WO2024242513A1 - Method for measuring location using wi-fi nan in v2x communication - Google Patents

Abstract

One embodiment relates to a terminal related to V2X in a wireless communication system, the terminal comprising: at least one processor; and at least one computer memory which can be operatively connected to the at least one processor and stores instructions which, when executed, cause the at least one processor to perform operations, wherein the operations comprise allowing the terminal to: search for a NAN cluster including a first device and a second device; receive NAN SDF subscribe including ranging information from the first device and the second device; measure a relative distance to the first device and a relative distance to the second device on the basis of NAN ranging and an FTM sequence; receive the absolute location of the first device and the absolute location of the second device through NAN SDF follow-up; and determine the location of the terminal on the basis of a relative distance between the terminal and the first device, a relative distance between the terminal and the second device, the absolute location of the first device, and the absolute location of the second device. The terminal derives zero or more contact points between a first circle based on the relative distance between the terminal and the first device and the absolute location of the first device, and a second circle based on the relative distance between the terminal and the second device and the absolute location of the second device, and determines the location of the terminal on the basis of the zero or more contact points and a GPS location.

Description

Location measurement method using WI-FI NAN in V2X communication

The following description is about the operation method and device of a terminal and server related to the location measurement method and procedure using NAN (Neighbor Awareness Network) in V2X (Vehicle-to-Everything).

Wireless communication systems provide various types of communication services, such as voice and data. 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) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi carrier frequency division multiple access (MC-FDMA) systems.

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

V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and objects with built-in infrastructure through wired/wireless communication. V2X can be divided into types such as 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.

Meanwhile, as more and more communication devices require greater communication capacity, there is a growing need for improved mobile broadband communication over existing Radio Access Technology (RAT). Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed, and the next-generation radio access technology that considers improved mobile broadband communication, massive MTC (Machine Type Communication), URLLC (Ultra-Reliable and Low Latency Communication), etc. can be called new RAT (new radio access technology) or NR (new radio). V2X (vehicle-to-everything) communication can also be supported in NR.

The embodiments address a method and procedure for location measurement using Wi-Fi NAN in V2X as a technical challenge.

One embodiment is a terminal related to V2X in a wireless communication system, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: performing a search procedure for a NAN cluster including a first device and a second device by the terminal; receiving a NAN SDF Subscribe including Ranging information from the first device and the second device by the terminal; measuring a relative distance from the first device and a relative distance from the second device based on NAN Ranging and FTM Sequence by the terminal; receiving an absolute location of the first device and an absolute location of the second device by the terminal through NAN SDF Follow-up; And the terminal determines the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device, wherein the terminal derives zero or more contact points between a first circle based on the relative distance from the first device and the absolute location of the first device, and a second circle based on the relative distance from the second device and the absolute location of the second device, and determines the location of the terminal based on the zero or more contact points and the GPS location.

One embodiment is a method for operating a terminal related to V2X in a wireless communication system, wherein the terminal performs a search procedure for a NAN cluster including a first device and a second device; the terminal receives a NAN SDF Subscribe including Ranging information from the first device and the second device; the terminal measures a relative distance with the first device and a relative distance with the second device based on NAN Ranging and FTM Sequence; the terminal receives an absolute location of the first device and an absolute location of the second device through NAN SDF Follow-up; And the terminal determines the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device, wherein the terminal derives zero or more contact points between a first circle based on the relative distance from the first device and the absolute location of the first device, and a second circle based on the relative distance from the second device and the absolute location of the second device, and determines the location of the terminal based on the zero or more contact points and the GPS location.

A nonvolatile computer-readable storage medium storing at least one computer program including instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a terminal, the operations comprising: causing the terminal to perform a search procedure for a NAN cluster including a first device and a second device; the terminal to receive a NAN SDF Subscribe including Ranging information from the first device and the second device; the terminal to measure a relative distance from the first device and a relative distance from the second device based on NAN Ranging and FTM Sequence; the terminal to receive an absolute location of the first device and an absolute location of the second device through a NAN SDF Follow-up; And the terminal determines the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device, wherein the terminal derives zero or more contact points between a first circle based on the relative distance from the first device and the absolute location of the first device, and a second circle based on the relative distance from the second device and the absolute location of the second device, and determines the location of the terminal based on the zero or more contact points and the GPS location.

The terminal can determine the center of a third circle having a diameter equal to a line segment connecting the first contact point near the GPS location and the GPS location as the location of the terminal based on the fact that there are two contact points.

The above terminal can determine the location of the terminal by further considering GPS accuracy and FTM accuracy.

The terminal can correct the position of the terminal adjacent to a position having a higher accuracy among the first contact point and the GPS position.

Based on the fact that the terminal has one contact point, the terminal can determine the one contact point as the location of the terminal without considering the GPS location.

The above one contact point may be a point where the first circle and the second circle are inscribed.

The terminal can determine the center of gravity of a triangle having a line segment connecting the first device and the second device as a base and the GPS location as a vertex as the location of the terminal based on the fact that the contact point is 0.

The above first device and the above second device may be fixed devices.

The above Ranging information may be information that distance will be measured through the NAN Ranging.

The above terminal can calculate RTT (Round trip time) through transmission and reception of Wi-Fi packets including a timestamp through the FTM Sequence, and measure the relative distance to the first device and the relative distance to the second device using the RTT.

The above NAN SDF Subscribe may include range_configuration_parameters corresponding to the above Ranging information.

The above NAN SDF Follow-up may include V2X service data.

In one embodiment, the accuracy of the location measured by GPS by V2X devices is generally low, but by correcting the location through Wi-Fi Aware's FTM (Fine Timing Measurement), more precise location measurement is possible.

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

Figure 1 illustrates a system to which the present disclosure is applied.

Figure 2 shows an example of a tile using a quadtree.

Figure 3 shows an example of how a subscription area is set.

Figure 4 illustrates the V2X protocol stack.

Figure 5 shows an example of Geocasting using MQTT in V2X.

Figures 6 to 8 are drawings for explaining NAN.

Figures 9 to 18 are drawings for explaining embodiment(s).

Figures 19 to 22 are drawings illustrating various devices to which the embodiment(s) can be applied.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, the same or similar components will be given the same reference numbers and redundant descriptions will be omitted. The suffixes "module" and "part" used for components in the following description are given or used interchangeably only in consideration of the ease of writing the specification, and do not have a distinct meaning or role in themselves. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the attached drawings are only for easily understanding the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings.

Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but these terms do not limit the components. The above terms are used only to distinguish one component from another.

When an element is referred to as being "connected" or "coupled" to another element, it should be understood that it can be directly connected or coupled with the other element, but that there may be other elements in between. On the other hand, when an element is referred to as being "directly connected" or "directly coupled" to another element, it should be understood that there are no other elements in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms “comprise” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but it is to be understood that this does not exclude the possibility of the addition or presence of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

A vehicle according to one embodiment of the present specification may be or may be defined as a means of transportation that runs on a road or a track. The vehicle may include an automobile, a ship, an aircraft, a train, a motorcycle, a bicycle, and the like. The vehicle may include an internal combustion engine vehicle powered by an engine, a hybrid vehicle powered by an engine and an electric motor, an electric vehicle powered by an electric motor, and a combination thereof.

A V2X (Vehicle-to-Everything) device according to one embodiment of the present specification may be an existing V2X device, or may mean a device that provides V2X functions and V2X services to users based on software, in which case it may also be referred to as a Soft V2X device. A V2X device may be a UE (User Equipment), an MS (Mobile Station), an MT (Mobile Terminal), a UT (User Terminal), a mobile phone, a laptop, a handheld device, a tablet, a drone, a home appliance, etc. A V2X device may be mounted on a vehicle or an electronic device as an onboard unit (OBU) to provide V2X functions and services to the vehicle. A V2X device placed inside or outside a vehicle may be connected to a vehicle via a wireless interface to provide V2X functions and V2X services to the vehicle.

