more processors 102, 202. To this end, the one or more transceivers 106, 206 may include (analog) oscillators and / or filters. For example, the one or more transceivers 106, 206 may up-convert an OFDM baseband signal into an OFDM signal via an (analog) oscillator and / or a filter under the control of the one or more processors 102, 202, and transmit the up-converted OFDM signal at a carrier frequency. The one or more transceivers 106 , 206 may receive an OFDM signal at a carrier frequency and, under the control of the one or more processors 102 , 202 , down-convert the OFDM signal via an (analog) oscillator and / or a filter to an OFDM baseband signal.

[0075] although Figure 2 1 , the wireless devices 100 and 200 may further include additional components. The additional components 140 may be configured differently depending on the type of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power supply unit / battery, an input / output (I / O) device (e.g., an audio I / O port, a video I / O port), a drive device, and a computing device. The additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies such as a wired or wireless connection.

[0076] In an implementation of the present disclosure, a UE may operate as a transmitting device in an uplink (UL) and as a receiving device in a downlink (DL). In an implementation of the present disclosure, a BS may operate as a receiving device in an UL and as a transmitting device in a DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device 100 acts as a UE and the second wireless device 200 acts as a BS. For example, a processor 102 connected to, installed on, or started in the first wireless device 100 may be adapted to perform UE behavior according to an implementation of the present disclosure or control a transceiver 106 to perform UE behavior according to an implementation of the present disclosure. A processor 202 connected to, installed on, or started in the second wireless device 200 may be adapted to perform BS behavior according to an implementation of the present disclosure or control a transceiver 206 to perform BS behavior according to an implementation of the present disclosure.

[0077] In this disclosure, a BS is also referred to as a Node B (NB), an eNode B (eNB), or a gNB.

[0078] Figure 3 An example of a UE to which an implementation of the present disclosure is applied is shown.

[0079] Figure 3 An example of a UE to which an implementation of the present disclosure is applied is shown.

[0080] Reference Figure 3 , UE 100 may correspond to Figure 2 A first wireless device 100 is provided.

[0081] UE 100 includes a processor 102 , a memory 104 , a transceiver 106 , one or more antennas 108 , a power management module 141 , a battery 142 , a display 143 , a keypad 144 , a subscriber identity module (SIM) card 145 , a speaker 146 , and a microphone 147 .

[0082] The processor 102 may be adapted to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor 102 may be an application processor. The processor 102 may include at least one of a DSP, a CPU, a GPU, a modem (modulator and demodulator). Examples of the processor 102 can be found at MANUFACTURED BY SNAPDRAGON TM Series processors, Manufactured by EXYNOS TM Series processors, A series of processors manufactured by Made by HELIO TM Series processors, ATOM manufactured TM series processors or corresponding to the next generation processors.

[0083] The memory 104 is operatively coupled to the processor 102 and stores various information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium, and / or other storage devices. When the embodiment is implemented in software, the techniques described herein may be implemented using modules (e.g., procedures, functions, etc.) that execute the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. The modules may be stored in the memory 104 and executed by the processor 102. The memory 104 may be implemented within the processor 102 or external to the processor 102, in which case these may be communicatively coupled to the processor 102 via various means known in the art.

[0084] The transceiver 106 is operatively connected to the processor 102 and transmits and / or receives radio signals. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include a baseband circuit to process radio frequency signals. The transceiver 106 controls one or more antennas 108 to transmit and / or receive radio signals.

[0085] The power management module 141 manages the power of the processor 102 and / or the transceiver 106. The battery 142 provides power to the power management module 141.

[0086] The display 143 outputs a result processed by the processor 102. The keypad 144 receives an input to be used by the processor 102. The keypad 144 may be displayed on the display 143.

[0087] The SIM card 145 is an integrated circuit designed to securely store the International Mobile Subscriber Identity (IMSI) number and its associated keys used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0088] The speaker 146 outputs sound related results processed by the processor 102. The microphone 147 receives sound related input to be used by the processor 102.

[0089] Figure 4 An example 5G system structure is illustrated to which implementations of the present specification may be applied.

[0090] The 5G system (5GS; 5G system) structure consists of the following network functions (NFs).

[0091] -AUSF (Authentication Server Function)

[0092] -AMF (Access and Mobility Management Function)

[0093] - DN (Data Network), such as operator service, Internet access, or third-party service

[0094] -USDF (Unstructured Data Storage Function)

[0095] -NEF (Network Exposure Function)

[0096] -I-NEF (Intermediate NEF)

[0097] -NRF (Network Repository Function)

[0098] -NSSF (Network Slice Selection Function)

[0099] -PCF (Policy Control Function)

[0100] -SMF (Session Management Function)

[0101] -UDM (Unified Data Management)

[0102] -UDR (Unified Data Repository)

[0103] -UPF (User Plane Function)

[0104] -UCMF (UE Radio Capability Management Function)

[0105] -AF(Application Function)

[0106] -UE (User Equipment)

[0107] -(R)AN ((Radio) Access Network)

[0108] -5G-EIR (5G Equipment Identity Register)

[0109] -NWDAF (Network Data Analysis Function)

[0110] -CHF (billing function)

[0111] In addition, the following network functions can be considered.

[0112] -N3IWF (Non-3GPP Interworking Function)

[0113] -TNGF (Trusted Non-3GPP Gateway Function)

[0114] -W-AGF (wired access gateway function)

[0115] Figure 4 The 5G system architecture for a non-roaming case represented using reference points is shown, which shows how the various network functions interact with each other.

