CN112243210B

CN112243210B - Conflict-free multiple access method, device and system suitable for media application of Internet of vehicles

Info

Publication number: CN112243210B
Application number: CN202011101047.9A
Authority: CN
Inventors: 刘凯; 王龙坤; 曹先彬; 张涛; 罗喜伶; 王珺珺; 许乙付
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2020-10-15
Filing date: 2020-10-15
Publication date: 2021-09-03
Anticipated expiration: 2040-10-15
Also published as: CN112243210A

Abstract

The application provides a conflict-free multiple access method, a conflict-free multiple access device and a conflict-free multiple access system suitable for media application of Internet of vehicles, wherein the method comprises the following steps: in a first interval or a second interval of a time slot to be occupied, a first busy tone signal sent by other vehicles is not monitored, the time slot to be occupied comprises a first interval, a second interval, a third interval and a fourth interval with a time sequence relation, the first busy tone signal is used for indicating that the time slot to be occupied is requested to be occupied, and then a channel is monitored continuously; and if the second busy tone signal and the third busy tone signal sent by other vehicles are not monitored in the third interval of the time slot to be occupied, transmitting data through the fourth interval of the time slot to be occupied. The method can effectively reduce the access conflict and the combination conflict in the network and reduce the data transmission time delay.

Description

Conflict-free multiple access method, device and system suitable for media application of Internet of vehicles

Technical Field

The present application relates to communications technologies, and in particular, to a collision-free multiple access method, apparatus, and system suitable for media applications in the internet of vehicles.

Background

With the development of communication technology, vehicles also need to communicate, and the vehicles can transmit data through time slots. When different vehicles need to occupy the same time slot, collision occurs, and therefore the vehicles cannot adopt the time slot to finish data transmission.

In the prior art, unique time slots are configured for each vehicle, and different vehicles adopt the respective unique time slots to transmit data, so that the problem of time slot conflict is solved.

However, in the prior art, because a unique time slot needs to be configured for each vehicle, a problem that part of the time slots cannot be adopted in time may occur, thereby causing resource waste; further, since a part of the time slot cannot be used for transmitting data, the data cannot be transmitted in time.

Disclosure of Invention

The application provides a conflict-free multiple access method, a conflict-free multiple access device and a conflict-free multiple access system which are suitable for vehicle networking media application, and the conflict can be generated in the communication process, particularly in the vehicle communication process, so that the problem that the data cannot be transmitted timely to influence the network performance is solved.

In a first aspect, the present application provides a collision-free multiple access method for media applications in a vehicle networking, applied to a current vehicle, the method comprising:

monitoring a first busy tone signal sent by other vehicles in a first interval or a second interval of a time slot to be occupied, wherein the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signal is used for indicating that the time slot to be occupied is requested to be occupied and continuously monitoring a channel;

and if a second busy tone signal and a third busy tone signal sent by other vehicles are not monitored in a third interval of the time slot to be occupied, wherein the second busy tone signal is used for indicating a vehicle in the same area as the current vehicle to request to occupy the time slot to be occupied, and the third busy tone signal is used for indicating an existing vehicle in an adjacent area adjacent to the current vehicle to request to occupy the time slot to be occupied, transmitting data through a fourth interval of the time slot to be occupied.

In one possible design, the method further includes:

if a first busy tone signal sent by other vehicles is monitored in a first interval of a time slot to be occupied, a fourth busy tone signal is initiated in a second interval of the time slot to be occupied, wherein the fourth busy tone signal is used for indicating that the time slot is requested to be occupied.

In a possible design, when the number of micro-slots occupied by the first busy tone signal is equal to a first preset number, the fourth busy tone signal is carried on a first micro-slot of a second interval of the to-be-occupied time slot;

and when the number of the micro time slots occupied by the first busy tone signal is greater than a first preset number, the fourth busy tone signal is borne on a second micro time slot of a second interval of the time slots to be occupied.

In one possible design, the first predetermined number is 2.