In various embodiments of the present disclosure, “/” and “,” should be interpreted as representing “and/or”. For example, “A/B” can mean “A and/or B”. Furthermore, “A, B” can mean “A and/or B”. Furthermore, “A/B/C” can mean “at least one of A, B, and/or C”. Furthermore, “A, B, C” can mean “at least one of A, B, and/or C”.

In various embodiments of the present disclosure, “or” should be interpreted as meaning “and/or.” For example, “A or B” can include “only A,” “only B,” and/or “both A and B.” In other words, “or” should be interpreted as meaning “additionally or alternatively.”

Figure 1 illustrates a system to which the present disclosure is applied.

The system includes a UE (111) (or a V2X device/device) and a server (121) (or a V2X server). The UE (111) can communicate with the server (121) via a base station (131) or an RSU (132). The UE (111) can communicate with the base station (131), the RSU (Road Side Unit) (132), a neighboring vehicle (133), and/or a neighboring UE using a wireless communication protocol. There is no limitation on the wireless communication protocol, and may include, for example, DSRC (Dedicated Short Range Communications), C-V2X (Cellular-V2X), WiFi, Bluetooth, and/or 3GPP (3rd Generation Partnership Project) based cellular communication protocols (e.g., WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution), NR (New Radio), etc.).

The server (121) receives V2X messages from one or more UEs (111) within the area it manages. The server (121) can forward one or more collected V2X messages to the subscribed UEs (111).

A V2X message is a message that is transmitted periodically or aperiodically by a UE (111) (or an RSU (132)) to a server (121) and provides status information of the UE (111) (or a device managed by the RSU (132)). For example, the UE (111) can transmit 10 V2X messages per second. The server (121) collects V2X messages from multiple UEs and forwards the V2X messages to subscribed UEs.

The following table shows examples of information elements included in V2X messages. Not all information elements are required, and the names are only examples. Information elements may be added/changed/deleted depending on policy or situation.

designation explanation V2X ID A temporary identifier to identify the UE transmitting this message. Randomly selected by the UE and may change periodically. The size may be 4 octets. position Indicates the location of the UE. May include latitude, longitude, and elevation. Positional Accuracy Includes the quality of various parameters used to model the accuracy of positioning. Velocity Indicates the speed of the UE. Heading Indicates the current heading (direction of motion) of the UE. Path History Defines a geometric path reflecting V2X device's movement over some period of time and/or distance Acceleration Represents the acceleration of the UE. May contain a set of acceleration values along three orthogonal directions of the UE: the longitudinal axis, the lateral axis, and the vertical axis. Device Type Indicates the type of UE. Examples: pedestrian, vehicle, bicycle, etc. Publishing Area The area where the UE transmits V2X messages to the server. The publish area contains one or more tiles at each level.

The V2X message that the UE (111) transmits to the server (121) is called an UL (uplink) V2X message, and the V2X message that the server (121) transmits to the UE (111) is called a DL (downlink) V2X message.

The UE (111) may include a processor (112) and a memory (113). The processor (112) implements the function of the UE (111) and may include one or more software modules. The UE (111) may further include various additional devices depending on the function, such as a display, a user interface, and a wireless modem.

The server (121) includes computing hardware that is connected to one or more base stations (131) and/or RSUs (132) and provides V2X functions and services to the UE (111). The server (121) may be a MEC (Mobile/Multi-access Edge Computing)-based server or a centralized-based server. The server (121) may be called by other names such as a Geocast server, a Soft V2X server, a V2X application server, etc. The server (121) may include a processor (122) and a memory (123). The processor (122) implements the functions of the server (121) and may include one or more software modules.

The processor (112, 122) may include an application-specific integrated circuit (ASIC), a central processing unit (CPU), an application processor (AP), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), a microcontroller, a chipset, a logic circuit, a data processing device, and/or a combination thereof. In the software implementation of the embodiments below, software codes for performing the functions described herein may be stored in the memory (113, 123) and processed by the processor (112, 122).

The memory (113, 123) can store information accessible by the processor (112, 122). The information can include instructions executable by the processor (112, 122) and/or data processed by the processor. The memory (113, 123) can include any form of computer-readable medium that operates to store information. For example, the memory (113, 123) can include a read only memory (ROM), a random access memory (RAM), a digital video disc (DVD), an optical disc, a flash memory, a solid state drive (SSD), a hard drive, and combinations thereof.

MQTT (Message Queuing Telemetry Transport) is used as a message protocol between UE (111) and server (121), but this is only an example. AMQP (Advanced Message Queuing Protocol), HTTP (HyperText Transfer Protocol) and/or vendor specific protocols may be used.

Now, let's describe in more detail the setting of the area for V2X service. Hereinafter, tile refers to the basic geographical unit for setting the subscription area. Hereinafter, the tile shape is shown as a square, but it is only an example. There is no limitation on the shape of the tile, such as polygon or circle.

Figure 2 shows an example of a tile using a quadtree.

A quadtree represents a partition of space in two dimensions by decomposing a map (i.e. a world map) into four equal quadrants, subquadrants, and so on. The size of the quadrants varies depending on the zoom level, and each quadrant corresponds to a tile. Here, we show the cases where the levels are 1, 2, and 3. As the level increases, the size of the tiles decreases. At each level, a unique ID (identifier) is assigned to the tiles. The tile ID can have a number of bits corresponding to the level. For example, each internal node of the quadtree can have four subordinate parts.

The UE can obtain the ID of the tile it is located in based on its location information (e.g., latitude and longitude). The UE and/or the server can adjust the level according to the situation to adjust the size of the area.

In the following examples, the areas for V2X services are as follows.

- Management area: When one or more servers manage the area in a distributed manner to serve a large number of users or a wide area, the area managed by the server. The management area includes one or more tiles.

- Subscription area: The area to which the UE has requested a subscription from the server. The subscription area may be called by other names such as the concerned area, the impact area, and the Geocast area. The subscription area contains one or more tiles. The subscription area may be included in one management area, or may be defined across multiple management areas by multiple servers.

- Publishing area: The area where the UE transmits V2X messages to the server. The publishing area may include one or more tiles at each level. The publishing area may indicate the tile where the UE is currently located. Part or all of the publishing area may overlap with the subscription area.

Figure 3 shows an example of how a subscription area is set.

A first subscription area is set for a first UE (310) (e.g., a left-sloping hash around a person associated with the first V2X device (310)), and a second subscription area is set for a second UE (320) (e.g., a right-sloping hash around a vehicle associated with/corresponding to the second V2X device (320). Each UE can set/change/delete a subscription area periodically or aperiodically (e.g., when its location changes). Each UE can request the server to set/change/delete a subscription area.

The number of tiles included in the first subscription area is 9, and the number of tiles included in the second subscription area is 25, but there is no limitation on the number of tiles included in the subscription area or the shape of the subscription area. The subscription area may include a tile where the UE is located. Alternatively, the subscription area may include one or more tiles excluding the tile where the UE is located.

A first UE (310) can generate a first V2X message and send it periodically to a server. A second UE (320) can generate a second V2X message and send it periodically to a server.

The server may forward one or more V2X messages received within or around the subscription area to UEs associated with the subscription area.

A device that sets up a subscription area may be called a ‘subscriber device’. A device that transmits V2X messages to a server may be called a ‘publisher device’. A UE may be a subscriber device, a provider device, or both a subscriber device and a provider device. The server may forward V2X messages transmitted by provider devices within the management area to the subscriber device.