[0116] exist Figure 4 In the figure, for the clarity of the point-to-point diagram, UDSF, NEF and NRF are not described. However, all network functions shown can interact with UDSF, UDR, NEF and NRF as needed.

[0117] For clarity, Figure 4 The connections between the UDR and other NFs (e.g., PCF) are not shown in FIG. Figure 4 The connection between NWDAF and other NFs (eg, PCF) is not shown.

[0118] The 5G system architecture includes the following reference points.

[0119] -N1: Reference point between UE and AMF.

[0120] -N2: Reference point between (R)AN and AMF.

[0121] -N3: Reference point between (R)AN and UPF.

[0122] -N4: Reference point between SMF and UPF.

[0123] -N6: Reference point between UPF and data network.

[0124] -N9: Reference point between two UPFs.

[0125] The following reference points illustrate the interactions that exist between NF services in a NF.

[0126] -N5: Reference point between PCF and AF.

[0127] -N7: Reference point between SMF and PCF.

[0128] -N8: Reference point between UDM and AMF.

[0129] -N10: Reference point between UDM and SMF.

[0130] -N11: Reference point between AMF and SMF.

[0131] -N12: Reference point between AMF and AUSF.

[0132] -N13: Reference point between UDM and AUSF.

[0133] -N14: Reference point between two AMFs.

[0134] -N15: Reference point between the PCF and AMF in case of non-roaming scenario, and between the PCF and AMF of the visited network in case of roaming scenario.

[0135] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network).

[0136] - N22: Reference point between the AMF and the NSSF.

[0137] In some cases, it may be necessary to connect two NFs to each other to serve the UE.

[0138] <C2 Communication>

[0139] C2 communication is a user plane link that conveys messages containing command and control information regarding the operation of the UAV from the UAV controller or Unmanned Aerial System Service Management (UAS Service Management) to the UAV or reports telemetry data from the UAV to its UAV controller or the UTM.

[0140] When using the 3GPP network as the transport network to support UAS services, consider the following C2 communications to provide UAS services by ensuring the QoS of C2 communications:

[0141] Direct C2 communication: The UAV controller and the UAV establish a direct C2 link to communicate with each other, and both use the radio resources configured and scheduled by the 5G network for direct C2 communication to register with the 5G network.

[0142] Network-assisted C2 communication: The UAV controller and the UAV register with the 5G network and establish corresponding unicast C2 communication links and communicate with each other via the 5G network. Additionally, both the UAV controller and the UAV can register with the 5G network via different NG-RAN nodes. The 5G network needs to support a mechanism for handling reliable routing of C2 communications.

[0143] UTM navigation C2 communication: The UAV has been provided with a pre-arranged flight plan (e.g., a 4D polygon array) for autonomous flight. However, the UTM still maintains a C2 communication link with the UAV to periodically monitor the UAV's flight status, verify the flight status against the latest dynamic restrictions, provide route updates, and navigate the UAV if necessary.

[0144] Generally, direct C2 communication and network-assisted C2 communication are used by a human operator using the UAV controller. The UTM uses UTM navigation C2 communication to provide a clear flight route and route updates. To ensure the service availability and reliability of C2 communications for UAS operations, especially when the UAV is flying beyond the line of sight (BLOS) of the operator, redundant C2 communication links can be established for any C2 communication link from the UAV controller or the UTM to the UAV.

[0145] For reliability and service availability considerations, more than one C2 communication can be enabled, one of which serves as a backup link for C2 communication, or switches between applicable C2 communication links.

[0146] - For example, direct C2 communications may be used initially, and then switch to network-assisted C2 communications while the UAV BLOS is flying.

[0147] - For example, UTM navigation C2 communications can be used when needed, such as for air traffic control, when the UAV is approaching a no-drone zone, and when a potential security threat is detected.

[0148] Four control modes are considered in C2 communications for UAV operations, which have different requirements on message interval, size, and end-to-end latency, including steering waypoints, direct joystick steering, autonomous flight via UTM, and proximity to autonomous navigation infrastructure.

[0149] - Steering to waypoint: The control message contains the flight declaration (eg, waypoint) sent from the UAV controller or UTM to the UAV. This control mode is used for both direct C2 communication and network-assisted C2 communication.

[0150] - Direct Joystick Steering: Control messages contain direction instructions sent from the UAV controller to the UAV, while optionally providing video traffic from the UAV to the UAV controller as feedback. This control mode is used for both direct C2 communication and network-assisted C2 communication.

[0151] -Automatic flight via UTM: Control messages contain a pre-arranged flight plan (e.g., 4D polygon array) sent from UTM to the UAV, after which the UAV flies autonomously with periodic position reporting. This control mode is used for UTM navigation C2 communications.

[0152] - Close to autonomous navigation infrastructure: Control messages contain directional instructions (e.g., waypoints, altitude, and speed) from the UTM to the UAV. When the UAV is landing / taking off, the UTM coordinates more closely with the autonomous navigation infrastructure (e.g., a vertiport or package distribution center). This control mode is used for UTM navigation C2 communications.

[0153] C2 communication via PC5 may be used to implement the above-mentioned direct C2 communication.

[0154] V2X (Vehicle to Everything) communication will be described. For V2X communication, the following definitions may be used:

[0155] - V2X Application: An application that uses one or more V2X services (e.g., active safety applications for vehicles, emergency warnings, vehicle safety and awareness, etc.) V2X applications may operate against a V2X application server.

[0156] -V2X Communications: Communications that support V2X services using Uu and / or PC5 reference points. V2X services are enabled through various types of V2X applications such as vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I) and vehicle-to-network (V2N).

