CN111770431A

CN111770431A - Perception base station in road traffic environment and message forwarding method and device thereof

Info

Publication number: CN111770431A
Application number: CN201910240005.4A
Authority: CN
Inventors: 单单; 陈颖
Original assignee: Alibaba Group Holding Ltd
Current assignee: Alibaba Group Holding Ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-10-13

Abstract

The embodiment of the application discloses a perception base station in a road traffic environment and a message forwarding method and a device thereof, wherein the perception base station comprises: a message obtaining module, configured to receive a message, where the message includes information of an expected propagation direction of the message; and the message forwarding processing module is used for determining whether to forward the message by determining whether the perception base station is positioned in the expected propagation direction of the message. By the embodiment of the application, each message can be propagated to and only to the effective action direction of the message, and the network bandwidth is saved while the effectiveness of message propagation is ensured.

Description

Perception base station in road traffic environment and message forwarding method and device thereof

Technical Field

The application relates to the technical field of vehicle-road cooperation, in particular to a perception base station in a road traffic environment and a message forwarding method and device thereof.

Background

In the fields of automatic driving, intelligent transportation and the like, a highly intelligent automatic driving vehicle can effectively sense the surrounding environment, acquire the information of the type, position, direction, size, speed and the like of nearby targets, and make a reasonable driving decision by combining the driving state of the vehicle to complete the driving of the vehicle, so that the manual driving labor is replaced, and the highly automatic driving process is realized.

Currently, there are two main types of automatic driving perception systems: and vehicle-mounted sensor network perception and vehicle road cooperative perception. Under the mode of vehicle-mounted sensor network perception, the automatic driving automobile needs to be provided with numerous autonomous sensors (laser radar, millimeter wave radar, cameras and the like) to acquire enough abundant and diversified sensing information, and is matched with powerful computing equipment to process data rapidly in real time to acquire a complete perception result. However, due to the limitation caused by the low visual angle of the vehicle, the vehicle is in various traffic driving environments, and the sensing process of the vehicle is not enough and is difficult to complete a comprehensive sensing function. In addition, this method has a great dependence on the vehicle's own sensor system, and if a fault occurs, it has a great influence on the safety of automatic driving.

In the Vehicle-road cooperative system, a perception base station performs information interaction with an On-Board Unit (OBU) mounted in a nearby Vehicle through an RSU (road side Unit) in a V2X (Vehicle to evolution) system, so as to realize a plurality of applications such as advanced driving assistance and intelligent transportation. In this way, the requirements for the assembly condition and the calculation capability of the sensor of the vehicle can be reduced, and therefore, the method has a wider application prospect.

In order to meet the requirements of various applications, the sensing base station can acquire information through various means such as sensing, communication and the like, encapsulate the information into messages and broadcast the messages through the RSU. The sensing means of the sensing base station mainly comprises the steps of acquiring data of sensors such as a camera, a millimeter wave radar and a laser radar, processing the data in a computing unit through an image or signal processing algorithm, and finally acquiring information of roads and traffic participants, such as lane line coordinates, positions and speeds of vehicles and pedestrians. The communication means of the base station mainly includes acquiring information such as road information, information of traffic participants, weather, emergency notification, and the like from wireless communication devices such as V2X, Wi-Fi, a mobile communication network (e.g., 4G), and the like, and wired communication devices such as an optical fiber, an ethernet, and the like. The information is encapsulated into a message that is sent to the recipient via the RSU.

Because the distance between different sensing base stations is smaller than the communication distance, the sensing base station may receive messages broadcast in other adjacent sensing base stations, but under the condition of blind forwarding, some messages may not be effectively delivered to a more required receiving party, and the like.

Therefore, how to realize effective forwarding of messages between base stations becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The application provides a perception base station in a road traffic environment and a message forwarding method and device thereof, which can enable each message to be transmitted to and only to the effective action direction of the message, and save network bandwidth while ensuring the effectiveness of message transmission.

The application provides the following scheme:

a perception base station in a road traffic environment, the perception base station comprising:

the message obtaining module is used for obtaining a message, wherein the message comprises the information of the expected propagation direction of the message;

and the message forwarding processing module is used for determining whether to forward the message by determining whether the perception base station is positioned in the expected propagation direction of the message.

A method for processing message forwarding of a perception base station comprises the following steps:

a first perception base station obtains a message, wherein the message comprises the information of the expected propagation direction of the message;

determining whether the first cognitive base station is located in an expected propagation direction of the message;

and determining whether to forward the message according to the judgment result.

A method of message generation in a road traffic environment, comprising:

obtaining information in a road traffic environment;

determining expected propagation direction information for the information;

and writing the expected propagation direction information into a corresponding field in a message structure body to generate a message, so that a receiver of the message determines whether to forward the message by judging whether the associated perception base station is in the expected propagation direction.

A message structure is disclosed, which is composed of a message structure,

the message is used for being forwarded through a perception base station in a road traffic environment;

the structure body of the message comprises an expected propagation direction field and an expected propagation range information field, and the information field is used for determining whether to forward the message by judging whether the sensing base station receiving the message is positioned in the expected propagation direction and the expected propagation range of the message.

A perception base station message forwarding processing device is applied to a first perception base station and comprises the following components:

a message obtaining unit, configured to obtain a message, where the message includes expected propagation direction information of the message;

a first judging unit, configured to judge whether the first sensing base station is located in an expected propagation direction of the message;

and the determining unit is used for determining whether to forward the message according to the judgment result.

A message generating apparatus in a road traffic environment, comprising:

an information obtaining unit for obtaining information in a road traffic environment;

an expected propagation direction information determining unit for determining expected propagation direction information of the information;

and the message generating unit is used for writing the expected propagation direction information into a corresponding field in a message structure body to generate a message, so that a receiver of the message determines whether to forward the message by judging whether the associated perception base station is in the expected propagation direction.

