Vehicle-road communication method, road side unit, vehicle-mounted unit, equipment and medium

Abstract

The embodiment of the invention provides a vehicle-road communication method, a road side unit, a vehicle-mounted unit, equipment and a medium, and relates to the technical field of communication. The method comprises the following steps: in response to a received first air interface message of a vehicle-mounted unit, constructing a one-hop vehicle-mounted unit set and a two-hop vehicle-mounted unit set according to the first air interface message; screening a one-hop relay node according to the connection number and path loss corresponding to the one-hop on-board unit so as to send a relay message of the road side unit to a two-hop on-board unit which is directly communicated with the one-hop relay node through the one-hop relay node; constructing a three-hop on-board unit set according to the second air interface message of the two-hop on-board unit; according to the connection number and the path loss corresponding to the two-hop on-board unit, screening a two-hop relay node, and sending a relay message to a three-hop on-board unit connected with the two-hop relay node through the two-hop relay node; and carrying out recursion according to the steps until a preset stop condition is reached. According to the method, the relay nodes are gradually screened to diffuse the relay information, and meanwhile, the risks of broadcast storm and channel congestion are avoided.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a vehicle-road communication method, a roadside unit, a vehicle-mounted unit, a device and a medium. Background Art

[0002] In modern intelligent transportation systems, vehicle-road cooperative technology achieves rapid information exchange through direct communication between the on-board unit (OBU) and the road side unit (RSU), thereby improving road safety and traffic efficiency. However, in actual applications, it is found that due to the limited coverage of the RSU, the OBU outside its coverage cannot receive important information broadcast by the RSU, such as road condition warnings ahead or traffic control notifications, which greatly limits the effectiveness and timeliness of information dissemination. Especially in complex urban environments, buildings, terrain or other obstacles may further weaken the signal strength, making the information coverage area more limited. Therefore, how to break through the limitations of the physical coverage of the RSU and ensure that all vehicles in motion can receive key safety information has become an important technical challenge that needs to be solved urgently.

[0003] In the related technology, the communication coverage of RSU can be expanded by increasing the number of RSUs, optimizing the deployment location of RSUs, enhancing the transmission power and receiving sensitivity of RSUs, or through relay technology. However, although increasing the number of RSUs can directly and effectively expand the coverage, this method requires high infrastructure construction costs, which is not only a considerable expense financially, but also may encounter difficulties in site selection, especially in the city center or protected areas. In addition, as the number of RSUs increases, the complexity of managing and maintaining these devices also increases, which puts higher requirements on operators. Optimizing the deployment location of RSUs requires obtaining accurate traffic flow data, which is not always feasible, especially in areas with weak data collection and analysis capabilities. The optimization process may be complex and time-consuming, requiring professional evaluation and planning, and even so, it is still difficult to completely avoid the existence of coverage dead spots. Enhancing the transmission power and receiving sensitivity of RSUs may cause electromagnetic interference, affecting the normal operation of surrounding electronic equipment, and increasing the receiving sensitivity may also introduce more noise, affecting the communication quality. Summary of the invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, an embodiment of the present invention provides a vehicle-road communication method, a roadside unit, a vehicle-mounted unit, a device and a medium.

[0005] In a first aspect, an embodiment of the present invention provides a vehicle-road communication method, including:

[0006] In response to receiving a first air interface message sent by at least one on-board unit, a one-hop on-board unit set and a two-hop on-board unit set are constructed according to the first air interface message; the first air interface message includes identification information of a roadside unit and an on-board unit having a direct communication link with the on-board unit, a direct communication link exists between the one-hop on-board unit included in the one-hop on-board unit set and the roadside unit, a direct communication link exists between the two-hop on-board unit included in the two-hop on-board unit set and the one-hop on-board unit, and no direct communication link exists between the two-hop on-board unit and the roadside unit;

[0007] According to the number of connections and path loss corresponding to the one-hop on-board unit, at least one one-hop relay node is selected from the one-hop on-board unit set to send the relay message from the roadside unit to the two-hop on-board unit in direct communication with the roadside unit through the at least one one-hop relay node; the number of connections indicates the number of two-hop on-board units in direct communication with the one-hop on-board unit;

[0008] According to the second air interface message of the two-hop on-board unit, a three-hop on-board unit set is constructed, wherein a direct communication link exists between the three-hop on-board units included in the three-hop on-board unit set and the two-hop on-board unit, and no direct communication link exists between the three-hop on-board unit and the one-hop on-board unit;

[0009] According to the number of connections and path loss corresponding to the two-hop on-board unit, at least one two-hop relay node is selected from the two-hop on-board unit set, so as to send the relay message to the three-hop on-board unit in direct communication with the two-hop on-board unit through the at least one two-hop relay node;

[0010] Follow the above steps recursively until the preset stop condition is reached.

[0011] In a second aspect, an embodiment of the present invention provides a vehicle-road communication method, which is applied to a vehicle-mounted unit, including:

[0012] In response to receiving a relay request from a roadside unit, sending a first air interface message to the roadside unit, wherein the first air interface message includes identification information of the roadside unit and the onboard unit that have a direct communication link with the onboard unit;

[0013] In response to receiving the relay node indication from the roadside unit, a relay message from the roadside unit is sent to the onboard unit in direct communication with the roadside unit.

[0014] In a third aspect, an embodiment of the present invention provides a roadside unit, including:

[0015] A construction module, configured to, in response to receiving a first air interface message sent by at least one on-board unit, construct a one-hop on-board unit set and a two-hop on-board unit set according to the first air interface message; the first air interface message includes identification information of a roadside unit and an on-board unit having a direct communication link with the on-board unit, a direct communication link exists between the one-hop on-board unit included in the one-hop on-board unit set and the roadside unit, a direct communication link exists between the two-hop on-board unit included in the two-hop on-board unit set and the one-hop on-board unit, and no direct communication link exists between the two-hop on-board unit and the roadside unit; and, according to a second air interface message of the two-hop on-board unit, construct a three-hop on-board unit set, a direct communication link exists between the three-hop on-board unit included in the three-hop on-board unit set and the two-hop on-board unit, and no direct communication link exists between the three-hop on-board unit and the one-hop on-board unit;

[0016] A screening module is used to screen out at least one one-hop relay node from the one-hop on-board unit set according to the number of connections and path loss corresponding to the one-hop on-board unit, so as to send the relay message from the roadside unit to the two-hop on-board unit connected thereto through the at least one one-hop relay node; the number of connections indicates the number of two-hop on-board units that directly communicate with the one-hop on-board unit; and, according to the number of connections and path loss corresponding to the two-hop on-board unit, screen out at least one two-hop relay node from the two-hop on-board unit set, so as to send the relay message to the three-hop on-board unit that directly communicates with it through the at least one two-hop relay node.

