Method for V2X service and server using the same

Abstract

A server for a vehicle-to-everything (V2X) service receives a subscription request for requesting to subscribe to the V2X service from a first V2X device, and sets a subscription area for the first V2X device. The server publishes at least one V2X message published by at least one second V2X device associated with the subscription area to the first V2X device.

Description

Technical Field

[0001] The present disclosure relates to a method for a vehicle-to-everything (V2X) service and a server using the method. Background Art

[0002] A vehicle is a device that moves passengers from one place to another. A representative example is a car. Vehicle-to-everything (V2X) communication technology, which means vehicle-to-object communication, refers to a technology in which vehicles communicate with other vehicles, pedestrians, road infrastructure, servers, etc. to provide a range of services.

[0003] For V2X, standardization organizations such as the Institute of Electrical and Electronics Engineers (IEEE), the Third Generation Partnership Project (3GPP), etc. provide various communication specifications. Dedicated Short Range Communication (DSRC) is a communication standard protocol based on IEEE 802.11p. Cellular-V2X (C-V2X) is a communication standard protocol based on the 3GPP cellular communication protocol. Generally, V2X focuses on vehicle safety through direct communication between vehicles, but recently V2X includes vehicle-to-infrastructure communication that communicates with peripheral devices via a network.

[0004] Attempts are being made to expand V2X technology to apply to pedestrians and other electronic devices, rather than simply for vehicle safety (eg, vehicle-to-vehicle and vehicle-to-peripheral device). Summary of the invention

[0005] Technical issues

[0006] The present disclosure provides a method for a vehicle-to-everything (V2X) service and a server using the method.

[0007] Technical Solution

[0008] In one aspect, a server for V2X services includes: a processor; and a memory, the memory being operatively coupled to the processor and configured to store instructions, which when executed by the processor, cause the server to perform functions. The functions include the following steps: receiving a subscription request for requesting to subscribe to a V2X service from a first V2X device; configuring a subscription area for the first V2X device; receiving at least one V2X message published by at least one second V2X device associated with the subscription area; and publishing at least one V2X message to the first V2X device.

[0009] On the other hand, a method for V2X service includes the following steps: receiving a subscription request for requesting subscription to V2X service from a first V2X device; configuring a subscription area for the first V2X device; receiving at least one V2X message published by at least one second V2X device associated with the subscription area; and publishing at least one V2X message to the first V2X device.

[0010] Beneficial Effects

[0011] V2X services can be provided to a wider range of users and vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A system to which the embodiment of the present specification is applied is shown.

[0013] Figure 2 An example of a system architecture of a V2X device and a V2X server is shown.

[0014] Figure 3 An example of tiles using a quadtree is shown.

[0015] Figure 4 An example is shown in which a subscription area is set.

[0016] Figure 5 is a flowchart illustrating a method for V2X service according to an embodiment of the present specification.

[0017] Figure 6 A message format according to an embodiment of the present specification is shown.

[0018] Figure 7 An example in which a subscription area is changed is shown.

[0019] Figure 8 An example in which LOD is applied is shown.

[0020] Fig. 9 An example is shown in which a subscription area is set.

[0021] Fig.10 Another example in which a subscription area is set is shown.

[0022] Fig.11 Another example in which a subscription area is set is shown.

[0023] Fig.12 Another example in which a subscription area is set is shown.

[0024] Fig.13 An example of handover between V2X servers is shown. DETAILED DESCRIPTION

[0025] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same figure numbers regardless of the figure numbers, and repeated descriptions thereof will be omitted. The suffixes "module" and "unit" of the components used in the following description are given or mixed only in consideration of the convenience of writing the specification, and they themselves do not have different meanings or functions. In addition, when describing the embodiments disclosed in this specification, if it is determined that the detailed description of the related known technology may confuse the subject matter of the embodiments disclosed in this specification, its detailed description will be omitted. In addition, the drawings are only for the convenience of understanding the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the drawings.

