Method for transmitting data in wireless communication system, and device therefor

Abstract

A method for performing communication in a wireless communication system, and a device therefor, according to various embodiments, are provided. The device can request, from a network supporting an issuance- and subscription-based message protocol, a subscription to a first subscription topic, receive a message on the basis of the first subscription topic, receive first metadata on the basis of a metadata topic, and change the first subscription topic to a second subscription topic on the basis of the first metadata.

Description

Method for transmitting data in a wireless communication system and device therefor

[0001] The present invention relates to a method for transmitting and receiving data based on a message protocol in a wireless communication system and a device therefor.

[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] A method according to one aspect of the present invention comprises the steps of requesting a network supporting a publish-and-subscribe based message protocol to subscribe to a first subscription topic; receiving a message based on the first subscription topic; receiving first metadata based on a metadata topic; and changing the first subscription topic to a second subscription topic based on the first metadata; wherein a subscription period of the message can be changed based on the second subscription topic.

[0018] Alternatively, the first metadata includes information about at least one subscription period, and the subscription period of the message is changed to one subscription period corresponding to the second subscription topic among the at least one subscription period.

[0019] Alternatively, the first device is characterized in that it selects one of the at least one subscription cycle based on status information for a geographic area associated with a location of the first device.

[0020] Alternatively, the second subscription topic is characterized in that it is directly defined by the first device based on the selected one subscription cycle.

[0021] Alternatively, the string of the second subscription topic is characterized in that it is defined as a string that adds a string related to the one subscription period to the string of the first subscription topic.

[0022] Alternatively, the first metadata is characterized in that it further includes mapping information between at least one road condition and at least one subscription period.

[0023] Alternatively, the method further comprises receiving second metadata for updating the at least one subscription period based on a change in traffic conditions in a geographic area associated with the first device.

[0024] Alternatively, the message protocol is characterized by being a Message Queuing Telemetry Transport (MQTT) protocol or an Advanced Message Queuing Protocol (AMQP).

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

[0026] According to another aspect, a first device performing the above-described method may be provided.

[0027] According to another aspect, a processing device may be provided for controlling a first device performing the method described above.

[0028] A method by a network according to another aspect may include receiving a subscription request from a first device for a first subscription topic related to a publish-and-subscribe based message protocol; publishing a message to the first device based on the first subscription topic; and publishing first metadata to the first device for changing the subscription topic and subscription period of the first device based on a metadata topic.

[0029] According to another aspect, a network performing the method described above may be provided.

[0030] According to another aspect, a processing device may be provided for controlling a network performing the method described above.

[0031] According to various embodiments, data / messages can be transmitted and received more accurately and efficiently in a wireless communication system.

[0032] 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.

[0033] 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.

[0034] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

[0035] Figure 2 shows the structure of the LTE system.

[0036] Figure 3 shows the structure of the NR system.

[0037] Figure 4 shows the structure of a radio frame of NR.

[0038] Figure 5 shows the slot structure of an NR frame.

[0039] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0040] FIG. 7 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0041] 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.

[0042] 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.

[0043] FIG. 10 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0044] Figure 11 shows a radio protocol architecture for SL communication.

[0045] Figure 12 shows a terminal performing V2X or SL communication.

[0046] Figure 13 shows resource units for V2X or SL communication.

[0047] FIG. 14 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0048] 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.

[0049] Figure 16 is a diagram for explaining the AMQP protocol for transmitting V2N messages, and Figure 17 is a diagram for explaining the MQTT protocol for transmitting V2N messages.

[0050] Figure 18 is a diagram illustrating a method for changing the publication cycle and / or subscription cycle using metadata.

[0051] Figure 19 is a diagram for explaining a method of transmitting metadata based on the packet format of MQTT.

[0052] Figure 20 is a diagram illustrating a method for adjusting the publication cycle of messages / data through metadata based on metadata topics.

[0053] Figure 21 is a drawing for explaining how the first device changes the subscription cycle.

[0054] FIG. 22 is a diagram illustrating how a network performs an operation for changing the subscription cycle of a first device.

[0055] Figure 23 illustrates a communication system applied to the present invention.

[0056] Figure 24 illustrates a wireless device applicable to the present invention.

[0057] Figure 25 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.

[0058] Figure 26 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0059] 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).

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] Figure 3 shows the structure of the NR system.

[0072] 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.

[0073] Figure 4 shows the structure of a radio frame of NR.

[0074] 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).

[0075] 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).

[0076] 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.

[0077] 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

[0078] 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.

[0079] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0080] 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.

[0081] 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.

[0082] 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).

[0083] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0084] 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).

[0085] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0086] Figure 5 shows the slot structure of an NR frame.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] New network characteristics in 6G may include:

[0092] - Satellite integrated network

[0093] - 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).

[0094] - Seamless integration of wireless information and energy transfer

[0095] - 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.

[0096] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0097] - small cell networks

[0098] - Ultra-dense heterogeneous network

[0099] - High-capacity backhaul

[0100] - 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.

[0101] - Softwarization and virtualization

[0102] Below, the core implementation technologies of the 6G system are described.

[0103] - 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.

[0104] - 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.

[0105] 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.

[0106] - Large-scale MIMO technology

[0107] - Hologram beamforming (HBF)

[0108] - Optical wireless technology

[0109] - Free-space optical transmission backhaul network (FSO backhaul network)

[0110] - Quantum communication

[0111] - Cell-free communication

[0112] - Integration of wireless information and power transmission

[0113] - Integration of wireless communication and sensing

[0114] - Integrated access and backhaul network

[0115] - Big data analysis

[0116] - Reconfigurable intelligent surface

[0117] - metaverse

[0118] - Blockchain

[0119] 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.

[0120] - 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.

[0121] - 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.

[0122] - 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).

[0123] 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.

[0124] Below, the SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information are described.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] Figure 12 shows a terminal performing V2X or SL communication.

[0133] 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).

[0134] 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.

[0135] 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.

[0136] 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.

[0137] Figure 13 shows resource units for V2X or SL communication.

[0138] 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.

[0139] 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.

[0140] 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:

[0141] (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.

[0142] (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.

[0143] (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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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).

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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 by itself within the set resource pool. For example, the terminal can select resources by itself 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 by itself within a 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] Below, we describe in detail how a network can provide V2X services based on a message protocol.

[0162] MQTT (Message Queuing Telemetry Transport) protocol / AMQP

[0163] Figure 16 is a diagram for explaining AMQP (Advanced Message Queuing Protocol) for transmitting V2N messages, and Figure 17 is a diagram for explaining MQTT protocol for transmitting V2N messages.

[0164] Referring to Figure 16 (a), the AMQP protocol can be a message protocol that operates as a composition of a publisher, a broker, and a subscriber. The AMQP 1.0 protocol is an open standard protocol for asynchronous message transmission. This protocol standardizes communication between message-oriented middleware and clients, and can provide a high level of reliability, security, and interoperability. AMQP supports message orientation, queuing, routing (point-to-point, publish / subscribe), reliable, and secure transmission. It is widely used in various enterprise messaging applications. The AMQP 1.0 protocol message format is a binary protocol, enabling efficient message processing. The message structure consists of several parts, such as a header, properties, and a body, to support complex communication requirements.