[0017] In a fourth aspect, an embodiment of the present invention provides a vehicle-mounted unit, including:

[0018] A sending module, configured to send a first air interface message to the road side unit in response to receiving a relay request from the road side unit, wherein the first air interface message includes identification information of the road side unit and the vehicle-mounted unit that have a direct communication link with the vehicle-mounted unit;

[0019] The forwarding module is used for sending the relay message from the roadside unit to the vehicle-mounted unit that directly communicates with the roadside unit in response to receiving the relay node indication from the roadside unit.

[0020] In a fifth aspect, an embodiment of the present invention provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; the memory is used to store computer programs; and the processor is used to implement the vehicle-road communication method provided by any embodiment of the present invention when executing the program stored in the memory.

[0021] In a sixth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the vehicle-road communication method provided by any embodiment of the present invention.

[0022] The technical solution provided by the embodiment of the present invention brings at least the following beneficial effects:

[0023] The vehicle-road communication method provided by the embodiment of the present invention is that the roadside unit, in response to receiving the first air interface message sent by the vehicle-mounted unit within the communication coverage, constructs a one-hop vehicle-mounted unit set and a two-hop vehicle-mounted unit set, and selects at least one one-hop relay node from the one-hop vehicle-mounted unit set according to the number of one-hop vehicle-mounted units connected to the two-hop vehicle-mounted units and the path loss, so as to forward the relay message from the roadside unit to the two-hop vehicle-mounted unit through the at least one one-hop relay node, and forward the second air interface message of the two-hop vehicle-mounted unit to the roadside unit, and the roadside unit constructs a three-hop vehicle-mounted unit set based on the second air interface message, and selects at least one two-hop relay node from the two-hop vehicle-mounted unit set according to the number of two-hop vehicle-mounted units connected to the three-hop vehicle-mounted units and the path loss, so as to forward the relay message from the roadside unit to the three-hop vehicle-mounted unit through the at least one two-hop relay node, and recursively performs the above steps until a preset stop condition is reached. The method gradually spreads the information of the roadside unit to a wider area by gradually selecting relay nodes. This solution based on the cooperative forwarding mechanism between on-board units can effectively improve the range and reliability of information dissemination without increasing the cost of infrastructure construction, ensuring that even on-board units far away from roadside units can obtain necessary traffic safety information. Moreover, the embodiment of the present invention selects the optimal relay node based on the number of connections and path loss between the current on-board unit and the next-hop on-board unit. The selection of the optimal relay node through path loss can ensure the reliability and effectiveness of information dissemination, while reducing the delay of information dissemination; the number of connections to the next-hop on-board unit can ensure the use of the least relay nodes for information forwarding, avoiding the risk of causing broadcast storms and channel congestion, maximizing the spatial coverage of message transmission, and improving communication efficiency and network resource utilization, further improving the reliability and effectiveness of information dissemination, and achieving optimal information coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0025] Figure 1 A schematic diagram showing a flow chart of a vehicle-road communication method according to an embodiment of the present invention;

[0026] Figure 2A schematic diagram showing an application environment of the vehicle-road communication method provided by an embodiment of the present invention is shown;

[0027] Figure 3 A schematic diagram of a process of selecting a relay node in a vehicle-road communication method provided by an embodiment of the present invention is shown;

[0028] Figure 4 A schematic diagram showing a flow chart of a vehicle-road communication method provided by an embodiment of the present invention;

[0029] Figure 5 A schematic diagram of the structure of a roadside unit provided by an embodiment of the present invention is shown;

[0030] Figure 6 A result schematic diagram of the vehicle-mounted unit provided by an embodiment of the present invention is shown;

[0031] Figure 7 A schematic structural diagram of an electronic device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0032] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0033] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0034] Figure 1 A schematic flow chart of a vehicle-road communication method according to an embodiment of the present invention is shown. Figure 2 FIG. 2 is a schematic diagram showing an application environment of the vehicle-road communication method provided by an embodiment of the present invention. Figure 2As shown in FIG. 1 , the application environment includes a roadside unit and multiple vehicle-mounted units. Some vehicle-mounted units are within the communication coverage of the roadside unit, and these vehicle-mounted units can directly receive messages sent by the roadside unit. Other vehicle-mounted units are not within the communication coverage of the roadside unit, and these vehicle-mounted units cannot communicate directly with the roadside unit. Figure 2 As shown, OBU1, OBU2, OBU3 and OBU4 are within the communication coverage of the roadside unit RSU1 and can communicate directly with RSU1. 10 It is not within the communication coverage of RSU1 and cannot communicate directly with RSU1. There is a direct communication link between OBU5 and OBU1. There is a direct communication link between OBU6 and OBU1. There is a direct communication link between OBU7 and OBU3. There is a direct communication link between OBU8 and OBU6. There is a direct communication link between OBU9 and OBU7. OBU 10 There is a direct communication link with OBU7. As a message source, the roadside unit RSU1 sends information to multiple on-board units within the communication coverage, and dynamically selects at least one on-board unit as a relay node to broadcast messages to on-board units outside the communication coverage in a hierarchical manner.

[0035] like Figure 1 As shown, the vehicle-road communication method provided by the embodiment of the present invention includes:

[0036] Step S101: In response to receiving a first air interface message sent by at least one onboard unit, a roadside unit constructs a one-hop onboard unit set and a two-hop onboard unit set according to the first air interface message.