In one possible design, the first busy tone signal is carried on any two minislots in a first interval of the timeslot to be occupied.

In one possible design, the method further includes:

if second busy tone signals sent by other vehicles are monitored in a third interval of the time slot to be occupied, initiating a third busy tone signal in the third interval of the time slot to be occupied;

and when detecting that the second busy tone signals in the third interval of the time slot to be occupied are all finished, initiating a third busy tone signal and monitoring the next time slot.

In one possible design, the method further includes:

and if the second busy tone signals sent by other vehicles are not monitored in the third interval of the time slot to be occupied and the third busy tone signals sent by other vehicles are monitored, monitoring the next time slot.

In one possible design, before transmitting data through the fourth interval of the to-be-occupied time slot, the method further includes:

initiating a second busy tone signal in a third interval of the time slot to be occupied;

and if other second busy tone signals and other third busy tone signals are not monitored in the micro-slot except the second micro-slot after the currently initiated second busy tone signal is determined to be finished, executing a step of transmitting data through a fourth interval of the to-be-occupied time slot.

In one possible design, the method further includes:

and if other second busy tone signals and/or other third busy tone signals are monitored in the micro-time slot except the second micro-time slot after the currently initiated second busy tone signal is determined to be finished, monitoring the next time slot.

In one possible design, when transmitting data through the fourth interval of the slot to be occupied, the method further includes:

when the fourth interval of the time slot to be occupied can bear the data, transmitting the data through the fourth interval of the time slot to be occupied;

and when the fourth interval of the time slot to be occupied can not bear the data, transmitting part of data in the data through the fourth interval of the time slot to be occupied, and transmitting the rest of data in the data through the next time slot.

In one possible design, transmitting the remaining data in the data through the next slot further includes:

transmitting a first busy tone signal in a first interval of a next time slot;

if a fourth busy tone signal sent by other vehicles is not monitored in a second micro time slot of a second interval of the next time slot, adopting a third interval and a fourth interval of the next time slot to transmit data;

and if the fourth busy tone signals sent by other vehicles are monitored in the second micro-slot of the second interval of the next time slot, adopting a time slot competition mode to compete for the next time slot.

In one possible design, the number of minislots occupied by the second busy tone signal is greater than 2, and the number of minislots occupied by the third busy tone signal is equal to 1.

In a second aspect, the present application provides a collision-free multiple access apparatus for media applications in car networking, the apparatus being applied to a current vehicle, the apparatus comprising:

the system comprises a first monitoring unit, a second monitoring unit and a third monitoring unit, wherein the first monitoring unit is used for not monitoring first busy tone signals sent by other vehicles in a first interval or a second interval of a time slot to be occupied, the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signals are used for indicating that the time slot to be occupied is requested to be occupied and continuously monitoring a channel;

and the second monitoring unit is used for transmitting data through a fourth interval of the time slot to be occupied if a second busy tone signal and a third busy tone signal sent by other vehicles are not monitored in a third interval of the time slot to be occupied, wherein the second busy tone signal is used for indicating a vehicle in the same area as the current vehicle to request to occupy the time slot to be occupied, and the third busy tone signal is used for indicating an existing vehicle in an adjacent area adjacent to the current vehicle to request to occupy the time slot to be occupied.

In one possible design, the apparatus further includes: the third monitoring unit is used for initiating a fourth busy tone signal in a second interval of the time slot to be occupied if a first busy tone signal sent by other vehicles is monitored in the first interval of the time slot to be occupied, wherein the fourth busy tone signal is used for indicating that the time slot is requested to be occupied.

In one possible design, the first predetermined number is 2.

In one possible design, the apparatus further includes: a fourth monitoring unit, configured to initiate a third busy tone signal in a third interval of the to-be-occupied time slot if a second busy tone signal sent by another vehicle is monitored in the third interval of the to-be-occupied time slot;

and the sending unit is used for initiating a third busy tone signal and monitoring the next time slot when detecting that the second busy tone signals in the third interval of the time slot to be occupied are all finished.