[0165] Meanwhile, C-Road leverages AMQP 1.0 in the transportation and mobility fields to achieve reliable data exchange. They leverage AMQP's extensible and flexible framework for communication between various transportation management systems and devices. Referring to Figure 16 (b), the AMQP protocol format can consist of header, delivery-annotations, message-annotations, properties, application properties, application data, and footer fields. Here, C-Road's application properties can provide metadata describing the message content. Application properties contain information necessary for the receiver to interpret and appropriately process the message, thereby improving the efficiency and accuracy of communication. Furthermore, providing metadata through application properties can play a crucial role in ensuring that messages reach their intended destinations appropriately.

[0166] The MQTT protocol features lightweight network traffic and low bandwidth requirements, making it suitable for resource-constrained environments such as IoT devices and mobile applications. The MQTT protocol is based on a publish / subscribe model, enabling efficient message delivery and ensuring secure message delivery even in unstable network environments. The MQTT protocol is being adopted by various IoT platforms and V2N services due to its simple implementation and lightweight protocol structure, which facilitates widespread adoption.

[0167] Referring to Fig. 17 (a), the MQTT protocol may be a message protocol having a structure that operates as a composition of a publisher (or client), a broker, and a subscriber (or client or client device). Here, subscription and publication of messages may be performed based on topics. For example, a subscriber may receive only messages corresponding to its requested topic from the broker, and a publisher may transmit a message to the broker with a topic set to specify the target to receive its message. For example, a broker may filter messages to be published to a subscriber based on topics.

[0168] Referring to Fig. 17 (b), the MQTT protocol format can be composed of a fixed header, a variable header, and a payload. Referring to Fig. 17 (c), the fixed header of the MQTT protocol can always be included in all MQTT messages and contains message type and message length information. The variable header is optional and can contain different information depending on the message type. The payload contains the actual message data and can be defined according to the message type. The fixed header included in the MQTT control packet can define essential information including the packet type. This is because the 4th to 7th bits of the first byte of the packet define various MQTT states from CONNECT to DISCONNECT. Flags that provide additional information and functions can be set differently depending on the specific control packet type and can play a role in controlling the operation of the packet in detail. Remaining Length can tell you the total length of the control packet, including the variable header and payload.

[0169] The variable header includes a packet identifier and a property length, and the information allocated through these can play a significant role in the processing and routing of the message. In this regard, the MQTT 5.0 standard added a new section that allows user-defined properties (User Properties) to be included in the variable header. The User Properties can allow users to include additional information in the message. For example, a sender can define additional information for specific purposes or management from a service perspective. The User Properties are a way to exchange user-defined data between a client and a server, and can be defined multiple times for various information in a single message. The MQTT standard states that User Properties are not limited and are maintained universally, but can be extended as needed by users. Additionally, control packets of various states, such as CONNECT, CONNACK, PUBLISH, Will Properties, PUBACK, PUBREC, PUBREL, PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK, DISCONNECT, and AUTH, may contain user properties. These properties must be composed of UTF-8 (Unicode Transformation Format - 8-bit) character string pairs, and can be expressed in the form of Key and Value.

[0170] Below, we will explain in detail the data publication / subscription cycle principle of the server / client based on the MQTT protocol.

[0171] A scenario where all clients in a specific road area simultaneously publish (publish) and subscribe (subscribe) using the MQTT protocol can be implemented as follows. This scenario allows vehicles on the road within a given geographic area to exchange data and interact in real time.

[0172] 1. Preparation

[0173] (1) Client Registration and Authentication: Each vehicle must go through an appropriate authentication process before connecting to the MQTT broker. This ensures that the vehicle only allows data transmission and reception from trusted sources.

[0174] (2) Discovery Phase: This phase identifies the geographic region in which the client is located, using geographic location information, corresponding to the geographic region defined by the operator. The client can receive data corresponding to a specific road region. During the discovery phase, the broker or server can provide the client with topic information related to a message protocol (e.g., MQTT protocol).

[0175] (3) Topic Structure Design: Each vehicle or infrastructure can publish and subscribe to specific topics. Topics can be categorized as road / area1 / traffic, road / area2 / safety, etc. For example, MQTT clients in a specific region can simultaneously publish and subscribe to messages through topics specific to that region.

[0176] 2. Publish / subscribe to messages

[0177] (1) Message Publication: A client (or vehicle) can publish messages based on MQTT topics, periodically or when specific events occur, such as road conditions, its own status, or emergency messages. For example, a client can establish a session with the server or broker through authentication and discovery procedures. Using the established session, the client can publish messages based on a specific topic (a topic selected / configured in relation to the client's location in the topic information).

[0178] (2) Message Reception: A client (or vehicle, V2N device) can subscribe to messages published by other vehicles / clients or infrastructure to receive real-time information updates. For example, a client can subscribe to messages based on a specific topic (a topic selected / configured based on the client's location in the topic information).

[0179] (3) Data processing: The received data can be processed on the screen of the app, the vehicle's HMI (Human Machine Interface), navigation system, safety system, or driver assistance system, and delivered to the driver / user or appropriate feedback can be provided.

[0180] Meanwhile, when transmitting a V2X message or V2N message using the above-described message protocol, there may be problems as described below.

[0181] Specifically, in the AMQP protocol, when a sender creates a message, control information can be added in a key-value class structure through the Application-property section. This data (e.g., the control information) is not specifically defined by the AMQP standard and is application-dependent, so it can be used in various ways. The main role of the Application-property is to provide the AMQP broker with information essential for properly routing or filtering messages. For example, the AMQP broker can forward a message to a specific destination queue based on a specific value of the Application-property, or the subscriber can perform actions such as processing or ignoring a subscribed message based on a specific value of the Application-property. In addition, the Application-property can be used to convey additional metadata, such as the priority, expiration date, type, and location reference of the message, between applications. At the C-road stage, metadata for transmitting ITS messages such as Decentralized Environmental Notification Message (DENM) and Infrastructure to Vehicle Information Message (IVIM) can be defined through application properties to provide services such as road guidance, hazard warning, and GLOSA.

[0182] This type of transmission method (e.g., defining / providing metadata through application-properties) has a problem in that the header size tends to increase because the application-properties of AMQP / C-Road define required and optional information in a single template. This can lead to problems that can increase network latency. In applications that require large-scale data transfer and fast processing, the delay caused by this increase in header size can affect the performance of the entire system. If all metadata of C-road's application-properties were included without distinction between required and optional, approximately 70 to 80 bytes of metadata could be included in each transmission packet.

[0183] Meanwhile, the MQTT protocol may require information extension for efficient transmission of the V2N2X layer, as it does not define initialization information for filtering and service layers such as AMQP / C-road. Starting with the MQTT 5.0 standard, a user properties section with a Key=Value format of UTF-8 string pairs has been added to the Variable Header, which allows users to specify the context and processing of the message. If a terminal cannot read the Key, the corresponding part (e.g., the user properties section) may be ignored and the binary area corresponding to the corresponding part may not be accessed.