[0026] Terms including ordinal numbers (such as first, second, etc.) may be used to describe various elements, but the elements are not limited by the terms. The above terms are only used for the purpose of distinguishing one component from another.

[0027] When an element is referred to as being "connected" or "coupled" to another element, it is understood that it can be directly connected or coupled to another element, but other elements may exist between them. On the other hand, when it is mentioned that a certain element is "directly connected" or "directly coupled" to another element, it should be understood that there are no other elements in between.

[0028] Unless the context clearly dictates otherwise, a singular expression includes a plural expression.

[0029] In the present application, terms such as "include" or "have" are intended to indicate the existence of features, quantities, steps, operations, components, parts or a combination thereof described in the specification, but it should be understood that this does not exclude the possibility of adding or existing one or more other features, quantities, steps, operations, components, parts or a combination thereof.

[0030] A vehicle according to an embodiment of the present specification may be defined as a means of transport that travels on a road or track. The vehicle may include a car, a ship, an airplane, a train, a motorcycle, a bicycle, etc. The vehicle may include an internal combustion engine vehicle having an engine as a power source, a hybrid vehicle having an engine and an electric motor as a power source, an electric vehicle having an electric motor as a power source, and a combination thereof.

[0031] The vehicle-to-everything (V2X) device according to an embodiment of the present specification refers to a device that provides V2X functions and V2X services to users based on software, and is also referred to as a SoftV2X device. The V2X device can be implemented based on hardware and / or software in an electronic device operated by a user (such as a user equipment (UE), a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a cellular phone, a laptop, a handheld device, a tablet computer, a drone, consumer electronics, etc.). The V2X device can be installed on a vehicle or an electronic device as an on-board unit (OBU) to provide V2X functions and services to the vehicle. The V2X device disposed inside or outside the vehicle can be connected to the vehicle through a wireless interface to provide V2X functions and V2X services to the vehicle.

[0032] Figure 1 A system to which the embodiment of the present specification is applied is shown.

[0033] The system includes a V2X device 100 and a V2X server 200. The V2X device 100 can communicate with the V2X server 200 through a base station 310 or a roadside unit (RSU) 320. The V2X device 100 can communicate with the base station 310, the RSU 320, the neighboring vehicle 350 and / or the neighboring V2X device using a wireless communication protocol. The wireless communication protocol is not limited. The wireless communication protocol may include dedicated short-range communication (DSRC), cellular-V2X (C-V2X), WiFi, Bluetooth and / or a cellular communication protocol based on the third generation partnership project (3GPP) (e.g., wideband code division multiple access (WCDMA), long term evolution (LTE), new radio (NR), etc.).

[0034] The V2X server 200 receives one or more V2X messages from the V2X devices 100 within the management area. The V2X server 200 may forward the collected one or more V2X messages to the subscribing V2X devices 100.

[0035] The V2X message may be periodically or aperiodically sent by the V2X device 100 (or the RSU 320) to the V2X server 200, and is a message that provides status information of the V2X device 100 (or a device managed by the RSU 320). For example, the V2X device 100 may send 10 V2X messages per second. The V2X server 200 collects V2X messages from a plurality of V2X devices and forwards the V2X messages to subscribing V2X devices.

[0036] The following table shows examples of information elements included in a V2X message. Not all information elements are required and the names are just examples. Information elements may be added / changed / deleted depending on policy or circumstances.

[0037] [Table 1]

[0038]

[0039] A V2X message transmitted by the V2X device 100 to the V2X server 200 is referred to as an uplink (UL) V2X message, and a V2X message transmitted by the V2X server 200 to the V2X device 100 is referred to as a downlink (DL) V2X message.

[0040] The V2X device 100 may include a processor 110 and a memory 120. The processor 110 implements the functions of the V2X device 100 and may include one or more software modules. The V2X device 100 may also include various additional devices (such as a display, a user interface, and a wireless modem) according to the functions.