According to the specific embodiments provided herein, the present application discloses the following technical effects:

by the embodiment of the application, the expected propagation direction can be provided in the structural body of the message, so that after the sensing base station receives the message and before forwarding, whether the sensing base station is located in the expected propagation direction of the message can be judged firstly, if so, the forwarding is performed, and otherwise, the forwarding is not needed. In this way, accurate control of the direction in which messages are propagated in the cognitive base station can be achieved, so that each message can be propagated to and only in their effective direction of action, saving network bandwidth while ensuring the effectiveness of message propagation.

In a preferred embodiment, the message may further include information of an expected propagation range, so that when performing forwarding determination, in addition to determining an expected propagation direction, the message may also be determined to determine the expected propagation range, and when sensing that the base station is located in the expected propagation direction and the expected propagation range of the message, the message may be forwarded again, so that the message may be more effectively controlled to propagate in a certain direction and range.

In addition, whether the current perception base station has forwarded the message can be judged, if not, the judgment of the direction and the range is triggered, and therefore the network storm problem is avoided.

Of course, it is not necessary for any product to achieve all of the above-described advantages at the same time for the practice of the present application.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of a road and cognitive base station deployment scheme provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a "network storm" scenario provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of another "network storm" situation provided by an embodiment of the present application;

fig. 4 is a schematic diagram of a cognitive base station provided in an embodiment of the present application;

FIG. 5 is a flow chart of a method provided by an embodiment of the present application;

FIG. 6 is a flow chart of another method provided by embodiments of the present application;

FIG. 7 is a flow chart of yet another method provided by an embodiment of the present application;

FIG. 8 is a schematic view of an apparatus provided by an embodiment of the present application;

fig. 9 is a schematic diagram of another apparatus provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments that can be derived from the embodiments given herein by a person of ordinary skill in the art are intended to be within the scope of the present disclosure.

In order to facilitate understanding of the technical solutions provided in the embodiments of the present application, first, a manner of deploying a sensing base station in a vehicle-road cooperative system related in the embodiments of the present application and reasons of problems such as "network storm" in the prior art are introduced below.

In the vehicle-road cooperative system, the sensing result of the sensing base station is broadcast to nearby vehicles through the RSU in the V2X system. The sensing results mainly comprise information of positions, speeds and the like of traffic participants such as pedestrians, vehicles and the like, and the information is packaged in a message. After the vehicle receives the messages through the OBU, the danger in the driving process can be predicted in advance, and actions such as alarming, automatic emergency braking and the like are taken to deal with the dangers. The sensing range of a single sensing base station is limited, and in order to cover all areas of a road in an all-around dead-angle-free manner, a plurality of base stations can be continuously deployed on two sides of the road according to respective sensing distances, sense different sections of the road simultaneously, and broadcast messages carrying sensing results respectively through respective RSUs. The spacing between base stations is typically about equal to twice the perceived distance. Since the effective communication distance (around 500 meters) of the V2X system is typically greater than twice the perceived distance (within 200 meters), the messages broadcast by an RSU can be received not only by nearby OBUs, but also by neighboring RSUs. For example, as shown in fig. 1, the messages broadcast by RSU a can be received by

vehicles

101, 102, 103, etc., while RSU a can also receive the messages broadcast by RSU B. Similarly, the messages broadcast by RSU B can be received by vehicles 104, etc., while RSU B can also receive the messages broadcast by RSU a. In addition, after receiving the message broadcast by the adjacent RSU, the RSU can continuously transmit the message to a farther direction, and the beyond visual range perception capability is obtained in a relay mode.

In the prior art, the forwarding behavior of the RSU on the message is similar to the forwarding behavior of the router in the communication network on the IP data packet, but improper relay or forwarding causes a "network storm" problem, that is, the data packet is forwarded for an unlimited number of times, so that all the bandwidth in the network is exhausted, and other effective data cannot be transferred. For example, as shown in FIG. 2, the original message sent by RSU-1 is cyclically relayed by three adjacent RSUs; this problem arises because each RSU forwards messages received by itself without discrimination.

In addition, the inventor of the present application finds that different types of messages have different requirements on propagation modes in the process of implementing the present application. In terms of propagation direction, ordinary road traffic information, such as the number, location, speed, etc. of vehicles on a road, should be forwarded in the opposite direction of traffic flow, so that vehicles behind the road can know the road information ahead; the emergency message, such as the location and path of the ambulance, should be forwarded forward in the direction of the road so that the vehicle in front can be informed that an ambulance is present behind and can take an avoidance. Different message propagation ranges are different, for example, road traffic information on urban roads can be propagated for 1 kilometer; at high speed, the vehicle needs to acquire road information at a longer distance ahead due to a higher vehicle speed, and the corresponding message needs to be spread farther, for example, 3 km. Similarly, the expected propagation range of a message of the traffic information class may reach several kilometers, but the expected propagation range of a message for the inter-vehicle collision warning class may be only a few hundred meters. The different types of messages also have different requirements on real-time. For example, traffic participant information typically requires an end-to-end transmission delay within 100 milliseconds; the information such as road congestion information, defects such as potholes and accumulated water on the road surface, road repairing and closing information, average vehicle speed and the like generally requires that the end-to-end transmission delay can be about 1 second. In the embodiment of the present application, a message with an expected propagation distance on the order of several hundred meters and high real-time requirement may be referred to as a "short-distance propagation message", and a message with an expected propagation distance on the order of several kilometers and low real-time requirement may be referred to as a "long-distance propagation message".

However, as an omnidirectional wireless communication device, the RSU transmits a message in the form of broadcasting, that is, radiating electromagnetic waves carrying the message to all directions; the RSU can only control the radiation range of the message and cannot control the radiation direction of the message. Therefore, the message sent by each RSU will be naturally received by at least two RSUs adjacent to each other on the left and right. For example, in FIG. 2, the message sent by RSU-2 is received by at least RSU-1 and RSU-3. Therefore, the network storm problem cannot be solved by simply adjusting the physical layer transmission power of the RSU, and an addressing and routing mechanism must be added in a higher layer protocol to realize the directional propagation of the message.