[0157] - V2X messages: Dedicated message types used for V2X services (e.g. Intelligent Transportation System (ITS) messages).

[0158] -V2X service: A data service provided to a V2X application and optionally to a V2X application server. A V2X service belongs to a V2X service type. A V2X service is connected to one or more V2X applications, and a V2X application can be connected to one or more V2X services.

[0159] - V2X Service Type: V2X service type identified by ITS-AID (ITS Application Identifier) ​​or PSID (Provider Service Identifier).

[0160] There are two operation modes for V2X communication: V2X communication via PC5 reference point and V2X communication via Uu reference point. These two operation modes can be used by UE independently for transmission and reception.

[0161] V2X communications via the PC5 reference point are supported by LTE and / or NR.

[0162] V2X communication via the Uu reference point is supported by E-UTRA connected to 5GC and / or NR connected to 5GC. V2X communication via the Uu reference point may be unicast only.

[0163] <Layer 2 Link Establishment via PC5 Reference Point>

[0164] Figure 5a and Figure 5b The layer 2 link establishment process is illustrated.

[0165] 1. The UE determines the destination layer 2 ID for receiving PC5 unicast link establishment signaling.

[0166] 2. The ProSe application layer of UE-1 provides application information for PC5 unicast communication. The application information includes ProSe service information (application layer ID of the UE). The application layer ID of the target UE may be included in the application information.

[0167] The ProSe application layer of UE-1 may provide the ProSe application requirements for the unicast communication. UE-1 determines the PC5 QoS parameters and PFI.

[0168] If UE-1 decides to reuse the existing PC5 unicast link, the UE triggers the Layer 2 Link Modification procedure.

[0169] 3. UE-1 sends a direct communication request message to initiate the unicast layer 2 link establishment procedure. The direct communication request message contains the following information.

[0170] - Source user information: the application layer ID of the originating UE (ie, the application layer ID of UE-1).

[0171] - If the ProSe application layer has provided the application layer ID of the target UE in step 2, it contains the following information.

[0172] - Target user information: Application layer ID of the target UE (ie, the application layer ID of UE-2).

[0173] -ProSe service information: Information about the ProSe identifier requesting Layer 2 link establishment.

[0174] - Security information: Information used for security settings

[0175] The source layer 2 ID and the target layer 2 ID are used to send the direct communication request message. The destination layer 2 ID can be a broadcast or unicast layer 2 ID. If a unicast layer 2 ID is used, the target user information must be included in the direct communication request message.

[0176] UE-1 sends a direct communication request message via PC5 by broadcast or unicast using the source layer 2ID and the target layer 2ID.

[0177] The default PC5 DRX settings can be used to send and receive this message.

[0178] 4. Security with UE-1 is set as follows.

[0179] 4a. If the direct communication request message contains target user information, the target UE (ie, UE-2) responds by establishing security with UE-1.

[0180] 4b. If the direct communication request message does not contain target user information, the UE interested in using the ProSe service announced via the PC5 unicast link with UE-1 should respond by establishing security with UE-1.

[0181] If security protection is enabled, UE-1 sends the following information to the target UE.

[0182] If IP communication is used, the following information is sent to the destination UE.

[0183] -IP address configuration: For IP communication, this link requires IP address configuration, indicating one of the following values: "DHCPv4 server" if the initiating UE only supports IPv4 addressing mechanism, that is, if it acts as a DHCPv4 server; or "IPv6 router" if the initiating UE only supports IPv6 addressing mechanism, that is, if it acts as an IPv6 router; or "DHCPv4 server and IPv6 router" if the initiating UE supports both IPv4 and IPv6 addressing mechanisms; or "address assignment not supported" if the initiating UE supports neither IPv4 nor IPv6 addressing mechanism.

[0184] - Link-local IPv6 address: When UE-1 does not support the IPv6 IP addressing mechanism, that is, when the IP address setting indicates "address assignment not supported", a locally formed link-local IPv6 address based on RFC 4862.

[0185] - When security protection is enabled, UE-1 sends QoS information to the destination UE.

[0186] QoS Information: Information about PC5 QoS flows. For each PC5 QoS flow, PFI and corresponding PC5 QoS parameters (i.e., PQI and conditionally other parameters, such as MFBR / GFBR, etc.).

[0187] - When security protection is enabled, UE-1 sends optional PC5 QoS rules to the destination UE.

[0188] The source layer 2 ID is used for the security setup process. The destination layer 2 ID is set to the source layer 2 ID of the received direct communication request message.

[0189] Upon receiving the Security Setup Procedure message, UE-1 obtains the Layer 2 ID of the peer UE for future communication of signaling and data traffic on the unicast link.

[0190] 5. The destination UE that has successfully established security with UE-1 sends a direct communication accept message to UE-1.

[0191] 5a. (Layer 2 link establishment towards UE) If the direct communication request message contains target user information, the target UE (ie, UE-2) shall respond with a direct communication accept message if the application layer ID of UE-2 matches.

[0192] 5b. (Layer 2 Link Establishment for ProSe Services) If the Direct Communication Request message does not contain target user information, the UEs interested in using the announced ProSe services shall respond to the request by sending Direct Communication Accept messages (UE-2 and UE-4).

[0193] The direct communication acceptance message should contain the following contents.

[0194] -Source user information: the application layer ID of the UE that sends the direct communication acceptance message.

[0195] -QoS information: Information about PC5 QoS flows. For each PC5 QoS flow, the PFI requested by UE-1 and the corresponding PC5 QoS parameters (ie, PQI and conditionally other parameters, such as MFBR / GFBR, etc.) and optionally the related ProSe identifier.