[0037] Optionally, when the roadside unit determines that the communication range needs to be expanded, a relay request is broadcast. The relay request is used to instruct the on-board unit that receives the relay request to feedback the identification of the roadside unit and the on-board unit with which it directly communicates. The on-board unit that receives the relay request feeds back a first air interface message to the roadside unit. The first air interface message includes identification information of the roadside unit and the on-board unit that have a direct communication link with the on-board unit. Based on all the first air interface messages received, the roadside unit confirms the set of on-board units that can communicate directly (i.e., the one-hop on-board unit set) and the set of on-board units that cannot communicate directly (i.e., the two-hop on-board unit set). There is a direct communication link between the one-hop on-board unit included in the one-hop on-board unit set (denoted as D1) and the roadside unit. There is a direct communication link between the two-hop on-board units included in the two-hop on-board unit set (denoted as D2) and the one-hop on-board unit, and there is no direct communication link between the two-hop on-board unit and the roadside unit.

[0038] Optionally, the specific implementation example is as follows: OBU nAfter receiving the relay request from RSU1, OBU n According to the identification information of the vehicle-mounted unit and the identification information of the roadside unit with which it directly communicates, a first air interface message is generated and sent to RSU1. n The first air interface message sent builds a one-hop onboard unit set. Figure 2 In the example shown, a set of on-board units includes: OBU1, OBU2, OBU3 and OBU4.

[0039] RSU1 identifies the OMUs that are within the direct communication range of the one-hop OMU set but are not within the direct coverage range of RSU1 through the first air interface message.

[0040] For any OBU n ∈D1,OBU n The set of all OBU IDs that receive air interface messages is recorded as O(OBUn). For all OBU sets {OBU1, OBU2, ... OBUm} in D1, calculate D2 = O(OBU1) ∪ O(OBU2) ∪ ... ∪ O(OBUm) - D1. After processing, there is a direct communication link between the OBU in D2 and the OBU in D1, and there is no direct communication link between the OBU in D2 and RSU1. Figure 2 In the example shown, the two-hop on-board unit set includes: OBU5, OBU6 and OBU7.

[0041] RSU1 sends the IDs of the on-board units hierarchically divided into one-hop and two-hop to each on-board unit in D1.

[0042] Step S102: According to the number of connections and path loss corresponding to the one-hop on-board unit, at least one one-hop relay node is selected from the one-hop on-board unit set to send the relay message from the roadside unit to the two-hop on-board unit that directly communicates with it through the at least one one-hop relay node.

[0043] This step is to find one or more one-hop on-board units in the one-hop on-board unit set as relay nodes to realize the communication between the roadside unit and the two-hop on-board unit. The roadside unit selects the optimal one or more one-hop on-board units as relay nodes according to the number of connections and path loss corresponding to the one-hop on-board units, ensuring that all two-hop on-board units can receive relay messages from the roadside unit. Among them, the number of connections indicates the number of two-hop on-board units that directly communicate with the one-hop on-board unit. Path loss refers to the energy attenuation caused by the increase in distance during the propagation of a wireless signal. In an embodiment of the present invention, it is used to indicate the energy loss caused by the signal during the propagation process between two adjacent two-hop on-board units. The size of the path loss depends on many factors, including but not limited to signal frequency, propagation distance, environment type (such as urban, suburban, rural), atmospheric conditions, etc.

[0044] Optionally, when a one-hop relay node is selected, the roadside unit sends a relay node indication to the one-hop relay node. The one-hop onboard unit that receives the relay node indication sends the relay message from the roadside unit to the two-hop onboard unit that directly communicates with it.

[0045] In this step, the reliability and effectiveness of information transmission can be ensured by screening the optimal relay node through path loss, while reducing the delay of information transmission; screening the optimal relay node through the number of connections can ensure that the least relay nodes are used for information forwarding, avoiding the risk of causing broadcast storms and channel congestion, maximizing the spatial coverage of message transmission, and improving communication efficiency and network resource utilization, further improving the reliability and effectiveness of information transmission, and achieving optimal information coverage.

[0046] Step S103: construct a three-hop onboard unit set according to the second air interface message of the two-hop onboard unit, wherein a direct communication link exists between the three-hop onboard units included in the three-hop onboard unit set and the two-hop onboard units, and no direct communication link exists between the three-hop onboard units and the one-hop onboard units.

[0047] Optionally, in response to receiving a relay message from a one-hop relay node, the two-hop on-board unit sends a second air interface message to the one-hop relay node. The second air interface message includes identification information of the on-board unit that has a direct communication link with the two-hop on-board unit. The one-hop relay node forwards the second air interface message to the roadside unit. In response to receiving the second air interface message, the roadside unit constructs a three-hop on-board unit set. There is a direct communication link between the three-hop on-board unit and the two-hop on-board unit, and there is no direct communication link between the three-hop on-board unit and the one-hop on-board unit or the roadside unit. The process by which the roadside unit constructs the three-hop on-board unit set is similar to the process of constructing the two-hop on-board unit set, and will not be repeated here to avoid repetition. Figure 2 In the example shown, the three-hop on-board unit set includes: OBU8, OBU9 and OBU10 .

[0048] Step S104: According to the number of connections and path loss corresponding to the two-hop on-board unit, at least one two-hop relay node is selected from the two-hop on-board unit set, so as to send the relay message from the two-hop on-board unit to the three-hop on-board unit connected thereto through the at least one two-hop relay node. The purpose of this step is to find one or more two-hop on-board units in the two-hop on-board unit set as relay nodes to realize the communication between the roadside unit and the three-hop on-board unit. The selection process is similar to step S102, and will not be repeated here to avoid repetition.

[0049] Step S105: recursively perform the above steps until a preset stop condition is reached.

[0050] According to the above steps, the next-hop OMU set is gradually constructed, and the relay nodes are selected according to the number of connections and path loss to realize the communication between the roadside unit and the next-hop OMU, until all OMUs receive the relay message from the roadside unit or a new OMU set cannot be constructed.