In communication networks, the "network storm" problem can typically be solved by setting a maximum number of hops for a packet. For example, the header of the IPv4 packet contains an 8-bit ttl (time to live) field, and the initial value may be set to 64 or some other value greater than 0; the router will subtract 1 from the field each time it forwards the packet; the TTL field of the packet becomes 0 and is discarded by the router. The same approach can be used by the cognitive base station to solve the network storm problem, but this solution is imperfect. The main problem is that in many application scenarios, messages of base stations are required to be spread within a preset range, however, different sensing base stations may have different sensing ranges and base station distances, and thus the spreading range of the messages cannot be accurately controlled by the method of setting TTL. For example, it is desirable that messages of base stations propagate within a range of 1 km and it is assumed that the distance between base stations is 200 m, and thus TTL of the messages is set to 5. However, limited to practical circumstances, the actual distance between base stations is 150 meters, and therefore, with TTL set to 5, the actual propagation range of the message is only 750 meters. In practical applications, it is difficult to assume that each base station knows the exact distance between all base stations in a large range around it, because the deployment of base stations may be constantly updated. A message propagation range less than expected may result in some critical information being missed by important recipients, for example, congestion information for one intersection must be passed to another intersection 1 km away to allow the vehicle to avoid congestion without turning around, but if only 750 meters are passed, this will not work. Message propagation ranges greater than expected waste network bandwidth and even cause network congestion.

In another conceivable scheme, since the message sent by the base station carries the geographical location of the traffic participant, the RSU may check the distance between the current base station and the traffic participant in the message before forwarding the message, and discard the message when the distance is greater than expected. However, this approach still may lead to network storm problems. For example, in the common road network shown in FIG. 3, RSU-1 expects messages to be forwarded a distance equal to 1000 meters, but to have a neighborhood of 500 meters in diameter in its vicinity; if the messages are filtered by only depending on the calculation of the distance, the messages can be circularly propagated among the RSU-2, the RSU-3, the RSU-4 and the RSU-5 and never stop.

Furthermore, the network storm problem can also be solved by a method for calculating the total propagation delay of the message. For example, the RSU accumulates processing delay and communication delay caused by itself in a certain field of a message each time the message is forwarded; when the delay exceeds a threshold value, the message carrying the delay will no longer be forwarded by the RSU. However, similar to the TTL-based method, this method also cannot accurately control the message propagation range.

In view of the above situation, embodiments of the present application provide a solution, in which a new message structure expression manner may be provided, specifically, an expected propagation direction field of a message may be added on the basis of an existing message structure, and in a preferred manner, an expected propagation range field may also be included. Thus, after a specific message producer produces a message, the specific expected direction and the expected range can be determined according to the information content carried by the specific message, the application scene, the target to be conveyed, the function to be played and the like, and the specific expected direction value and the specific expected range value are written into the message structure. The message producer may be a plurality of, for example, the sensing base station itself, or a related application in an intelligent traffic light device having a connection relationship with the sensing base station, such as network, wired communication, wireless communication, or the like, or a related application in a cloud master control system, or the like. For example, for accident information or the like about a location on a highway, since the influence is mainly given to a range of vehicles behind the location, the expected direction may be a direction backward from the place of the accident, and does not need to be propagated forward; in addition, the expected influence range can be estimated according to the severity degree of a specific accident and the like, and the required propagation distance can be determined. Alternatively, for the message that emergency vehicles such as ambulance need to pass on the highway, it is usually required that the vehicle in front is prepared in advance, so the expected propagation direction may be forward propagation, and the specific propagation range may be determined according to the current information such as vehicle speed. In addition, in the indoor road scene, if traffic congestion occurs at a certain intersection, the propagation direction, the propagation distance, and the like of the message can be determined according to the road section, the direction, and the like affected by the specific congestion condition.

In this way, since the structure of the message contains the expected propagation direction and propagation range information, for the base station receiving the message, it can be determined whether the message is in the expected propagation direction and propagation range according to the direction, distance, and the like relative to the sender of the previous hop, and if so, forwarding can be performed, otherwise, forwarding is not necessary. In addition, in order to prevent the occurrence of a network storm, each base station can judge whether the message exists in the historical forwarding record or not according to the Hash value of the message and the like after receiving the message, and if the message is already forwarded, the message can not be forwarded. Therefore, by the method, the message can be more accurately propagated while the network storm is prevented, the effectiveness of message propagation is ensured, the network bandwidth is saved, and unnecessary propagation resource waste is avoided.

The following describes in detail a specific technical solution provided in an embodiment of the present application.

Example one

First, an embodiment of the present application provides a sensing base station in a vehicle-road coordination system, and referring to fig. 4, the sensing base station may specifically include:

a message obtaining module 401, configured to obtain a message, where the message includes information of an expected propagation direction of the message;

a message forwarding processing module 402, configured to determine whether to forward the message by determining whether the cognitive base station is located in an expected propagation direction of the message.

During specific implementation, a plurality of perception base stations are arranged in the system, and the distance between adjacent perception base stations is smaller than the communication distance of the perception base stations; the perception base stations transmit messages in a broadcasting mode, so that the messages broadcast by the first perception base station can be received by at least one second perception base station adjacent to the first perception base station. In addition, in practical application, in order to better implement the scheme of the embodiment of the present application, the following preparation work may be performed: first, it can ensure that the message sent by each sensing base station can be received only by the adjacent sensing base station (one hop distance) by adopting the methods commonly used in the wireless communication system, such as adjusting the transmission power, checking the Media Access Control (MAC) address, etc. (of course, this will improve the performance of the system, but is not the limiting condition of the embodiment of the present application); secondly, each base station knows the geographical position of the base stations adjacent to the base station; furthermore, the RSU of each base station has a unique MAC address, and each base station only knows the MAC addresses of the RSUs of the base stations adjacent to it. Therefore, after each base station receives the message, the base station which sends the message and the position information of the base station which sends the message can be accurately known, so that the direction, the distance and the like relative to the previous hop can be conveniently calculated, and whether the message is in the expected direction and the range of the message can be further determined.

