Method for performing communication in wireless communication system and device therefor

Abstract

Disclosed are a method for configuring a reference time by a first device in a wireless communication system and a device therefor according to various embodiments. Disclosed are a method and a device therefor, the method comprising the steps of: configuring a first reference time on the basis of a network time protocol (NTP); receiving a first message from a second device; adjusting the first reference time based on the NTP to a second reference time based on a global positioning system (GPS) time on the basis that information on the GPS time is included in the first message; and transmitting a second message on the basis of the second reference time.

Description

Method for performing communication in a wireless communication system and device therefor

[0001] A method for transmitting a message based on a set reference time in a wireless communication system and a device therefor are provided.

[0002] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0003] Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). SL is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0004] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0005] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive machine type communication (MTC), and ultra-reliable and low latency communication (URLLC) can be called new radio access technology (RAT) or new radio (NR). NR can also support vehicle-to-everything (V2X) communication.

[0006] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

[0007] In relation to V2X communication, in RATs prior to NR, methods for providing safety services based on V2X messages such as Basic Safety Message (BSM), Cooperative Awareness Message (CAM), and Decentralized Environmental Notification Message (DENM) were mainly discussed. V2X messages may include location information, dynamic information, attribute information, etc. For example, a terminal may transmit a CAM of a periodic message type and / or a DENM of an event triggered message type to another terminal.

[0008] For example, a CAM may include basic vehicle information such as dynamic vehicle status information, such as direction and speed, static vehicle data, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast a CAM, and the latency of the CAM may be less than 100 ms. For example, in the event of an emergency, such as a vehicle breakdown or accident, a terminal may generate a DENM and transmit it to other terminals. For example, all vehicles within the transmission range of the terminal may receive the CAM and / or DENM. In this case, the DENM may have a higher priority than the CAM.

[0009] Since then, various V2X scenarios have been proposed in NR in relation to V2X communications. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, and remote driving.

[0010] For example, based on vehicle platooning, vehicles can dynamically form groups and move together. For example, to perform platoon operations based on vehicle platooning, vehicles in the group can receive periodic data from the lead vehicle. For example, vehicles in the group can use this periodic data to narrow or widen the gap between vehicles.

[0011] For example, based on improved driving, vehicles can become semi-autonomous or fully automated. For example, each vehicle can adjust its trajectories or maneuvers based on data acquired from local sensors of nearby vehicles and / or nearby logical entities. Furthermore, for example, each vehicle can share driving intentions with nearby vehicles.

[0012] For example, based on extended sensors, raw data, processed data, or live video data acquired through local sensors can be exchanged between vehicles, logical entities, pedestrian terminals, and / or V2X application servers. Thus, for example, a vehicle can perceive its environment better than it can perceive using its own sensors.

[0013] For example, based on remote driving, a remote driver or V2X application can operate or control the remote vehicle for people who cannot drive or for remote vehicles located in hazardous environments. For example, in cases where the route is predictable, such as public transportation, cloud computing-based driving can be utilized to operate or control the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

[0014] Meanwhile, a method to specify service requirements for various V2X scenarios, such as vehicle platooning, enhanced driving, expanded sensors, and remote driving, is being discussed in NR-based V2X communication.

[0015] The technical challenge is to provide a more accurate and efficient way to transmit and receive data / messages.

[0016] The technical challenges are not limited to the technical challenges mentioned above, and other technical challenges not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0017] In a wireless communication system according to one aspect, a method for setting a reference time by a first device may include the steps of setting a first reference time based on NTP (Network Time Protocol); receiving a first message from a second device; adjusting the first reference time based on NTP to a second reference time based on GPS time based on the first message including information about GPS (Global Positioning System) time; and transmitting a second message based on the second reference time.

[0018] Alternatively, the second reference time is characterized in that it is determined by applying a specific offset to the GPS time.

[0019] Alternatively, the specific offset is characterized in that it is determined based on the acquisition delay of the RTT (Round Trip Time) or UDP (User Datagram Protocol) diagram (Datagram) between the first device and the second device.

[0020] Alternatively, the first message is characterized in that it further includes offset information related to the GPS time and information on an acquisition time interval of the GPS time.

[0021] Alternatively, the method comprises the steps of transmitting a message including a bootstrap URI (Uniform Resource Identifier) ​​and a location of the first device to a network; and obtaining information about a URI for connecting to the second device adjacent to the location of the first device from the network.

[0022] Alternatively, the first message is characterized in that it is received based on the URI.

[0023] Alternatively, the second message is characterized in that it is transmitted to peripheral devices via the server.

[0024] Alternatively, the second device is characterized as being an infrastructure or an Intelligent Transportation System (ITS) for providing a V2X (Vehicle-to-Everything) service.

[0025] According to another aspect, a non-transitory computer-readable storage medium having recorded thereon commands for performing the method of setting the above-described reference time may be provided.

[0026] According to another aspect, a first device may be provided that performs the method of setting the above-described reference time.

[0027] According to another aspect, a processing device may be provided for controlling a first device that performs a method of setting a reference time.

[0028] According to another aspect, a method for providing information on a reference time in a wireless communication system includes the steps of: receiving a GPS signal including information on a Global Positioning System (GPS) time; transmitting a first message including information on the GPS time to a first device; and receiving a second message from the first device, wherein based on the first message being transmitted to the first device, the second message can be received based on a second reference time based on the GPS rather than a first reference time based on the Network Time Protocol (NTP).

[0029] According to another aspect, a non-transitory computer-readable storage medium having recorded thereon instructions for performing the method of providing information on the above-described reference time may be provided.

[0030] According to another aspect, a second device may be provided that performs the method of providing information about the reference time described above.

[0031] According to another aspect, a processing device may be provided for controlling a second device that performs the method of providing information about the reference time described above.

[0032] According to various embodiments, data / messages can be transmitted and received more accurately and efficiently in a wireless communication system.

[0033] The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0034] The drawings attached to this specification are intended to provide an understanding of the present invention, illustrate various embodiments of the present invention, and together with the description of the specification serve to explain the principles of the present invention.

[0035] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

[0036] Figure 2 shows the structure of the LTE system.

[0037] Figure 3 shows the structure of the NR system.

[0038] Figure 4 shows the structure of a radio frame of NR.

[0039] Figure 5 shows the slot structure of an NR frame.

[0040] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0041] FIG. 7 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0042] FIG. 8 illustrates an example of a typical scenario of an NTN based on a transparent payload, according to one embodiment of the present disclosure.

[0043] FIG. 9 illustrates an example of a typical scenario of an NTN based on a regenerative payload, according to one embodiment of the present disclosure.

[0044] FIG. 10 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0045] Figure 11 shows a radio protocol architecture for SL communication.

[0046] Figure 12 shows a terminal performing V2X or SL communication.

[0047] Figure 13 shows resource units for V2X or SL communication.

[0048] FIG. 14 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0049] FIG. 15 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure.

[0050] FIG. 16 is a diagram for explaining a method for performing V2X communication between multiple platforms.