[0196] -Optional PC5 QoS rules.

[0197] - If using IP communication:

[0198] -IP Address Configuration: IP communication requires IP address configuration for this link and indicates one of the following values.

[0199] - "DHCPv4 Server" if the destination UE supports only IPv4 addressing mechanism, i.e. it acts as a DHCPv4 server; or

[0200] - "IPv6 Router" if the target UE supports only IPv6 addressing mechanisms, i.e. it acts as an IPv6 router; or

[0201] - "DHCPv4 server and IPv6 router" if the target UE supports both IPv4 and IPv6 addressing mechanisms; or

[0202] - "Address assignment not supported" if the destination UE supports neither IPv4 nor IPv6 address assignment mechanisms.

[0203] - Link-local IPv6 address: When the target UE does not support the IPv6 IP addressing mechanism, that is, when the IP address configuration indicates "address assignment not supported", a locally formed link-local IPv6 address based on RFC 4862, and UE-1 may include the link-local IPv6 address in the direct communication request message. The destination UE shall include a non-conflicting link-local IPv6 address.

[0204] If both UEs (ie, the originating UE and the destination UE) choose to use link-local IPv6 addresses, duplicate address detection as defined in RFC 4862 must be disabled.

[0205] If the initiating UE or the target UE indicates IPv6 routing support, the corresponding addressing procedure is performed after the layer 2 link is established and the link-local IPv6 address is ignored.

[0206] The ProSe layer of the UE that establishes a PC5 unicast link forwards the PC5 link identifier assigned to the unicast link and the PC5 unicast link related information to the AS layer. The PC5 unicast link related information includes layer 2 ID information (i.e., source layer 2 ID and destination layer 2 ID). This allows the AS layer to maintain the PC5 link identifier together with the PC5 unicast link related information.

[0207] Two UEs can negotiate the PC5 DRX settings of the AS layer, and can set the PC5 DRX parameter values for each pair of source and destination layer 2 IDs of the AS layer.

[0208] 6. ProSe data is sent via the unicast link set as shown below.

[0209] The PC5 link identifier and PFI are provided to the AS layer together with the ProSe data.

[0210] Optionally, additional layer 2 ID information (i.e., source layer 2 ID and target layer 2 ID) is provided to the AS layer.

[0211] The UE implementation is designed to provide layer 2 identification information to the AS layer.

[0212] UE-1 uses the source layer 2 ID (i.e., the layer 2 ID of this unicast link of UE-1) and the destination layer 2 ID (i.e., the layer 2 ID of this unicast link of the peer UE) to send ProSe data.

[0213] Since the PC5 unicast link is bidirectional, the peer UE of UE-1 can send ProSe data to UE-1 via the unicast link with UE-1.

[0214] <Handoff between PC5 and Uu>

[0215] Figure 6 Scenarios showing the handoff of the direct communication path between PC5 and Uu are presented.

[0216] The direct communication path handoff scenario between PC5 and Uu refers to Figure 6 the handoff between (a) the Uu path and (b) the PC5 path in

[0217] "Direct communication path handoff between the PC5 and Uu reference points" refers to the process of handoff between the Uu direct communication path and the PC5 direct communication path when the UE communicates with other UEs. The direct communication path via the PC5 reference point means performing communication with other UEs only using 5G ProSe direct communication. The direct communication path via the Uu reference point means performing communication with other UEs via the network.

[0218] <Disclosure of this specification>

[0219] The proposed method of supporting C2 connection may consist of a combination of one or more of the following behaviors / configurations / steps.

[0220] In this specification, C2 communication and C2 connection are used interchangeably.

[0221] In this specification, user equipment (UE) and terminal may be described interchangeably.

[0222] This description focuses on the proposal.

[0223] The method for supporting C2 connection proposed in this specification can be extended / changed and applied not only to UAS services but also to other services (e.g., ProSe services, V2X services, etc.) In this case, C2 communication / C2 connection can be interpreted interchangeably as communication / connection between two UEs.

[0224] This specification may provide a method of addressing a C2 connection via PC5.

[0225] The unmanned aerial vehicle (UAV) and the unmanned aerial vehicle controller (UAV-C) may communicate with each other via a C2 connection via PC5. There may be situations where the signal strength / condition of the C2 connection via PC5 is weak or degraded. For example, due to an obstacle between the two UEs, they may be separated from each other.

[0226] The UE may measure the PC5 signal strength on the unicast link. Therefore, it may be considered useful to provide the application layer with the signal strength / status (e.g., strong / good, weak / poor) of the C2 connection via PC5. The PC5 signal strength of the unicast link measured by the UE may be provided to the application layer at the UE.

[0227] In particular, this information is beneficial to the UAV-C so that the user (e.g., drone pilot) knows the status of the C2 connection and can decide what to do with the C2 communication. For example, the UAV-C can switch to the C2 connection via the network, or can disconnect from the C2 connection after the UAV lands. To help the UAV-C (or user) determine what to do with the C2 communication, an indication of whether the C2 connection via the network is available can also be provided in the application layer of the UAV-C.

[0228] The layer of the UAV-C that collects the above-mentioned C2 connection related information (i.e., C2 connection state information) in the above-mentioned method and provides it to the application may be referred to as a "UAS layer". In the context of the UAS, the UAS layer may perform PC5-related operations related to operations performed by the V2X layer and the ProSe layer in the respective contexts of V2X and ProSe.

[0229] The UAS layer may also be referred to by other names (eg, U2X (UAV to Everything) layer, UAV layer, etc.).

[0230] The application layer of the UAV-C may request the UAS layer to switch to or disconnect from the C2 connection via the network. For example, these requests may be based on the C2 connection state information provided by the UAS layer.