The specific message may be generated by a message generator, specifically may be a road condition sensing result message locally generated by a certain sensing base station and broadcasted outwards, or may also be a signal lamp state message generated by a device such as an associated intelligent traffic signal lamp, or may also be a notification message generated by a control center in the cloud, and the like. The specific applications may be in different operating environments, but all require the generation of relevant messages and broadcast by the cognitive base station. And the application itself can know the information type, action, scene and/or affected road section carried by the specific message, so that the specific expected propagation direction can be determined according to the information, or the information of the expected propagation range can be determined and written into the corresponding field in the message structure, and then the specific message to be sent is generated. Wherein the desired propagation direction comprises one-way, two-way, or multi-way propagation. In order to meet different requirements on the propagation range expression mode in different scenarios, the expected propagation range is expressed in a plurality of modes, and the structure body of the specific message may further include a range type field, for example, the structure body may specifically include an expected propagation distance, an expected propagation hop count, or expected propagation time information. The manner of generating the message, the definition of the relevant fields in the message structure, and the like will be described in detail later.

The message obtaining module 401 is mainly configured to, after receiving a message from another sensing base station, before forwarding the message, determine, by the message forwarding processing module 402, whether the current sensing base station is located in an expected direction and an expected range of the message, and then determine whether to forward the message.

When the message is forwarded, the message is still sent in a broadcast mode, after other adjacent base stations receive the message, the message forwarding processing module continues to judge whether the message is still in the expected direction and the expected range of the message, if so, the message is forwarded continuously, otherwise, the message is not forwarded, and the like.

In practical application, in order to prevent a "network storm" phenomenon, the message forwarding processing module may further determine whether the sensing base station has forwarded the message, and if not, trigger the judgment of the expected propagation direction and/or range. Otherwise, the user can directly exit, and does not need to forward any more, and does not need to judge the direction and/or the range.

The following describes the processing method of the forwarding message in detail by two specific sensing base stations according to the embodiment.

Example two

The second embodiment provides a method for forwarding and processing a message of a sensing base station in a road traffic environment, where, for the sensing base station that receives the message, before forwarding the received message, the method may first determine, by a forwarding processing module, that the message has not been forwarded before, and the current sensing base station forwards the message in an expected direction of the message, otherwise, the message does not need to be forwarded, so as to avoid a network storm and achieve accurate control of a message sending direction and distance.

Specifically, referring to fig. 5, the method may specifically include:

s501: a first perception base station obtains a message, wherein the message comprises the information of the expected propagation direction of the message;

as described above, the specific message may be a local message generated by the current base station in a sensing manner, or may also be a foreign message received in a communication manner, where the source of the foreign message may be various, and the foreign message may be other sensing base stations, an intelligent traffic light device, a cloud control center, and so on.

S502: determining whether the first cognitive base station is located in an expected propagation direction of the message;

s503: and determining whether to forward the message according to the judgment result.

After receiving a particular message, it may be determined whether the first cognitive base station is located in an expected propagation direction of the message in order to determine whether it needs to be forwarded.

In a preferred embodiment, the message further includes information of an expected propagation range of the message, and at this time, in addition to determining whether the first sensing base station is located in an expected propagation direction of the message, it may also be determined whether the first sensing base station is located within the expected propagation range of the message; determining that the message needs to be forwarded if the first cognitive base station is located in an expected propagation direction and within an expected propagation range of the message. That is, the specific implementation method can be as shown in fig. 6:

s601: a first perception base station obtains a message, wherein the message comprises expected propagation direction information and expected propagation range information of the message;

s602: judging whether the first perception base station is positioned in the expected propagation direction and the expected propagation range of the message;

s603: and determining whether to forward the message according to the judgment result.

In order to determine whether forwarding is required or not in the presence of the expected propagation range information and to facilitate the receiver of the next hop to determine the range in the case of forwarding, the expected propagation range may be modified according to a completion amount (a completed distance, a completed hop count, time, and the like) of the propagation range of the message generated by the forwarding action of this time, and if the modified value is greater than 0, it may be determined that forwarding is required, and meanwhile, the modified value may be used as a second sensing base station of the receiver of the next hop of the message to determine whether forwarding is required to be continued according to the modified expected propagation range. That is, for a specific base station, the information about the expected propagation range in the received message structure may specifically refer to the remaining expected propagation range, and the value is obtained according to the difference between the original expected propagation range and the completed propagation range. That is, each time a message is forwarded, the remaining expected propagation range may be modified according to the range completed by the forwarding.

Specifically, when determining whether the first sensing base station is located in the expected propagation direction and the expected propagation range of the message, the direction and the range may be determined respectively. When judging the direction, firstly, the position information of the third perception base station of the last hop sender of the message can be determined, then the direction information of the first perception base station relative to the third perception base station is calculated, and then whether the direction is in the expected direction or not is judged. There may be multiple expected directions of the message, and one direction data and a threshold value C may be set in each expected direction. After calculating the direction information relative to the last third sensing base station, the numerical value of the direction field can be obtained for each expected direction in the message, if the error between all the numerical values and the direction _ local is greater than a threshold value C, the process exits, otherwise, the subsequent operation is continuously executed. Wherein, C is a design parameter and can be adjusted according to actual needs.