In one possible design, further comprising: and the fifth monitoring unit is used for monitoring the next time slot if the second busy tone signals sent by other vehicles are not monitored in the third interval of the time slot to be occupied and the third busy tone signals sent by other vehicles are monitored.

In one possible design, before transmitting data through the fourth interval of the timeslot to be occupied, the second listening unit is further configured to:

In one possible design, the apparatus further includes: and the sixth monitoring unit is used for monitoring the next time slot if other second busy tone signals and/or other third busy tone signals are monitored in the micro time slots except the second micro time slot after the second busy tone signal initiated currently is determined to be ended.

When the second listening unit is configured to transmit data through the fourth interval of the to-be-occupied time slot, the apparatus is specifically configured to:

In one possible design, when the second listening unit is configured to transmit the remaining data in the data through the next timeslot, the second listening unit is specifically configured to:

transmitting a first busy tone signal in a first interval of a next time slot;

In a third aspect, the present application provides a controller comprising: a memory, a processor;

a memory for storing the processor-executable instructions;

the processor is configured to perform the method of any of the first aspect according to the executable instructions.

In a fourth aspect, the present application provides a computer-readable storage medium having stored thereon computer-executable instructions for implementing the method according to any one of the first aspect when executed by a processor.

In a fifth aspect, the present application provides a program product comprising: a computer program stored in a readable storage medium from which the computer program can be read by at least one processor of a server, execution of the computer program by the at least one processor causing the server to perform the method of any one of the first aspects.

In a sixth aspect, the present application provides a collision-free multiple access system for media applications in a vehicle networking, comprising at least one vehicle; wherein each said vehicle is adapted to perform the method of any of the first aspects.

According to the conflict-free multiple access method, the conflict-free multiple access device and the conflict-free multiple access system suitable for the media application of the Internet of vehicles, first busy tone signals sent by other vehicles are not monitored in a first interval or a second interval of a time slot to be occupied, the time slot to be occupied comprises the first interval, the second interval, a third interval and a fourth interval with a time sequence relation, and the first busy tone signals are used for indicating that the time slot to be occupied is requested to be occupied and continuing monitoring a channel; if the second busy tone signal and the third busy tone signal sent by other vehicles are not monitored in the third interval of the time slot to be occupied, data are transmitted through the fourth interval of the time slot to be occupied, and then the probability of collision when the vehicles occupy the time slot can be reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic diagram of a vehicle access conflict provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a vehicle merge conflict provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of another vehicle merge conflict provided by the embodiments of the present application;

fig. 4 is a schematic flowchart of a conflict-free multiple access method suitable for media applications in the internet of vehicles according to an embodiment of the present application;

fig. 5 is a schematic diagram of a channel provided in an embodiment of the present application;

fig. 6 is a schematic diagram of a timeslot provided in an embodiment of the present application;

FIG. 7 is a flow chart illustrating another conflict-free multiple access method suitable for media applications in the Internet of vehicles according to an embodiment of the present application;

FIG. 8 is a flow chart illustrating yet another conflict-free multiple access method for media applications in the Internet of vehicles according to an embodiment of the present application;

fig. 9 is a schematic diagram of a vehicle time slot contention provided in an embodiment of the present application;

FIG. 10 is a diagram illustrating a first contention result of a time slot of vehicles in the same region according to an embodiment of the present application;

FIG. 11 is a diagram illustrating a second contention result of the vehicle time slots in the same region according to an embodiment of the present application;

FIG. 12 is a diagram illustrating a third contention result of the vehicle time slots in the same region according to an embodiment of the present application;

fig. 13 is a diagram illustrating a first result of time slot contention for vehicles in different regions according to an embodiment of the present application;

FIG. 14 is a diagram illustrating a second result of time slot contention for vehicles in different zones according to an embodiment of the present application;