[0051] The vehicle-road communication method provided by the embodiment of the present invention gradually spreads the information of the roadside unit to a wider area by gradually screening relay nodes. This solution based on the cooperative forwarding mechanism between vehicle-mounted units can effectively improve the dissemination range and reliability of information without increasing the cost of infrastructure construction, ensuring that even vehicle-mounted units far away from the roadside unit can obtain necessary traffic safety information. Moreover, the embodiment of the present invention combines the number of connections and path loss between the current vehicle-mounted unit and the next-hop vehicle-mounted unit to screen the optimal relay node. Screening the optimal relay node through path loss can ensure the reliability and effectiveness of information dissemination, while reducing the delay of information dissemination; the number of connections to the next-hop vehicle-mounted unit can ensure that the least relay nodes are used for information forwarding, avoiding the risk of causing broadcast storms and channel congestion, maximizing the spatial coverage of message transmission, and improving communication efficiency and network resource utilization. It further improves the reliability and effectiveness of information dissemination and achieves optimal information coverage.

[0052] Figure 3 FIG. 2 is a schematic diagram showing a flow chart of selecting relay nodes in a vehicle-road communication method according to an embodiment of the present invention. Figure 3 As shown, the process of selecting relay nodes includes:

[0053] Step S301: determining the number of connections corresponding to the n-hop on-board unit, that is, determining the number of (n+1)-hop on-board units that the n-hop on-board unit directly connects to.

[0054] Step S302: sort the n-hop on-board units in descending order of the number of connections.

[0055] Step S303: Determine whether there are multiple n-hop onboard units with the largest number of connections. If yes, jump to step S305; if no, jump to step S304.

[0056] Step S304: Select the n-hop on-board unit with the largest number of connections as the n-hop relay node.

[0057] Step S305: The multiple n-hop on-board units with the largest number of connections constitute a set of optional relay nodes, and for each optional relay node in the set of optional relay nodes, its path loss is calculated.

[0058] Step S306: select the optional relay node with the smallest path loss as the n-hop relay node.

[0059] Step S307: deleting the n-hop relay node in the n-hop on-board unit set, and deleting the (n+1)-hop on-board unit in the (n+1)-hop on-board unit set that directly communicates with the n-hop relay node.

[0060] Step S308: Determine whether the (n+1)-hop onboard unit set is empty. If so, the process ends; otherwise, jump to step S301 to continue screening n-hop relay nodes.

[0061] For step S305, the path loss can be determined according to the energy fading mode between the n-jump vehicle-mounted unit and the (n+1)-jump vehicle-mounted unit, and the energy fading mode can be determined according to the channel model, and the channel model can be determined according to the real-time road conditions and the vehicle position. As an optional example, the channel model provided in this embodiment includes LOS channel, NLOS channel and NLOSv channel. LOS (Line of Sight) channel refers to the path where the signal is directly transmitted from the transmitting end to the receiving end without any obstacles in the middle. Since there is no obstruction, the signal attenuation of the LOS channel is small, so the signal quality is good and the transmission efficiency is high. NLOS (Non-Line of Sight) channel refers to the signal encountering obstacles during transmission, resulting in reflection, refraction or scattering of the signal, thereby changing the propagation path. Due to the change in the signal path, the signal attenuation of the NLOS channel is large, the signal quality is poor, and the transmission efficiency is low. NLOSv (NLOS blocked by Vehicle) channel refers to the signal encountering obstacles and reflecting during transmission, and may also undergo multiple reflections. The signal attenuation in this channel environment is more serious, and the signal quality is further reduced. The embodiment of the present invention calculates the path loss through the LOS channel, the NLOS channel and the NLOSv channel to select the relay node, fully considers the line-of-sight (LOS) and non-line-of-sight (NLOS) communication environment between vehicles, and can more accurately evaluate the path loss.

[0062] As an optional example, the channel model between the n-hop on-board unit and the (n+1)-hop on-board unit may be determined according to the following process:

[0063] Determine a map position relationship between the n-hop on-board unit and the (n+1)-hop on-board unit according to the vehicle state information of the n-hop on-board unit and the vehicle state information of the (n+1)-hop on-board unit, wherein the map position relationship indicates the positions of the n-hop on-board unit and the (n+1)-hop on-board unit on the map;

[0064] According to the map message from the roadside unit, determine the obstacle information between the n-hop on-board unit and the (n+1)-hop on-board unit, where the obstacle information indicates whether there is an obstacle between the n-hop on-board unit and the (n+1)-hop on-board unit, the location of the obstacle, and the type of the obstacle;

[0065] According to the map position relationship and obstacle information, the channel model between the n-hop on-board unit and the (n+1)-hop on-board unit is determined.

[0066] Among them, the vehicle status message (Basic Safety Message) is a basic message type in the Internet of Vehicles. The BSM message is the basis of vehicle-to-vehicle communication (V2V). It contains basic information such as the vehicle's location, speed, direction, etc., and is used for traffic safety and traffic flow optimization between vehicles. Map messages (map messages) can be broadcast by roadside units, including intersection information, road section information, lane information, and connection relationships between roads in a local area. A single map message can contain map data for multiple intersections or areas. Road conditions and vehicle locations can be determined in real time based on vehicle status messages and map messages.

[0067] In the case where it is determined that there is no obstacle between the n-jump on-board unit and the (n+1)-jump on-board unit according to the map position relationship and the obstacle information, the channel model between the n-jump on-board unit and the (n+1)-jump on-board unit is determined to be a LOS channel. In the case where it is determined that there is an obstacle between the n-jump on-board unit and the (n+1)-jump on-board unit according to the map position relationship and the obstacle information, and the obstacle meets the first preset condition, the channel model between the n-jump on-board unit and the (n+1)-jump on-board unit is determined to be a NLOS channel. In the case where it is determined that there is an obstacle between the n-jump on-board unit and the (n+1)-jump on-board unit according to the map position relationship and the obstacle information, and the obstacle meets the second preset condition, the channel model between the n-jump on-board unit and the (n+1)-jump on-board unit is determined to be a NLOSv channel. Among them, the first preset condition and the second preset condition can be set according to the scene, and the present invention is no longer limited here. As an optional example, the first preset condition and the second preset condition indicate the relative position relationship between the obstacle and the vehicle, the type and number of obstacles, etc.