When the expected range is judged, the judgment can be respectively carried out according to different specific range types, specifically, the value of the range type field in the message structure body can be firstly taken out to determine the specific range type. And then taking out the specific preset range value, and judging according to the specific range value under the range type. For example, if the range type is the expected propagation distance, the distance from the third sensing base station to the first sensing base station may be calculated, if the difference obtained by subtracting the distance from the third sensing base station to the first sensing base station from the expected propagation distance is greater than zero, the forwarding may be performed, and before the forwarding, the difference is determined as the modified expected propagation range information and written back to the structure of the message.

If the range type is the expected number of propagation hops; subtracting the expected propagation hop count information by one, if the result is greater than or equal to zero, determining that the first sensing base station is in the expected propagation range and can perform forwarding, and before forwarding, determining the result of subtracting the expected propagation hop count by one as modified expected propagation range information, and writing back the modified expected propagation range information into the structural body of the message. Otherwise, if the value is less than 0, exiting.

In addition, the range type of the expected propagation range is an expected propagation time; then the distance of the first sensing base station relative to the third sensing base station can be calculated, the transmission time of the message transmitted from the third sensing base station to the first sensing base station is determined according to the calculated distance, the expected transmission time and the calculated transmission time from the third sensing base station to the first sensing base station are calculated, and whether the first sensing base station is in the expected propagation range is determined according to whether the difference is greater than zero; if yes, the message can be forwarded, the difference value is determined as the modified expected propagation range information before forwarding, and the modified expected propagation range information is written back to the structural body of the message.

In addition, in order to prevent the occurrence of a "network storm" phenomenon, after receiving the message, the first sensing base station may also first determine whether the message has been forwarded by the first sensing base station, and if so, may not forward the message any more. Otherwise, the subsequent determination steps regarding the direction and the range can be entered, and then whether forwarding is needed or not is further determined.

Specifically, when determining whether the first sensing base station has forwarded the message, there may be a plurality of ways. For example, in one approach, the aware base station can maintain a historical forwarding record in which a digital fingerprint (e.g., Hash value, etc.) of a message that has been forwarded can be maintained. Therefore, when a message is received each time, the hash value of the message can be calculated firstly, then the hash value of the message is compared with the hash value of each message in the historical forwarding record, and whether the current sensing base station forwards the message or not can be determined according to the comparison result.

It should be noted that, regarding the expected propagation range information of a specific message, as described above, after the same message is propagated once, the propagation range information may be changed, and the remaining propagation range information may be recorded in the message. For example, if the initial expected propagation range of a message is 3 hops, then after each forwarding, the specific propagation range may be decremented by one and written back to the corresponding field in the structure. Therefore, the value of the propagation range field in the message structure changes after the same message is forwarded each time. At this time, if the hash operation is directly performed by using the values in all the fields of the message, the hash values calculated after being forwarded each time are different, and it cannot be determined whether the messages are the same by comparing the hash values. Thus, in a particular implementation, when generating a hash value for a message, the information on the fields of the structure that are associated with the expected propagation range may be first removed and then calculated.

In summary, according to the embodiment of the present application, an expected propagation direction can be provided in a structure of a message, so that after receiving the message, specifically before forwarding, the sensing base station can first determine whether the sensing base station is located in the expected propagation direction of the message, and if so, then forwarding is performed, otherwise, forwarding is not necessary. In this way, it is possible to achieve accurate control of the direction in which messages are propagated in the cognitive base station, ensuring that each message can be propagated to and only in their effective direction of action, saving network bandwidth while ensuring the effectiveness of message propagation.

EXAMPLE III

The third embodiment provides a message generating method in an intelligent transportation system from the perspective of a message producer, and referring to fig. 7, the method may specifically include:

s701: obtaining information in a road traffic environment;

the specific information may be acquired by a sensor system, and may specifically include road condition information, condition information of traffic participants on a road, state information of traffic lights, sign line information on a road, accident information, congestion condition information, and the like.

S702: determining an expected direction of propagation of the information;

s703: and writing the expected propagation direction information into a corresponding field in a message structure body to generate a message, so that a receiver of the message determines whether to forward the message by judging whether the associated perception base station is in the expected propagation direction.

In specific implementation, the expected propagation range information of the information can be determined, and the expected propagation range information is written into a corresponding field in the message structure body. During specific implementation, the information is classified according to the information type, the action, the scene and/or the influenced road section of the information; then, the expected propagation direction and the expected propagation range are determined according to the classification result. In the embodiment of the present application, a plurality of different range types may be provided, and when the expected propagation range is expressed, the specific range type may be determined first, and then a specific range value may be set in the corresponding type.

Specifically, the message structure may be defined as follows:

the fields associated with the embodiments of the present application are shown in bold font previously described. Wherein directionNum describes the expected propagation direction of the message transmission; on a straight line, the specific value of directionNum may be equal to 1 or 2, while in an intersection it may be equal to an integer between 1 and 4. timeStamp is the timeStamp set when the message was generated. The range type is the range type of the expected propagation range, and the range is the specific expected propagation range.

Wherein, table 1 gives detailed definitions of the value ranges of the rangeType and range.

TABLE 1

That is, when the ranging type is 1, the representative range type is "maximum propagation distance", and the range value in this case may be expressed by a distance value in units of "meter" or the like. When range type is 2, the range type represents "maximum propagation hop count", and the range value may be expressed by a positive integer, for example, when range is 3, it represents that the message is propagated for at most 3 hops in the corresponding direction, and then no further propagation is needed. When the range type is 3, the representative range type is "maximum propagation time", and the range value at this time may be expressed by a time value in units of "second" or the like, that is, the representative corresponding message only needs to propagate within an expected time range, beyond which time, the message loses meaning, and may not need to be forwarded any more, and so on.

By reasonably setting the numerical values in the table 1, different requirements on the expected propagation range expression modes under various different scenes can be met. In addition, various different types of messages can be distinguished by setting specific propagation range values. For example, for the short-Range and long-Range messages, the short-Range message carrying the vehicle position and speed may be set to ranging type 1, Max Range 500 meters; the long-distance travel message carrying the road congestion information may set a rangeType of 1, a Max Range of 2000 meters, and so on.