[0184] In the MQTT protocol, MQTT topics can be used to filter messages. However, filtering based on MQTT topics can be applied before receiving messages. For example, message filtering based on MQTT topics can be performed during the broker's message publishing phase. This can mean that the receiver cannot pre-filter all data. MQTT topic-based message filtering may not be suitable for sophisticated filtering operations that selectively process necessary information or allow the client to select specific information. Furthermore, defining MQTT topics for all filtering information can result in excessively long topic strings. This increases topic management complexity and reduces system efficiency. Therefore, extending message filtering through methods other than MQTT topics can be advantageous from a server perspective, enabling sophisticated and efficient data exchange and data curation with clients. For example, utilizing other curation information, rather than topics, can enable sophisticated and efficient data exchange and data curation between the server and the client. Therefore, by separately defining necessary information using user properties within the V2N2X layer, the length of the topic string can be optimized, thereby improving system efficiency.

[0185] Regarding the publishing and subscription of messages / data, designing and optimizing the principles of the publish (or, pub) and subscribe (or, sub) cycles in the MQTT protocol can play a crucial role in the efficiency and responsiveness of a communication system. These subscription / publish cycles can be influenced by the following factors:

[0186] - Publish interval: The publication interval determines how often specific data / message is transmitted to the MQTT broker. For example, the publication interval should be set short to convey emergency road conditions or accident information. On the other hand, when the vehicle is stationary, the publication interval can be set / determined to a relatively longer period.

[0187] - Subscription cycle or subscription interval: The subscription cycle refers to how often a client receives data / messages from the server. Typically, most systems based on the MQTT protocol can receive data based on the cycle of the client that published the message / data (e.g., the publication cycle) or by automatically routing the data to the client whenever the server has a new message. For example, the subscription cycle can be determined based on the publication cycle of the message publisher or the cycle at which the server routes the received message to other clients.

[0188] Setting these publish / subscribe cycles can be crucial for optimizing the overall performance and efficiency of a system and requires dynamic adjustments based on specific circumstances. However, prior art lacks a specific method or system for adaptively adjusting the publish / subscribe cycle. Consequently, the publish / subscribe cycle is determined solely by the publisher's judgment. This can lead to the following problems:

[0189] - ① If the issuance cycle is determined by the limited recognition scope of the issuing entity, inefficient or incorrect (transmission cycle) message / data transmission may occur.

[0190] ② Synchronization, stable / consistent message queuing: If each issuer adjusts / determines message transmission cycles based on their own judgment, maintaining message synchronization and consistency across the system can become difficult. Furthermore, duplicate message issuance, message omission, or delays in message publishing / subscription can occur. This can undermine the reliability of road safety systems, which must provide accurate, real-time information.

[0191] - ③ Absence of change notification (e.g., lack of notification means for changes in the publication / subscription cycle): If the server / broker does not properly notify changes in the publication cycle, subscribers (e.g., subscribing clients) may misunderstand the frequency or timing of the messages / data they receive, or set the wrong subscription cycle. For example, if messages are published at too slow a cycle, it may be difficult to generate feedback for timely and safe driving actions.

[0192] - ④ Existing V2X communication systems have a fixed data transmission cycle, so they cannot respond flexibly even when road conditions change rapidly, which limits their ability to actively respond to emergency situations.

[0193] - ⑤ The MQTT protocol can provide efficient lightweight messaging, but it does not include a mechanism to dynamically adjust the transmission frequency of data / messages, which may limit optimization of server traffic and / or energy consumption.

[0194] - ⑥ The transmission cycle of static data / messages may not reflect the diversity and volatility of road usage conditions, and may cause unnecessary network load due to data transmission at an unnecessarily high frequency.

[0195] To address these issues, methods and systems that can recognize current road conditions while reducing client load may be needed. For example, a collaborative system approach between the client and server may be necessary. To achieve this, the server may additionally include artificial neural networks (AI), algorithmic analyzers (e.g., digital twins), and V2X managers.

[0196] The following requirements may be considered for the application of this proposed method.

[0197] - Enhanced factors can be defined in the description of the application properties of existing AMQP / C-Road.

[0198] - It can be extended to an MQTT-based V2N2X layer that is more advanced than the application properties. It must also be compatible with existing MQTT receivers.

[0199] - A method can be proposed to minimize inefficient header delivery redundancy in the V2N2X layer compared to AMQP / C-Road.

[0200] - A layer needs to be supported that can filter ITS messages and provide processing guidance, as defined by the V2N2X layer.

[0201] The proposed invention based on the above-described requirements can be applied in the following ways.

[0202] - As a method for extending the V2N2X layer based on MQTT 5.0, V2N2X metadata can be defined by utilizing user properties in the MQTT variable header.

[0203] - By defining it as a UTF-8 key-value pair, as in the definition of MQTT user properties, existing MQTT clients can ignore keys that they cannot read even if they receive them. In this case, (the UTF-8 key-value pair) can be extended to be compatible with existing MQTT receivers.

[0204] - V2N2X metadata can be transmitted separately as two TOPIC tracks by defining required attributes and additional attributes. Required data / messages can be defined for all packets, and additional attributes (e.g., attributes that do not need to be transmitted for every packet, but are not optional attributes) can be defined as TOPICs for other transmission tracks, and metadata can be published / subscribed through the additional attributes. This can reduce redundancy because not all packets need to be received through messages / packets / data every time, and flexible metadata transmission and reception can be enabled through additional topics (e.g., additional attributes). For example, a TOPIC string of metadata defined for an additional attribute for metadata can be obtained by acquiring a TOPIC string included in the Required data during the publication packet phase connecting the initial session, and can subscribe to (or publish) metadata using the acquired TOPIC string. The metadata can have a period independent of the ITS message period, and the period can be changed depending on the attribute (or additional attribute).

[0205] Below, the above-described requirements and proposed methods are described in more detail.

[0206] Figure 18 is a diagram illustrating a method for changing the publication cycle and / or subscription cycle using metadata.

[0207] Before going into a specific description of the proposed method, the following prerequisites and requirements may be required for the application of the proposed method.

[0208] - ① All clients can subscribe to metadata containing information such as '@client ID' and '@interval'. Such metadata can be obtained through MQTT user properties, data elements preceding the payload, and / or separate topics.

[0209] - ② The app server may additionally include an MQTT Temporal client with the same properties as the clients of road users. The Temporal client of the app server has the function of issuing messages / metadata to clients under the management of the app server.

[0210] - ③ The app server can configure a digital twin of the area (or geographical area) it is managing, configure metadata according to appropriate purpose and judgment, and transmit / issue the configured metadata to clients under its management through the Temporal client.

[0211] - ④ The above-described solutions / requirements can be managed based on "@Client ID", and can support the function of provisioning metadata (e.g., metadata for managing individual clients and supporting efficient transmission) rather than relaying data / messages in a publication manner. For example, referring to Fig. 18, meta / C0, meta / C1, meta / C2, and meta / C3 can be topics defined for transmission of metadata provided to individual clients. The app server can use each of meta / C0, meta / C1, meta / C2, and meta / C3 to publish or provision metadata corresponding to each client (via a temporary client).

[0212] - ⑤ The proposed system can be based on protocols such as MQTT / AMQP, can utilize a subscription / publish model for data / message exchange among all vehicles and road users, and the app server must be able to manage and provide traffic data and metadata in real time.

[0213] - ⑥ The app server can analyze various variables such as road conditions, weather conditions, and traffic volume in real time, and based on the analysis results, determine the optimal message / data publication / subscription cycle for clients that are subscribed or under management, and dynamically create and manage metadata for controlling / adjusting such publication / subscription cycle.