[0068] Optionally, when the channel model is a LOS channel, the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit is determined according to the following formula (1):

[0069] PL LOS =a1+a2log 10 d+a3log 10 f c +X α (1)

[0070] Among them, PL LOS represents the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit. d represents the Euclidean distance between the n-hop on-board unit and the (n+1)-hop on-board unit. α represents shadowing, the attenuation of signal power due to obstacles between the transmitter and receiver through absorption, reflection, scattering and diffraction, set to 3dB. c represents the communication frequency between the n-hop vehicle-mounted unit and the (n+1)-hop vehicle-mounted unit, for example, 5905 Hz-5925 Hz. a1, a2, a3 represent preset coefficients respectively. As an optional example, a1=38.77, a2=16.7, a3=18.2.

[0071] Optionally, when the channel model is a NLOS channel, the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit is determined according to the following formula (2):

[0072] PL NLOS =a4+a5 log 10 d+a6log 10 f c +X α (2)

[0073] PL NLOS represents the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit. a4, a5, a6 represent preset coefficients respectively, and a4<a1, a5>a2, a6>a3. As an optional example, a4=36.85, a5=30, a6=18.9.

[0074] Optionally, when the channel model is a NLOSv channel, the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit is determined according to the following formula (3):

[0075] PL NLOSv =PL NLOS +A NLOSv (3)

[0076] PL NLOSvA represents the path loss between the n-hop on-board unit and the (n+1)-hop on-board unit. NLOSv represents the additional attenuation coefficient, which is modeled using a lognormal random variable and standard deviation, and different values ​​are obtained according to the vehicle distribution. If the minimum value between the antenna heights of the n-hop vehicle-mounted unit and the (n+1)-hop vehicle-mounted unit is greater than the height of the obstruction, then μ = σ = 0; if the maximum value between the antenna heights of the n-hop vehicle-mounted unit and the (n+1)-hop vehicle-mounted unit is less than the height of the obstruction, then μ = 9 + max (0, 15log 10 (d)-41)dB, σ=4.5dB; for other cases, μ=5+max(0,15log 10 (d)-41)dB, σ=4dB. The antenna height of the n-hop vehicle-mounted unit and the antenna height of the (n+1)-hop vehicle-mounted unit can both be determined through the vehicle status message.

[0077] When the path loss between an n-hop on-board unit and an (n+1)-hop on-board unit is determined according to the above formula (1), (2) or (3), for each n-hop on-board unit, the average path loss is calculated based on the path loss between it and all the connected (n+1)-hop on-board units, and the n-hop on-board unit with the smallest average path loss is used as the n-hop relay node.

[0078] refer to Figure 2 , taking the one-hop on-board unit set and the two-hop on-board unit set as examples to illustrate the process of selecting a one-hop relay node:

[0079] 1) For any OBU n ∈D1, in OBU n Calculate |O(OBU n )∩D2|, representing OBU n Directly connected to Numn OBUs in set D2.

[0080] 2) For D1 = {OBU1, OBU2, OBU3, OBU4}, each on-board unit calculates Num1, Num2, Num3, Num4 respectively and sends them to RSU1.

[0081] 3) RSU1 calculates MAX{Num1, Num2, Num3, Num4}, that is, determines one or more on-board units in D1 that are directly connected to the OBU in D2. If MAX{Num1, Num2, .., Numm} = Numi, then |MAX{Num1, .., Numn, .. Numm}| = 1, that is, there is only one on-board unit with the largest number of direct connections. At this time, the on-board unit with the largest number of direct connections is selected as the relay node, and the on-board unit is deleted from D1, and the two-hop on-board units that can communicate directly with the on-board unit are deleted from D2, and jump to step 7). Otherwise, continue to step 4).

[0082] 4) If there is more than one one-hop on-board unit in D1 that has the largest number of direct connections to the two-hop on-board units in D2, that is, |MAX{Num1,Num2,Num3,Num4}|>1, then a potential relay node set (denoted as C1) is formed for the multiple one-hop on-board units with the largest number of direct connections, and they are sorted according to the average path loss from each one-hop on-board unit in C1 to the directly connected two-hop on-board unit in D2.

[0083] 5) For any OBU j ∈C1, and perform the following processing:

[0084] OBU j Get MAP message from RSU1;

[0085] From OBU j The directly connected two-hop on-board unit obtains the vehicle status message;

[0086] Parse the location information of each directly connected two-hop on-board unit and analyze the OBU j The map position relationship with the directly connected two-hop on-board unit is used to determine the OBU j The energy attenuation mode with each directly connected two-hop on-board unit belongs to LOS (Line of Sight), NLOS (Non-Line of Sight) or NLOSv (NLOS blocked by Vehicle).

[0087] OBU j According to different energy fading modes, the path loss with each directly connected two-hop vehicle-mounted unit is calculated according to the above formulas (1) to (3)

[0088] According to formula (4), calculate OBU j Average path loss with each directly connected two-hop onboard unit:

[0089]

[0090] Among them, OBU kIndicates any OBU in the two-hop OBU set that can communicate directly with OBUj, NUM j For the two-hop vehicle-mounted unit set and OBU j The number of two-hop OBUs in direct communication, PL(OBU j ,OBU k ) indicates that the path loss is calculated according to equations (1) to (3).

[0091] OBU j The average path loss is sent to RSU1.

[0092] 6) RSU1 traverses all potential relay nodes in C1, calculates the average path loss of all potential relay nodes and sorts them, selects the potential relay node with the smallest average path loss in C1 as the one-hop relay node, deletes the one-hop relay node from D1, and deletes the two-hop on-board unit that can directly communicate with the one-hop relay node from D2.

[0093] 7) Determine whether the updated D2 is empty. If D2 is not empty, re-execute step 2), otherwise end.