[0041] The V2X server 200 is connected to one or more base stations 310 and / or RSU 320, and includes computing hardware that provides V2X functions and V2X services to the V2X device 100. The V2X server 200 may be a server based on mobile / multi-access edge computing (MEC) or a centralized server. The V2X server 200 may be referred to as other names such as a Geocast server or a SoftV2X server. The V2X server 200 may include a processor 210 and a memory 220. The processor 210 implements the functions of the V2X server 200 and may include one or more software modules.

[0042] The processors 110 and 210 may include an application specific integrated circuit (ASIC), a central processing unit (CPU), an application processor (AP), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a microcontroller, a chipset, a logic circuit, a data processing device and / or a combination thereof. In the software implementation for the following embodiments, the software code for executing the functions described herein may be stored in the memories 120 and 220 and executed by the processors 110 and 210.

[0043] The memories 120 and 220 may store information accessible to the processors 110 and 210. The information may include instructions executable by the processors 110 and 210 and / or data processed by the processors. The memories 120 and 220 may include any form of computer-readable media operable to store information. For example, the memories 120 and 220 include read-only memory (ROM), random access memory (RAM), digital video disk (DVD), optical disk, flash memory, solid-state drive (SSD), hard disk drive, and combinations thereof.

[0044] Figure 2An example of a system architecture of a V2X device and a V2X server is shown. Each module can be implemented in software, stored in a memory, and executed by a processor. Not all modules are required. Some modules can be omitted or modified, and more modules can be added. The name of each module is only an example and not a limitation.

[0045] The V2X device 400 includes a user interface (UI) module 410 , an application module 420 , a message layer module 430 , a client module 440 , and a network stack module 450 .

[0046] The UI module 410 may provide the user with the status, warnings, etc. of the V2X service and receive user input. The application module 420 may use the received message to perform risk assessment. The message layer module 430 processes the sending / receiving of messages.

[0047] The client module 440 performs client functions to support V2X services. The client module 440 includes an information collector 441, an area calculator 443, and a message queue telemetry transmission (MQTT) client protocol 444. The information collector 441 collects the location, sensor, and / or external information of the V2X device 400. The area calculator 443 determines a subscription area in which a V2X message is received from a V2X server. The MQTT client protocol 444 implements the MQTT client protocol.

[0048] The V2X server 500 includes a server module 510 and a network stack module 550. The server module 510 performs server functions to support V2X functions. The server module 510 includes a client manager 511, a message queue 512, and an MQTT server protocol 513. The client manager 511 manages clients connected to the V2X server 500. The message queue 512 includes a queue for storing messages to be relayed to the client, and manages the messages. The MQTT server protocol 513 implements the MQTT server protocol.

[0049] The network stack modules 450 and 550 implement IP network interfaces such as Transmission Control Protocol / Internet Protocol (TCP / IP) and User Datagram Protocol / Internet Protocol (UDP / IP).

[0050] MQTT is used as a message queue protocol, but this is only an example. Advanced Message Queuing Protocol (AMQP), Hypertext Transfer Protocol (HTTP), and / or vendor-specific protocols may be used.

[0051] Now, setting an area for V2X services will be described in more detail. In the following, a tile refers to a geographical basic unit for setting a subscription area. In the following, a rectangle is shown in the form of a tile, but this is only an example. There is no limitation on the shape of the tile, for example, a polygon or a circle.

[0052] Figure 3 An example of tiles using a quadtree is shown.

[0053] A quadtree represents the division of a two-dimensional space by decomposing a map (i.e., a world map) into four equal quadrants, sub-quadrants, etc. The size of the quadrants varies depending on the zoom level, and each quadrant corresponds to a tile. Here, levels 1, 2, and 3 are shown. The larger the level, the smaller the size of the tile. At each level, a unique ID is assigned to the tile. The tile ID may have a number of digits corresponding to the level.

[0054] The V2X device may obtain the ID of the tile it is located in based on its location information (eg, latitude and longitude). The V2X device and / or the V2X server may adjust the size of the area by adjusting the level according to the situation.