[0214] - ⑦ Clients can select the data / message publication cycle / interval that best suits their circumstances based on metadata provided by the app server or broker. Alternatively, clients should be able to change the topics they subscribe to as needed.

[0215] Below, specific methods for dynamically controlling the transmission cycle of messages / data based on the above-described proposed method and requirements are described in detail.

[0216] Figure 19 is a diagram for explaining a method of transmitting metadata based on the packet format of MQTT.

[0217] Referring to Fig. 19 (a), a conventional MQTT packet may include a fixed header of 2 bytes in length and a variable header. The fixed header may include information / sub-fields regarding packet type, flags, and remaining length. The variable header may include values ​​according to the packet type and flags, and may be used to convey detailed information about the message.

[0218] Based on the above-described suggestions, the packet structure for receiving metadata through MQTT extension headers and additional topics for the V2N2X layer can be as shown in Fig. 19 (b). In order to efficiently manage metadata in the V2N2X system, a method may be considered in which metadata is defined as required properties and additional properties, and the metadata of required properties and the metadata of additional properties are transmitted through two separate topic paths, respectively. For example, required data or metadata of required properties must be included in all packets, and additional data or metadata of additional properties do not need to be transmitted repeatedly and can be transmitted through a separately defined topic. This method can reduce redundant data transmission and effectively support the flexibility of metadata transmission.

[0219] The above-described method may require preparatory actions to receive additional metadata via a string of mandatory topics included / defined in the publish packet when connecting the initial session related to MQTT. For example, a topic for metadata (or a metadata topic) may be provided during the setup phase of the mandatory topic defined for transmission of the publish packet for connecting the initial session. A metadata topic defined in this way can support sending and receiving metadata at a frequency changed according to the needs depending on the attribute, independently of the transmission frequency of the ITS message.

[0220] The behavior of the client (or broker, server, or receiver) in this regard may be as follows.

[0221] - The client can perform initialization and filtering roles by parsing V2N2X layer extension data with information from MQTT's User property.

[0222] - The client can receive a string of 'metaTopic' for transmitting required information and metadata in the V2N2X layer extension data.

[0223] - The client can manage TOPICs for message reception and TOPICs for metadata reception separately. For example, metadata related to V2N2X layer data received as TOPIC "ITS / V2N / Tileinfo / meta" can be received through a separately defined topic (e.g., ITS / V2N / Tileinfo / meta). In this system, only essential initialization data is included, and additional metadata can be received through additionally defined topics.

[0224] Below, specific embodiments of the proposed method described above are described.

[0225] Client A connected to an application related to V2N or V2N service can start moving / driving in a region called “Seocho-gu”. Client A can initialize the application to receive ITS messages. Client A can send a connection request (CONNECT) to the MQTT broker, and the MQTT broker can send a connection acknowledgment (CONNACK) to establish / configure a connection with Client A. Client A can obtain information about regional topic creation rules related to “Seocho-gu” to receive information / messages provided by the ITS service. The operator can provide information about a corresponding topic or topic creation rule according to the location information of Client A, and various topic creation rules can be defined according to the provision method of the operator. Client A can transmit a subscription (SUBSCRIBE) request for a (subscription) topic of V2N / tile to the broker (here, tile can mean a receiving section for filtering according to the location information of Client A, for example, means a topic for receiving only V2N packets for the location of the tile). The broker can send a SUBACK response to the SUBSCRIBE request of the client A to the client A.

[0226] Meanwhile, Client B can PUBLISH a V2X or ITS message transmitted / published from another server to the broker. At this time, Client B may be located within the area / geographical region of a potential event adjacent to Client A, and the topic string (Topic String) can be a V2N packet, etc. PUBLISHed as a V2N / tile (e.g., the same topic as Client A's V2N / tile), and the published packet / message may include V2N2X metadata in the User property part. The User property of this published packet may include a key (= metatopic) for which additional metadata is provided. In addition, V2N2X additional metadata may be PUBLISHed as a topic of V2N / tile / metatopic.

[0227] When client B initiates a PUBLISH of a packet (e.g., an MQTT packet) to a topic of V2N / tile, client A can receive packets (e.g., MQTT packets) / messages subscribed to the topic of V2N / tile. Client A can identify a key (=metatopic) that provides additional metadata obtained by parsing the User property part in the MQTT packet and request a SUBSCRIBE to the broker for a topic with the string V2N / tile / metatopic. In this case, the broker can send a SUBACK response to the SUBSCRIBE request of client A, through which client A can establish a subscription to the topic with the string V2N / tile / metatopic. Client A can store the additional metadata received through such subscription as a configuration. An application (App) can obtain consent from the user to apply certain settings (e.g., low power mode based on message interval adjustment) within additional metadata. With such consent, Client A can perform the algorithms and operations provided through the additional metadata and receive corresponding enhanced services through the application (App).

[0228] Below, we describe in detail how to dynamically adjust the transmission cycle / publication cycle of messages / data based on the publish / subscribe method of metadata / additional metadata through the additional topics described above.

[0229] 1. Solution: Adjusting the publish / subscribe cycle through individual metadata.

[0230] In a scenario where all clients share data through publish / subscribe based on the same TOPIC (=A), how can the app server adjust the cycle of publishing / subscribing data / messages at the digital twin's discretion (for example, when composing messages / data with the same Topic A and adjusting the publication cycle, the subscription cycle can also be automatically adjusted)

[0231] Each client can publish messages / data based on a topic corresponding to its location / area. Additionally, if necessary, each client can subscribe to messages / data that can obtain local road condition information through the topic. Furthermore, each client can subscribe to / receive metadata through an additional TOPIC (or metadata TOPIC) for metadata acquisition.

[0232] Each client can be identified by a unique client ID. In this case, the server can create a metadata TOPIC (e.g., client212 / Meta) corresponding to each client ID. Each client can obtain its corresponding metadata TOPIC in advance through a service discovery procedure or an initial configuration procedure, and can periodically receive updates on the publication cycle of messages / data based on the metadata TOPIC. The string of the metadata topic can be defined in the user properties or defined / received according to a policy defined by the business / operator. The metadata can include information about each client's current publication / transmission cycle, network status, traffic conditions, expected changes, etc. The metadata is transmitted in JSON / XML format, and each field of the metadata can include information necessary to adjust the client's transmission cycle.

[0233] For example, the metadata described above can be defined as in Table 5.

[0234] {"metadataId": "SoftV2X_meta1","metaVersion": "1.0",“clientId: “212”,"communicationDetails": {"recommendedTransmissionRange": {"minInterval": "0.1 seconds","maxInterval": "3 seconds"} -> option 1"originalTransmissionInterval": "0.1 seconds""recommendedTransmissionInterval": "3 seconds" -> option 2"adjustmentWindow": "600""trafficCondition": {"level": "low","description": "Light traffic"},"vehicleData": {"speed": "30 km / h","location": "123.42314 N, 118.23123 W"},"networkStatus": {"bandwidth": "10 Mbps","latency": "90 ms"},"environmentalFactors": {"weather": "clear","visibility": "good"},},"updateTimestamp": "2024-04-18T12:30:00Z"}

[0235] Here, metadataId is a unique identifier of metadata, clientId is a unique identifier of the client, originalTransmissionInterval is the current client's message / data issuance / transmission cycle, recommendedTransmissionInterval is a new message / data issuance / transmission cycle recommended based on data analyzed by the server, recommendedTransmissionRange contains the Min and Max values ​​of the new message / data issuance cycle recommended based on data analyzed by the server, trafficCondition contains information about the current traffic conditions around the client, vehicleData contains information about the current speed and location of the client's vehicle, networkStatus contains information about the bandwidth and latency of the network to which the client is connected, environmentalFactors contains information about environmental factors such as current weather and visibility conditions, and updateTimestamp may contain information about the last updated time of metadata information.