Thus, for each desired direction, the message format may define a descriptive form rangeType toward the direction, the desired propagation range, and a propagation range value corresponding to the descriptive form. For example, a heading angle of message propagation may be specified in the direction field, the unit being angle, a value of "1" specified in the rangeType field to represent that the descriptive form of the expected propagation range is distance, and a specific value of the expected propagation range specified in the range.

Through the above definition, when a producer of various messages produces specific messages, the expected propagation direction and the expected propagation range and the corresponding expression mode thereof required by the specific messages can be determined according to information such as the type, the action, the scene and/or the affected road section required by the messages, and then the information is written into the field corresponding to the message structure.

Specifically, when the expected propagation direction and the expected propagation range required by the message and the corresponding expression mode thereof are determined, the information can be determined according to information such as the type, the action, the scene, the influence road section and the like required to be carried by the specific message. In specific implementation, the messages can be classified according to the information, and the messages generated by the message producer are classified, so that each message can be transmitted to and only transmitted to the effective action range of the message, and the network bandwidth is saved while the effectiveness of message transmission is ensured. Specific classification methods may include, but are not limited to, several of the following:

a) dividing the message into short distance transmission message and long distance transmission message according to the expected transmission distance of the message; short-distance transmission messages are generally transmitted in a line-of-sight range or a block range, and the transmission range of long-distance transmission messages breaks through the two limits; the category information affects the setting of the expected propagation range, and the expected propagation range can be expressed by the distance information;

b) according to the expected propagation direction of the message, the method is divided into three types of one-way propagation message, two-way propagation message and multi-way propagation message; the unidirectional transmission message and the bidirectional transmission message are mostly generated at base stations deployed at two sides of the highway, and the multidirectional transmission message is mostly generated at base stations deployed in urban environment; the category information affects the setting of the expected propagation direction;

c) dividing the messages into real-time messages and non-real-time messages according to the requirements of the messages on time delay; real-time messages typically require an end-to-end delay of a message during propagation to be within 100 milliseconds, while non-real-time messages typically require an end-to-end delay of a message during propagation to be within 1 second. This category information affects the setting of the expected propagation range, which can be expressed by the length of time of the propagation.

d) Dividing the information into single road section information and multi-path section information according to the influence range of the information on the traffic flow; a single road segment message affects only the traffic participants of the current road bounded by the traffic light or block, while a multi-road segment message affects the traffic participants across the traffic light or block. The category information may also influence the setting of the expected propagation range, which may be expressed in terms of the number of hops propagated, since each road segment may be provided with a cognitive base station.

The short-range broadcast message mainly carries information of dynamic (normal operation) traffic participants, including but not limited to:

a. continuous variation of information such as positions, orientations and speeds of traffic participants such as pedestrians, motor vehicles, bicycles and tricycles;

b. sudden changes in information or states of pedestrians, traffic participants such as motor vehicles, bicycles, tricycles, etc., such as sudden braking, lane changes, sudden falls of pedestrians or self-service vehicles, etc.;

c. the amount of change of information such as the position, orientation, speed and the like of a pedestrian, a motor vehicle, a bicycle, a tricycle and the like relative to a road, such as the position away from the next intersection, the optimal speed and the like;

d. the rules or information of the road itself, such as the number of lanes, the highest and lowest speed limits, traffic light phase information, etc.

The long-distance transmission message is mainly information which affects the overall traffic condition, and generally includes information which has a relatively long duration and affects the surrounding roads connected with the current road, including but not limited to:

a. traffic flow related information such as information on congestion or smoothness of a road, an average vehicle speed at a certain end of a road, an average waiting time at an intersection, and the like;

b. road condition-related information such as accidents such as road repair, road closure, construction, car accidents, etc., restriction rules, toll rules, etc.;

c. information gathered by the participants of the vulnerable traffic, such as the crowd of students crossing a road, a bus station or a dense distribution of people or bicycle streams in the subway, etc.

Specifically, for a certain message, the message may be divided into multiple categories according to different dimensions at the same time, wherein the classification results in different dimensions related to the direction or the range are included, so that the expected propagation direction and the range can be determined. For example, the information carried in a message may be traffic accident information somewhere on a highway, and since the message is generally only useful to traffic participants behind that location on the highway, the message may be classified as a one-way travel message, with the direction of travel being backward (as opposed to vehicular direction); meanwhile, since the traffic accident information is used, the influence range may be relatively large, and thus, a wide-range transmission is required. In addition, since it may not be known in advance when the car accident can be solved, it is more reasonable to express the expected range information with the maximum propagation distance. Thus, the expected direction information in the message may be, propagating backwards; the type range type of the expected range is 1, the specific range value is represented by a certain distance length, and so on.

After the fields related to the expected propagation direction and the expected propagation range are added in the specific message structure, the base station at the receiver of the message can determine whether the message needs to be forwarded by judging whether the message is located in the expected propagation direction and the propagation range, so that the propagation direction and the range of the message can be accurately controlled. Various information generated in a specific traffic environment can be more accurately sent to more needed traffic participants, and the network bandwidth is saved while the effectiveness of message propagation is ensured.

Example four

The fourth embodiment provides a message structure, wherein,

the message is used for being sent through a perception base station in a road traffic environment;

Wherein the expected propagation range field comprises: a range type field, and a propagation range value field.

The range type includes an expected propagation distance, an expected propagation hop count, or an expected propagation time.

It should be noted that, in the embodiment of the present application, the message may be specifically sent to other sensing base stations, may also be sent to traffic participants such as vehicles, or may also be sent to a remote server, or the like.

Corresponding to the second embodiment, an embodiment of the present application further provides a device for forwarding and processing a message of a sensing base station, referring to fig. 8, where the device may be specifically applied to a first sensing base station, and includes:

a message obtaining unit 801, configured to obtain a message, where the message includes expected propagation direction information of the message;

a first determining unit 802, configured to determine whether the first sensing base station is located in an expected propagation direction of the message;

a determining unit 803, configured to determine whether to forward the message according to the determination result.