[0055] In the following embodiments, the area of ​​V2X service is defined as follows.

[0056] -Management area: An area managed by a V2X server. A management area contains one or more tiles.

[0057] -Subscription area: The area to which a V2X device requests to subscribe to a V2X server. A subscription area may be referred to by other names such as an area of ​​interest, an area of ​​influence, or a geographic broadcast area. A subscription area contains one or more tiles. A subscription area may be included in one management area and may be defined across multiple management areas managed by multiple V2X servers.

[0058] - Publication area: The area where the V2X device publishes V2X messages to the V2X server. The publication area may contain one tile in each level. The publication area may indicate the tile where the V2X device is currently located. Some or all of the publication area may overlap with the subscription area.

[0059] Figure 4 An example is shown in which a subscription area is set.

[0060] The first subscription area is set to the first V2X device 710, and the second subscription area is set to the second V2X device 750. Each V2X device may set / change / delete a subscription area periodically or aperiodically (e.g., when its position is changed). Each V2X device may request the V2X server to set / change / delete a subscription area.

[0061] 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 the number of tiles included in the subscription area or the shape of the subscription area is not limited. The subscription area may include the tile where the V2X device is located. Alternatively, the subscription area may include one or more tiles other than the tile where the V2X device is located.

[0062] The V2X server may forward one or more V2X messages received in or around the subscription area to the V2X device corresponding to the subscription area. The V2X server delivers the V2X message received in the first subscription area to the first V2X device 710. The V2X server delivers the V2X message received in the second subscription area to the second V2X device 750. The V2X server may deliver a V2X message whose publishing area belongs to the subscription area to the V2X device.

[0063] Each V2X device may receive a V2X message announced by a device in and / or around the subscription area through the V2X server. The first V2X device 710 may generate a first V2X message and periodically send the first V2X message to the V2X server. The second V2X device 750 may generate a second V2X message and periodically send the second V2X message to the V2X server. Since the first V2X device 710 is located in the second subscription area, the V2X server may forward the first V2X message to the second V2X device 750. Since the second V2X device 750 is not located in the first subscription area, the V2X server does not forward the second V2X message to the first V2X device 710.

[0064] Figure 5 is a flowchart illustrating a method for V2X service according to an embodiment of the present specification.

[0065] In step S510, the V2X device sends a subscription request to the V2X server requesting to subscribe to the V2X service. The subscription request may include information about the identifier, location, etc. of the V2X device. The V2X server may send a subscription response for approving or rejecting the subscription to the V2X device in response to the subscription request.

[0066] In step S520, the V2X device may send a zone configuration related to the V2X service to the V2X server. The zone configuration may be included in a separate message or included in the subscription request. The zone configuration includes information about the configuration and / or modification of the subscription zone.

[0067] In step S530 , the V2X server may collect V2X messages from V2X devices in the management area and perform message filtering.

[0068] The V2X server receives a first V2X message from a second V2X device (step S541), and receives a second V2X message from a third V2X device (step S542). Assume that the second V2X device belongs to the subscription area of ​​the first V2X device, and the third V2X device does not belong to the subscription area of ​​the first V2X device.

[0069] At step S550, the V2X server publishes a first V2X message belonging to a subscription area of ​​the first V2X device to the first V2X device. If there are multiple V2X messages to be sent to the first V2X device, the multiple V2X messages may be announced individually or as a single message.

[0070] A device that sets a subscription area after completing a subscription request may be referred to as a "subscriber device". A device that sends a V2X message to a V2X server may be referred to as a "provider device". A V2X device may be a subscriber device, a provider device, or both a subscriber device and a provider device. The V2X server may forward a V2X message sent by a provider device in a management area to a subscriber device. In this example, the first V2X device is a subscriber device, and the second V2X device and the third V2X device are provider devices.

[0071] The V2X server may forward a V2X message related to the subscription area of ​​the subscriber device, which is sent by a provider device (referred to as a "subscribed provider device"), to the subscriber device. In this example, the second V2X device is a subscribed provider device, but the third V2X device is not a subscribed provider device. This is because the V2X message of the third V2X device is not delivered to the first V2X device.