The server can forward V2X messages of provider devices that are “associated” with the subscription area of the subscriber device to the subscriber device. A provider device that is associated with the subscription area of the subscriber device may be referred to as a “subscribed provider device.” A provider device that is associated with the subscription area of the subscriber device may satisfy at least one of the following conditions (i) to (iii): (i) Part or all of the publish area of the provider device overlaps with the subscription area of the subscriber device. (ii) Part or all of the subscription area of the provider device overlaps with the subscription area of the subscriber device. (iii) The location where the provider device transmits the V2X messages is within the subscription area of the subscriber device.

According to condition (i) or (iii), the server forwards the V2X message received within the first subscription area to the first UE (310). The server forwards the V2X message received within the second subscription area to the second UE (320).

Since the first UE (310) is located within the second subscription area, the server can forward the first V2X message to the second UE (320). The second UE (320) is a subscriber device, and the first UE (310) is a subscribed provider device.

Since the second UE (320) is not located within the first subscription area (which means that condition (i) or condition (iii) is not satisfied), the server does not forward the second V2X message to the first UE (310). (For example, the person may be in the subscription area of the vehicle and the vehicle may receive a V2X message from the person, but the vehicle may not be in the subscription area of the person yet and the person may not receive a V2X message from the vehicle depending on the situation.) That is, by setting different areas or zones to the first V2X device (310) and the second V2X device (320), the second V2X device (320) may recognize the first V2X device (310) but may not recognize the first V2X device (310) yet. This is because the subscription area of the second V2X device (320) is much smaller than that of the first V2X device (310). The second UE (320) is not a provider device of the first UE (310). However, considering condition (ii), the second UE (320) can be a provider device of the first UE (310). (For example, even if conditions (i) and (iii) are not met, the server can still be configured to forward messages from the second V2X device to the first V2X device if condition (ii) is met.)

FIG. 4 illustrates a Soft V2X protocol stack or V2N2X (Vehicle-to-Network-to-Everything) protocol stack that can operate in UE, smartphones, etc. Each layer of the Soft V2X protocol stack will be described with reference to FIG. 4. Here, Soft V2X refers to a V2X communication method in which the method described below is used, and the description below is not limited to the term Soft V2X. In addition, other terms that refer to communication methods corresponding to the description below can also be considered to correspond to Soft V2X in the present invention.

Cellular Modem is a layer (physical layer or media layer) for modems that use cellular networks. Cellular networks are networks that divide regions into multiple cells to form and operate communications networks, where a cell refers to a divided region that includes one base station. Cellular network communication technologies may include 5G NR (New RAT), LTE (Long Term Evolution), etc. Unlike V2X, Soft V2X performs unicast communications.

In the Soft V2X protocol, the network/transport layer uses IP/TCP used in cellular networks.

The TLS (Transport Layer Security) layer is to ensure confidentiality by using transport layer security, and the certificate uses X.509, an ITU-T standard based on public key infrastructure (PKI). In addition, the Soft V2X protocol is configured to perform a Geocast function that transmits messages only to users in a specific area, and uses MQTT (Message Queuing Telemetry Transport), a publish-subscribe based messaging protocol, for this purpose.

Continuing, Soft V2X uses messages defined in SAE J2735 (BSM, PSM, RSA, etc.). SAE J2735 defines signal standards for V2V/V2I communication, including messages, data frames, element formats, and structures, and the main messages are as shown in Table 2 below.

Key Messages Scope of use detail BSM(Basic Safety Message) V2V Provides overall safety-related information, broadcasting communication at 100ms intervals PVD(Probe Vehicle Data) V2I Transmits 'Prove data' (vehicle operation status) collected in the vehicle to the RSU MapData I2V Provides information on intersection and road terrain data SPaT(SinglePhaseAndTiming) I2V Provides information on signal phase and time synchronization of handlers at intersections (in conjunction with MapData) RTCMCorrections
(Real-Time Differential Correction Maritime) I2V Message to provide RTCM correction information PSM(PersonalSafetyMessage) V2P Providing information about pedestrians in danger zones PDM(ProveDataManagement) I2V Messages for managing PVD messages RSA(RoadSideAlert) V2X Support for ad-hoc message generation from public safety vehicles and RSUs SSM(SignalStatusMessage) I2V Used for Response to requests for equipment operation status SRM(SignalRequestMessage) V2I A message for vehicles entering an intersection to obtain service information from the signal controller. TIM(TravelerInformationMessage) I2V Information messages about various traffic information, emergencies, advance road work, etc. CSR(CommonSafetyRequest) V2V Request message for support of safety information exchange data EVA(EmergencyVehicleAlert) V2X Provide information to emergency vehicles ICA(IntersectionVehicleAlert) V2X Provides information on hazardous conditions for vehicles near intersections NMEACorrections I2V Used for transmitting messages in the initial GPS data format over the DSRC channel. testMessages00-15 N/A Use in the form of customized messages for each region Not Assigned N/A Assign when adding new message content

Next, the Classification layer performs an algorithm to generate data necessary for risk assessment, and the Application layer can determine the risk based on the data submitted for classification and notify pedestrians and drivers with smartphones of the risk.

Figure 5 shows an example of Geocasting using MQTT in Soft V2X. In legacy V2X that uses broadcast communication, devices in the same area can naturally receive messages (such as BSM) through the broadcast channel. However, since Cellular networks use unicast communication, Soft V2X can achieve the same effect as broadcasting by performing unicast transmission to all devices in the same area using MQTT.

In order to communicate MQTT, a secure session is first established between all nodes and the server using TLS. Each node first performs the CONNECT process and then can perform the SUBSCRIBE process on a specific topic (S501~S503 in Fig. 5). At this time, the topic selection is selected differently depending on the region. The map can be divided into tiles and the same topic value can be assigned to each tile. Therefore, each node selects a topic according to the tile it is located in and performs SUBSCRIBE. For example, in Fig. 5, Nodes 1, 2, and 3 are all in the same tile (region) and SUBSCRIBE to the same topic 1. (S504~506 in Fig. 5)

When Node1 transmits PUBLISH (BSM) to the MQTT server (S507), the server transmits PUBLISH (BSM) in unicast to all Nodes subscribed to topic1 (S508, S509). Nodes 2 and 3 perform classification and threat assessment based on the received BSM message, and if a risk is detected, they notify the smartphone user (pedestrian, driver). Cars transmit BSM and pedestrians transmit PSM, and these messages basically contain information necessary for risk detection (ID, location, speed, acceleration, direction, etc.).

NAN (Neighbor Awareness Network)

Wi-Fi Aware (NAN; Neighbor Awareness Network, Wi-Fi Aware) is a communication standard of the MAC layer that uses the 802.11 PHY defined by the Wi-Fi Alliance as it is. While the existing Wi-Fi aims for Internet connection through AP, Wi-Fi Aware was developed for the purpose of searching for services and exchanging simple messages between surrounding devices. NAN devices form a NAN cluster, and devices within the NAN cluster can synchronize the transmission and reception sections and advertise (Publish) or subscribe (Subscribe) to search for upper-layer services. It can also send and receive short-length messages such as the NAN SDF (Service Discovery Frame) Follow-up Message. Fig. 6(a) shows the form of the NAN Cluster defined in the standard. In addition, Wi-Fi Aware provides a function called NAN Ranging that measures the distance between NAN devices, so that two NAN devices can measure the distance to each other based on the transmission time of packets when they exchange FTM packets.

Figure 6(b) shows the functional structure defined in the NAN standard. NAN uses the existing physical layer of Wi-Fi as it is, and defines the NAN Engine including the upper MAC (Medium Access Control) layer and search (NAN Discovery), distance (Ranging), and data communication (NAN Data). The NAN Engine provides the NAN API, which provides NAN functions to upper arbitrary applications.