[0094] The vehicle-road communication method provided by the embodiment of the present invention flexibly adjusts the relay nodes according to the real-time road conditions and vehicle position changes, dynamically selects the optimal relay nodes, ensures the efficiency and stability of the relay nodes, and improves the reliability of information transmission; by expanding the communication range layer by layer, from the roadside unit to the one-hop vehicle-mounted unit, and then from the one-hop vehicle-mounted unit to the two-hop vehicle-mounted unit, it is recursively expanded to all discoverable vehicle-mounted units in turn, until all vehicle-mounted units within the coverage area can receive the information. This mechanism greatly improves the breadth and timeliness of information coverage, and can ensure the continuity of communication and the timeliness of information dissemination in complex urban environments or scenes with obstacles. The hierarchical organization of the vehicle-mounted units and the selection of relay nodes are implemented by the roadside unit, and the number of connections of the relay nodes and the average communication energy attenuation are implemented by the vehicle-mounted unit, which together constitute a distributed computing architecture, reduce the resource requirements of the roadside unit and the vehicle-mounted unit, and reduce costs.

[0095] Figure 4 FIG. 2 is a flow chart of a vehicle-road communication method provided by another embodiment of the present invention. Figure 4 As shown, the method includes:

[0096] Step S401: The roadside unit determines whether to perform relay communication according to the type of the message to be sent. Relay communication is used to indicate that the message to be sent is transmitted to the vehicle-mounted unit outside the communication coverage of the roadside unit by screening relay nodes layer by layer.

[0097] Optionally, in this embodiment, multiple message types may be preset, such as an emergency type and a general type. If the type of the message to be sent is an emergency type, relay communication is determined to be performed. If the type of the message to be sent is a general type, relay communication is determined not to be performed.

[0098] Step S402: When the roadside unit determines to perform relay communication, it determines the preset stop condition according to the priority of the message to be sent. Different priorities correspond to different stop conditions. As an optional example, if the type of the message to be sent is an emergency message and the priority is the highest priority, the stop condition is: if a new on-board unit cannot be found, the relay communication is stopped. If the type of the message to be sent is an emergency message and the priority is a medium priority, the stop condition is: when the number of relays reaches k, the relay communication is stopped. k is a positive integer greater than 1, for example 5. The number of relays is the same as the number of hops of the relay node. For example, if a one-hop relay node sends a message to a two-hop on-board unit, the number of relays is 1, and if a two-hop relay node sends a message to a three-hop on-board unit, the number of relays is 2.

[0099] Step S403: The roadside unit sends a relay request and a preset stop condition to at least one vehicle-mounted unit.

[0100] Step S404: the roadside unit receives a first air interface message sent by at least one vehicle-mounted unit, and constructs a one-hop vehicle-mounted unit set and a two-hop vehicle-mounted unit set according to the first air interface message.

[0101] Step S405: the roadside unit selects at least one one-hop relay node from the one-hop on-board unit set according to the number of connections and path loss corresponding to the one-hop on-board unit.

[0102] Step S406: The roadside unit sends a relay node indication to the one-hop relay node.

[0103] Step S407: the one-hop relay node sends a relay message to the two-hop on-board unit that directly communicates with it in response to receiving the relay node instruction.

[0104] Step S408: the two-hop on-board unit sends a second air interface message to the one-hop relay node in response to receiving the relay message sent by the one-hop relay node.

[0105] Step S409: In response to receiving the second air interface message, the one-hop relay node sends the second air interface message to the road side unit.

[0106] Step S410: In response to receiving the second air interface message, the roadside unit constructs a three-hop onboard unit set according to the second air interface message.

[0107] Step S411: the roadside unit selects at least one two-hop relay node from the two-hop on-board unit set according to the number of connections and path loss corresponding to the two-hop on-board units.

[0108] Step S412: the roadside unit sends a relay node indication to the two-hop relay node through the one-hop relay node.

[0109] Step S413: the two-hop relay node sends a relay message to the three-hop on-board unit that directly communicates with it in response to receiving the relay node instruction.

[0110] Step S414: The roadside unit recursively performs the above steps until a preset stop condition is reached.

[0111] The vehicle-road communication method provided by the embodiment of the present invention can effectively break through the limitation of the communication coverage of the roadside unit by expanding the communication range layer by layer, from the roadside unit to the one-hop on-board unit, and then from the one-hop on-board unit to the two-hop on-board unit, and then recursively expand to all discoverable on-board units in sequence, so that vehicles far away from the coverage area of ​​the roadside unit can also receive key information while keeping the infrastructure cost low. This mechanism greatly improves the breadth and timeliness of information coverage. The hierarchical organization of the on-board units and the selection of relay nodes are implemented by the roadside units, and the number of connections of the relay nodes and the average communication energy attenuation are implemented by the OBU, which together constitute a distributed computing architecture.

[0112] Figure 5 FIG. 2 shows a schematic diagram of the structure of a roadside unit provided by an embodiment of the present invention. Figure 5 As shown, the roadside unit 500 includes:

[0113] A construction module 501 is used for, in response to receiving a first air interface message sent by at least one on-board unit, constructing a one-hop on-board unit set and a two-hop on-board unit set according to the first air interface message; the first air interface message includes identification information of a roadside unit and an on-board unit having a direct communication link with the on-board unit, a direct communication link exists between the one-hop on-board unit included in the one-hop on-board unit set and the roadside unit, a direct communication link exists between the two-hop on-board unit included in the two-hop on-board unit set and the one-hop on-board unit, and no direct communication link exists between the two-hop on-board unit and the roadside unit; and, according to a second air interface message of the two-hop on-board unit, constructing a three-hop on-board unit set, a direct communication link exists between the three-hop on-board unit included in the three-hop on-board unit set and the two-hop on-board unit, and no direct communication link exists between the three-hop on-board unit and the one-hop on-board unit;

[0114] The screening module 502 is used to screen out at least one one-hop relay node from the one-hop on-board unit set according to the number of connections and path loss corresponding to the one-hop on-board unit, so as to send the relay message from the roadside unit to the two-hop on-board unit connected thereto through the at least one one-hop relay node; the number of connections indicates the number of two-hop on-board units that directly communicate with the one-hop on-board unit; and, according to the number of connections and path loss corresponding to the two-hop on-board unit, screen out at least one two-hop relay node from the two-hop on-board unit set, so as to send the relay message to the three-hop on-board unit that directly communicates with it through the at least one two-hop relay node.