FIG. 15 is a diagram illustrating a third result of time slot contention for vehicles in different regions according to an embodiment of the present application;

FIG. 16 is a diagram illustrating a fourth result of time slot contention for vehicles in different regions according to an embodiment of the present application;

FIG. 17 is a diagram illustrating a fifth result of time slot contention for vehicles in different zones according to an embodiment of the present application;

FIG. 18 is a schematic diagram illustrating a result of a vehicle continuing to occupy a next time slot according to an embodiment of the present application;

FIG. 19 is a schematic diagram illustrating another embodiment of the present disclosure as a result of a vehicle continuing to occupy a next timeslot;

fig. 20 is a schematic structural diagram of a collision-free multiple access apparatus suitable for media applications in car networking according to an embodiment of the present application;

fig. 21 is a schematic structural diagram of another conflict-free multiple access apparatus suitable for media applications in car networking according to an embodiment of the present application;

fig. 22 is a schematic structural diagram of a controller provided in an embodiment of the present application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

With the rapid increase of the number of vehicles on the road and the gradual increase of the vehicle density, the road becomes increasingly crowded, and traffic jam and traffic accidents are frequent. To solve the above problems, the academic world has proposed the concept of an intelligent transportation system. The intelligent traffic system has the main idea that various advanced technologies are integrated in the traffic system, so that the connection among roads, vehicles and drivers is enhanced, and the purposes of reducing traffic jam and improving driving safety are achieved. As one of the cores of intelligent transportation systems, the internet of vehicles has received much attention in recent years. During communication between vehicles, data can be transmitted through time slots. However, since each vehicle moves at a high speed and the topology of the entire network changes frequently, when different vehicles need to occupy the same time slot, access collision and merging collision may occur, which may result in that the vehicles cannot complete data transmission using the time slot. And when the amount of data to be transmitted is large, for example, media data needs to be transmitted, the throughput of the network is not large enough, so that the data cannot be transmitted in time.

Access conflict: when a plurality of vehicles in the same area attempt to occupy the same available time slot, a conflict occurs, and all vehicles attempting to occupy the current time slot cannot successfully occupy. Such collisions are known as access collision problems.

In one example, fig. 1 is a schematic diagram of a vehicle access conflict provided in an embodiment of the present application. In fig. 1, three vehicles, namely vehicle a, vehicle B and vehicle C, are in the same area and all attempt to occupy the same time slot, which results in collision, and the three vehicles, namely vehicle a, vehicle B and vehicle C, cannot complete data transmission by using the time slot, and can only wait for a period of time and then reselect the time slot to transmit data.

And (3) merging conflict: when a plurality of vehicles occupying the same time slot in different areas enter the same area due to the position change between the vehicles, the messages sent by the vehicles collide. This is known as the merge conflict problem. In the internet of vehicles, there are two situations where merging conflicts occur, one is that vehicles occupying the same time slot run in the same direction, the speed of the front vehicle is lower than that of the rear vehicle, the relative distance between the two vehicles is lower than the two-hop transmission distance of the message as time goes on, and merging conflicts occur after entering the same area.

In one example, fig. 2 is a schematic diagram of a vehicle merge conflict provided by an embodiment of the present application. In fig. 2, the vehicles a and B are originally in the same area (area 1), the vehicles C and D are originally in another area (area 2), both the vehicles a and D attempt to transmit data in the same time slot, and since the speed of the vehicle a is greater than that of the vehicle D, when the vehicles a and D transmit data in the same time slot after the vehicle a enters the areas where the vehicles C and D are located, a merge collision occurs.

The other is that the vehicles run in opposite directions, the relative distance between two vehicles in different areas is less than the message two-hop transmission distance, and merging conflict occurs after entering the same area.