[0236] While the proposed methods describe topic-based metadata acquisition, HTTP (HyperText Transfer Protocol)-based metadata acquisition may also be possible. For example, access to HTTP's Rest API (Representational State Transfer Application Programming Interface) can be defined in the user properties mentioned above or acquired through a discovery process, and the metadata can be acquired through the acquired HTTP Rest API. Alternatively, metadata can be acquired through a pre-known access address via a contract.

[0237] Data can be input from various data sources, not just road clients. This data may include information on road traffic conditions, traffic accidents, weather conditions, network conditions, etc. For example, this data may include RSU camera image information, weather conditions, bandwidth, etc. This data can be transmitted to the server in real time, and the server can continuously monitor and analyze the received data to dynamically adjust the message / data generation / transmission cycle for each client.

[0238] When the Digital Twin of the app server determines that the message / data issuing / transmitting cycle needs to be changed from "@issue_interval = 0.1" to "@issue_interval = 1" for "@client_Id=212" depending on road conditions, the Temporal Client of the app server can publish / provision metadata containing information about the change in the issuing cycle to the topic "client212 / Meta" corresponding to "@client_Id=212". The client with Client ID = 212 can receive the metadata through the subscription topic for the metadata, client212 / Meta, and adjust / control the message / data transmission / issuing cycle according to "@issue_interval = 1" included in the metadata.

[0239] The specific process of adjusting the transmission / publication cycle of messages / data using metadata can be as follows.

[0240] (1) Data analysis and metadata creation

[0241] The server can analyze (environmental) information (e.g., traffic conditions, vehicle data, network conditions, environmental factors, etc.) collected from various data sources in real time. Based on the analysis results, the server can generate metadata (SoftV2X_meta1) for a specific client (e.g., client 212). Here, the metadata can include information about communication details such as transmission cycles and traffic conditions.

[0242] (2) Metadata issuance / provisioning

[0243] The server can publish / provision the generated metadata to the client in JSON (JavaScript Object Notation) format. The metadata can include information about the client's identification information, current and recommended publication / transmission cycles, traffic conditions, etc. The metadata can be delivered via a TOPIC (e.g., client212 / Meta) to which the corresponding client is subscribed. For example, the server can generate the metadata, publish / provision the generated metadata as a temporary client, and deliver it to the client.

[0244] (3) Subscribe to / receive metadata

[0245] The client (212) can subscribe to / receive metadata through the subscribed TOPIC (e.g., a metadata topic pre-configured / obtained for transmission of metadata). Here, the metadata may optionally include information about the above-described "@recommendedTransmissionRange" or "@recommendedTransmissionInterval". If the metadata includes "recommendedTransmissionRange", the client (212) can select / set its own appropriate transmission cycle within the publication / transmission cycle defined in recommendedTransmissionRange. In this case, a flexible publication / transmission cycle can be set for the client (212), but the complexity of the system may increase. In contrast, indicating / setting the transmission / publication cycle of messages / data through "recommendedTransmissionInterval" can be clearer and simpler to develop than the "recommendedTransmissionRange" approach. Considering these pros and cons, the two methods can be used in a hybrid manner. For example, the setting of the issue / transmission cycle based on "recommendedTransmissionInterval" is performed with priority, but in a situation where dynamic adjustment of the issue / transmission cycle is required (e.g., when the user requires battery management or the user setting is applied), the flexibility to dynamically adjust the issue / transmission cycle within the range defined in "recommendedTransmissionRange" can also be provided. In this case, the metadata can include information about "@recommendedTransmissionRange" and "@recommendedTransmissionInterval". The maintenance time of the issue / transmission cycle according to the metadata can be set through "adjustmentWindow" included in the metadata.For example, if the adjustmentWindow of the metadata contains a value corresponding to 600 (seconds), the occurrence / transmission cycle according to the metadata may be continued / maintained for 10 minutes.

[0246] (4) Feedback mechanism

[0247] The client (212) can monitor the effectiveness of the publication / transmission cycle adjusted by the metadata. If necessary, the client (212) can transmit / publish metadata containing feedback information for further adjustment of the publication / transmission cycle to the server. In this case, the server can update the publication / transmission cycle based on the feedback information and publish / provision metadata containing information about the updated publication / transmission cycle. For example, the metadata can be published aperiodically as needed.

[0248] For example, in the following cases, the method of adjusting the issuance / transmission cycle of messages / data through the above-described metadata can be performed.

[0249] - If the speed of a vehicle associated with a client (e.g., a vehicle equipped / included with the client) is stable (within ±5 km / h), the frequency of issuing messages / data from the client may be reduced to 0.1 Hz via metadata. Alternatively, even during stable driving, weather conditions may be given priority. For example, sudden deterioration of weather conditions, such as rain / snow, thick fog, or road conditions that indicate sinkholes or ice, may be detected. In this case, the server may increase the frequency of issuing messages / data from the client via metadata even if the speed of the vehicle associated with the client is stable.

[0250] - When a large vehicle (e.g., a large vehicle equipped with / containing a client) changes lanes abruptly, or an emergency vehicle (e.g., an emergency vehicle equipped with / containing a client) requires rapid movement, the server may increase the frequency of issuing messages / data from the client via metadata.

[0251] - If a change in speed of a vehicle associated with a client (e.g., a vehicle equipped / included with the client) exceeds 5 km / h, the server may increase the frequency at which messages / data are issued from the client (e.g., to 1 Hz). Alternatively, if a sudden change of 10 km / h or more is detected, BSM / CAM data or messages may be transmitted immediately and the frequency at which messages / data are issued from the client may be reset to 1 Hz.

[0252] - When the battery level of a device related to a vehicle (e.g., a client terminal mounted / included in a vehicle) is below a certain threshold (e.g., 33%) and is not charged, the server may reduce the frequency of issuing messages / data of the client (e.g., increase the issuing cycle) to save power of the client.

[0253] - If a pedestrian associated with a client is not in a traffic-intensive environment or is moving in a safe environment (e.g., a pedestrian is walking in a park or using a safe, car-free walkway), the server may use metadata to decrease the frequency of the client's message / data transmission. Conversely, if a pedestrian associated with a client is on a busy road, close to a road, or entering an intersection, the server may use metadata to increase the frequency of the client's message / data transmission (e.g., decrease the transmission cycle).

[0254] - If a bicycle associated with a client is riding on a bicycle-only road with no cars, the server can reduce the frequency of issuing messages / data from said client (e.g., increase the issuing cycle) via metadata.

[0255] The method of changing the transmission cycle related to the conditions described above can be considered by considering parameters as shown in Table 6 below.