FIG. 7 illustrates an example of a connection type of a V2X service to which the present embodiment can be applied. The V2X service considered in the present disclosure is a service or application that is composed of devices such as vehicles, pedestrians, and fixed facilities and communicates with each other for traffic safety, energy conservation, and mobility efficiency. In the embodiment, it has a connection type of V2I (Vehicle-to-Interface) or V2C (Vehicle-to-Cloud) that exchanges information with other V2X devices via the Internet or cloud, but is not limited thereto, and can be applied to direct vehicle-to-vehicle communication or vehicle-to-infrastructure communication, etc. In the V2X service of the embodiment, the devices of the vehicle and the pedestrian can use various communication methods to connect to the Internet network. For example, in FIG. 7, the pedestrian is connected to the Internet cloud via the mobile communication (LTE/5G) of the smartphone, and the vehicle communicates via the mobile communication of the driver's smartphone or OBU, or C-V2X, WAVE. CCTV or RSU can be connected to the Internet via wired Ethernet.

FIG. 8 illustrates an example of a V2X Service/Application and a communication interface that can be used in the present embodiment. The V2X device considered in the present disclosure supports Wi-Fi and Wi-Fi NAN (Wi-Fi Aware) technology in addition to the communication technology used for existing V2X services. This is a very common situation in existing ICT devices such as smartphones, and devices such as OBUs and RSUs can also support multiple communication interfaces without much difficulty. In the case of existing mobile communication technologies, they are used for V2X services in the same way as before, and the GPS interface is used to measure the location of the V2X device in the same way as before. At this time, NAN (Wi-Fi Aware) can be used to additionally search for services whether nearby V2X devices support the same V2X service, to transmit and receive short-length additional data, and to measure the distance to the counterpart through FTM.

Below, an embodiment of the present invention is described in which a Soft V2X terminal searches for V2X services, measures location, and performs location correction based on NAN.

A terminal according to one embodiment may include at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations.

The above operations can be performed by the terminal performing a search procedure (912 of FIG. 9) for a NAN cluster including a first device (NAN 1 of FIG. 9) and a second device (NAN 2), and the terminal can receive (914, 921) a NAN SDF Subscribe including Ranging information from the first device and the second device.

The above terminal can measure the relative distance to the first device and the relative distance to the second device based on NAN Ranging and FTM Sequence.

Additionally, the terminal can receive the absolute location of the first device and the absolute location of the second device through NAN SDF Follow-up (916, 923).

The terminal can determine the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device.

Here, the terminal can derive zero or more contact points between a first circle based on a relative distance from the first device and an absolute position of the first device, and a second circle based on a relative distance from the second device and an absolute position of the second device, and determine a location of the terminal based on the zero or more contact points and a GPS location.

The above embodiment is illustrated in detail in Fig. 9. First, each step will be examined in detail through a description related to Fig. 9, and a method for determining the position of the terminal will be described.

In step 911, all of these fixed devices are located within the same Wi-Fi transmission range, so they form the same NAN Cluster. In addition, they all participate in and support the same V2X service/application called “com.example.v2xapp”. Step 912) The operation of Publish may be different depending on the policy of the device or service belonging to the NAN Cluster. In this embodiment, an embodiment is one in which NAN1, NAN2, and NAN3 all support unsolicited publish and solicited publish at the same time. In addition, both a method using only solicited publish and a method using only unsolicited publish are included. In addition, NAN1, NAN2, and NAN3 may be subscriber devices rather than devices supporting only publishers, or devices supporting both publishers and subscribers. The embodiment shows an example in which three fixed NAN devices periodically send unsolicited publish. At this time, the SDF Publish message includes the V2X service name “com.example.v2xapp” and ranging information that can measure the relative distance through FTM thereafter.

Step 913 is when NAN4, a moving V2X device, moves around a NAN cluster formed by NAN1, NAN2, and NAN3. At this time, it searches for a surrounding NAN cluster on the Wi-Fi listen channel (ex, CH6 in 2.4GHz) according to the synchronization method defined in Wi-Fi Aware. If a surrounding NAN cluster is found, it synchronizes and participates in the corresponding NAN cluster.

Step 914 is the process in which the NAN4 device actively (solicited) sends a subscription to receive a solicited publish message from a publisher performing the same V2X service in the vicinity. As described above, the NAN SDF Publish/Subscription must include the V2X service name and Ranging information, which is information on future distance measurement through NAN Ranging.

Step 915 represents a process of measuring a relative distance between a NAN4 device and a NAN1 device through NAN Ranging. In the embodiment, the NAN4 device first sends a NAN Ranging Request, and the NAN1 device responds to this by sending a Ranging Response. When the Ranging Request and Response are exchanged in this manner, the two devices calculate the RTT (Round trip time) by transmitting and receiving a Wi-Fi packet including a timestamp through the FTM Sequence. Through this, NAN4 can calculate the relative distance from NAN1. Optionally, the NAN 4 device can inform the NAN1 device of the calculated relative distance through a Ranging Report. In the present embodiment, the NAN 4 sends the Ranging Request first, but the invention is not limited thereto, and the NAN1 device can also send the Ranging Request first to measure the distance and send the measured result to the NAN 4 device through a Ranging Report.

Step 916 is a process of sending the absolute location of the NAN1 device to NAN4 through a NAN SDF Follow-up message. As described above, the location of NAN1 is used as a reference location for other mobile devices, so it must be precise location information where NAN1 is installed. The NAN SDF Follow-up may include the BSM or PSM message described above, and may also include additional information specialized for V2X services. In an embodiment, the NAN4 device that receives this NAN SDF Follow-up message can know the absolute location information corresponding to the latitude and longitude of NAN1 and the relative distance from the NAN1 device confirmed through the previous FTM. In the embodiment, the absolute location is confirmed by performing SDF Follow-up after distance measurement through FTM, but it is also technically possible to perform SDF Follow-up first and then check the relative distance through FTM. The FTM process can be performed more than once, because the relative distance also changes as the location of the moving NAN4 device changes. Packets used in this FTM process are processed with the highest priority within the device and protocol stack to minimize transmission and processing delays.

Steps 921 and 922 represent the process of performing the same process that was performed between NAN4 and NAN1 between NAN4 and NAN2.

As described above, by the procedure illustrated in FIG. 9, the terminal can know the relative distance from the first device, the relative distance from the second device, the absolute position of the first device, and the absolute position of the second device.

Accordingly, the terminal can derive zero or more contact points between a first circle based on the relative distance from the first device and the absolute position of the first device, and a second circle based on the relative distance from the second device and the absolute position of the second device, as described above, and determine the location of the terminal based on the zero or more contact points and the GPS location.

For example, based on the fact that there are two contact points, the terminal may determine the center of a third circle having a diameter equal to a line segment connecting a first contact point close to the GPS location and the GPS location as the location of the terminal. The terminal may further consider GPS accuracy and FTM accuracy to determine the location of the terminal. In addition, the terminal may correct the location of the terminal adjacent to a location having a higher accuracy among the first contact point and the GPS location.

Fig. 10 shows an example with two contact points, Fig. 11 shows an example with one contact point, and Figs. 12 and 13 show examples with zero contact points. The terms used in each drawing are as follows.

- Loc _GPS (NAN4): NAN4's own location acquired through its own GPS interface.

- Loc _absolute (NAN1): Absolute location (latitude, longitude, altitude) of NAN1 device. When NAN1 is installed as a fixed device, the exact location is entered.