In one example, fig. 3 is a schematic diagram of another vehicle merge conflict provided by the embodiment of the present application. In fig. 3, the vehicle a and the vehicle B are originally in the same area (area 1), the vehicle C and the vehicle D are originally in another area (area 2), both the vehicle a and the vehicle D attempt to transmit data in the same time slot, and since the vehicle a and the vehicle D travel toward each other, a merge collision occurs when the vehicle a and the vehicle D simultaneously transmit data using the same time slot after the vehicle a enters the areas where the vehicle C and the vehicle D are located.

For the above problem of access conflict and merge conflict, in one example, when a vehicle has a data transmission requirement, it needs to wait until a channel is in an idle state, and then the vehicle contends to occupy a time slot, and a vehicle with a high data priority can successfully occupy the time slot. If the vehicle is not occupied successfully, the next free time slot is waited. However, when the density of vehicles is high, the efficiency of data transmission is greatly affected by the inevitable collision problem.

In one example, each time frame comprises a plurality of time slots, each vehicle occupies a respective time slot, and when data needs to be transmitted, different vehicles adopt respective unique time slots to transmit data, so that the problem of time slot collision is solved. However, each vehicle is configured with a unique time slot, and a problem that part of the time slots cannot be adopted in time may occur, so that time slot resources are wasted, the utilization rate of resources in a channel is low, and data transmission delay is high.

In one example, different time periods transmit data in different ways. When the vehicle density is low, if the vehicle has a data transmission demand, the vehicle needs to wait until the channel is in an idle state, then the vehicle contends to occupy the time slot, and the vehicle with high data priority can successfully occupy the time slot. If the vehicle is not occupied successfully, the next free time slot is waited. When the vehicle density is high, each vehicle occupies a respective time slot, and data is transmitted in the respective time slot. However, when the channel resources are limited, if the vehicle density is too high, the efficiency of vehicle data transmission is low.

The application provides a conflict-free multiple access method, a conflict-free multiple access device, a conflict-free multiple access controller and a conflict-free multiple access storage medium, which are suitable for media applications of the internet of vehicles and aim to solve the technical problems in the prior art.

The following describes the technical solutions of the present application and how to solve the above technical problems with specific embodiments. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present application will be described below with reference to the accompanying drawings.

Fig. 4 is a schematic flowchart of a collision-free multiple access method suitable for media applications in the internet of vehicles according to an embodiment of the present application. As shown in fig. 4, the method includes:

101. the method comprises the steps that a first busy tone signal sent by other vehicles is not monitored in a first interval or a second interval of a time slot to be occupied, wherein the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signal is used for indicating that the time slot to be occupied is requested to be occupied and continuing monitoring a channel.

For example, the execution subject of the embodiment may be a current vehicle, or a controller of the current vehicle, or other equipment or devices that may implement the present solution, which is not limited by the embodiment. In this embodiment, an execution subject is described as a current vehicle.

In the internet of vehicles, when the vehicles communicate with each other, each vehicle is provided with a half-duplex transceiver for completing the transmission and reception of data. In addition, each vehicle is provided with a GPS or Beidou positioning systemFor obtaining current location information and ensuring time synchronization. Fig. 5 is a schematic diagram of a channel provided in an embodiment of the present application, and as shown in fig. 5, the channel may include a plurality of time slots with the same time length. Each time slot is divided into four intervals, namely a first interval, a second interval, a third interval and a fourth interval, and the four intervals have a time sequence relation. Fig. 6 is a schematic diagram of a timeslot provided in an embodiment of the present application, and as shown in fig. 6, the timeslot is divided into a plurality of minislots, where a length of each minislot is Δ, for example, Δ is 10 μ s; wherein the first interval is composed of N_pmsA number of minislots, N_pmsIs a positive integer greater than or equal to 1; a second interval consisting of 2 minislots; a third interval of N_cmsA number of minislots, N_cmsIs a positive integer greater than or equal to 1; and the fourth interval consists of the rest part of the time slot.

In the current time slot, if the vehicle wants to transmit data, the vehicle monitors whether a first busy tone signal transmitted by other vehicles exists in a first interval and a second interval in the time slot. The first busy tone signal represents that the current time slot to be occupied is occupied by other vehicles. And if the first busy tone signal is not monitored, starting to monitor a third interval of the current time slot to be occupied.