[0231] It may be assumed that the UAV and UAV-C support C2 communication via PC5 and C2 communication via the network. Alternatively, if the UAV and UAV-C do not support C2 communication via the network, switching to the C2 connection via the network may not be performed, and providing information indicating whether the C2 connection via the network is available to the application layer may not be performed.

[0232] The following figures are intended to illustrate specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals / messages / fields depicted in the figures are only for illustration, and the technical features of the present disclosure are not limited to the specific names used in the figures.

[0233] Figure 7 The disclosed embodiments according to the present specification are illustrated.

[0234] 1. For C2 communication via PC5 reference point (ie, C2 connection via PC5), UE-1 (UAV-C) and UE-2 (UAV) may establish a layer 2 link. UE-1 and UE-2 may communicate with each other via the C2 connection through PC5.

[0235] The Layer 2 link establishment process can be referred to Figure 5a and Figure 5b .

[0236] 2. The UAS layer of UE-1 may provide C2 connection status information to the application layer. Such provision of C2 connection status information may be performed periodically. Alternatively, the provision of C2 connection status information may be performed based on the measured PC5 signal strength of the unicast link being less than a set signal strength threshold.

[0237] C2 connection status information may include the following:

[0238] a) Signal strength / status of the C2 connection via PC5 (e.g., strong / good, weak / poor)

[0239] If the measured PC5 signal strength of the unicast link is less than (or equal to) the configured signal strength threshold, the signal strength / state of the C2 connection via PC5 may be set to weak / poor. Alternatively, based on the measured PC5 signal strength of the unicast link, the signal strength / state (strong / good or weak / poor) of the C2 connection via PC5 may be set in an implementation manner. For example, the signal strength / state of the C2 connection may be set in the form of a level (e.g., 1, 2, 3, where the larger the number, the better) or high / medium / low, etc. After the UAS layer of UE-1 notifies the application layer that the signal strength / state of the C2 connection via PC5 is weak / poor, the UAS layer of UE-1 may notify the application layer when the signal strength / state of the C2 connection via PC5 becomes strong / good. The UAS layer may receive one or more of the following information from the access layer (AS) layer: the measured PC5 signal strength information of the unicast link, indicating that the measured PC5 signal strength information of the unicast link is less than (or equal to) the set signal strength threshold.

[0240] b) An indication of whether a C2 connection via the network is available.

[0241] Whenever the signal strength / status of the above-mentioned C2 connection via PC5 is provided to the application layer, an indication of whether the C2 connection via the network is available can be provided. Alternatively, only when the signal strength / status of the C2 connection via PC5 is weak / poor, an indication of whether the C2 connection via the network is possible can be provided to the application layer.

[0242] The indication of whether a C2 connection via the network is possible may be information about whether it is possible or not. Alternatively, the indication may be provided via b) only when a C2 connection via the network is possible, and b) may not be provided if a C2 connection via the network is not possible. Conversely, b) may indicate that a C2 connection via the network is not possible, and b) may not be provided if a C2 connection via the network is possible.

[0243] Through b), the application layer can infer / identify whether a C2 connection via the network (or switching to a C2 connection via the network) is possible.

[0244] To determine a), UE-1 may measure the PC5 signal strength of the unicast link established with UE-2 (i.e., the C2 connection via PC5). These measurements may be performed periodically. The signal strength / status of the unicast link may be an indication of link quality or whether QoS is met. Alternatively, whether QoS is met may be provided as separate information.

[0245] For the signal strength measurement of unicast links, reference may be made to the content of signal strength measurement of unicast links performed by remote UE for UE selection / reselection of network relays defined in TS24.554V1.2.0 and TS 38.300V17.0.0. For example, what the remote UE measures may be understood by replacing / extending what the UAV-C measures.

[0246] Basically, UE-1 can measure the PC5 signal strength from the traffic, PC5-S message, PC5 discovery message (etc.) sent by UE-2.

[0247] To determine b), UE-1 may request information from UE-2 about whether UE-2 has a network connection for a C2 connection. Alternatively, UE-2 may provide UE-1 with information about whether UE-2 can connect to the network for a C2 connection. UE-2 may (periodically) measure the PC5 signal strength of the unicast link with UE-1, and if the measured PC5 signal strength is below a configured threshold, UE-2 may provide UE-1 with information about whether UE-2 can connect to the network for a C2 connection. Then, based on whether both UE-1 and UE-2 can connect to the network for a C2 connection, UE-1 may determine whether a C2 connection via the network is possible.

[0248] In contrast, UE-1 can infer / determine whether UE-2 can connect to the network for C2 connection without providing information from UE-2 (for example, based on the location of UE-2 provided by the network, a C2 connection has been established with UE-2 via the network (however, actual C2 communication or exchange of C2-related services is being performed through the C2 connection via PC5), a connection other than the C2 connection via the network has been established, etc.). In the above, the existing PC5-S message can be extended and used, or a new PC5-S message can be defined and used, so that UE-1 can obtain information from UE-2 (regarding whether UE-2 can connect to the network for C2 connection).

[0249] The fact that the UE is able to connect to the network can be interpreted in many different ways, such as attaching / registering with the EPC / 5GC, being within the coverage of the network, being able to select a cell, creating a PDN connection / PDU session, being able to connect to a data network, being able to connect to the Internet, being able to communicate with a UAS service provider (USS), performing / completed USS UAV authorization / authentication (UUAA), performing / completed authorization of C2, etc.