[0115] Optionally, the screening module 502 is also used for: when there is only one one-hop on-board unit with the largest number of connections, using the one-hop on-board unit with the largest number of connections as a one-hop relay node; when there are multiple one-hop on-board units with the largest number of connections, using the one-hop on-board unit with the smallest path loss as a one-hop relay node; deleting the one-hop relay node from the one-hop on-board unit set, and deleting the two-hop on-board unit that directly communicates with the one-hop relay node from the two-hop on-board unit set, so as to update the one-hop on-board unit set and the two-hop on-board unit set; screening a new one-hop relay node according to the number of connections and path loss corresponding to the one-hop on-board unit in the updated one-hop on-board unit set; repeating the above steps until the updated two-hop on-board unit set is empty.

[0116] In an optional embodiment, the screening module 502 is also used to: calculate the path loss between the one-hop on-board unit and the two-hop on-board unit according to the following process: determine the energy attenuation mode between the one-hop on-board unit and the two-hop on-board unit according to the vehicle status information of the one-hop on-board unit and the vehicle status information of the two-hop on-board unit; calculate the path loss between the one-hop on-board unit and the two-hop on-board unit according to the energy attenuation mode.

[0117] In an optional embodiment, the screening module 502 is also used to: determine the map position relationship between the one-hop on-board unit and the two-hop on-board unit based on the vehicle status information of the one-hop on-board unit and the vehicle status information of the two-hop on-board unit; determine the obstacle information between the one-hop on-board unit and the two-hop on-board unit based on the map message from the roadside unit; determine the channel model between the one-hop on-board unit and the two-hop on-board unit based on the map position relationship and the obstacle information; determine the energy attenuation mode between the one-hop on-board unit and the two-hop on-board unit based on the channel model between the one-hop on-board unit and the two-hop on-board unit.

[0118] In an optional embodiment, the screening module 502 is further used for:

[0119] When it is determined that there is no obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, determining that a channel model between the one-hop on-board unit and the two-hop on-board unit is a LOS channel;

[0120] When it is determined that there is an obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, and the obstacle meets a first preset condition, determining that a channel model between the one-hop on-board unit and the two-hop on-board unit is an NLOS channel;

[0121] When it is determined that there is an obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, and the obstacle meets the second preset condition, it is determined that the channel model between the one-hop on-board unit and the two-hop on-board unit is an NLOSv channel.

[0122] In an optional embodiment, the roadside unit further includes an identification module, which is used to: determine whether to perform relay communication according to the type of the message to be sent; and send a relay request to the at least one vehicle-mounted unit if it is determined that relay communication is to be performed.

[0123] In an optional embodiment, the identification module is further used to: when it is determined to perform relay communication, determine the preset stop condition according to the priority of the message to be sent.

[0124] Figure 6 FIG. 2 shows a schematic diagram of the structure of the vehicle-mounted unit provided by an embodiment of the present invention. Figure 6 As shown, the vehicle-mounted unit 600 includes:

[0125] A sending module 601 is configured to send a first air interface message to the roadside unit in response to receiving a relay request from the roadside unit, wherein the first air interface message includes identification information of the roadside unit and the vehicle-mounted unit that have a direct communication link with the vehicle-mounted unit;

[0126] The forwarding module 602 is configured to send the relay message from the roadside unit to the onboard unit that directly communicates with the roadside unit in response to receiving the relay node indication from the roadside unit.

[0127] Figure 7 FIG. 1 is a schematic diagram showing the structure of an electronic device according to an embodiment of the present invention. Figure 7 As shown, the electronic device includes:

[0128] Processor 701, communication interface 702, memory 703 and communication bus 704, wherein processor 701, communication interface 702, memory 703 communicate with each other via communication bus 704.

[0129] Memory 703, used for storing computer programs;

[0130] The processor 701 is used to implement the vehicle-road communication method provided by any embodiment of the present invention when executing the program stored in the memory 703.

[0131] The communication bus mentioned in the above terminal can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0132] The communication interface is used for communication between the above terminal and other devices.

[0133] The memory may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0134] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0135] In another embodiment of the present invention, a computer-readable storage medium is provided, in which instructions are stored. When the computer-readable storage medium is executed on a computer, the computer executes the vehicle-road communication method described in any one of the above embodiments.

[0136] In another embodiment provided by the present invention, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute the vehicle-road communication method described in any one of the above embodiments.

[0137] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

[0138] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0139] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A vehicle-road communication method, characterized in that: include: In response to receiving a first air interface message sent by at least one on-board unit, constructing a one-hop on-board unit set and a two-hop on-board unit set according to the first air interface message; The first air interface message includes identification information of a roadside unit and a vehicle-mounted unit having a direct communication link with the vehicle-mounted unit, a direct communication link exists between the one-hop vehicle-mounted unit included in the one-hop vehicle-mounted unit set and the roadside unit, a direct communication link exists between the two-hop vehicle-mounted unit included in the two-hop vehicle-mounted unit set and the one-hop vehicle-mounted unit, and no direct communication link exists between the two-hop vehicle-mounted unit and the roadside unit; According to the number of connections and path loss corresponding to the one-hop on-board unit, at least one one-hop relay node is selected from the one-hop on-board unit set to send the relay message from the roadside unit to the two-hop on-board unit in direct communication with the roadside unit through the at least one one-hop relay node; the number of connections indicates the number of two-hop on-board units in direct communication with the one-hop on-board unit; According to the second air interface message of the two-hop on-board unit, a three-hop on-board unit set is constructed, wherein a direct communication link exists between the three-hop on-board units included in the three-hop on-board unit set and the two-hop on-board unit, and no direct communication link exists between the three-hop on-board unit and the one-hop on-board unit; According to the number of connections and path loss corresponding to the two-hop on-board unit, at least one two-hop relay node is selected from the two-hop on-board unit set, so as to send the relay message to the three-hop on-board unit in direct communication with the two-hop on-board unit through the at least one two-hop relay node; Follow the above steps recursively until the preset stop condition is reached.