- Loc _absolute (NAN2): Absolute location (latitude, longitude, altitude) of the NAN2 device. When NAN2 is installed as a fixed device, the exact location is entered.

- Distance _NAN1->NAN4 : Relative distance between NAN1 and NAN4, distance measured through FTM

- Distance _NAN2->NAN4 : Relative distance between NAN2 and NAN4, distance measured through FTM

- Loc _FTM (NAN4), Loc _{FTM_Opposite} (NAN4): Two points calculated using the equation of a circle using the values of the absolute position and the relative position. An example is a case where two circles meet at two points. In this case, among the two points A and B, the point of contact closer to Loc _GPS (NAN4) is defined as Loc _FTM (NAN4), and the point of contact farther from Loc _GPS (NAN4) is defined as Loc _{FTM_Opposite} (NAN4). The Loc _FTM (NAN4) point becomes the expected location of NAN4 calculated using FTM. There must be at least one point of contact between the two circles, but there may be cases where there is no point of contact depending on the difference in measurement time or the movement of NAN4 during measurement.

- Loc _real (NAN4): The location of the real NAN4 corrected according to the location correction method in this disclosure.

- Loc _real : Corrected location of NAN4 device based on the above information

Referring to Fig. 10, it is determined within a circle whose diameter is Loc _GPS and Loc _FTM . If the accuracy of the location measured via GPS and the location measured via FTM are the same, Loc _real can be determined as the center of the gray circle, but the location can be adjusted depending on the accuracy of each interface, the difference in environmental factors, and the policy in determining Loc _real . That is, if the accuracy of FTM in Fig. 10 is relatively higher than that of GPS, Loc _real is determined as a location moved in the direction of Loc _FTM from the center of the circle. Conversely, if the accuracy of GPS is relatively high, Loc _real is determined as a location moved in the direction of Loc _GPS . In addition, the accuracy between NAN1 and FTM and between NAN2 and FTM can also differ. This can differ depending on signal strength, such as RSSI included in Wi-Fi packet transmission. In this case, a weight is applied in the direction measured by the positioning/distance with high accuracy, and Loc _real is adjusted and determined. If you obtain FTM distances from three or more fixed devices via Wi-Fi Aware, more precise location determination is possible.

As another example, based on the fact that the terminal has one contact point, the terminal can determine the one contact point as the location of the terminal without considering the GPS location. The one contact point may be a point where the first circle and the second circle are circumscribed or inscribed. In this regard, FIG. 11 illustrates a case where the circle has one contact point when calculating the FTM location based on information acquired from two fixed-position devices in NAN4. If the two fixed devices, NAN1 and NAN2, and the mobile device, NAN4, are positioned in a straight line, the location calculated through FTM becomes one. That is, Loc _FTM (NAN4) and Loc _{FTM_Opposite} (NAN4) become the same point. In this case, Loc _FTM is determined as the corresponding contact point without comparing it with its own GPS location to determine a separate Loc _FTM .

을 그린다. 이때 원의 둘레와 맞닿는 점 A와 점B를 계산하여 찾을 수 있다. 이 점A, 점B, NAN4 기기에서 GPS로 수신한 위치인 Loc_GPS 을 꼭지점으로 하는 삼각형을 구할 수 있게 된다. 이 삼각형의 무게중심인 도 12의 별표 위치를 Loc_real 로 결정 할 수 있다. 본 개시에서는 삼각형의 무게중심을 Loc_real 로 결정하는 예를 보였으나, 이에 한정하지 않고 앞서 설명한 것과 같이 오차의 차이, 환경적인 요인, 정책 등에 따라서 가중치를 적용하여 Loc_real 변경되어 결정될 수 있다.As another example, the terminal can determine the center of gravity of a triangle having the line segment connecting the first device and the second device as its base and the GPS location as its vertex as the location of the terminal based on the fact that the contact point is 0. In this regard, FIG. 12 shows an example of a case where there is no contact point between two circles when a circle with each distance (Distance _NAN1->NAN4 , Distance _NAN2->NAN4 ) as its radius is expressed based on information received from two fixedly located devices during calculation. The reason why such a contact point occurs is - 1) it occurs because the distance between the two fixed devices is far, 2) a large error occurs in performing FTM with the fixed device, 3) the mobile body (NAN4) moves while performing FTM with each fixed device, etc., and various other reasons. In this case, the Loc _FTM calculated based on the contact point of the circle as described above cannot be derived. In this case, the actual location can be corrected by the following method. A straight line connecting the absolute positions of the two fixed devices

Draw. At this time, points A and B that touch the circumference of the circle can be calculated and found. It is possible to obtain a triangle with points A, B, and Loc _GPS, which is the location received by GPS from the NAN4 device, as vertices. The center of gravity of this triangle, the star location in Fig. 12, can be determined as Loc _real . In this disclosure, an example of determining the center of gravity of the triangle as Loc _real is shown, but it is not limited thereto, and as explained above, Loc _real can be changed and determined by applying weights depending on the difference in error, environmental factors, policies, etc.

을 그린다. 이때 원의 둘레와 맞닿는 점 A와 점B를 계산하여 찾을 수 있다. 이 점A, 점B, NAN4 기기에서 GPS로 수신한 위치인 Loc_GPS 을 꼭지점으로 하는 삼각형을 구할 수 있게 된다. 이 삼각형의 무게중심인 도 13의 별표 위치를 Loc_real 로 계산할 수 있다. 본 개시에서는 삼각형의 무게중심을 Loc_real 로 결정하는 예를 보였으나, 이에 한정하지 않고 앞서 설명한 것과 같이 오차의 차이, 환경적인 요인, 정책 등에 따라서 변경될 수 있다.Figure 13 is similar to the above, in which the two circles have 0 points of contact and one circle is inside the other circle. In this case, Loc _real can also be inferred similarly to what was explained above. A straight line connecting the absolute positions of two fixed devices

Draw. At this time, points A and B that touch the circumference of the circle can be calculated and found. It is possible to obtain a triangle with points A, B, and Loc _GPS, which is the location received by GPS from the NAN4 device, as vertices. The center of gravity of this triangle, the star location in Fig. 13, can be calculated as Loc _real . In this disclosure, an example of determining the center of gravity of the triangle as Loc _real is shown, but it is not limited thereto and may be changed according to the difference in error, environmental factors, policy, etc. as explained above.

Fig. 14 is an example of a NAN cluster configuration according to the above embodiment. In the embodiment of Fig. 14, all devices perform V2X services/applications (e.g., com.example.v2xapp) through an existing mobile communication network as shown in Fig. 14, and at the same time, all devices additionally have a Wi-Fi Aware (NAN) interface. Among them, NAN1, NAN2, and NAN3 devices have fixed locations and form a cluster according to the NAN standard. NAN4 (vehicle) and NAN5 (pedestrian) are moving entities, and when they are within the Wi-Fi transmission range of the NAN cluster while moving, they search for and synchronize with the cluster according to the NAN standard. After synchronization, each device performs NAN service search through publish and subscribe. NAN1 (901), NAN2 (902), and NAN3 (903) devices are devices with fixed locations, such as roadside RSU devices or traffic lights. (904) The device is a V2X device that moves, such as a vehicle or pedestrian.

Each device is a device that performs V2X service with existing communication methods such as mobile communication or Ethernet as described above, and additionally has a Wi-Fi Aware interface. In addition, these NAN1, NAN2, and NAN3 devices are devices installed by service providers, governments, local governments, etc., so the location of the corresponding device can be known relatively accurately, and the absolute location of the corresponding device at the time of installation can be input into an API defined in a setting file within the device. In the embodiment, the latitude and longitude of the location of NAN1 are 37.5353445, 126.8473708, NAN2 is installed at 37.5353714, 126.8473008, and NAN3 is installed at 37.5360714, 126.8477988. The latitude and longitude can be expressed as setAbsoluteLocation (bool movable, double latitude, double longitude, double elevation).