[0051] FIG. 17 and FIG. 18 are diagrams for explaining a method for providing reference time information based on the GPS time of a reference time entity.

[0052] Figure 19 is a drawing for explaining how the first device sets the reference time.

[0053] Figure 20 is a drawing for explaining how the second device provides reference time information.

[0054] Figure 21 illustrates a communication system applied to the present invention.

[0055] Figure 22 illustrates a wireless device applicable to the present invention.

[0056] Figure 23 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service.

[0057] Figure 24 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0058] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0059] Sidelink refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). Sidelink is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0060] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0061] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be called new radio access technology (RAT) or new radio (NR). NR can also support V2X (vehicle-to-everything) communication.

[0062] The following technologies can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0063] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0064] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0065] Figure 2 illustrates the architecture of an applicable LTE system. This may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0066] Referring to FIG. 2, the E-UTRAN includes a base station (20; BS) that provides a control plane and a user plane to a terminal (10). The terminal (10) may be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. The base station (20) refers to a fixed station that communicates with the terminal (10), and may be referred to by other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, etc.

[0067] Base stations (20) can be connected to each other via the X2 interface. The base station (20) is connected to an EPC (Evolved Packet Core, 30) via the S1 interface, more specifically, to an MME (Mobility Management Entity) via the S1-MME, and to an S-GW (Serving Gateway) via the S1-U.

[0068] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway with the E-UTRAN as its endpoint, and the P-GW is a gateway with the PDN as its endpoint.

[0069] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to Layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in Layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0070] Figure 3 shows the structure of the NR system.

[0071] Referring to FIG. 3, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 7 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, the gNB is connected to the access and mobility management function (AMF) via the NG-C interface, and the gNB is connected to the user plane function (UPF) via the NG-U interface.

[0072] Figure 4 shows the structure of a radio frame of NR.

[0073] Referring to FIG. 4, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0074] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0075] Table 1 below shows the number of symbols per slot ((N)) depending on the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame ((N frame,u slot ) and the number of slots per subframe ((N subframe,u slot ) is an example.

[0076] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0077] Table 2 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to SCS when extended CP is used.

[0078] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0079] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0080] In NR, multiple numerologies, or SCSs, can be supported to support various 5G services. For example, a 15 kHz SCS can support wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS can support dense urban areas, lower latency, and wider carrier bandwidth. A 60 kHz or higher SCS can support bandwidths greater than 24.25 GHz to overcome phase noise.

[0081] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0082] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0083] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0084] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0085] Figure 5 shows the slot structure of an NR frame.

[0086] Referring to Figure 5, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0087] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0088] Meanwhile, the wireless interface between terminals or between terminals and a network may be composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. Furthermore, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. Furthermore, for example, the L3 layer may refer to an RRC layer.

[0089] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to an embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0090] New network characteristics in 6G may include:

[0091] - Satellite integrated network

[0092] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0093] - Seamless integration of wireless information and energy transfer

[0094] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0095] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0096] - small cell networks

[0097] - Ultra-dense heterogeneous network

[0098] - High-capacity backhaul

[0099] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0100] - Softwarization and virtualization

[0101] Below, the core implementation technologies of the 6G system are described.

[0102] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0103] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by using sub-THz communication with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0104] Figure 7 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of Figure 7 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) a widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array techniques to overcome range limitations.

[0105] - Large-scale MIMO technology

[0106] - Hologram beamforming (HBF)

[0107] - Optical wireless technology

[0108] - Free-space optical transmission backhaul network (FSO backhaul network)

[0109] - Quantum communication

[0110] - Cell-free communication

[0111] - Integration of wireless information and power transmission

[0112] - Integration of wireless communication and sensing

[0113] - Integrated access and backhaul network

[0114] - Big data analysis

[0115] - Reconfigurable intelligent surface

[0116] - metaverse

[0117] - Block chain

[0118] Unmanned aerial vehicles (UAVs): UAVs, or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base stations (BSs) can be installed on UAVs to provide cellular connectivity. UAVs may offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (eMBB), URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0119] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication. Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, in the future, autonomous driving will go beyond simply providing warnings or guidance messages to drivers and may require active intervention in vehicle operation and direct control of the vehicle in dangerous situations. To this end, the amount of information that needs to be transmitted and received may become enormous, so 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

[0120] - Non-terrestrial networks (NTN): NTN may refer to a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform). FIG. 8 illustrates an example of a typical NTN scenario based on a transparent payload according to an embodiment of the present disclosure. FIG. 9 illustrates an example of a typical NTN scenario based on a regenerative payload according to an embodiment of the present disclosure. The embodiments of FIG. 8 or FIG. 9 may be combined with various embodiments of the present disclosure. Referring to FIG. 8, a satellite (or UAS platform) may create a service link with a UE. The satellite (or UAS platform) may be connected to a gateway via a feeder link. The satellite may be connected to a data network via the gateway. A beam footprint may refer to an area where a signal transmitted by a satellite can be received. Referring to Figure 9, a satellite (or UAS platform) can establish a service link with a UE. A satellite (or UAS platform) connected to a UE can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the replay payload, a satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between a satellite and another satellite, a feeder link between the satellite and the gateway may be required. Figures 8 and 9 are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios.For example, a satellite (or UAS platform) may implement a transparent or regenerative (with onboard processing) payload. For example, a satellite (or UAS platform) may generate multiple beams over a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) may vary depending on the onboard antenna diagram and minimum elevation angle. For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may not be altered. For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to equipping the satellite (or UAS platform) with all or part of the base station functionality.

[0121] - Integrated Sensing and Communication (ISAC): Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a device to connect to the object through a network, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of a wireless sensing service, i.e., a sensing operation, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing may provide an opportunity to enhance existing communication systems from a communication network to a wireless communication and sensing network. FIG. 10 illustrates an example of a sensing operation according to an embodiment of the present disclosure. The embodiment of FIG. 10 may be combined with various embodiments of the present disclosure. Specifically, FIG. 10 (a) illustrates an example of sensing using a sensing receiver and a sensing transmitter located at the same location (e.g., monostatic sensing), and FIG. 10 (b) illustrates an example of sensing using a separated sensing receiver and a sensing transmitter (e.g., bistatic sensing).

[0122] Figure 11 illustrates a radio protocol architecture for SL communication. Specifically, Figure 11 (a) illustrates the user plane protocol stack of NR, and Figure 11 (b) illustrates the control plane protocol stack of NR.

[0123] Below, the SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information are described.

[0124] SLSS is an SL-specific sequence and may include a Primary Sidelink Synchronization Signal (PSSS) and a Secondary Sidelink Synchronization Signal (SSSS). The PSSS may be referred to as a Sidelink Primary Synchronization Signal (S-PSS), and the SSSS may be referred to as a Sidelink Secondary Synchronization Signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 Gold sequences may be used for the S-SSS. For example, a terminal may detect an initial signal and acquire synchronization using the S-PSS. For example, a terminal may acquire detailed synchronization and detect a synchronization signal ID using the S-PSS and the S-SSS.