2. The method according to claim 1, characterized in that The selecting at least one one-hop relay node from the one-hop on-board unit set according to the number of connections and the path loss corresponding to the one-hop on-board unit comprises: When there is only one one-hop on-board unit with the largest number of connections, use the one-hop on-board unit with the largest number of connections as a one-hop relay node; In the case where there are multiple one-hop on-board units with the largest number of connections, the one-hop on-board unit with the smallest path loss is used as a one-hop relay node; the one-hop relay node is deleted from the one-hop on-board unit set, and the two-hop on-board unit that directly communicates with the one-hop relay node is deleted from the two-hop on-board unit set to update the one-hop on-board unit set and the two-hop on-board unit set; a new one-hop relay node is screened according to the number of connections and path loss corresponding to the one-hop on-board unit in the updated one-hop on-board unit set; and the above steps are repeated until the updated two-hop on-board unit set is empty.

3. The method according to claim 1 or 2, characterized in that: The path loss between the one-hop OMU and the two-hop OMU is calculated according to the following process: Determining an energy fading mode between the one-hop onboard unit and the two-hop onboard unit according to the vehicle state information of the one-hop onboard unit and the vehicle state information of the two-hop onboard unit; According to the energy fading mode, a path loss between the one-hop on-board unit and the two-hop on-board unit is calculated.

4. The method according to claim 3, characterized in that: The step of determining the energy fading mode between the one-hop onboard unit and the two-hop onboard unit according to the vehicle state information of the one-hop onboard unit and the vehicle state information of the two-hop onboard unit includes: Determine a map position relationship between the one-hop onboard unit and the two-hop onboard unit according to the vehicle status information of the one-hop onboard unit and the vehicle status information of the two-hop onboard unit; Determining obstacle information between the one-hop on-board unit and the two-hop on-board unit according to a map message from the roadside unit; Determining a channel model between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information; An energy fading mode between the one-hop on-board unit and the two-hop on-board unit is determined according to a channel model between the one-hop on-board unit and the two-hop on-board unit.

5. The method according to claim 4, characterized in that The determining, according to the map position relationship and the obstacle information, a channel model between the one-hop on-board unit and the two-hop on-board unit comprises: When it is determined that there is no obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, determining that a channel model between the one-hop on-board unit and the two-hop on-board unit is a LOS channel; When it is determined that there is an obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, and the obstacle meets a first preset condition, determining that a channel model between the one-hop on-board unit and the two-hop on-board unit is an NLOS channel; When it is determined that there is an obstacle between the one-hop on-board unit and the two-hop on-board unit according to the map position relationship and the obstacle information, and the obstacle meets the second preset condition, it is determined that the channel model between the one-hop on-board unit and the two-hop on-board unit is an NLOSv channel.

6. The method according to claim 1, characterized in that Before receiving the first air interface message sent by at least one on-board unit, the method further includes: Determine whether to perform relay communication according to the type of the message to be sent; In the case where it is determined to perform relay communication, a relay request is sent to the at least one on-vehicle unit.

7. The method according to claim 6, characterized in that The method further comprises: In the case of determining to perform relay communication, the preset stop condition is determined according to the priority of the message to be sent.

8. A vehicle-road communication method, characterized in that: Applied to vehicle-mounted units, including: In response to receiving a relay request from a roadside unit, sending a first air interface message to the roadside unit, wherein the first air interface message includes identification information of the roadside unit and the onboard unit that have a direct communication link with the onboard unit; In response to receiving the relay node indication from the roadside unit, a relay message from the roadside unit is sent to the onboard unit in direct communication with the roadside unit.

9. A roadside unit, characterized in that: include: A construction module, configured to, in response to receiving a first air interface message sent by at least one on-board unit, construct a one-hop on-board unit set and a two-hop on-board unit set according to the first air interface message; the first air interface message includes identification information of a roadside unit and an on-board unit having a direct communication link with the on-board unit, a direct communication link exists between the one-hop on-board unit included in the one-hop on-board unit set and the roadside unit, a direct communication link exists between the two-hop on-board unit included in the two-hop on-board unit set and the one-hop on-board unit, and no direct communication link exists between the two-hop on-board unit and the roadside unit; and, according to a second air interface message of the two-hop on-board unit, construct a three-hop on-board unit set, a direct communication link exists between the three-hop on-board unit included in the three-hop on-board unit set and the two-hop on-board unit, and no direct communication link exists between the three-hop on-board unit and the one-hop on-board unit; A screening module is used to screen out at least one one-hop relay node from the one-hop on-board unit set according to the number of connections and path loss corresponding to the one-hop on-board unit, so as to send the relay message from the roadside unit to the two-hop on-board unit connected thereto through the at least one one-hop relay node; the number of connections indicates the number of two-hop on-board units that directly communicate with the one-hop on-board unit; and, according to the number of connections and path loss corresponding to the two-hop on-board unit, screen out at least one two-hop relay node from the two-hop on-board unit set, so as to send the relay message to the three-hop on-board unit that directly communicates with it through the at least one two-hop relay node.

10. A vehicle-mounted unit, characterized in that: include: A sending module, configured to send a first air interface message to the road side unit in response to receiving a relay request from the road side unit, wherein the first air interface message includes identification information of the road side unit and the vehicle-mounted unit that have a direct communication link with the vehicle-mounted unit; The forwarding module is used for sending the relay message from the roadside unit to the vehicle-mounted unit that directly communicates with the roadside unit in response to receiving the relay node indication from the roadside unit.

11. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, configured to implement the method according to any one of claims 1 to 8 when executing a program stored in a memory.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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