Continuing, FIG. 15 details the search for an existing V2X service/application through the NAN service search among the above descriptions. In FIG. 15, V2X Device A and V2X Device B are existing V2X service component terminals. For example, they can be a vehicle OBU, a smartphone mounted on a vehicle, a pedestrian's smartphone, an RSU located on the roadside, a traffic light, and the like. The device performs a service by connecting to the Internet or the Cloud based on existing mobile communication, or performs a service through vehicle-to-vehicle communication or vehicle-to-infrastructure communication. If the device requires location information, it can confirm its own location through a positioning interface that the existing device has, such as GPS or GNSS. As described above in FIG. 4, the V2X Device proposed in the invention supports both a mobile communication interface and a NAN interface, and can be connected to the NAN interface through a NAN Engine. In the embodiment, the service name of the V2X service/application is exemplified as “com.example.v2xapp”. The service can perform subscription and publication according to the API or method defined in the NAN standard. By including the service name in this publish/subscribe, the V2X device can search for the service.

The NAN standard largely defines three publishing methods.

1) In the case of unsolicited publish, an entity providing or operating a service periodically publishes a service without a request from another entity. In Fig. 6(a), the V2X Service/Application of Device A calls the Publish API to the NAN Engine and includes its service name, “com.example.v2xapp”. The NAN Engine periodically transmits publish to surrounding devices even if there is no request from other surrounding devices. At this time, a V2X Device using the same service searches for the service and notifies the V2X Service/Application if it subscribes to the same service based on matching_filter or service name.

2) In the case of solicited publish, there is a request from a subscriber to search for a service, and a device that provides/participates in the same service as the service of the request performs a publish in response to this. In the figure, V2X Device B calls the Subscribe API to the NAN Engine from the V2X Service/Application at a certain point in time. At this time, the service name is transmitted including com.example.v2xapp. The subscribe is transmitted to the surrounding NAN devices, and at this time, V2X Device A that provides/participates in the same service responds with SDF Publish in response to the service search.

3) If a subscribe request comes while performing an unsolicited publish by using 1) and 2) together, a solicited publish can be responded to.

When the above service search is completed, Device A and Device B can send and receive additional messages. This means that SDF Follow-up can send and receive additional information required for the service after the service search. For example, location information, sensor information, or additional information for the service can be sent between V2X services/applications without a separate Wi-Fi session establishment.

The SDF Publish, SDF subscribe, and SDF Follow-up messages used for service discovery follow the format of the NAN standard, and Table 3 shows examples of primitives of the main settings to support V2X services.

NAN SDF Publish:
service_name: A string in UTF-8 format representing the name of the V2X service/application (ex: com.example,v2xapp)
matching_filter_tx: Hash value for matching service response conditions provided/participated in
matching_filter_rx: Hash value for filtering subscribe messages
service_speicif_info: Contains specific information about V2X services
configuration_parameter
- publish type: Both unsolicited and solicited transmissions
- discovery range: any NAN devices within range
- solicited transmission type: unicast or multicast
- Announcement period: reasonable short duration (ex 100ms)
- NAN Ranging flag: set to 1 (NAN ranging is mandatory)
- Awake DW Interval: set to 1, 2, 4, 8 and 16
- Further Service Discovery flag: set to 1
- NAN Discovery flag: set to 0
range_configuration_parameters
- ranging resolution - Determines the accuracy required from the ranging
- raging interval - maximum interval between two ranging measurements
- raging indication condition - Continuous, Ingress, Egress, both_ingress_egress
- geofence description - inner threshold, outer threshold
NAN SDF Subscribe: service_name: A string in UTF-8 format indicating the name of the V2X service/application (ex: com.example,v2xapp)
matching_filter_tx: Hash value for matching service response conditions provided/participated in
matching_filter_rx: Hash value for filtering subscribe messages
service_speicif_info: Contains specific information about V2X services
configuration_parameter:
- subscribe type: Passive or Active
- discovery range: any NAN devices within range
- query_period: reasonable period
- NAN Ranging flag: set to 1 (NAN ranging is mandatory)
- Awake DW Interval: set to 1, 2, 4, 8 and 16
- NAN Discovery flag: set to 0
range_configuration_parameters
- ranging resolution - Determines the accuracy required from the ranging
- raging interval - maximum interval between two ranging measurements
- raging indication condition - Continous, Ingress, Egress, both_ingress_egress
- geofence description - inner threshold, outer threshold
NAN SDF Follow-up Service ID: Hash value of service_name found through service search
Instance ID: Publish ID or Subscribe ID
Requestor Instance ID: Requestor's Publish ID or Subscribe ID
Service Control
- A value indicating whether the current SDF is publish, subscribe, or follow-up. If it is follow-up, it is indicated as 0b10.
- Displays whether a matching filter exists, whether a Service Response Filter exists, whether a Service Info exists, Discovery Range settings, and whether a bind bitmap exists in bitmap format.
Binding Bitmap: Value for binding with the searched service.
Matching Filter Length: Matching filter length
Matching Filter
Service Response Filter
Service Info Length
Service Info: Transmission of service-specific data (V2X service data)

After service discovery, the NAN SDF Follow-up message can transmit and receive additional data specific to the discovered V2X service. The NAN SDF Follow-up message is transmitted and received based on the Service ID and Instance ID of the discovered service, and the maximum size of the message that can be sent at one time is limited to 255 bytes according to the standard. Fig. 16 shows the format of the BSM (Basic Safety Message) or PSM (Personal Safety Message) of the V2X service through the NAN Follow-up message format. The NAN Service Discovery frame has the form of an IEEE 802.11 public action frame, and the OUI Type specifies the NAN frame in the header as 0x13. It also includes one or more NAN attributes. The following shows an embodiment of the NAN Follow-up message for a Soft V2X service. What is proposed in this disclosure is a method for transmitting a safety message (ex. BSM; Basic Safety Message or PSM; Personal Safety Message) used in V2X through a NAN Follow-up message. Alternatively, it may include messages containing information such as the location (latitude, longitude, altitude), speed, direction, acceleration, and device characteristics of the V2X entity, without being limited to the message format defined in the standard.

During this service search process, the search requester can check whether the searched device is a fixed device or a mobile device. For example, when using BSM or PSM, the value in BasicVehicleClass, which is a data type that indicates the type of vehicle, i.e., the type of V2X device, can be indicated as “Other V2X Equipped Device Types”, “infrastructure-TypeUnknown”, “infrastructure-Fixed”, or “infrastructure-Movable” for fixed equipment. The search requester, the Subscriber, parses the BSM or PSM message included in the NAN SDF, and if the type of the corresponding device is a fixed device, determines that the latitude and longitude values included in the BSMcoreData of the corresponding device are absolute locations that can be reliably referenced.

Another example is the case of using the Service Specific Message in Fig. 6. In the case of the Service Specific Message, it can be specifically defined in the V2X service or similar service, and this can be as exemplified in Tables 4 and 5 below. The corresponding value can be encoded and decoded according to the method defined by the service or system.