[0125] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in NR V2X, for evaluating PSBCH performance, the payload size of PSBCH may be 56 bits, including a 24-bit CRC.

[0126] S-PSS, S-SSS and PSBCH may be included in a block format supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0127] Meanwhile, in the NR SL system, multiple numerologies having different SCS and / or CP lengths may be supported. In this case, as the SCS increases, the length of the time resource for a transmitting terminal to transmit an S-SSB may become shorter. Accordingly, the coverage of the S-SSB may decrease. Therefore, in order to ensure the coverage of the S-SSB, the transmitting terminal may transmit one or more S-SSBs to a receiving terminal within one S-SSB transmission period according to the SCS. For example, the number of S-SSBs that the transmitting terminal transmits to the receiving terminal within one S-SSB transmission period may be pre-configured or configured for the transmitting terminal. For example, the S-SSB transmission period may be 160 ms. For example, an S-SSB transmission period of 160 ms may be supported for all SCSs.

[0128] For example, when the SCS is 15 kHz at FR1, the transmitting terminal can transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, when the SCS is 30 kHz at FR1, the transmitting terminal can transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission period. For example, when the SCS is 60 kHz at FR1, the transmitting terminal can transmit one, two, or four S-SSBs to the receiving terminal within one S-SSB transmission period.

[0129] For example, when the SCS is 60 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, or 32 S-SSBs to the receiving terminal within one S-SSB transmission period. For example, when the SCS is 120 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, 32, or 64 S-SSBs to the receiving terminal within one S-SSB transmission period.

[0130] Meanwhile, when the SCS is 60 kHz, two types of CP may be supported. In addition, the structure of the S-SSB transmitted by the transmitting terminal to the receiving terminal may be different depending on the CP type. For example, the CP type may be Normal CP (NCP) or Extended CP (ECP). Specifically, for example, when the CP type is NCP, the number of symbols to which the PSBCH is mapped within the S-SSB transmitted by the transmitting terminal may be 9 or 8. On the other hand, for example, when the CP type is ECP, the number of symbols to which the PSBCH is mapped within the S-SSB transmitted by the transmitting terminal may be 7 or 6. For example, the PSBCH may be mapped to the first symbol within the S-SSB transmitted by the transmitting terminal. For example, the receiving terminal receiving the S-SSB may perform an Automatic Gain Control (AGC) operation in the first symbol section of the S-SSB.

[0131] Figure 12 shows a terminal performing V2X or SL communication.

[0132] Referring to FIG. 12, the term "terminal" in V2X or SL communication may primarily refer to a user's terminal. However, if a network device such as a base station transmits and receives signals according to a communication method between terminals, the base station may also be considered a type of terminal. For example, terminal 1 may be a first device (100), and terminal 2 may be a second device (200).

[0133] For example, terminal 1 can select a resource unit corresponding to a specific resource within a resource pool, which represents a set of resources. Then, terminal 1 can transmit an SL signal using the resource unit. For example, terminal 2, which is a receiving terminal, can be configured with a resource pool in which terminal 1 can transmit a signal, and can detect a signal from terminal 1 within the resource pool.

[0134] Here, if terminal 1 is within the connection range of the base station, the base station can inform terminal 1 of the resource pool. On the other hand, if terminal 1 is outside the connection range of the base station, another terminal can inform terminal 1 of the resource pool, or terminal 1 can use a pre-configured resource pool.

[0135] In general, a resource pool can be composed of multiple resource units, and each terminal can select one or multiple resource units to use for its SL signal transmission.

[0136] Figure 13 shows resource units for V2X or SL communication.

[0137] Referring to Figure 13, the entire frequency resources of the resource pool can be divided into NF units, and the entire time resources of the resource pool can be divided into NT units. Therefore, a total of NF * NT resource units can be defined within the resource pool. Figure 13 illustrates an example where the resource pool repeats with a cycle of NT subframes.

[0138] As illustrated in Figure 13, a single resource unit (e.g., Unit #0) may appear periodically and repeatedly. Alternatively, to achieve diversity effects in the time or frequency dimensions, the index of the physical resource unit to which a single logical resource unit is mapped may change in a predetermined pattern over time. In this resource unit structure, a resource pool may refer to a set of resource units that a terminal wishing to transmit an SL signal can use for transmission.

[0139] Resource pools can be subdivided into several categories. For example, based on the content of the SL signal transmitted from each resource pool, resource pools can be categorized as follows:

[0140] (1) Scheduling Assignment (SA) may be a signal that includes information such as the location of resources used by a transmitting terminal for transmission of an SL data channel, MCS (Modulation and Coding Scheme) or MIMO (Multiple Input Multiple Output) transmission method required for demodulation of other data channels, and TA (Timing Advance). SA may also be transmitted multiplexed with SL data on the same resource unit, in which case the SA resource pool may mean a resource pool in which SA is multiplexed with SL data and transmitted. SA may also be called an SL control channel.

[0141] (2) The SL data channel (Physical Sidelink Shared Channel, PSSCH) may be a resource pool used by a transmitting terminal to transmit user data. If SA is multiplexed and transmitted together with SL data on the same resource unit, only the SL data channel excluding SA information may be transmitted from the resource pool for the SL data channel. In other words, the REs (Resource Elements) that were used to transmit SA information on individual resource units within the SA resource pool may still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting terminal may transmit the PSSCH by mapping it to consecutive PRBs.

[0142] (3) A discovery channel may be a resource pool for transmitting terminals to transmit information such as their IDs. Through this, transmitting terminals can enable neighboring terminals to discover them.

[0143] Even if the content of the SL signal described above is the same, different resource pools may be used depending on the transmission and reception properties of the SL signal. For example, even if it is the same SL data channel or discovery message, it may be again divided into different resource pools depending on the transmission timing determination method of the SL signal (for example, whether it is transmitted at the time of reception of a synchronization reference signal or whether it is transmitted by applying a certain timing advance at the time of reception), the resource allocation method (for example, whether the base station designates transmission resources for individual signals to individual transmitting terminals or whether individual transmitting terminals independently select individual signal transmission resources within the resource pool), the signal format (for example, the number of symbols each SL signal occupies in one subframe or the number of subframes used for transmission of one SL signal), the signal strength from the base station, the transmission power strength of the SL terminal, etc.

[0144] FIG. 14 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 14 can be combined with various embodiments of the present disclosure. In the embodiment of FIG. 14, it is assumed that there are three BWPs.

[0145] Referring to Figure 14, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other. Furthermore, a PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0146] The BWP can be set by Point A, an offset from Point A (NstartBWP), and a bandwidth (NsizeBWP). For example, Point A can be an outer reference point of a PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) are aligned. For example, the offset can be the PRB spacing between the lowest subcarrier in a given numerology and Point A. For example, the bandwidth can be the number of PRBs in a given numerology.