[0072] The subscribed provider device may be located within the subscription area of ​​the subscriber device. The subscribed provider device sends its own V2X messages within the subscription area. Part or all of the publication area of ​​the subscribed provider device may overlap with the subscription area.

[0073] Although the provider device is not located in the subscription area, if the signal transmission range of the provider device overlaps with the subscription area, the provider device can be a subscribed provider device. The provider device is located outside the subscription area, but if the RSU or base station receiving the V2X message of the provider device is located in the subscription area, the provider device can become a subscribed provider device.

[0074] A subscription area may also be set for a provider device as a subscriber device. When the subscription area of ​​the provider device and the subscription area of ​​the subscriber device overlap partially or completely, the provider device may become a subscribed provider device.

[0075] Message filtering is the filtering of V2X messages to be sent to the V2X device that has completed the subscription request by the V2X server. Message filtering can be referred to as the process of selecting a subscribed provider device associated with a subscriber device among multiple provider devices. The filtering conditions can be defined differently according to the subscription area and / or the status of the V2X device. For example, if the number of V2X devices in the subscription area is large, the filtering conditions can be modified so that more messages are filtered out.

[0076] The filtering condition may be related to the risk level associated with a given V2X device. There are many user devices such as pedestrians, vehicles, bicycles, and motorcycles in the subscription area, and the V2X server may calculate the risk level of each V2X device based on V2X messages received from other user devices around the V2X device. The V2X server may calculate the risk level by filtering unnecessary messages or information. For example, V2X messages between pedestrians may be filtered out. This is because it may not be necessary to assess the risk of collision between pedestrians. V2X messages for bicycles traveling at low speeds may be filtered out. This is because it may be considered to be the same risk level as that of pedestrians. V2X messages for vehicles residing in a delay / congestion area may be filtered out because the risk of collision is small. When the V2X device is behind a decelerating vehicle, the V2X server may specify a high risk level. When the V2X device enters a safe zone (e.g., a non-traffic zone), the V2X server may filter out most V2X messages unless there is an emergency. The V2X server may add or modify filtering conditions taking into account the subscription area or the situation of the V2X device.

[0077] Figure 6 The message format according to the embodiment of the present specification is shown. The MQTT protocol extension is used to add a V2X function based on the MQTT protocol.

[0078] The message 600 for subscription and notification of V2X services includes a fixed header 610, a variable header 620, an extended payload 630, and a basic payload 640. The extended payload 630 includes an extension (E)-length 631, an E-flag 632, and an E-data 633. The name and order of each field are just examples. The E-length 631 indicates the length of the extended payload 630. The E-flag 642 includes at least one of H (heading), L (position), V (speed), E (event), ST (transmitter type) / RT (receiver type), and MT (message type).

[0079] Figure 7 An example in which a subscription area is changed is shown. The subscription area may be changed by a V2X device.

[0080] The V2X device located at tile 3000 sets 9 tiles 0333, 1222, 1223, 2111, 3000, 3001, 2113, 3002 and 3003 as subscription areas.

[0081] When the V2X device moves to tile 0333, the V2X device establishes a new subscription area. The new subscription area includes tiles 0330, 0331, 1220, 0332, 0333, 1222, 2110, 2111, and 3000.

[0082] There is no restriction on how to change and / or update the subscription area. In one embodiment, the V2X device may predefine the shape of the reference tile (e.g., the release tile) and the subscription area associated with the reference tile. In order to define the updated subscription area, the V2X device may provide information about the updated reference tile to the V2X server. In another embodiment, the V2X device may provide information about the difference between the previous subscription area and the updated subscription area to the V2X server. Information about tiles 0330, 0331, 1220, 0332, and 2110 to be newly subscribed and / or information about tiles 1223, 3001, 2113, 3002, and 3003 to be unsubscribed may be provided.