[0250] UE-1 may determine that both it and UE-2 must be network-reachable to establish a C2 connection via the network. Alternatively, if UE-2 is network-reachable, UE-1 may determine that a C2 connection via the network is possible.

[0251] UE-1 and UE-2 may negotiate the above-mentioned C2 connection state information (or b) during layer 2 link formation and / or modification, or UE-1 may inform or request UE-2.

[0252] Whether and how the UE acting as a UAV-C will provide C2 link status information to the application layer (e.g., periodically or based on events) may be provided to the UE as a policy / parameter for C2 communication. In addition, the set signal strength threshold may be provided to the UE as a policy / parameter for C2 communication, or may be provided to the UE via the RAN. Alternatively, the set signal strength threshold may be implementation-specific information / value of the UE.

[0253] In addition, whether any C2 connection state information should be provided can also be provided to the UE as part of the policy / parameters for C2 communication. Providing b) to the application layer can be based on information indicating that a C2 connection via the network is allowed / authorized (or switched to a C2 connection via the network). In addition, providing the C2 connection state information to the application layer can be based on UE implementation, or can be based on user settings / requests.

[0254] As part of the policy / parameters of the above-mentioned C2 communication, the method provided to the UE may refer to the authorization and provision method for V2X services defined in TS23.287 V17.2.0 and the authorization and provision method for ProSe services defined in TS23.304 V17.2.1. That is, as part of the policy / parameters of the above-mentioned C2 communication, various methods may be used (e.g., provided in the mobile equipment (ME) of the UE, set in the UICC of the UE, provided / changed by the application server for the UE; provided / changed by the application server for the UE via the PCF; provided / changed by the PCF for the UE).

[0255] 3. The application layer of UE-1 may request the UAS layer to switch to or disconnect from the C2 connection via the network. Such a switching or disconnection request of UE-1 may be performed based on the C2 connection state information provided by the UAS layer.

[0256] Steps 2 and 3 may involve user interaction, which may be beyond the scope of this description.

[0257] 4. UE-1 may determine whether to switch to or disconnect from the C2 connection via the network. The determination of UE-1 may be based on the request from the application layer in step 3. Alternatively, the determination of UE-1 may be based on the measured PC5 signal strength of the unicast link being lower than a configured threshold (which may be regarded as a state / quality degradation of the unicast link or a situation where QoS cannot be met).

[0258] If the measured PC5 signal strength of the unicast link is below the configured threshold, UE-1 may determine whether to perform a handover to a C2 connection via the network or a C2 disconnection even if no handover or disconnection request from the application layer is provided in step 3. This determination may be made based on the policy / parameters of the C2 communication provided to UE-1 or based on the UE implementation.

[0259] In step 3, if there is no request from the application layer and the measured PC5 signal strength on the unicast link is not lower than the configured threshold, UE-1 may maintain and continue to use the C2 connection via PC5.

[0260] A) If UE-1 determines to perform handover from the C2 connection via PC5 to the C2 connection via the network, step 5 and step 6 may be performed.

[0261] 5. If UE-1 and UE-2 have not yet attached to the EPC or registered with the 5GC, they may attach to the EPC or register with the 5GC. In addition, if UE-1 and UE-2 have not yet established a PDN association or PDU session for C2 communication, they may do so. UE-2 may also require authorization and UUAA (USS UAV Authorization / Authentication) from C2.

[0262] UE-1 may not need to perform EPC attachment / 5GC registration and PDN connection / PDU session establishment for UE-2 in order to facilitate C2 communication with UE-2 via the network. Alternatively, only EPC attachment / 5GC registration may be performed. UE-1 may connect to the network without using PDN connection / PDU session (e.g., connecting to the network via WiFi / WLAN, etc.).

[0263] UE-1 and UE-2 may perform a handover from a C2 connection via PC5 to a C2 connection via the network. A path switch may be performed. The handover may be performed using a PC5-S message.

[0264] The existing PC5-S message may be extended and used for the PC5-S message, or a new PC5-S message (eg, path switch request / authorization) may be defined and used for the PC5-S message. Alternatively, for the switching process, a method of switching a path between PC5 and Uu may be performed.

[0265] UE-1 and UE-2 may communicate with each other through a C2 connection via the network.

[0266] Once the switch to the C2 connection via the network is completed, the application layer may be informed of this fact.

[0267] 6. The unicast link between UE-1 and UE-2 may be released.

[0268] B) If UE-1 determines to perform C2 disconnection, step 7 may be executed.

[0269] 7. The unicast link between UE-1 and UE-2 may be released.

[0270] The release of the unicast link between UE-1 and UE-2 in step 6 and step 7 may be performed on a per-area basis.

[0271] In the above-mentioned C2 connection state information, providing an indication to the application layer whether a C2 connection via the network is possible and performing a switch to the C2 connection via the network may be performed based on a UE supporting it, or based on an allowed / authorized C2 connection via the network (or a switch to a C2 connection via the network). The permission / authorization information may be provided to the UE as part of a policy / parameter for C2 communication.

[0272] The policies / parameters of C2 communication can be interpreted as policies / parameters for UAS services, UAS-related behaviors, or PC5-related behaviors of the UE. Providing these policies / parameters to the UE can refer to the authorization and provision methods defined in TS23.287 V17.2.0 and TS23.304 V17.2.1.

[0273] The C2 connection via the above network may also mean the C2 connection via Uu / LTE-Uu / NR-Uu.

[0274] Although the present specification describes the UAV-C performing actions such as measuring the PC5 signal strength of the unicast link with the UAV, providing C2 connection status information to the application layer, and determining to switch to or disconnect the C2 connection via the network, the UAV may perform these actions instead. In this case, it may be assumed that there is no user interaction.