[0147] SLSS (Sidelink Synchronization Signal) is a SL (sidelink) specific sequence and may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal) and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS and length-127 Gold sequences may be used for S-SSS. For example, a terminal may detect an initial signal (signal detection) and obtain synchronization using S-PSS. For example, the terminal can obtain detailed synchronization using S-PSS and S-SSS and detect a synchronization signal ID.

[0148] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0149] S-PSS, S-SSS and PSBCH may be included in a block format supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0150] FIG. 15 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure. The embodiment of FIG. 15 may be combined with various embodiments of the present disclosure.

[0151] Referring to (a) of FIG. 15, in resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S1500, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0152] For example, a first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. For example, a CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal, and the base station may transmit a DCI related to activation or release of the CG resource to the first terminal.

[0153] In step S1510, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S1520, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S1530, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S1540, the first terminal may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a rule set in advance. For example, the DCI may be DCI for scheduling SL.

[0154] Referring to (b) of FIG. 15, in resource allocation mode 2, a terminal can determine SL transmission resources within SL resources set by a base station / network or preset SL resources. For example, the set SL resources or preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting resources within the set resource pool. For example, the terminal can select resources within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S1510, a first terminal that has selected resources within the resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to a second terminal using the resources. In step S1520, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S1530, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0155] Referring to (a) or (b) of FIG. 15, for example, a first terminal may transmit an SCI to a second terminal on a PSCCH. Alternatively, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, an SCI transmitted on a PSCCH may be referred to as a 1st SCI, a 1st SCI, a 1st-stage SCI, or a 1st-stage SCI format, and an SCI transmitted on a PSSCH may be referred to as a 2nd SCI, a 2nd SCI, a 2nd-stage SCI, or a 2nd-stage SCI format.

[0156] Referring to (a) or (b) of FIG. 15, in step S1530, the first terminal may receive a PSFCH. For example, the first terminal and the second terminal may determine PSFCH resources, and the second terminal may use the PSFCH resources to transmit HARQ feedback to the first terminal.

[0157] Referring to (a) of FIG. 15, in step S1540, the first terminal may transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0158] Meanwhile, the aforementioned sidelink can be defined as terminal-to-terminal communication or direct communication between terminals. In this case, the PSCCH can be defined as a physical control channel for terminal-to-terminal communication, the PSSCH as a physical data channel or physical shared channel for terminal-to-terminal communication, and the PSFCH as a physical feedback transmission channel between terminals.

[0159] Meanwhile, the SoftV2X service or SoftV2X system is a system in which a SoftV2X server receives a VRU message or a PSM (Personal Safety Message) from a VRU (Vulnerable Road User) or a V2X vehicle through a UU interface for V2X communication, and transmits information on surrounding VRUs or vehicles based on the VRU message or PSM message, or analyzes the road conditions on which surrounding VRUs or vehicles are moving, and transmits a message to notify surrounding VRUs or vehicles of a collision warning based on the analyzed information. Here, the VRU message or PSM message is a message transmitted to the SoftV2X server through the UU interface, and may include mobility information on the VRU, such as the location, moving direction, moving path, and speed of the VRU. In other words, the SoftV2X system receives mobility information on VRUs and / or vehicles related to V2X communication through the UU interface, and a softV2X server, such as a network, controls the driving path of the VRU, the VRU movement flow, etc. based on the received mobility information. Alternatively, the SoftV2X system can be configured in relation to V2N communications.

[0160] Below, a method for providing V2X services through a network based on the above-described contents is described in detail.

[0161] Network-to-network interface structure using messaging protocols in V2N services

[0162] V2X services play a significant role in ensuring safety, including collision prevention, and efficiently controlling traffic flow by allowing road users (vehicles, RSUs, pedestrians, etc.) to communicate with surrounding road users about their status information (location, speed, size, etc.) or environmental information (maps, signal information, etc.). Currently, various V2X services using various communication methods (short-range communication, long-range communication) exist, and service level requirements (SLREs) have been defined to ensure the organic operation of V2X services involving multiple ITS stations.

[0163] These V2X messages can be generated by vehicles and infrastructure to convey information about the surrounding environment, road conditions, situations, and events. V2X messages can be used for various purposes, such as vehicle-to-vehicle interaction, vehicle-to-infrastructure communication, object detection, and warning systems. V2X messages can be generated by vehicles or infrastructure and can contain information about the surrounding environment, situations, and events. Furthermore, V2X messages can include information collected through the vehicle's sensors, GPS information, and communication devices, and can be structured in a standardized format. These standardized V2X messages can include various data, such as location, speed, acceleration, lane change information, and traffic light status. Alternatively, V2X messages can be transmitted in one direction or two directions, and the information contained in the V2X messages can be updated and processed in real time. In V2X environments that require low-latency communication, rapid message transmission is essential, and a delay time of several milliseconds or less can be very important for rapid situational responses, such as accident prevention or collision warning. Additionally, because V2X message-based communication relies on real-time interaction between vehicles and infrastructure, the speed and reliability of message delivery can play a critical role in ensuring that drivers are warned in a timely manner and vehicles can react to situations in a timely manner.

[0164] Among V2X connections, V2N communication (i.e., SoftV2X, as described above) plays a key role in modern distributed systems. Messaging protocols for such communication play a crucial role in facilitating and enhancing this communication. Among messaging protocols, the MQTT (Message Queuing Telemetry Transport) protocol can include clients, servers, and brokers as core components. This messaging protocol connects multiple clients using a broker that acts as an IP protocol-based relay. Clients can publish messages and subscribe to desired topics using the MQTT protocol. The server accepts client connections, manages connections with clients, and routes and relays messages from clients and others. The server or network is also commonly referred to as an MQTT broker. An MQTT broker is a central server that relays and coordinates communication between MQTT clients, delivering messages published by clients to other clients that have subscribed. Such V2N communication can provide enhanced services that handle diverse information by interconnecting information transmitted from different operators or national and regional infrastructures.

[0165] In order to provide reliable and accurate information for network-based V2N communication (or long-range V2X communication) and PC5-based V2X communication (or short-range V2X communication), all devices and networks must share and synchronize the same time. If the reference time is not synchronized, it is difficult to ensure accurate timestamps of communication messages, which may cause communication errors, delays, and confusion. The times that C-V2X (Short Range) devices and V2N (Long Range) devices handle or synchronize may be different. For example, C-V2X devices (e.g., OBU) typically set GPS time as the reference time and issue messages based on GPS time. In contrast, V2N devices (or issues messages to a server) generally set the reference time based on the NTP (Network Time Protocol) time, which is the reference time of the server. These C-V2X devices and V2N devices (or V2X communications based on PC5 and V2N communications based on Uu) require time synchronization to exchange real-time information and maintain a safe driving environment. Accurate time synchronization ensures reliable V2X communications between vehicles and the network. For this purpose, it may be crucial to provide accurate time information using a time synchronization server and standardized protocols.

[0166] Specifically, the synchronization differences between C-V2X (Short Range) devices and V2N (Long Range) devices are as follows.