In a specific implementation, the apparatus may further include:

a second determining unit, configured to determine whether the first sensing base station has forwarded the message, and trigger the determination of the expected propagation direction if the message has not been forwarded.

The second determining unit may be specifically configured to:

calculating to obtain digital fingerprint information of the message; and comparing the digital fingerprint information with digital fingerprint information of forwarded messages stored in a historical forwarding record, and determining whether the perception base station forwards the messages or not according to a comparison result.

In specific implementation, the message also comprises the information of the expected propagation range of the message;

in this case, the apparatus may further include:

a third judging unit, configured to judge whether the first sensing base station is located within an expected propagation range of the message;

the determining unit may specifically be configured to:

determining that the message needs to be forwarded if the first cognitive base station is located in an expected propagation direction and within an expected propagation range of the message.

Wherein the expected propagation range information included in the message is: remaining expected propagation range information, the remaining expected propagation range determined from a difference between the initial expected propagation range and the completed propagation range; when the digital fingerprint information of the message is calculated, the relevant information of the expected propagation range field is removed and then the calculation is carried out.

In addition, the apparatus may further include:

and the range modification unit is used for modifying the expected propagation range according to the completion quantity of the transmission range of the message generated by the current transmission behavior before the message is transmitted, so that a second perception base station serving as a next hop receiving party of the message transmitted at the time judges whether the message needs to be continuously transmitted according to the modified expected propagation range.

The first determining unit may specifically include:

a position determining subunit, configured to determine position information of a third sensing base station of a previous hop sender of the message;

a direction calculating subunit, configured to calculate direction information of the first sensing base station relative to the third sensing base station;

a direction judging subunit, configured to judge whether a deviation between the calculated direction and the expected propagation direction is within a threshold range, and if so, determine that the cognitive base station is located in the expected propagation direction of the message.

Wherein the expected propagation direction of the message is multiple;

the direction determination subunit may be specifically configured to:

determining deviations between the calculated direction and a plurality of expected propagation directions, respectively;

determining that the cognitive base station is located in an expected direction of propagation of the message if the deviation from one of the expected directions of propagation is within a threshold range.

Wherein the expected propagation range information in the message comprises a range type field and a propagation range value field;

the third determining unit may specifically include:

an expression mode determining subunit, configured to determine an expression mode of an expected propagation range according to the information in the range type field, and determine a range value in the expression mode according to the information in the propagation range value field;

and the range judging subunit is used for determining whether the perception base station is positioned in the expected propagation range of the message according to the range value in the expression mode.

Wherein the range types include: an expected propagation distance;

the range determining subunit may be specifically configured to:

determining the position information of a third perception base station of a previous hop sender of the message;

subtracting the distance from the third cognitive base station to the first cognitive base station from the expected propagation distance value, and if the difference is greater than zero, determining that the cognitive base station is within the expected propagation range of the message.

Alternatively, the range types include: expected number of propagation hops;

the range determining subunit may be specifically configured to:

and performing a minus one operation on the expected propagation hop value, and if the result is greater than zero, determining that the first perception base station is in the expected propagation range.

Alternatively, the range types include: an expected travel time;

the range determining subunit may be specifically configured to:

calculating a distance from the third cognitive base station to the first cognitive base station;

determining a transmission time for the message to pass from the third cognitive base station to the first cognitive base station according to the calculated distance;

subtracting the transmission time from the third cognitive base station to the first cognitive base station from the expected transmission time, and if the difference is greater than zero, determining that the first cognitive base station is within the expected propagation range.

Corresponding to the three phases of the embodiment, the embodiment of the present application further provides a message generating device in a road traffic environment, referring to fig. 9, the device may specifically include:

an information obtaining unit 901 for obtaining information in a road traffic environment;

an expected propagation direction information determining unit 902 for determining expected propagation direction information of the information;

a message generating unit 903, configured to write the expected propagation direction information into a corresponding field in a message structure, and generate a message, so that a receiver of the message determines whether to forward the message by determining whether an associated sensing base station is in the expected propagation direction.

In a specific implementation, the apparatus may further include:

an expected propagation range determining unit configured to determine expected propagation range information of the information;

the message generation unit may be further configured to: and writing the expected propagation range information into a corresponding field in a message structure body.

Wherein the expected propagation direction and the expected propagation range of the information may be determined by:

the classification unit is used for classifying the information according to the information type, the action, the scene and/or the influenced road section of the information;

and the determining unit is used for determining the expected propagation direction and the expected propagation range according to the classification result.

In addition, the method can also comprise the following steps:

the range type information determining unit is used for determining the range type information of the expected propagation range information according to the dimension information according to which the information is classified;

and the expression mode determining unit is used for expressing the expected propagation range information according to the range type information and writing the range type information into a corresponding field in the message structure body.

Wherein the classification unit may specifically be configured to:

dividing the information into short-distance propagation information and long-distance propagation information according to the expected propagation distance of the information;

at this time, the expected propagation range is expressed by distance information.

Wherein the short-range propagation information comprises: the position, orientation, continuous variation, sudden variation or variation with respect to the road of the traffic participant, or the rules or information of the road itself;

the long-distance propagation information includes: traffic flow-related information, road condition-related information, or information gathered by vulnerable traffic participants.

Alternatively, the classification unit may specifically be configured to:

the information is divided into one-way, two-way and multi-way information according to the expected propagation direction of the message.

Alternatively, the classification unit may specifically be configured to:

dividing real-time messages and non-real-time messages according to the requirements of information on time delay;

at this time, the expected propagation range is expressed by the time length of propagation.

Alternatively, the classification unit may specifically be configured to:

dividing the information into single road section information and multi-path section information according to the influence range of the information on the traffic flow;

at this time, the expected propagation range is expressed by the number of hops propagated.