[0256] Parameters (quantifying each variable) - Time of day (T): Traffic volume by time of day, rush hour, night, etc. - Road type (S): Traffic flow according to each characteristic such as highway, urban road, rural road, etc. - Weather condition (W): Reflecting weather conditions such as rain, snow, fog, clear weather, etc. - Traffic volume (C): Number of vehicles on a road or at a specific time of day - Events and special circumstances (E): Sports events, performances, festivals, etc. - Road hazards (R): Road work, temporary road closures, sinkholes, icy roads, etc.* is the weight interval adjustment value for each variable = if (interval / cycle control value < threshold 1) -> low interval (or, relatively short message / data issuance period) else if (threshold 1 ≤ traffic condition score < threshold 2) -> medium interval else -> high interval (or, relatively long message / data issuance period)

[0257] 2. Solution 2: Adjusting the subscription cycle through subscription topics

[0258] Figure 20 is a diagram illustrating a method for adjusting the publication cycle of messages / data through metadata based on metadata topics.

[0259] Referring to FIG. 20, the server can provide information about multiple subscription cycles or multiple subscription topics as a single metadata for multiple clients, as information related to subscription cycles. Unlike the previously described method, the server provides clients with information about multiple subscription topics related to setting / determining subscription cycles, and each client can select a subscription topic appropriate to its situation from among the multiple subscription topics and subscribe to messages / data based on the selected subscription topic.

[0260] (1) Structure design of metadata topics

[0261] Each client can obtain information about the publication topic and subscription topic during the service discovery process and establish a connection with the server. For example, if a client receives data / messages in the Yangjae-dong area, the publication topic may be set to Yangjae-dong / A, and the subscription topic may also be set to Yangjae-dong / A. Here, the publication cycle and subscription cycle according to the publication topic and subscription topic (the initial publication topic and subscription topic acquired during the initial setup process) may be identical (e.g., 1 second). Meanwhile, according to the method described below, the subscription topic may be changed to Yangjae-dong / A / 0.5 (e.g., 0.5 seconds), thereby adjusting the subscription cycle / interval of the message / data.

[0262] The V2X manager can manage and publish / generate metadata that reflects real-time traffic conditions in each area. The metadata may include information about the transmission / publishing cycles of V2X messages that reflect the current conditions of a certain road area, and may include information defining additional subscription topic strings related to the transmission / publishing cycles.

[0263] (2) Server data analysis and digital twinning, metadata provisioning logic

[0264] The server can collect object recognition data, real-time traffic data, weather information, and road condition information from various sources, including road users, pedestrians, and cameras. In this case, the server can build and monitor a digital twin that aligns with the actual road in real time, both in time and space. The server can then publish appropriate V2X messages and metadata to subscribed clients regarding events occurring within the digital twin.

[0265] (3) Method for obtaining metadata of subscription clients

[0266] A subscription client can adaptively adjust the reception cycle / interval of its data / messages by analyzing the received metadata. For example, the subscription client can determine / select the final subscription cycle based on information about current road conditions, expected traffic volume, and special events. In this case, the client can efficiently adjust the subscription cycle of its messages / data based on the latest traffic information. For example, the metadata may include information about multiple subscription cycles (and / or multiple subscription topics) associated with the subscription client. In this case, the subscription client can select a subscription cycle appropriate to the circumstances of the subscription client among the multiple subscription cycles based on collected / obtained traffic environment information, define a subscription topic corresponding to the selected subscription cycle, and subscribe to messages from the server based on the defined subscription topic. For example, if subscription topic 1 is defined as a subscription topic corresponding to subscription cycle 1, the subscription client can subscribe to a message having a topic associated with subscription topic 1 set for each subscription cycle 1. Meanwhile, the server can also publish a message with the subscription topic 1 set every subscription period 1.

[0267] Metadata related to Solution 2 can be defined as shown in Table 7 below.

[0268] {"metadataId": "SoftV2X_meta1","metaVersion": "1.0","clientId: "212""communicationDetails": {"recommendedTransmission": {"baseInterval": "0.1 seconds","alternativeIntervals": [{"trafficCondition": "normal","recommendedInterval": "0.5 seconds"},{"trafficCondition": "light traffic","recommendedInterval": "2.0 seconds"}]}"networkStatus": {"bandwidth": "10 Mbps","latency": "90 ms"},"environmentalFactors": {"weather": "clear","visibility": "good"},},"publishTimestamp": "2024-04-18T12:30:00Z"}

[0269] Here, metadataId is the unique identifier of the metadata, clientId is the unique identifier of the client, baseInterval is the client's default subscription / transmission cycle, alternativeIntervals is the new subscription / transmission cycle recommended based on data analyzed by the server, and recommendedInterval is the new subscription / transmission cycle value recommended based on data analyzed by the server. trafficCondition contains information about the current traffic conditions around the client, networkStatus contains information about the bandwidth and latency of the network to which the client is connected, environmentalFactors contains information about environmental factors such as current weather and visibility conditions, and publishTimestamp can contain information about the last update of the information contained in the metadata.

[0270] For example, a server can collect real-time traffic data, weather information, and local events in the Yangjae-dong area, and build a digital twin on the server based on the received information (e.g., road condition information). The digital twin can reflect a traffic condition score that takes various factors into account, and the server can define a default cycle of `0.1 seconds`, an alternative cycle of `0.5 seconds`, or `2.0 seconds` based on the traffic condition score. The cycle defined in this way is included in the metadata, and the server can publish the metadata to clients through the topic of Yangjae-dong / meta. Such metadata can be published periodically. A subscribed client can change the current subscription topic to a subscription topic corresponding to a `2.0 second` cycle when traffic conditions are light and weather conditions are good (e.g., subscription topic = Yangjae-dong / A / 1.0 changed to Yangjae-dong / A / 2.0).

[0271] Alternatively, if a sudden rain shower occurs, the server can regenerate and publish metadata. The metadata may define only a baseInterval and not alternativeIntervals. A client subscribed to such metadata can change the subscription topic based on the subscribed metadata (e.g., the subscription topic changes from Yangjae-dong / A / 2.0 to Yangjae-dong / A / 1.0). Later, if the weather improves again and traffic flow improves, the server can publish metadata containing alternativeIntervals with a base period of `0.1 seconds`, alternative periods of `1.0 seconds`, and `3.0 seconds`. In this case, the client can change the subscription period based on the judgment condition. For example, a client subscribed to the metadata can change the subscription topic from Yangjae-dong / A / 1.0 to Yangjae-dong / A / 3.0.

[0272] The above-described proposed method can be expected to have the following technical effects.

[0273] First, in a scenario where all clients subscribe / publish to the same TOPIC (=A) and share data, the app server can adjust / adapt the subscription / publishing cycle / interval (e.g., the clients' message / data subscription / publishing) as a digital twin. In this case, a personalized approach allows for individual data transmission cycle adjustments for each client, maximizing communication efficiency and optimizing network resources. Furthermore, road condition monitoring through digital twins enables the provision of accurate and timely real-time data tailored to each client's location and situation, enabling each client to gain accurate situational awareness. Furthermore, the server can continuously analyze data and dynamically adjust the subscription / publishing cycle in response to changing road conditions. Furthermore, by allowing clients to adjust their transmission cycles, a more personalized communication strategy can be adopted based on each client's conditions and needs.