[0275] Figure 8 A process of a first UE according to the disclosure of this specification is shown.

[0276] 1. The first UE may perform C2 communication with the second UE through a C2 (Command and Control) connection via PC5.

[0277] 2. The first UE may measure the signal strength of the C2 connection via PC5.

[0278] 3. The first UE may send C2 connection state information from the UAS (Unmanned Aerial System) layer of the first UE to the application layer of the first UE.

[0279] The C2 connection state information may include information on the measured signal strength of the C2 connection via the PC 5 .

[0280] 4. The first UE may determine whether to i) switch from the C2 connection via the PC5 to the C2 connection via the network or ii) disconnect the C2 connection via the PC5 based on a request from the application layer of the first UE based on the C2 connection state information.

[0281] The first UE may be a UAV-C (Unmanned Aerial Vehicle - Controller) and the second UE may be a UAV.

[0282] The step of sending the C2 connection status information may be performed based on the measured signal strength being lower than a threshold.

[0283] The first UE may receive a configuration from the base station.

[0284] The configuration may include a threshold value.

[0285] The C2 connection state information may include whether the first UE can perform a C2 connection via the network.

[0286] The C2 connection state information may include the quality of the C2 connection via the PC 5 or whether the QoS (Quality of Service) of the C2 connection via the PC 5 is satisfied.

[0287] The first UE may request the second UE for information on whether the second UE can perform a C2 connection via a network.

[0288] The first UE may receive information from the second UE whether the second UE may perform a C2 connection via the network.

[0289] The C2 connection state information may include information on whether the second UE can perform a C2 connection via the network.

[0290] Fig. 9 The process of the base station according to the disclosure of this specification is shown.

[0291] 1. The base station may send a configuration to the first UE (User Equipment).

[0292] The configuration may include a threshold value.

[0293] The first UE may perform C2 (Command and Control) communication with the second UE through a C2 connection via the PC5.

[0294] The first UE may measure the signal strength of the C2 connection via PC5.

[0295] The UAS (Unmanned Aerial System) layer of the first UE may send the C2 connection state information to the application layer of the first UE.

[0296] The C2 connection state information may include information on the measured signal strength of the C2 connection via the PC 5 .

[0297] The first UE may determine whether to i) switch from the C2 connection via the PC 5 to the C2 connection via the network or ii) disconnect the C2 connection via the PC 5 based on a request from the application layer of the first UE based on the C2 connection state information.

[0298] The first UE may be a UAV-C (Unmanned Aerial Vehicle - Controller) and the second UE may be a UAV.

[0299] The sending of the C2 connection state information may be performed based on the measured signal strength being lower than a threshold. The C2 connection state information may include whether the first UE can perform a C2 connection via the network.

[0300] The C2 connection state information may include the quality of the C2 connection via the PC 5 or whether the QoS (Quality of Service) of the C2 connection via the PC 5 is satisfied.

[0301] The first UE may request the second UE for information on whether the second UE can perform a C2 connection via a network.

[0302] The first UE may receive information from the second UE whether the second UE may perform a C2 connection via the network.

[0303] The C2 connection state information may include information on whether the second UE can perform a C2 connection via the network.

[0304] Hereinafter, an apparatus for performing communication according to some embodiments of the present specification will be described.

[0305] For example, the first UE may include a processor, a transceiver, and a memory.

[0306] For example, a processor may be configured to be operatively coupled to a memory and a processor.

[0307] The processor may execute: performing C2 communication with the second UE via a C2 (command and control) connection via PC5; measuring the signal strength of the C2 connection via PC5; sending C2 connection status information from the UAS (unmanned aerial system) layer of the first UE to the application layer of the first UE; wherein the C2 connection status information includes information related to the measured signal strength of the C2 connection via PC5, and based on the C2 connection status information, determining whether to i) switch from the C2 connection via PC5 to the C2 connection via the network or ii) disconnect the C2 connection via PC5 based on a request from the application layer of the first UE.

[0308] Hereinafter, a processor for providing communication according to some embodiments of the present specification will be described.

[0309] The processor is configured to: perform C2 communication with the second UE through a C2 (command and control) connection via PC5; measure the signal strength of the C2 connection via PC5; send C2 connection status information from the UAS (unmanned aerial system) layer of the first UE to the application layer of the first UE; wherein the C2 connection status information includes information related to the measured signal strength of the C2 connection via PC5, and based on the C2 connection status information, determine whether to i) switch from the C2 connection via PC5 to the C2 connection via the network or ii) disconnect the C2 connection via PC5 based on a request from the application layer of the first UE.

[0310] Hereinafter, a non-transitory computer-readable medium storing one or more instructions for providing a multicast service in wireless communication according to some embodiments of the present specification will be described.

[0311] According to some embodiments of the present disclosure, the technical features of the present disclosure may be directly implemented as hardware, software executed by a processor, or a combination of the two. For example, in wireless communications, the method performed by the wireless device may be implemented in hardware, software, firmware, or any combination thereof. For example, the software may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or other storage media.

[0312] Some examples of storage media are coupled to the processor so that the processor can read information from the storage media. Alternatively, the storage medium can be integrated into the processor. The processor and the storage medium can reside in an ASIC. As another example, the processor and the storage medium can reside as separate components.

[0313] Computer readable media may include tangible and non-volatile computer readable storage media.

[0314] For example, the non-volatile computer readable medium may include a random access memory (RAM), such as a synchronous dynamic random access memory (SDRAM), a read-only memory (ROM), or a non-volatile random access memory (NVRAM). Read-only memory (EEPROM), flash memory, magnetic or optical data storage media, or other media that can be used to store instructions or data structures, or non-volatile computer readable media may also include combinations of the above.