102. And if a second busy tone signal and a third busy tone signal sent by other vehicles are not monitored in a third interval of the time slot to be occupied, wherein the second busy tone signal is used for indicating the vehicles in the same area with the current vehicle to request to occupy the time slot to be occupied, and the third busy tone signal is used for indicating the vehicles in the adjacent area adjacent to the current vehicle to have the vehicles to request to occupy the time slot to be occupied, transmitting data through a fourth interval of the time slot to be occupied.

For example, if the vehicle that wants to send data does not monitor the busy tone signal in the first interval and the second interval of the current slot to be occupied, the vehicle starts to monitor the third interval of the current slot to be occupied. And monitoring whether a second busy tone signal and a third busy tone signal sent by other vehicles exist in a third interval in the current time slot, wherein the second busy tone signal is used for indicating the vehicles in the same area with the current vehicle to request to occupy the time slot to be occupied, and the third busy tone signal is used for indicating the vehicles in an adjacent area adjacent to the current vehicle and the vehicles which request to occupy the time slot to be occupied. And if the busy tone signal is not monitored in the third interval, the vehicle which wants to send the data transmits the data which wants to send through the fourth interval of the current time slot to be occupied.

In this embodiment, a first busy tone signal sent by another vehicle is monitored in a first interval or a second interval of a time slot to be occupied, where the time slot includes a first interval, a second interval, a third interval, and a fourth interval having a time sequence relationship, the first interval, the second interval, the third interval, and the fourth interval occupy a plurality of micro time slots respectively, and the first busy tone signal is used to indicate that the time slot to be occupied is requested to be occupied. By monitoring the first busy tone signal, the situation that the vehicle intends to access under the condition that the time slot is requested to be occupied can be avoided, and the collision probability can be reduced. And if the first busy tone signal is not monitored, monitoring a second busy tone signal and a third busy tone signal sent by other vehicles in a third interval of the time slot to be occupied. If the second busy tone signal and the third busy tone signal are not monitored, data is transmitted in a fourth interval. By monitoring the second busy tone signal and the third busy tone signal, the probability of collision when the vehicles want to access the current time slot at the same time can be reduced, and the problem that the network performance is affected due to the fact that data cannot be transmitted timely is effectively reduced. In addition, each vehicle only needs to be provided with a half-duplex transceiver to realize data transmission and reception, and the method is more economical.

Fig. 7 is a flowchart illustrating another conflict-free multiple access method suitable for media applications in the car networking according to an embodiment of the present application. As shown in fig. 7, the method includes:

201. the method comprises the steps that a first busy tone signal sent by other vehicles is not monitored in a first interval or a second interval of a time slot to be occupied, wherein the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signal is used for indicating that the time slot to be occupied is requested to be occupied and continuing monitoring a channel.

For example, this step may refer to step 101 in fig. 4, and is not described again.

202. And if a second busy tone signal and a third busy tone signal sent by other vehicles are not monitored in a third interval of the time slot to be occupied, wherein the second busy tone signal is used for indicating the vehicles in the same area with the current vehicle to request to occupy the time slot to be occupied, and the third busy tone signal is used for indicating the vehicles in the adjacent area adjacent to the current vehicle to have the vehicles to request to occupy the time slot to be occupied, transmitting data through a fourth interval of the time slot to be occupied.

For example, this step can be referred to as step 102 in fig. 4, and is not described again.

203. Monitoring first busy tone signals sent by other vehicles in a first interval or a second interval of a time slot to be occupied. And if the first busy tone signals sent by other vehicles are monitored in the first interval of the time slot to be occupied, initiating fourth busy tone signals in the second interval of the time slot to be occupied, wherein the fourth busy tone signals are used for indicating that the time slot is requested to be occupied.

In one example, the first busy tone signal is carried on any two minislots within a first span of the slot to be occupied.