[0274] Furthermore, a system that allows for adjustment of subscription / publishing cycles via metadata allows for dynamic adjustment of data / message transmission cycles based on real-time changing road conditions, thereby improving the efficiency of traffic information for road users. Furthermore, dynamic adjustment of data / message transmission cycles / intervals can optimize network load, and subscribing clients can effectively explore personalized communication strategies and data / message retrieval methods based on their status within the server's provisioned interval range (or transmission cycle range).

[0275] Figure 21 is a drawing for explaining how the first device changes the subscription cycle.

[0276] As described above, the first device may be a client device that subscribes to and publishes messages based on the message protocol of MQTT or AMQP. The first device may establish a session with a server or network related to the message protocol and then publish or receive messages based on the session. Here, the issuance and reception of the message may be performed based on topic information related to a geographical area, etc. For example, the first device may define a publication topic / subscription topic related to its location during an initial setup procedure with the network and then request the network to subscribe to the defined subscription topic. Thereafter, the first device may receive a message from the server or network based on the subscription topic. In addition, as described above, the first device may also obtain topic information for subscribing to or publishing metadata related to a subscription cycle or a change in a subscription topic through an initial setup procedure or a discovery procedure with the server or network. Meanwhile, the first device may be defined as a client, a client device, or a terminal, as a device that publishes a message to or receives a message from a network based on a message protocol.

[0277] Below, the operation on the first device or client side is described in more detail based on the proposed invention described in FIGS. 16 to 20.

[0278] Referring to FIG. 21, a first device may request a network to subscribe to a first subscription topic (S211). For example, the first device may define a first publication topic and a first subscription topic corresponding to its geographic location based on predefined topic definition rules, and transmit a message / packet requesting subscription to the defined first subscription topic to the network. In this case, the subscription cycle (or reception cycle) of the message based on the first subscription topic may be identical to the message publication cycle of the first device.

[0279] Next, the first device can receive a message from the network based on the first subscription topic (S213). For example, the first device can receive a message from another device published to a publication topic corresponding to the first subscription topic through the network. Here, the message from the other device can include status information of the other device (e.g., mobility information such as device type, speed, location, and direction of movement).

[0280] Next, the first device can receive first metadata (e.g., metadata including information for changing a subscription cycle of the first device) based on the metadata topic (S215). As described above, the first device can obtain information about a metadata topic for subscribing / publishing metadata from the network through an initial setup procedure / discovery procedure. Here, the first metadata can include information about at least one parameter among the parameters defined in Table 7. For example, as defined in Table 7, the first metadata can include information about at least one subscription cycle recommended / suggested for the first device, wherein each of the at least one subscription cycle can be mapped to one specific state information. Alternatively, the first metadata can include information about at least one subscription cycle associated with the first device and at least one subscription topic defined in correspondence with the at least one subscription cycle.

[0281] Next, the first device can change the subscription topic for subscribing to the message based on the first metadata (S217). For example, the first device can select one subscription period based on status information related to the first device (e.g., road / traffic condition information such as road conditions, weather conditions, and traffic volume described above). For example, the first device can determine one state from among a basic state, a normal state, a traffic congestion state, and a dangerous state based on surrounding road conditions (traffic volume such as congestion, smooth traffic, etc.), weather conditions, and event information, and select a subscription period corresponding to the determined one state. For example, when the one state is a traffic congestion state, the first device can select a subscription period mapped to the traffic congestion state from at least one subscription period included in the first metadata. When the first device selects one subscription period from among the at least one subscription period based on the road condition information, the first device can directly define a string of a subscription topic (or a second subscription topic) for subscribing to the message based on the selected subscription period (or a second subscription period). For example, as illustrated in FIG. 20, the first device can directly define the string of the second subscription topic by adding a string for the second subscription period to the string of the first subscription topic. In this case, the first device can change the subscription topic for receiving the message from the first subscription topic to the second subscription topic.

[0282] At this time, the subscription cycle (or, reception cycle) of the message may be changed according to a change in the subscription topic as described above. For example, the subscription cycle of the message may be changed from a first subscription cycle (a subscription cycle corresponding to the first subscription topic) to a second subscription cycle (a subscription cycle corresponding to the second subscription topic, e.g., a subscription cycle selected from at least one subscription cycle, or a subscription cycle corresponding to a cycle-related string included in a string of the second subscription topic) based on the subscription topic being changed from a first subscription topic to a second subscription topic.

[0283] Meanwhile, the network may route messages to devices having corresponding subscription topics, each corresponding to at least one subscription cycle. For example, the network may route messages to a device having a first subscription topic in a first subscription cycle corresponding to the first subscription topic, to a device having a second subscription topic in a second subscription cycle corresponding to the second subscription topic, and to a device having a third subscription topic in a third subscription cycle corresponding to the third subscription topic.

[0284] Alternatively, the network may continuously monitor whether traffic conditions in a geographic area associated with the first device have changed, and if it is determined that traffic conditions have changed after the issuance of the first metadata (e.g., occurrence of adverse weather conditions such as bad weather, fog, or snow, or occurrence of a new event such as a traffic accident), the network may issue second metadata to the first device for updating at least one subscription period according to the first metadata.

[0285] FIG. 22 is a diagram illustrating how a network performs an operation for changing the subscription cycle of a first device.

[0286] As described above, the network may be a server or broker that relays / routes V2X-related messages based on the aforementioned message protocol. The network may transmit / receive messages from devices and, based on the publication topic included in each received message, route the messages to other devices that have subscription topics mapped / corresponding to the publication topic.

[0287] Specifically, referring to FIG. 22, the network may receive a subscription request for a first subscription topic related to a publish-and-subscribe message protocol from a first device (S221). The network may route a message having a publication topic corresponding to the first subscription topic to which the first device has requested a subscription to the first device.

[0288] Next, the network can route messages containing status information of other devices to the first device based on the first subscription topic (S223). For example, the network, as the broker described above, can select messages with topics (e.g., publication topics) corresponding to the first subscription topic from among messages received from other devices, and route the selected messages to the first device.

[0289] Next, the network may issue first metadata based on the metadata topic (S225). For example, as described above, the network may issue the first metadata to a broker as a temporary client and transmit it to the first device. Here, the first metadata may include information related to at least one subscription period recommended / proposed in relation to road conditions based on the analysis results of road conditions, etc., of a geographic area associated with the first device, as described above. For example, the network may collect / analyze information related to road conditions for a geographic area corresponding to each subscription topic and determine at least one subscription period corresponding to each geographic area. In this case, the network may issue first metadata to the first device, including at least one subscription period determined for the geographic area to which the first device belongs, so that the first device can dynamically change / adjust the subscription period of the message. At this time, the network may define at least one subscription topic corresponding to each of the at least one subscription periods. For example, the network may define subscription topic 1 for subscription cycle 1, subscription topic 2 for subscription cycle 2, and subscription topic 3 for subscription cycle 3, and route the messages to the devices according to the subscription cycle of each subscription topic.

[0290] As described above, the network may expect the first device to subscribe to a message according to one of at least one subscription cycle that includes the metadata by publishing metadata using a metadata topic.

[0291] In this way, the proposed invention can efficiently dynamically adjust / change subscription cycles within the standard format of a message protocol simply by performing an operation to change subscription topics based on metadata. Alternatively, the proposed invention can ensure effective and proactive responses to the diversity and variability of road usage conditions by supporting dynamic changes to a device's subscription cycle through metadata within the standard format of a message protocol. Alternatively, the proposed invention can optimize network traffic and energy consumption even within the standard format of a message protocol by supporting dynamic changes to a device's subscription cycle through metadata.