[0315] Furthermore, the methods described herein may be implemented at least in part by a computer-readable communication medium carrying code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer.

[0316] According to some embodiments of the present disclosure, a non-transitory computer-readable medium stores one or more instructions. The one or more stored instructions may be executed by a processor of a base station.

[0317] The stored one or more instructions cause the processor to: perform C2 communication with the second UE via a C2 (command and control) connection via PC5; measure the signal strength of the C2 connection via PC5; send C2 connection status information from the UAS (unmanned aerial system) layer of the first UE to the application layer of the first UE; wherein the C2 connection status information includes information related to the measured signal strength of the C2 connection via PC5, and based on the C2 connection status information, determine based on a request from the application layer of the first UE whether to i) switch from the C2 connection via PC5 to the C2 connection via the network or ii) disconnect the C2 connection via PC5.

[0318] This description can have various effects.

[0319] For example, the UAV-C and the UAV performing C2 communication via the PC5 path may perform C2 communication via the network at an appropriate time.

[0320] The effects that can be obtained through the specific examples of this specification are not limited to the effects listed above. For example, there may be various technical effects that a person of ordinary skill in the relevant field can understand or deduce from this specification. Therefore, the specific effects of this specification are not limited to those explicitly described herein, and may include various effects that can be understood or derived from the technical characteristics of this specification.

[0321] The claims described herein may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. In addition, the technical features of the method claims of this specification and the technical features of the device claims may be combined to implement a device, and the technical features of the method claims of this specification and the technical features of the device claims may be combined and implemented as a method. Other implementations are within the scope of the following claims.

Claims

1. A method for performing communication performed by a first user equipment UE, the method The following steps are involved: performing C2 communication with the second UE via a command and control C2 connection via the PC 5; measuring the signal strength of the C2 connection via PC5; Sending C2 connection state information from an unmanned aerial system (UAS) layer of the first UE to an application layer of the first UE; The C2 connection status information includes information related to the measured signal strength of the C2 connection via PC5, Based on the C2 connection state information, it is determined based on a request from the application layer of the first UE whether to i) switch from the C2 connection via PC5 to the C2 connection via a network or ii) disconnect the C2 connection via PC5.

2. The method according to claim 1, in, The first UE is an unmanned aerial vehicle-controller UAV-C, and the second UE is a UAV.

3. The method according to claim 1 or claim 2, in, The step of sending the C2 connection status information is performed based on the measured signal strength being lower than a threshold.

4. The method according to claim 3, further comprising: The following steps are involved: Receive configuration from the base station, Wherein, the configuration includes the threshold.

5. The method according to any one of claims 1 to 4, in, The C2 connection status information includes whether the first UE is capable of performing a C2 connection via a network.

6. The method according to any one of claims 1 to 5, in, The C2 connection status information includes the quality of the C2 connection via the PC 5 or whether the quality of service QoS of the C2 connection via the PC 5 is satisfied.

7. The method according to any one of claims 1 to 6, further comprising: The following steps are involved: requesting the second UE for information on whether the second UE can perform a C2 connection via a network; as well as receiving, from the second UE, information whether the second UE is capable of performing a C2 connection via a network, The C2 connection status information includes the information on whether the second UE is capable of performing a C2 connection via a network.

8. A first user equipment UE performing communication, the first UE include: Transceiver; as well as processor, The processor performs operations including the method according to any one of claims 1 to 7.

9. A method for performing communication performed by a base station, the method The following steps are involved: Sending a configuration to a first user equipment UE, Wherein, the configuration includes a threshold value, wherein the first UE performs C2 communication with the second UE via a command and control C2 connection via PC5, The first UE measures the signal strength of the C2 connection via PC5, The unmanned aerial system (UAS) layer of the first UE sends C2 connection status information to the application layer of the first UE. The C2 connection status information includes information related to the measured signal strength of the C2 connection via PC5, The first UE determines whether to i) switch from the C2 connection via PC5 to the C2 connection via the network or ii) disconnect the C2 connection via PC5 based on a request from the application layer of the first UE based on the C2 connection state information.

10. The method according to claim 9, in, The first UE is an unmanned aerial vehicle-controller UAV-C, and the second UE is a UAV.

11. The method according to claim 9 or claim 10, in, The step of sending the C2 connection status information is performed based on the measured signal strength being lower than a threshold.

12. The method according to any one of claims 9 to 11, in, The C2 connection status information includes whether the first UE is capable of performing a C2 connection via a network.

13. The method according to any one of claims 9 to 12, in, The C2 connection status information includes the quality of the C2 connection via the PC 5 or whether the quality of service QoS of the C2 connection via the PC 5 is satisfied.

14. The method according to any one of claims 9 to 13, in, The first UE requests the second UE for information on whether the second UE can perform a C2 connection via a network, The first UE receives information from the second UE whether the second UE can perform a C2 connection via a network, The C2 connection status information includes the information on whether the second UE is capable of performing a C2 connection via a network.

15. A base station for performing communication, the base station include: Transceiver; as well as processor, The processor performs operations including the method according to any one of claims 9 to 14.

16. A first device in mobile communication, the first device include: at least one processor; as well as At least one memory storing instructions and being operatively connectable to the at least one processor to perform operations including the method according to any one of claims 1 to 7.

17. A non-volatile computer-readable storage medium having recorded thereon instructions, in, The instructions are executed by one or more processors so that the one or more processors perform operations including the method according to any one of claims 1 to 7.

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