From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be essentially or partially implemented in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments of the present application.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

The perception base station in the road traffic environment and the message forwarding method and device thereof provided by the application are introduced in detail, a specific example is applied in the description to explain the principle and the implementation mode of the application, and the description of the embodiment is only used for helping to understand the method and the core idea of the application; meanwhile, for a person skilled in the art, according to the idea of the present application, the specific embodiments and the application range may be changed. In view of the above, the description should not be taken as limiting the application.

Claims

1. A perception base station in a road traffic environment, the perception base station comprising:

2. The cognitive base station of claim 1,

the system comprises a plurality of perception base stations, wherein the distance between adjacent perception base stations is smaller than the communication distance of the perception base stations;

the perception base stations transmit messages in a broadcasting mode, and the messages broadcasted by the first perception base station can be received by at least one second perception base station adjacent to the first perception base station.

3. The cognitive base station of claim 1,

the message also comprises the expected propagation range information of the message;

the message forwarding processing module is specifically configured to determine whether to forward the message by determining whether the cognitive base station is located in an expected propagation direction and an expected propagation range of the message.

4. The cognitive base station of claim 3,

the expected propagation direction and the expected propagation range of the message are related to the type, action, scene and/or affected road segment of the information to be carried by the message.

5. The cognitive base station of any one of claims 1 to 4,

the message forwarding processing module is further configured to determine whether the sensing base station has forwarded the message, and if not, trigger the determination of the expected propagation direction and range.

6. A method for processing message forwarding of a cognitive base station is characterized by comprising the following steps:

7. The method of claim 6, further comprising:

and judging whether the first perception base station forwards the message or not, and triggering the judgment of the expected propagation direction if the message is not forwarded.

8. The method of claim 7,

the determining whether the first cognitive base station has forwarded the message includes:

calculating to obtain digital fingerprint information of the message;

and comparing the digital fingerprint information with digital fingerprint information of forwarded messages stored in a historical forwarding record, and determining whether the perception base station forwards the messages or not according to a comparison result.

9. The method according to any one of claims 6 to 8,

the method further comprises the following steps:

judging whether the first perception base station is positioned in an expected propagation range of the message;

the determining whether to forward the message according to the judgment result includes:

10. The method of claim 9,

the expected propagation range information included in the message is: remaining expected propagation range information, the remaining expected propagation range determined from a difference between the initial expected propagation range and the completed propagation range;

when the digital fingerprint information of the message is calculated, the relevant information of the expected propagation range field is removed and then the calculation is carried out.

11. The method of claim 10, further comprising:

before forwarding the message, modifying the expected propagation range according to the completion quantity of the forwarding behavior to the propagation range of the message, so that a second perception base station serving as a next hop receiving party of the message forwarded at the time judges whether the message needs to be forwarded continuously according to the modified expected propagation range.

12. The method of claim 5,

the determining whether the cognitive base station is located in an expected propagation direction of the message includes:

calculating direction information of the first perception base station relative to the third perception base station;

and judging whether the deviation between the calculated direction and the expected propagation direction is within a threshold value range, and if so, determining that the perception base station is positioned in the expected propagation direction of the message.

13. The method of claim 12,

the expected propagation direction of the message is multiple;

the determining whether the deviation between the calculated direction and the expected propagation direction is within a threshold range comprises:

14. The method of claim 9,

the expected propagation range information in the message comprises a range type field and a propagation range value field;

said determining whether said cognitive base station is within an expected propagation range of said message comprises:

determining an expression mode of an expected propagation range according to the information of the range type field, and determining a range value under the expression mode according to the information of the propagation range value field;

and determining whether the perception base station is positioned in the expected propagation range of the message according to the range value in the expression mode.

15. The method of claim 14,

the range types include: an expected propagation distance;

the determining whether the cognitive base station is located within an expected propagation range of the message according to the range value in the expression mode comprises:

16. The method of claim 14,

the range types include: expected number of propagation hops;

17. The method of claim 14,

the range types include: an expected travel time;

18. A method of message generation in a road traffic environment, comprising:

obtaining information in a road traffic environment;

determining expected propagation direction information for the information;

19. The method of claim 18, further comprising:

determining expected propagation range information for the information;

and writing the expected propagation range information into a corresponding field in a message structure body.

20. The method of claim 19,

determining an expected propagation direction and an expected propagation range of the information by:

classifying the information according to the information type, the action, the scene and/or the affected road section of the information;

and determining the expected propagation direction and the expected propagation range according to the classification result.

21. The method of claim 20, further comprising:

determining range type information of the expected propagation range information according to the dimension information according to which the information is classified;

and expressing the expected propagation range information according to the range type information, and writing the range type information into a corresponding field in a message structure body.

22. The method of claim 21,

the classifying the information includes:

the expected propagation range is expressed by distance information.

23. The method of claim 22,

the short-range propagation information includes: the position, orientation, continuous variation, sudden variation or variation with respect to the road of the traffic participant, or the rules or information of the road itself;

24. The method of claim 21,

the classifying the information includes:

25. The method of claim 21,

the classifying the information includes:

the expected propagation range is expressed by the length of time of propagation.

26. The method of claim 21,

the classifying the information includes:

the expected propagation range is expressed by the number of hops propagated.

27. A message structure, characterized in that,

28. The message structure of claim 27,

the expected propagation range field includes: a range type field, and a propagation range value field.

29. The message structure of claim 28,

30. The message forwarding processing device for the cognitive base station is applied to a first cognitive base station, and comprises the following components:

31. The apparatus of claim 30,

the device further comprises:

the determining unit is specifically configured to:

32. An apparatus for generating messages in a road traffic environment, comprising:

33. The method of claim 32, further comprising:

an expected propagation range information determining unit configured to determine expected propagation range information of the information;

the message generating unit is further configured to write the expected propagation range information into a corresponding field in a message structure.