[0167] UTC (Coordinated Universal Time) is an international standard time, a reference time for consistently displaying time around the globe. UTC is based on atomic clocks, offers second-by-second accuracy, and is used globally to synchronize time information across different regions and networks.

[0168] NTP (Network Time Protocol), associated with V2N communication, can synchronize time information based on UTC. NTP-based clients or V2N devices can receive UTC time information from an NTP server and periodically synchronize their local system's time. However, because NTP retrieves time information over a network (or the Internet), issues can arise due to network latency and time information accuracy. On the other hand, NTP synchronizes with UTC by considering the leap second. Furthermore, compared to GNSS, it can provide relatively accurate and seamless synchronization between devices.

[0169] GPS, which is relevant to C-V2X communications, is a system that provides location and time information based on signals transmitted via satellite. GPS time is synchronized with atomic clocks on Earth and can provide highly accurate time information. However, GPS time can be affected by factors such as the precise location of the GPS signal, obstacles, and weather conditions, as well as the reception quality. Furthermore, GPS time management methods can also affect accuracy. For example, the GPS acquisition cycle and data processing during background updates can also affect accuracy. Furthermore, GNSS data does not incorporate leap seconds, which can cause discrepancies from actual UTC time.

[0170] Hereinafter, a method for synchronizing each other in interconnection between terminals performing C-V2X communication (or C-V2X devices or C-V2X terminals) and terminals performing V2N communication (or V2N devices or V2N terminals) is described in detail.

[0171] FIG. 16 is a diagram for explaining a method for performing V2X communication between multiple platforms.

[0172] Due to the synchronization mismatch between terminals performing GPS-based C-V2X communication (or C-V2X terminals) and terminals performing NTP-based V2N communication (or V2N terminals), practical implementation issues are occurring due to interconnection. For example, if the reference time handled by the C-V2X terminal and the V2N terminal (e.g., App, Dedicated UE) is not the same or the management method is different, a time difference in the unit of seconds may occur between them.

[0173] Specifically, referring to FIG. 16, two different service providers may be connected or interworking. A first provider or server (SP-1) may set NTP time as a reference time, and a second provider or server (SP-2) may set GPS time as a reference time. In this case, the occurrence times of messages exchanged between the first provider (SP-1) and the second provider (SP-2) may not be synchronized. Due to this issue of synchronization mismatch due to the difference in reference times, even if a terminal for the first provider (SP-1) properly receives a message from a terminal for the second provider (SP-2), a problem may occur in which the message is not properly reflected in an actual collision assessment. In addition, if the first provider (SP-1) and the second provider (SP-2) are not synchronized with the reference time for generating messages from the Infrastructure Operator Owner (IOO), vehicles connected to the first provider (SP-1) or the second provider (SP-2) may not be able to accurately recognize that a police car is approaching. In addition, since the Traveler Information Message (TIM) for road works connected to the first provider (SP-1) is generated based on the NTP time of the first provider (SP-1), the reference time of the TIM message may not match the reference time of the second provider (SP-2). In addition, not all time-critical events may be properly detected due to the reference time difference between the providers.

[0174] Therefore, it is necessary to resolve the synchronization mismatch between such C-V2X terminals and V2N terminals, and the following methods 1 and 2 can be considered as methods for resolving the synchronization mismatch.

[0175] Method 1 may be a method of additionally constructing a reference time entity (or reference time server) for infrastructure for V2X communication (or, Intelligent Transportation System (ITS) system). The reference time entity includes a precise GPS time acquisition device that can use both a network channel (e.g., a channel for V2N communication) and a C-V2X channel based on GPS time, and can transmit reference time information on a reference time determined or set based on the GPS time to devices connected to the infrastructure. Here, the reference time information includes information on a reference time (or, ITS reference time, ITS unified time) determined / set based on the GPS time by the reference time entity, and the ITS reference time may be a reference time for synchronization of all devices that receive V2X services in relation to the ITS system or infrastructure. For example, devices that receive services through the ITS system or infrastructure can obtain the reference time information in a Push or Pull form from the reference time entity. Alternatively, the reference time information may be set for each preset unit area. In this case, the reference time entity or ITS system (or infrastructure) may provide reference time information for an area corresponding to the location where the devices are located. A C-V2X terminal within the connection range with the infrastructure may be provided with the reference time information of the reference time entity (i.e., the ITS reference time commonly applied to the ITS system determined / set based on GPS time or GNSS time) through a broadcast message based on the PC5 interface. A V2N terminal may provide or obtain the reference time information of the reference time entity by executing a REST API (Representational State Transfer API) through a network.Through this, C-V2X terminals and V2N terminals can provide or receive services for ITS after synchronization based on the reference time information of the reference time entity.

[0176] Method 2 relates to a method for sharing reference time information (or GPS time) between an application of a V2N terminal and a dedicated terminal of a vulnerable road user (VRU) (e.g., wearable devices connected via Bluetooth, etc.). For example, the application of the V2N terminal can provide reference time information acquired from a reference time entity to the dedicated terminal of the VRU. In this case, the dedicated terminal of the VRU can set the reference time by adding an offset (@TimeOffset) considering the round trip time (RTT) of the Transmission Control Protocol (TCP) or the acquisition delay of the User Datagram Protocol (UDP) datagram to the time included in the reference time information. For example, the dedicated terminal of the VRU can calculate / set the reference time by adding an offset (@TimeOffset) to the received GPS time considering the acquisition delay of the RTT of the TCP or the datagram of the UDP. In this case, the dedicated terminal can also perform collision assessment with the C-V2X terminal more precisely and accurately. In other words, the dedicated terminal of the VRU can also fairly accurately match the synchronization time or reference time with the C-V2X terminal by correcting the reference time information shared from the application of the V2N terminal considering the RTT or datagram acquisition delay, and through this synchronization matching, there is a technical effect of being able to perform collision assessment with the C-V2X terminal more accurately and precisely.

[0177] Below, a method for obtaining a reference time from a reference time entity based on method 1 and / or method 2 is described in detail.

[0178] FIG. 17 and FIG. 18 are diagrams for explaining a method for providing reference time information based on the GPS time of a reference time entity.

[0179] Referring to FIG. 17, the infrastructure providing V2X services may include a GPS receiver, a reference time entity, and an RSU (Road Side Unit). The infrastructure may be connected to V2N terminals (e.g., terminals based on a Uu interface) via the reference time entity, and may be connected to C-V2X terminals (e.g., terminals connected based on a PC5 interface) via the RSU.

[0180] The data flow and logical sequence between the infrastructure and terminals (i.e., C-V2X terminals and V2N terminals) may be as follows.

[0181] - ① The GPS receiver of the infrastructure can receive GNSS data (or GPS) from GNSS (Global Navigation Satellite System) satellites, convert the GNSS time contained in the GNSS data to UTC time, and transmit it to the reference time entity. Alternatively, the GPS receiver can transmit the GPS / GNSS time information itself received from the GNSS satellite to the reference time entity.

[0182] - ② All C-V2X terminals can obtain GPS time via a GPS receiver. They can also perform PPS (Packet Per Second) synchronization with the infrastructure as needed.