Parameter Description Device ID An ID value that can distinguish the device Fixed Device Device is fixed or mobile ex) 0 (fixed) Latitude Latitude of the device Longitude Hardness of the device Elevation Altitude of the device Accuracy Location accuracy … …

Parameter Description Device ID An ID value that can distinguish the device Fixed Device The device is a fixed device or a mobile device ex) 1 (mobile) Latitude Latitude of the device Longitude Hardness of the device Elevation Altitude of the device Accuracy Location accuracy Transmission Transmission status of the device (Drive, Parking, Reverse.) Speed Movement speed Heading Direction of movement Angle The degree of bend of the handle Brake Whether the brakes are working Size Size of the device Path Movement route … …

Figure 17 shows the process of searching for services provided by NAN and measuring distance based on FTM (Fine Timing Measurement). After searching for services through the Publisher and Subscriber described in the previous chapter, the two devices can perform Raging Measurement operation to check how far apart they are from each other. For Raging, FTM defined in IEEE 802.11 can be used, and NAN (Wi-Fi Aware) devices can optionally support FTM.

Step 1 in Figure 17 is about the connection and service operation of V2X services using existing mobile communications.

Step 2 is the process of searching for V2X services using mobile communication through the NAN interface, similar to Step 1, using the NAN service search method described in the previous section. At this time, the Ranging Information attribute must be included in SDF Publish and SDF Subscribe for service search.

Step 3 is the Ranging Measurement process via NAN. In general, a NAN device can perform both the role of an initiator that initiates FTM and a responder that responds to it, and in this embodiment, a subscriber that subscribes to service discovery acts as a NAN Ranging Initiator. After the Ranging Request and Ranging Response, the two devices exchange FTM packets for Ranging according to the method defined in IEEE 802.11. At this time, the distance between the two devices is calculated based on the time stamp in the packet.

Afterwards, through step 4, additional messages can be exchanged through the SDF Follow-up described in the previous section. In the case of this Follow-up message, it can be performed after or before the Ranging step 3 depending on the settings or message transmission order.

Fig. 18 is a flowchart showing a position correction algorithm according to one embodiment.

Step 1801 is the process initiated by the V2X device to determine whether it is a mobile device.

Step 1811 is the process of adding the absolute position of the device during installation or setup, as described in the previous section, if it is a fixed device. This absolute position is a position that has been precisely adjusted in advance to the actual position of the fixed device. This position information is then used for reference purposes by the mobile device.

Step 1812 is the process of configuring a Wi-Fi Aware cluster in an environment with fixed devices or a mix of fixed and mobile devices.

Step 1813 is the process by which a fixed device publishes the V2X service through solicited or unsolicited publish.

In step 1814, check whether the fixed device receives a subscription from another device. If no subscription is received, continue to wait and perform the publish process. If a subscription is received, move to step 1815.

Step 1815 is a process of transmitting and receiving to calculate the absolute position and relative distance of the corresponding fixed device through NAN Ranging and NAN SDF Follow-up proposed in the invention described in the previous section. When the response is completed for the subscribing device, the corresponding fixed device performs publishing again.

Step 1821 is a process of determining the location of the V2X device if it is a mobile device and has a positioning interface such as GPS. In the embodiment, the Loc _GPS location is determined.

Step 1822 is the process of searching for the surrounding NAN Cluster described in the previous section, synchronizing with the cluster, and searching for V2X services. This process follows the Wi-Fi Aware standard, and publishes the V2X service/application name performed by the device.

Step 1823 determines whether a device participating in the same V2X service in the vicinity is found through NAN service search. If not found, periodic or aperiodic service search can be re-executed.

Step 1824 is the process of measuring the distance to the device through FTM when a device supporting the same V2X service supporting NAN is found in the vicinity. Then, if the counterpart device has an absolute location (latitude, longitude), the absolute location of the device is confirmed through NAN SDF Follow-up.

Step 1825 checks whether two or more fixed devices or devices with absolute positions are found in the vicinity through such service search. As described in the previous section, the proposal of the present invention measures the distance to two or more devices with absolute positions to correct the position.

Step 1826 calculates the point of contact of the circles using the equation of the circle as described in the previous section, if two or more counterparts are found.

Step 1827 is the process of determining whether the number of contact points of the circle is 1 or more or whether there are no contact points.

Step 1828 is the process of finding the FTM-based location when there is more than one contact point of the circle, through which the V2X device can determine the Loc _FTM .

Step 1829-1 is the process of finding the center of the circle based on the position obtained through FTM and the position obtained through GPS.

Step 1829-2 is for the case where the number of contact points of the circle is 0, in which case the center of gravity of the triangle with the connecting line of the two fixtures and the contact points A, B of the circle and the GPS position as vertices is calculated as described in the previous section.

Step 1831 is the process of determining the policy for performing the actual detailed position correction. AccuracyGPS is the accuracy of the current position obtained through GPS and is determined by the number of GPS satellites and the strength of the signal. ThreasholdGPS is a value determined by the system or implementation. If the accuracy is higher than the threshold, it means that the position confirmed through GPS is sufficiently accurate. AccuracyFTM is the accuracy of the distance obtained through the current Wi-Fi FTM and the accuracy of the FTM varies depending on the Wi-Fi bandwidth, Delay, etc. If the Accuracy value is greater than the threshold, it means that the current Wi-Fi connection is fast enough to measure the FTM, so reliable distance measurement is possible. (AccuracyGPS > ThresholdGPS) && (AccuracyFTM > ThresholdFTM) means that both positioning methods are sufficiently accurate. In this case, proceed to step 1832.

Step 1832 is when the final corrected position is calculated, and since both GPS and FTM are sufficiently reliable, the final correction is made to the center of the circle of FTM-GPS if there is more than one previously calculated contact point, or to the center of gravity of the triangle if there are 0 contact points.

이 참이면 GPS가 FTM보다 정확한 위치 판단이 가능하다는 의미이고, 단계 1842 최종 위치 보정에서 GPS 위치에 가중치를 주어 보정한다. 이 가중치의 계산방법이나 정도는 시스템의 설정이나 구현에 따라 달라지게 된다.The operation of step 1841 is to compare which of the current GPS and FTM positioning reliability is more reliable. That is,

If this is true, it means that GPS can determine the location more accurately than FTM, and in step 1842, the GPS location is weighted and corrected in the final position correction. The calculation method or degree of this weight will vary depending on the system settings or implementation.

Step 1843 is the opposite case where the position accuracy of FTM is higher than that of GPS, and in this case, the position correction is weighted more toward FTM than GPS.

In a real environment, both GPS and FTM have errors depending on the satellite reception status, transmission environment, etc., and neither Loc _FTM (NAN4) nor Loc _GPS (NAN4) can accurately represent the position of a V2X device. In this disclosure, we propose an algorithm that minimizes the error of these two positioning methods and obtains a Loc _real value close to the actual position. This algorithm is applicable to a device that can perform both GPS and FTM positioning via Wi-Fi Aware. In this disclosure, an embodiment applied to V2X service has been mainly described, but applicable services are not limited to V2X, and can be applied to indoor/outdoor positioning, IoT, mobile, UAM, drones, airplanes, ships, etc.

In addition, although the embodiment exemplifies a fusion algorithm of positioning methods via GPS and Wi-Fi Aware, the technology of the invention is not limited to GPS and Wi-Fi FTM, and can be applied to all technologies that use a combination of two or more positioning methods, such as GPS+UWB, UWB+Wi-Fi, and Wi-Fi-Bluetooth.

Examples of communication systems to which the present disclosure applies

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

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

Fig. 19 illustrates a communication system (1) applied to the present disclosure.

Referring to FIG. 19, a communication system (1) applied to the present disclosure includes a wireless device, a base station, and a network. Here, the wireless device means 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 Thing) 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. Portable devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, 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.

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). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

Wireless communication/connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f)/base stations (200), and base stations (200)/base stations (200). Here, the 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 the wireless communication/connection (150a, 150b, 150c), a wireless device and a base station/wireless device, and a base station and a base station can transmit/receive wireless signals to/from each other. For example, the 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 disclosure.