In one example, when the number of minislots occupied by the first busy tone signal is equal to a first preset number, the fourth busy tone signal is carried on the first minislot of the second interval of the time slot to be occupied. The first preset number is 2.

In one example, when the number of minislots occupied by the first busy tone signal is greater than a first preset number, the fourth busy tone signal is carried on a second minislot of a second interval of the time slot to be occupied.

In one example, a single time slot duration T is set when only two vehicles are requesting to occupy the channel simultaneously_s2ms, delta is 10 mus, and the vehicle successfully monitors the probability of the occupation of the vehicle request in the first interval

At this time, the channel occupancy P in a single slot_oc＝Δ×N_pms×100％/T_s. N can be obtained by calculation_pmsThe greater the probability of successfully hearing occupancy by a vehicle request. But N is_pmsThe larger the size, the more channel resources the first interval occupies. Combining the probability of successfully hearing an occupancy by a vehicle request with the occupancy of channel resources in a single time slot, preferably N_pmsThe value is 5.

Illustratively, when the vehicle monitors first busy tone signals of other vehicles in a first interval of a current time slot to be occupied, the number of micro time slots occupied by the first busy tone signals is firstly judged. When the number of the micro time slots occupied by the first busy tone signal is equal to a first preset number, which represents that the current time slot to be occupied is requested to be occupied by one vehicle at the moment, a fourth busy tone signal is initiated in the first time slot of the second interval of the time slot to be occupied, and the fourth busy tone signal is used for indicating the condition that the time slot is requested to be occupied to the vehicles in the adjacent area. And when the number of the micro time slots occupied by the first busy tone signal is larger than a first preset number, the occupied current time slot is occupied by a plurality of vehicles at the moment, and a fourth busy tone signal is initiated in a second time slot of a second interval of the time slot to be occupied.

204. The next slot is listened to.

Illustratively, after step 203, the vehicle that wants to transmit data listens to the next time slot, and repeats the above steps to contend for the time slot.

In this embodiment, a first busy tone signal sent by another vehicle is monitored in a first interval or a second interval of a time slot to be occupied, where the time slot includes a first interval, a second interval, a third interval, and a fourth interval having a time sequence relationship, the first interval, the second interval, the third interval, and the fourth interval occupy a plurality of micro time slots respectively, and the first busy tone signal is used to indicate that the time slot to be occupied is requested to be occupied. By monitoring the first busy tone signal, the situation that the vehicle intends to access under the condition that the time slot is requested to be occupied can be avoided, and the collision probability can be reduced. If the first busy tone signals sent by other vehicles are monitored in the first interval of the time slot to be occupied, the fourth busy tone signals are initiated in the second interval of the time slot to be occupied, wherein if the number of the micro time slots occupied by the fourth busy tone signals is equal to 2, the busy tone signals are initiated in the first micro time slots of the second interval to inform the vehicles in the adjacent area and the local area that the time slot is requested to be occupied, the occupation is not attempted, the next time slot is waited, and the collision is avoided. If the number of the micro-slots occupied by the fourth busy tone signal is more than 2, the busy tone signal is initiated in the second micro-slot of the second interval to inform the vehicles in the adjacent area and the area that the time slot is already occupied, the occupation is not attempted, the vehicles which are already requested to be occupied wait for the next time slot, the vehicles which are already requested to be occupied compete to occupy the time slot, and the probability of vehicle conflict is reduced.

Fig. 8 is a flowchart illustrating yet another conflict-free multiple access method suitable for media applications in the internet of vehicles according to an embodiment of the present application. As shown in fig. 8, the method includes:

301. the method comprises the steps that a first busy tone signal sent by other vehicles is not monitored in a first interval or a second interval of a time slot to be occupied, wherein the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signal is used for indicating that the time slot to be occupied is requested to be occupied and continuing monitoring a channel.

For example, this step may be referred to as step 101 in fig. 4 in fig. 7, and is not described again.