[0183] - ③ When performing bootstrap, all V2N terminals can connect to the service discovery (announcement) channel of the infrastructure. When the V2N terminals connect to the service discovery channel, they can receive information about the endpoint or URI (Uniform Resource Identifier) ​​of the RestfulAPI that can receive the reference time. Here, the service discovery channel can utilize the service announcement channel of ETSI (European Telecommunications Standards Institute), SA (or, 3GPP SA), and can provide new bootstrap endpoints based on location.

[0184] Here, an endpoint can be a URL (Uniform Resource Locator) address designated for a client to access a specific resource or function of a server. Furthermore, a RESTful API is an API that follows the principles of REST (Representational State Transfer) and can provide a standardized method for clients to exchange data with a server. RESTful APIs are primarily used in web services and can exchange data based on the HTTP protocol. Furthermore, the bootstrap process can involve performing specific configuration or loading tasks during the network initialization and startup process.

[0185] - ④ The V2N terminal can access the reference time entity through the URI and / or endpoint related to the reference time entity of the infrastructure, and can obtain reference time information (e.g., including the ITS reference time commonly applied to the ITS system) from the reference time entity.

[0186] - ⑤ V2N terminals can determine / calculate / adjust the reference time (reference time for transmitting and receiving messages related to V2X service) by correcting the time included in the reference time information of the reference time entity (e.g., GPS time acquired by a GPS receiver) based on an offset (@offset) that takes into account the RTT for data with the infrastructure.

[0187] The syntax in Table 5 below may be a method or structure (Reference time data scheme) for processing time-related data obtained through a URL or URI obtained after a location-based bootstrap, or obtained through a service announcement channel.

[0188] ElementSemantics@wallClockTime(note: GPS time = Wall clock time)MandatoryUTC obtained through GPS time, reference time, or ITS reference time commonly applied to ITS systems determined based on GPS time@referenceTimeOffsetOptionalTime offset value that can be processed by errors or variables that may occur during acquisition of GPS time provided by a server or infrastructure@recommendedUpdateIntervalOptionalInterval value for acquisition of reference time information recommended by the Reference time server considering inbound traffic

[0189] Specific examples of the above-described method 1 are as follows.

[0190] (1) Example 1

[0191] A V2N terminal can access a specific region (e.g., Seocho-gu, Seoul). The V2N terminal can transmit a designated Bootstrap URI and current location information (e.g., - https: / www.ITS.co.kr / bootstrap / (latitude / longitude of Seocho-gu, Seoul)) related to the specific region to a (Bootstrap) server (or infrastructure).

[0192] The Bootstrap server can provide a URI that can access the location of a reference time entity built within the nearest infrastructure as a return value of the server. In other words, a V2N terminal can receive information (e.g., https: / / www.ITS.co.kr / seocho / referenceTime) from the Bootstrap server that includes its location information and a URI that can access the reference time entity built within the nearest infrastructure as a return value.

[0193] The above V2N terminal can access / connect to the provided URI and obtain reference time information through the UTC scheme. In other words, the V2N terminal can access the reference time entity of the nearest infrastructure through the URI transmitted from the Bootstrap server, receive reference time information related to ITS (e.g., ITS reference time commonly applied to ITS systems determined based on GPS time) from the reference time entity, and set / determine / adjust the reference time based on the transmitted reference time information.

[0194] For example, the V2N terminal can obtain 141113.999 (14 hours 11 minutes 13.999 seconds) from "@wallclock" of the reference time information. The V2N terminal can obtain 0.3 from "@referenceTimeOffset" of the reference time information, or obtain 0.3 by calculating RTT (e.g., Ping value). In this case, the V2N can set / adjust 141114.299 (14 hours 11 minutes 14.299 seconds), which is the value obtained by applying the value of referenceTimeOffset (or RTT) to the @wallclock (e.g., value of @wallclock + value of referenceTimeOffset), as the reference time. Alternatively, if the "@recommendedUpdateInterval" of the reference time information is 60, the V2N terminal can access the reference time entity once every 60 seconds to update / adjust the reference time.

[0195] (2) Example 2

[0196] A V2N terminal can access a specific region (e.g., Seocho-gu, Seoul). The V2N terminal can transmit a designated Bootstrap URI and current location information (e.g., - https: / www.ITS.co.kr / bootstrap / (latitude / longitude of Seocho-gu, Seoul)) related to the specific region to a (Bootstrap) server (or infrastructure).

[0197] The Bootstrap server can provide a URI that can access the location of the reference time entity built within the nearest infrastructure as a return value of the server. In other words, the V2N terminal can receive information (e.g., https: / / www.ITS.co.kr / seocho / SA) from the Bootstrap server that includes its location information and a URI that can access the reference time entity built within the nearest infrastructure as a return value.

[0198] A V2N terminal can obtain an SA channel identical to the template broadcast on a C-V2X channel, and obtain a URI (https: / www.ITS.co.kr / seocho / referenceTime) that can access a reference time entity based on the SA channel (or a channel that can perform V2X communication regardless of the network). The V2N terminal can access the URI and obtain information about the reference time (i.e., the ITS reference time commonly applied to the ITS system determined based on GPS time) through the UTC scheme.

[0199] Meanwhile, the ITS infrastructure (RSU, ITS station, etc.) receives GNSS data through an ultra-high-performance antenna. The infrastructure receives the GPS time within the GNSS data, and the reference time entity can share the ITS reference time determined / set based on the GPS time with devices receiving services from the ITS system and / or the RSU. Here, the ITS reference time can be used as a unified reference time for all V2X devices. The infrastructure can manage the value of the ITS reference time according to a reasonable update cycle and can update it in the form of a JSON (JavaScript Object Notation) file. Meanwhile, the RSU based on PC5 can prepare to transmit data on the ITS reference time provided by the reference time entity to the C-V2X terminal in a push format. The app of the C-V2X terminal (or, PC5 app) can receive information on the reference time by receiving it in a push format from the RSU and perform synchronization as the reference time for all V2X operations.

[0200] The V2N application (app) on the V2N terminal can transmit the current latitude / longitude values ​​to the initialization server via HTTP POST or GET, according to the Bootstrap method in Seocho-gu. The initialization server can then return a JSON file containing the optimal geo-casting server for the user's location and the corresponding reference time. The V2N app receives the reference time information from this file and receives various services with time values ​​synchronized with all road users in the area.