[0083] The V2X device may determine the size of the tile and / or the size of the subscription area taking into account the state or speed of the V2X device. For example, the level of detail (LOD) of the tile may be determined as LOD=A-Round(log2(round((B*C) / D))). Here, A is the level of the quadtree, B is the speed of the V2X device, C is the amount of time the V2X device wants to stay or expects to stay in a tile, and D is the length of one side in a tile. The function round(x) returns a number rounded to a given number x.

[0084] When A=25, D=1.2m, and the LOD according to B and C is as follows.

[0085] [Table 2]

[0086] Status of V2X devices B(m / sec) C(seconds) LOD Pedestrians - Walk slowly 0.83 10 22 Pedestrians - Normal walking 1.11 10 21 Pedestrians - fast walking 1.67 10 21 Pedestrians - running slowly 2.22 5 21 Pedestrians - fast running 3.33 5 21 bike 5.00 5 20 Electric Scooter 6.94 5 20 Low speed car 8.33 3 20 Cars in the city 16.67 3 19 Cars on the highway 27.78 3 18 Very fast car 41.67 3 18

[0087] Figure 8 An example in which LOD is applied is shown.

[0088] Vehicle 810, bicycle 820, and pedestrian 830 are considered V2X devices. Assume that the LOD of vehicle 810 is 14, the LOD of bicycle 820 is 17, and the LOD of pedestrian 830 is 20. For each V2X device, the size of the tile varies, and the size of the subscription area also varies. Assuming that the subscription area contains 9 tiles, the subscription areas of bicycle 820 and pedestrian 830 completely overlap with the subscription area of ​​vehicle 810. Therefore, the V2X message of vehicle 810 is sent to bicycle 820 and pedestrian 830 through the V2X server. The subscription area of ​​bicycle 820 and the subscription area of ​​pedestrian 830 do not overlap. Therefore, bicycle 820 and pedestrian 830 do not exchange V2X messages with each other.

[0089] By considering the status of the V2X device to determine the LOD, unnecessary message exchanges can be reduced.

[0090] Fig. 9 An example is shown in which a subscription area is set.

[0091] The subscription area can be determined according to the moving direction of the V2X device. Assume that a vehicle equipped with a V2X device is traveling from left to right at a high speed. The subscription area does not include tiles located behind the vehicle, but includes tiles located in front of the vehicle. The higher the vehicle speed, the greater the number of front tiles that can be included in the subscription area.

[0092] Since the subscription area is set along the traveling direction of the vehicle, the vehicle can pre-check the status of neighboring V2X devices (e.g., pedestrians, slow vehicles, etc.) located in the traveling direction through the V2X message received from the V2X server.

[0093] Fig.10 Another example in which a subscription area is set is shown.

[0094] It is assumed that the route through which the V2X device travels is pre-specified. The tiles on the route from the starting point to the destination point may be included in the subscription area. The V2X device may check the status of other devices located along the route in advance.

[0095] This is useful for emergency vehicles such as fire trucks and ambulances (emergency vehicles are equipped with V2X devices). Since the route of the emergency vehicle can be pre-specified, the V2X devices located in the subscription area can be notified of the presence of the emergency vehicle. The emergency vehicle can publish V2X messages not only on the tile where it is located but also on nearby tiles. The V2X message may include information indicating the emergency vehicle. By pre-announcement of the V2X message on the tile on the path of the emergency vehicle, neighboring vehicles subscribed to this tile can clear the lane in advance.

[0096] The V2X server can notify nearby V2X devices located in the subscription area set by the emergency vehicle in advance that the nearby V2X devices are near the route of the emergency vehicle. The nearby V2X devices can recognize the approach of the emergency vehicle and can change lanes in advance.

[0097] Fig.11 Another example in which a subscription area is set is shown.

[0098] The subscription area may be configured not only around the V2X device but also at an area relatively far away from the V2X device, for example, to predict traffic conditions in an area to be visited.

[0099] Fig.12 Another example in which a subscription area is set is shown.