[0292] Examples of communication systems to which the invention applies

[0293] 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.

[0294] 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.

[0295] Figure 23 illustrates a communication system applied to the present invention.

[0296] Referring to FIG. 23, 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.

[0297] 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).

[0298] 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.

[0299] Examples of wireless devices to which the present invention is applied

[0300] Figure 24 illustrates a wireless device applicable to the present invention.

[0301] Referring to FIG. 24, 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. 23.

[0302] 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.

[0303] 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 22.

[0304] Specifically, the processor (102) controls the transceiver (106) to request a subscription to a first subscription topic from a network supporting a publish-and-subscribe based message protocol, receive a message based on the first subscription topic, receive first metadata based on a metadata topic, and change the first subscription topic to a second subscription topic based on the first metadata. Here, the subscription period of the message may be changed based on the second subscription topic. For example, the subscription period of the message may be changed from a first subscription period defined for the first subscription topic to a second subscription period defined for the second subscription topic.

[0305] Alternatively, a processing device may be configured, comprising at least one processor (102) and a memory (104) for controlling a first device. In this case, the processing device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions, wherein the instructions, when executed by the at least one processor, cause the first device to: request a network supporting a publish-and-subscribe based message protocol to subscribe to a first subscription topic, receive a message based on the first subscription topic, receive first metadata based on a metadata topic, and change the first subscription topic to a second subscription topic based on the first metadata. Here, a subscription period of the message may be changed based on the second subscription topic.

[0306] At least one non-transitory computer-readable medium comprises instructions that, when executed by at least one processor, perform operations, wherein the operations may include requesting a network supporting a publish-and-subscribe based message protocol to subscribe to a first subscription topic, receiving a message based on the first subscription topic, receiving first metadata based on a metadata topic, and changing the first subscription topic to a second subscription topic based on the first metadata. Here, a subscription period of the message may be changed based on the second subscription topic.

[0307] 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.

[0308] 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 22.

[0309] Specifically, the processor (202) may receive a subscription request for a first subscription topic related to a message protocol based on publish and subscribe from a first device, publish a message to the first device based on the first subscription topic, and publish first metadata to the first device for changing the subscription topic and subscription period of the first device based on a metadata topic.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] Examples of wireless devices to which the present invention is applied

[0315] Figure 25 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.

[0316] Referring to FIG. 25, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 24 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 additional elements (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. 25. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 24. 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).

[0317] 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. 23, 100a), a vehicle (Fig. 23, 100b-1, 100b-2), an XR device (Fig. 23, 100c), a portable device (Fig. 23, 100d), a home appliance (Fig. 23, 100e), an IoT device (Fig. 23, 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. 23, 400), a base station (Fig. 23, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0318] In FIG. 25, 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 a set of one or more processors. 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.

[0319] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0320] Figure 26 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned or unmanned aerial vehicle (AV), a ship, or the like.

[0321] Referring to FIG. 26, 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. 25, respectively.

[0322] 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.

[0323] 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.

[0324] 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.

[0325] 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.

[0326] 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).

[0327] 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.

[0328] 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.

[0329] 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.

[0330] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In the method using the first device, A step of requesting a subscription to a first subscription topic from a network supporting a publish-and-subscribe based messaging protocol; A step of receiving a message based on the first subscription topic; A step of receiving first metadata based on a metadata topic; and A step of changing the first subscription topic to a second subscription topic based on the first metadata; A method in which the subscription cycle of the above message is changed based on the second subscription topic.

2. In paragraph 1, The above first metadata includes information about at least one subscription cycle, A method, characterized in that the subscription period of the above message is changed to one subscription period corresponding to the second subscription topic among the at least one subscription period.

3. In paragraph 2, A method characterized in that the first device selects one of the at least one subscription cycle based on status information for a geographic area associated with a location of the first device.

4. In paragraph 3, A method, characterized in that the second subscription topic is directly defined by the first device based on the selected one subscription cycle.

5. In paragraph 3, A method characterized in that the string of the second subscription topic is defined as a string obtained by adding a string related to the one subscription period to the string of the first subscription topic.

6. In paragraph 1, A method, characterized in that the first metadata further includes mapping information between at least one road condition and at least one subscription period.

7. In paragraph 1, A method, characterized in that it further comprises the step of receiving second metadata for updating said at least one subscription period based on a change in traffic conditions of a geographic area associated with said first device.

8. In paragraph 1, A method, characterized in that the above message protocol is an MQTT (Message Queuing Telemetry Transport) protocol or an AMQP (Advanced Message Queuing Protocol).

9. In at least one non-transitory computer-readable medium, Contains instructions that perform operations when executed by at least one processor, The above actions are, Request a subscription to the primary subscription topic from a network that supports a publish-subscribe based messaging protocol; Receive messages based on the first subscription topic above; Receive first metadata based on a metadata topic; and Including changing the first subscription topic to a second subscription topic based on the first metadata, At least one non-transitory computer-readable medium, wherein the subscription period of the above message is changed based on the second subscription topic. 10.RF(Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to request a subscription to a first subscription topic from a network supporting a publish-and-subscribe based message protocol, receives a message based on the first subscription topic, receives first metadata based on a metadata topic, and changes the first subscription topic to a second subscription topic based on the first metadata. A first device, wherein the subscription cycle of the above message is changed based on the second subscription topic.

11. In the processing device controlling the first device, at least one processor; and At least one memory connected to said at least one processor and storing instructions that perform operations when executed by said at least one processor; The above actions are, Request a subscription to the primary subscription topic from a network that supports a publish-subscribe based messaging protocol; Receive a message based on the first subscription topic and receive first metadata based on the metadata topic; and Including changing the first subscription topic to a second subscription topic based on the first metadata, A processing device in which the subscription period of the above message is changed based on the second subscription topic.

12. In the method by network, A step of receiving a subscription request for a first subscription topic related to a publish-and-subscribe based message protocol from a first device; A step of routing a message to the first device based on the first subscription topic; and A method comprising: issuing first metadata to the first device for changing a subscription topic and subscription period of the first device based on a metadata topic; 13. In at least one non-transitory computer-readable medium, Contains instructions that perform operations when executed by at least one processor, The above actions are, Receive a subscription request from a first device for a first subscription topic related to a publish-and-subscribe based messaging protocol; routing a message to the first device based on the first subscription topic; and At least one non-transitory computer-readable medium comprising issuing first metadata to the first device for changing a subscription topic and subscription period of the first device based on a metadata topic.

14. In the network, RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, A network in which the processor controls the RF transceiver to receive a subscription request for a first subscription topic related to a publish-and-subscribe based message protocol from a first device, to route a message to the first device based on the first subscription topic, and to issue first metadata to the first device for changing the subscription topic and subscription period of the first device based on a metadata topic.

15. In a processing device that controls a network, at least one processor; and At least one memory connected to said at least one processor and storing instructions that perform operations when executed by said at least one processor, The above actions are, Receive a subscription request from a first device for a first subscription topic related to a publish-and-subscribe based messaging protocol; routing a message to the first device based on the first subscription topic; and A processing device comprising: issuing first metadata to the first device for changing a subscription topic and subscription period of the first device based on a metadata topic.

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