[0201] For example, a V2N terminal may move to another area (e.g., Yongsan-gu) while performing synchronization for V2X operation based on reference time information provided through a reference time entity related to a specific area (e.g., Seocho-gu, Seoul) associated with its location. In this case, the V2N terminal continuously queries the initialization server based on its current location. For example, the V2N terminal may query the initialization server based on https: / www.ITS.co.kr / bootstrap / referenceTime / (longitudevalue)_(latidude value). The initialization server may receive the above query and provide JSON containing information about the reference time or may provide a URI of an infrastructure that can obtain the reference time closest to the location of the V2N terminal. In this case, if the location or coverage of the infrastructure is wide, the reference time information may be updated to reflect an offset for the delay measured through communication with the V2N terminal. The delay offset may be calculated by either the server or the V2N terminal. This operation of calculating an offset for delay and applying the offset to a reference time occurs continuously at a regular interval, and can obtain an optimal reference time that suits the current communication status. In this way, a V2N terminal can obtain reference time information from a corresponding reference time entity or network and synchronize with it as its location moves. All V2X devices within a specific area to which they have moved (e.g., Yongsan-gu, Seoul) can be synchronized based on the reference time information provided by the corresponding reference time entity, and can perform operations for V2X services based on the reference time information.

[0202] Next, referring to FIG. 18, a VRU or a user's V2N terminal having a separate dedicated terminal for V2N communication can obtain a reference time through an application.

[0203] In relation to the above-described method 2, when the application obtains a reference time based on GPS, the V2N terminal can synchronize the reference time with the dedicated terminal (or, the dedicated terminal of the VRU). In this case, a problem that may occur is that since the dedicated terminal receives the reference time obtained through the application of the V2N terminal via Bluetooth or Wifi, etc., a variable of delay related to the reference time may occur. Therefore, the V2N terminal needs to additionally provide @timeOffset, which can compensate for the delay, to the dedicated terminal. For example, the V2N terminal can provide information as defined in Table 6 below to the dedicated terminal.

[0204] ElementSemantics@wallClockTimeMandatoryUTC, reference time acquired by the terminal's App through GPS time@referenceTimeOffsetOptionalTime offset value that can be processed by errors or variables that may occur during the acquisition of GPS time provided by the terminal@recommendedUpdateIntervalOptionalRecommended acquisition interval value when the terminal acts as a reference time server

[0205] Next, an embodiment related to method 2 may be as follows.

[0206] A V2N terminal (or an application of a V2N terminal) can obtain reference time information (Wall clock time, ITS reference time, or GPS time) from a reference time entity through the process of the above-described Method 1. A dedicated terminal of a VRU connected to the V2N terminal can periodically communicate with an application of the V2N terminal to obtain and synchronize the reference time information (wallclockTime, ITS reference time). At this time, the dedicated terminal of the VRU can synchronize the Wall clock (or GPS time, reference time) based on a timeOffset value measured directly or by referring to the referenceTimeOffset value provided by the V2N terminal. Through this synchronization of the reference time, the dedicated terminal of the VRU can also perform operations related to V2X based on a reference time (or Wall clock) that has almost no error with the reference time (or Wall clock) of the C-V2X terminal, thereby performing collision assessment with the C-V2X terminal with a high degree of accuracy.

[0207] For example, the dedicated terminal of the VRU can obtain 141113.999 (14 hours 11 minutes 13.999 seconds) from the "@wallclock" of the reference time information of the V2N terminal. The dedicated terminal of the VRU can obtain 0.3 from the "@referenceTimeOffset" of the reference time information, or obtain 0.3 through calculation of the RTT (e.g., Ping value) with the V2N terminal. In this case, the dedicated terminal of the VRU can set / adjust 141114.299 (14 hours 11 minutes 14.299 seconds), which is the value obtained by applying the value of referenceTimeOffset (or RTT) to the @wallclock (e.g., the value of @wallclock + the value of referenceTimeOffset), as the reference time. Alternatively, if the “@ recommendedUpdateInterval” of the above reference time information is 60, the dedicated terminal of the VRU can access the application of the V2N terminal once every 60 seconds to update / adjust its reference time.

[0208] Figure 19 is a drawing for explaining how the first device sets the reference time.

[0209] The first device may be a device that performs V2N communication over a network based on the Uu interface described with reference to FIGS. 16 to 18. The first device may be wirelessly connected to the network through an application or the like.

[0210] Specifically, referring to FIG. 19, the first device can set a first reference time based on the Network Time Protocol (NTP) (S191). For example, the first device can obtain time information set in relation to NTP from an NTP server via the Internet and set the first reference time based on the time information. Here, the first reference time is network time, and as described above, there may be a certain level of error compared to the GPS-based reference time due to the communication environment, etc.

[0211] Next, the first device can receive a first message from the second device (S193). Specifically, the first device can transmit a message including a bootstrap URI (Uniform Resource Identifier) ​​and the location of the first device to the network in order to receive V2X-related services. In this case, information about a URI for connecting to the second device that is adjacent to the location of the first device can be obtained from the network. Here, the second device can be an infrastructure that provides V2X services as described above or an ITS system (or an ITS station). In this case, the first device can connect to or be connected to the second device based on the URI for the second device provided from the network, and receive the first message from the second device.

[0212] At this time, the first message may include information on the ITS reference time determined based on the GPS time acquired by the second device. In this case, the first device may adjust the first reference time based on NTP to the second reference time based on GPS time (i.e., the GPS-based reference time that is commonly set to be applied in the ITS system) based on the ITS reference time included in the first message (S195). That is, the first device may adjust / change the existing first reference time based on NTP to the second reference time based on GPS time in response to receiving the first message. Alternatively, the first message may further include offset information that needs to be applied in relation to setting / determining the second reference time as defined in Table 5 and / or information on the reception interval of the first message for setting the second reference time. Alternatively, the first device may directly calculate the offset to be applied to the GPS time without being provided with offset information through the first message. For example, the first device may calculate the RTT (Round Trip Time) or the UDP (User Datagram Protocol) datagram acquisition delay with the second device through the exchange of data / messages with the second device. In this case, the first device may determine an offset based on the RTT and / or the acquisition delay, apply the offset to the GPS time to determine the second reference time, and adjust / change the first reference time to the second reference time.

[0213] Next, the first device can transmit a second message based on the adjusted second reference time (S197). The second message can include status information of the first device (information for recognizing the first device, such as mobility information, identification information, etc.) and can be transmitted to peripheral devices via the second device (or a network). Specifically, the first device can transmit the second message including a timestamp set based on the second reference time. In this case, the first device can transmit the second message using a reference time based on GPS time, similarly to C-V2X terminals / devices that perform V2X communication based on the PC5 interface.

[0214] Figure 20 is a drawing for explaining how the second device provides reference time information.

[0215] The second device may be a network / infrastructure / ITS system / reference time entity that provides V2X services via a network as described above. The second device may provide reference time information to V2N devices for synchronizing with a common reference time with C-V2X devices receiving V2X services via the PC5 interface. Meanwhile, as described above, the V2N devices may transmit and receive messages using the NTP reference time (hereinafter, referred to as the first reference time) set based on time information acquired via the Internet.

[0216] Specifically, the second device can receive GPS signals containing GPS time information from GPS / GNSS satellites (S201). As described above, the second device can include a GPS receiver capable of acquiring GPS signals with high accuracy, and can receive GPS signals via the GPS receiver. The second device can acquire GPS time information based on the received GPS signals.