Examples of wireless devices to which this disclosure applies

FIG. 20 illustrates a wireless device applicable to the present disclosure.

Referring to FIG. 20, 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. 19.

A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and/or one or more antennas (108). The processor (102) controls the memory (104) and/or the transceiver (106), and may be configured to implement the descriptions, functions, procedures, suggestions, 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). Additionally, 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 codes including instructions for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem/circuit/chip 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 disclosure, a wireless device may also mean a communication modem/circuit/chip.

The second wireless device (200) includes one or more processors (202), one or more memories (204), and may additionally include one or more transceivers (206) and/or one or more antennas (208). The processor (202) may be configured to control the memories (204) and/or the transceivers (206), and implement the descriptions, functions, procedures, suggestions, 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). Additionally, 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 codes including instructions for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present 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 disclosure, a wireless device may also mean a communication modem/circuit/chip.

Hereinafter, 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 operational 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 operational 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, suggestions and/or methodologies 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, suggestions, methods and/or operational flowcharts disclosed herein.

The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The 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 the one or more processors (102, 202). The descriptions, functions, procedures, suggestions, 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 operational flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more of the following: included in one or more processors (102, 202), or stored in one or more memories (104, 204) and driven by one or more of the processors (102, 202). The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and/or sets of instructions.

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 comprised of 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.

One or more transceivers (106, 206) can transmit user data, control information, wireless signals/channels, etc., as described 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 described in the descriptions, functions, procedures, suggestions, methods and/or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled 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, and the like, as described 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) may 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 processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or filter.

Examples of vehicles or autonomous vehicles to which this disclosure applies

Fig. 21 illustrates a vehicle or autonomous vehicle to which the present disclosure applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned/unmanned aerial vehicle (AV), a ship, etc.

Referring to FIG. 21, 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).

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.), servers, etc. 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, a light 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.

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 a driving plan based on the acquired data. The control unit (120) can control the driving 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, the sensor unit (140c) can acquire vehicle status and surrounding environment information during autonomous driving. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on the newly acquired data/information. The communication unit (110) can transmit information on the vehicle location, autonomous driving route, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc. based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

Examples of AR/VR and vehicles to which this disclosure applies

Fig. 22 illustrates a vehicle to which the present disclosure applies. The vehicle may also be implemented as a means of transportation, a train, an aircraft, a ship, etc.

Referring to FIG. 22, the vehicle (100) may include a communication unit (110), a control unit (120), a memory unit (130), an input/output unit (140a), and a position measurement unit (140b).

The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with other vehicles or external devices such as base stations. The control unit (120) can control components of the vehicle (100) to perform various operations. The memory unit (130) can store data/parameters/programs/codes/commands that support various functions of the vehicle (100). The input/output unit (140a) can output AR/VR objects based on information in the memory unit (130). The input/output unit (140a) can include a HUD. The position measurement unit (140b) can obtain position information of the vehicle (100). The position information can include absolute position information of the vehicle (100), position information within a driving line, acceleration information, position information with respect to surrounding vehicles, etc. The position measurement unit (140b) can include GPS and various sensors.

For example, the communication unit (110) of the vehicle (100) can receive map information, traffic information, etc. from an external server and store them in the memory unit (130). The location measurement unit (140b) can obtain vehicle location information through GPS and various sensors and store them in the memory unit (130). The control unit (120) can generate a virtual object based on the map information, traffic information, vehicle location information, etc., and the input/output unit (140a) can display the generated virtual object on the vehicle window (1410, 1420). In addition, the control unit (120) can determine whether the vehicle (100) is being driven normally within the driving line based on the vehicle location information. If the vehicle (100) abnormally deviates from the driving line, the control unit (120) can display a warning on the vehicle window through the input/output unit (140a). In addition, the control unit (120) can broadcast a warning message regarding driving abnormalities to surrounding vehicles through the communication unit (110). Depending on the situation, the control unit (120) can transmit vehicle location information and information regarding driving/vehicle abnormalities to relevant organizations through the communication unit (110).

The embodiments described above can be applied to various mobile communication systems.

Claims (14)

In a wireless communication system, for a terminal related to V2X, at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, The terminal performs a search procedure for a NAN cluster including a first device and a second device; The terminal receives a NAN SDF Subscribe including Ranging information from the first device and the second device; The terminal measures the relative distance to the first device and the relative distance to the second device based on NAN Ranging and FTM Sequence; The terminal receives the absolute position of the first device and the absolute position of the second device through NAN SDF Follow-up; and Determining the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device; Including, The terminal derives zero or more points of contact between a first circle based on a relative distance from the first device and an absolute position of the first device, and a second circle based on a relative distance from the second device and an absolute position of the second device. A terminal that determines the location of the terminal based on the above 0 or more contact points and GPS locations. In the first paragraph, The terminal is a terminal, based on the fact that there are two contact points, which determines the center of a third circle having a diameter equal to a line segment connecting a first contact point close to the GPS location and the GPS location as the location of the terminal. In the second paragraph, The above terminal is a terminal that determines the location of the terminal by further considering GPS accuracy and FTM accuracy. In the third paragraph, The terminal is a terminal that corrects the position of the terminal adjacent to a position having a higher accuracy among the first contact point and the GPS position. In the first paragraph, A terminal, wherein the terminal determines the one contact point as the location of the terminal without considering the GPS location, based on the fact that the terminal has one contact point. In paragraph 5, The above one contact point is a terminal where the first circle and the second circle are inscribed. In the first paragraph, The terminal determines the center of gravity of a triangle having a line segment connecting the first device and the second device as a base and the GPS location as a vertex as the location of the terminal based on the fact that the contact point is 0. In the first paragraph, A terminal wherein the first device and the second device are fixed devices. In the first paragraph, The above Ranging information is information that the terminal will measure the distance through the above NAN Ranging. In the first paragraph, The terminal calculates RTT (Round trip time) through transmission and reception of Wi-Fi packets including timestamps through the FTM Sequence, and measures the relative distance from the first device and the relative distance from the second device using the RTT. In the first paragraph, The above NAN SDF Subscribe is a terminal including range_configuration_parameters corresponding to the above Ranging information. In the first paragraph, The above NAN SDF Follow-up is a terminal that includes V2X service data. In a wireless communication system, a method of operating a terminal related to V2X, The terminal performs a search procedure for a NAN cluster including a first device and a second device; The terminal receives a NAN SDF Subscribe including Ranging information from the first device and the second device; The terminal measures the relative distance to the first device and the relative distance to the second device based on NAN Ranging and FTM Sequence; The terminal receives the absolute position of the first device and the absolute position of the second device through NAN SDF Follow-up; and Determining the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device; Including, The terminal derives zero or more points of contact between a first circle based on a relative distance from the first device and an absolute position of the first device, and a second circle based on a relative distance from the second device and an absolute position of the second device. A method for determining the location of the terminal based on the zero or more contact points and GPS locations. A nonvolatile computer-readable storage medium storing at least one computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a terminal, The above actions are, The terminal performs a search procedure for a NAN cluster including a first device and a second device; The terminal receives a NAN SDF Subscribe including Ranging information from the first device and the second device; The terminal measures the relative distance to the first device and the relative distance to the second device based on NAN Ranging and FTM Sequence; The terminal receives the absolute position of the first device and the absolute position of the second device through NAN SDF Follow-up; and Determining the location of the terminal based on the relative distance from the first device, the relative distance from the second device, the absolute location of the first device, and the absolute location of the second device; Including, The terminal derives zero or more points of contact between a first circle based on a relative distance from the first device and an absolute position of the first device, and a second circle based on a relative distance from the second device and an absolute position of the second device. A storage medium for determining the location of the terminal based on the zero or more contact points and GPS locations.

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