[0100] The V2X device configures a subscription area. Although the V2X server is not set by the V2X device, additional subscription areas can be added by the V2X server. Taking into account the speed and direction of the V2X device, the V2X server can set additional subscription areas. For example, if there is a specific event (e.g., road construction, icy areas, accident-prone areas, etc.) in the location that the V2X device will enter in a short time, an additional subscription area can be configured. When the additional subscription area is configured, the V2X server can notify the V2X device. The V2X server forwards V2X messages received in the subscription area and the additional subscription area to the V2X device.

[0101] Fig.13 An example of handover between V2X servers is shown.

[0102] A large area may be controlled by multiple V2X servers. Server A may control management area A, and server B may control management area B. The subscription area of ​​a V2X device may be configured across management area A and management area B. When the subscription area of ​​a V2X device moves from management area A to management area B, switching information may be exchanged between servers. The switching information may include the subscription area of ​​the V2X device.

[0103] Multiple servers can divide and control overloaded areas. If management area A is overloaded, management area A is divided into two so that server A-1 and server A-2 can control it separately. When the overload is resolved, the divided areas can be merged and controlled by one server.

[0104] In the above examples, although the method has been described based on a flow chart using a series of steps or boxes, the present disclosure is not limited to the order of the steps, and some steps may be performed in a sequence different from the remaining steps or may be performed simultaneously with the remaining steps. In addition, those skilled in the art will appreciate that the steps shown in the flow chart are not exclusive, but may include other steps, or one or more steps in the flow chart may be deleted without affecting the scope of the present disclosure.

Claims

1. A device for vehicle-to-everything (V2X) service, the device comprising: processor; as well as A memory operatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the apparatus to perform functions comprising the following steps: determining a size of a subscription area for the V2X service based on a speed of the device and an amount of time the device is expected to stay in a tile, the subscription area comprising at least one tile, each tile comprising a geographic quadrant obtained based on a quadtree; Sending a subscription request for requesting to subscribe to a V2X service to a V2X server, the subscription request including a configuration of the subscription area or a modified area configuration; receiving, in response to the subscription request, a subscription response from the V2X server for approving the subscription; as well as At least one V2X message received by the V2X server from at least one provider V2X device is received from the V2X server, wherein the subscription area of ​​the device overlaps all or part of a subscription area of ​​each of the at least one provider V2X device.

2. The device according to claim 1, wherein: The size of the subscription area for the V2X service is periodically determined, and the subscription request is sent when the subscription area changes.

3. The device according to claim 1, wherein: The at least one V2X message includes a V2X ID identifying the at least one provider V2X device and a location of the at least one provider V2X device.

4. The device according to claim 1, wherein: The device and the V2X server are configured to exchange messages based on a message queue telemetry transport MQTT protocol.

5. A method for vehicle-to-everything (V2X) service, the method being performed by a V2X device and comprising the following steps: determining a size of a subscription area for the V2X service based on a speed of the device and an amount of time the V2X device is expected to stay in a tile, the subscription area comprising at least one tile, each tile comprising a geographic quadrant obtained based on a quadtree; Sending a subscription request for requesting to subscribe to a V2X service to a V2X server, the subscription request including a configuration of the subscription area or a modified area configuration; receiving, in response to the subscription request, a subscription response from the V2X server for approving the subscription; as well as At least one V2X message received by the V2X server from at least one provider V2X device is received from the V2X server, wherein the subscription area of ​​the V2X device overlaps all or part of a subscription area of ​​each of the at least one provider V2X device.

6. The method according to claim 5, wherein: The size of a subscription area for the V2X service is periodically determined, and the subscription request is sent when the subscription area changes.

7. The method according to claim 5, wherein: The at least one V2X message includes a V2X ID identifying the at least one provider V2X device and a location of the at least one provider V2X device.

8. The method according to claim 5, wherein: The V2X device and the V2X server are configured to exchange messages based on a message queue telemetry transport MQTT protocol.

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