[0217] Next, the second device can transmit a first message including reference time information calculated based on the GPS time information to the first device (S203). As described above, the first message can include reference time information, offset information (or an offset calculated based on an acquisition delay of an RTT, UDP diagram for a V2N device), and / or information about an acquisition time interval of the GPS time information (or reference time information) based on the first message. Meanwhile, the acquisition time interval can be determined based on the number of devices connected to the second devices, the speed of the devices, the density of the devices, etc.

[0218] Next, the second device can receive a second message including status information of the first device from the first device (S205). The second device can forward / transmit the second message to terminals surrounding the first device (or terminals subscribing to a topic set for an area related to the first device). Meanwhile, the second device can receive the second message based on a second reference time based on the GPS rather than a first reference time based on the Network Time Protocol (NTP) when the first message is transmitted to the first device.

[0219] In this way, the proposed invention can synchronize with a common reference time between V2N devices and V2X devices based on a PC5 interface by providing GPS-based time information to V2N devices performing V2X communication through a network. In addition, the proposed invention can effectively improve the accuracy of collision risk detection based on V2X messages and greatly improve the reliability of V2X services by providing services with a common reference time between devices receiving V2X services on an ITS system.

[0220] Examples of communication systems to which the invention applies

[0221] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0222] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0223] Figure 21 illustrates a communication system applied to the present invention.

[0224] Referring to FIG. 21, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0225] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0226] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0227] Examples of wireless devices to which the present invention is applied

[0228] Figure 22 illustrates a wireless device applicable to the present invention.

[0229] Referring to FIG. 22, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 21.

[0230] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chipset designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chipset.

[0231] A first wireless device or first apparatus (100) may include a processor (102), a memory (104), and a transceiver (106). The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 16 to 20.

[0232] Specifically, the processor (102) sets a first reference time based on NTP (Network Time Protocol), controls the transceiver (106) to receive a first message from a second device, and adjusts the first reference time based on NTP to a second reference time based on GPS time based on the fact that the first message includes information about GPS (Global Positioning System) time, and transmits the second message based on the second reference time.

[0233] Alternatively, a processing device controlling the first device (100) may be configured. In this case, the processing device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, based on being executed by the at least one processor, cause the first device to: set a first reference time based on NTP (Network Time Protocol), receive a first message from a second device, adjust the first reference time based on NTP to a second reference time based on GPS time based on the fact that the first message includes information about GPS (Global Positioning System) time, and transmit a second message based on the second reference time.

[0234] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0235] A second wireless device or network (200) may include a transceiver (206), a processor (202), and a memory (204). The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 16 to 20.

[0236] Specifically, the processor (202) can control the transceiver (206) to receive a GPS signal including information about a Global Positioning System (GPS) time, transmit a first message including information about the GPS time to a first device, and receive a second message from the first device. Here, based on the first message being transmitted to the first device, the second message can be received based on a second reference time based on the GPS rather than a first reference time based on the Network Time Protocol (NTP).

[0237] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0238] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For 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 one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0239] One or more memories (104, 204) may be coupled to 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 be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0240] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0241] Examples of wireless devices to which the present invention is applied

[0242] Figure 23 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service (see Figure 21).

[0243] Referring to FIG. 23, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 22 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and an additional element (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 23. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 22. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0244] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 21, 100a), a vehicle (Fig. 21, 100b-1, 100b-2), an XR device (Fig. 21, 100c), a portable device (Fig. 21, 100d), a home appliance (Fig. 21, 100e), an IoT device (Fig. 21, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 21, 400), a base station (Fig. 21, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0245] In FIG. 23, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of one or more processor sets. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0246] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0247] Figure 24 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, car, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0248] Referring to FIG. 24, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 23, respectively.

[0249] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0250] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0251] The wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PAN (personal area networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0252] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0253] In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally / similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

[0254] Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0255] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

[0256] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0257] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. A step of setting the first reference time based on NTP (Network Time Protocol); A step in which a first device receives a first message from a second device; A step of the first device adjusting the first reference time based on the NTP to a second reference time based on the GPS time, based on the first message including information about the GPS (Global Positioning System) time; and A method comprising the step of the first device transmitting a second message based on the second reference time.

2. In paragraph 1, A method, characterized in that the second reference time is determined by applying a specific offset to the GPS time.

3. In paragraph 2, A method, characterized in that the specific offset is determined based on an acquisition delay of a RTT (Round Trip Time) or a UDP (User Datagram Protocol) diagram (Datagram) between the first device and the second device.

4. In paragraph 1, A method, characterized in that the first message further includes offset information related to the GPS time and information on an acquisition time interval of the GPS time.

5. In paragraph 1, A step of transmitting a message including a bootstrap URI (Uniform Resource Identifier) ​​and a location of the first device to the network; and A method characterized by comprising the step of obtaining information about a URI for connecting to a second device adjacent to a location of the first device from the network.

6. In paragraph 5, A method, characterized in that the first message is received based on the URI.

7. In paragraph 1, A method, characterized in that the second message is transmitted to peripheral devices through a server.

8. In paragraph 1, A method, characterized in that the second device is an infrastructure or an Intelligent Transportation System (ITS) for providing a V2X (Vehicle-to-Everything) service.

9. A computer-readable recording medium having recorded thereon a program for performing the method described in Article 1. 10.RF(Radio Frequency) Transmitter / Receiver; and comprising a processor connected to the RF transceiver; A first device, wherein the processor sets a first reference time based on NTP (Network Time Protocol), controls the RF transceiver to receive a first message from a second device, and adjusts the first reference time based on NTP to a second reference time based on GPS time based on the first message including information about GPS (Global Positioning System) time, and transmits a second message based on the second reference time.

11. At least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions causing the first device to: A processing device that sets a first reference time based on NTP (Network Time Protocol), receives a first message from a second device, adjusts the first reference time based on NTP to a second reference time based on GPS time based on the first message including information about GPS (Global Positioning System) time, and transmits a second message based on the second reference time.

12. A step of receiving a GPS signal containing information about GPS (Global Positioning System) time; A step of transmitting a first message including information about the GPS time to the first device; and comprising a step of receiving a second message from the first device; A method wherein, based on the first message being transmitted to the first device, the second message is received based on a second reference time based on the GPS rather than a first reference time based on the Network Time Protocol (NTP).

13. A computer-readable recording medium having recorded thereon a program for performing the method described in Article 12. 14.RF(Radio Frequency) Transmitter / Receiver; and comprising a processor connected to the RF transceiver; The processor controls the RF transceiver to receive a GPS signal including information about a Global Positioning System (GPS) time, transmit a first message including information about the GPS time to a first device, and receive a second message from the first device. A network in which the second message is received based on a second reference time based on GPS rather than a first reference time based on NTP (Network Time Protocol), based on the first message being transmitted to the first device.

15. At least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions causing the network to: Receive a GPS signal including information about GPS (Global Positioning System) time, transmit a first message including information about the GPS time to a first device, and receive a second message from the first device; A processing device, wherein the second message is received based on a second reference time based on the GPS rather than a first reference time based on the Network Time Protocol (NTP), based on the first message being transmitted to the first device.

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