302. And if second busy tone signals sent by other vehicles are monitored in the third interval of the time slot to be occupied, initiating a third busy tone signal in the third interval of the time slot to be occupied. And when detecting that the second busy tone signals in the third interval of the time slot to be occupied are all finished, initiating a third busy tone signal and monitoring the next time slot.

In one example, the number of minislots occupied by the second busy tone signal is greater than 2, and the number of minislots occupied by the third busy tone signal is equal to 1.

In one example, when two vehicles intend to access the channel simultaneously, the vehicles randomly wait in the third interval of the time slotN micro time slots, and then sending a second busy tone signal of the micro time slot with the length of m, wherein the value range of N is an integer which is more than or equal to 0, the value range of m is an integer which is more than 2, and the sum of m and N is less than or equal to the total number N of the micro time slots in a third interval_cms. The values of the number n of the waiting micro time slots of the vehicle 1 and the number m of the micro time slots occupied by the second busy tone are n₁、m₁The number n of the waiting micro-slots of the vehicle 2 and the number n and m of the micro-slots occupied by the second busy tone are respectively n₂、m₂. When two vehicles are in the same area, the probability of avoiding collision by sending the second busy sound is as follows: p_s-one＝(1-r₁Q) × 100%, where q is the number of all combinations of the number of waiting slots before two vehicles transmit the second busy tone and the number of slots occupied by the second busy tone, and the formula for q is q ═ card ({ (n) ×₁，m₁，n₂，m₁)|m₁+n₁≤N_cms，m₂+n₂≤N_cms，m₁≥3，m₂≥3})。r₁Waiting for all the combinations of the number of the micro-slots and the number of the micro-slots occupied by the second busy sound, r, when two vehicles are in the same area₁＝card({(n₁，m₁，n₂，m₂)|n₁＝n₂，m₁＝m₂，m₁+n₁≤N_cms，m₂+n₂≤N_cmsm₁≥3，m₂Not less than 3). When two vehicles are in different areas, the probability of avoiding collision by sending the second busy sound is P_s-two＝(1-r₂/q)×100％。r₂When two vehicles are in different areas, waiting for all the combination numbers of the number of the micro-slots and the number of the micro-slots occupied by the second busy sound before sending the second busy sound,

the greater the number of minislots in the third interval (i.e., N)_cmsThe larger) the greater the probability of avoiding an access collision. But N is_cmsThe larger the size, the more channel resources are occupied. Occupancy of channel in single slot in third interval: p_oc＝Δ×N_cms×100％/T_sWherein, the value of delta is 10 mu s, T_sThe value is 2 ms. Combining the probability of avoiding collisions and the occupancy of the channel in both cases, preferably N_cmsThe number of values is 15.

Illustratively, a vehicle which wants to send data monitors random micro-slots in a third interval (the number of the monitored micro-slots is less than that of the micro-slots occupied by the third interval), if a second busy tone signal sent by another vehicle is monitored in the third interval of the time slot to be occupied, a third busy tone signal is sent in the third micro-slot of the second busy tone signal, and the rest vehicles which do not need to send data monitor the second busy tone signal sent by the other vehicle in the third interval of the time slot to be occupied, and also send a third busy tone signal in the third micro-slot of the second busy tone signal. And after monitoring the second busy tone signal in the third interval, the vehicle which wants to send data and the other vehicles which do not need to send data send a third busy tone signal in the second micro-slot after the second busy tone signal is ended, and if the micro-slot in the third interval is occupied completely, abandoning the data sending and monitoring the next time slot.

303. And if the second busy tone signals sent by other vehicles are not monitored in the third interval of the time slot to be occupied and the third busy tone signals sent by other vehicles are monitored, monitoring the next time slot.

Illustratively, if the vehicle which wants to transmit data does not monitor the second busy tone signals transmitted by other vehicles in the third interval, but monitors the third busy tone signals transmitted by other vehicles, which indicates that the vehicle has requested to occupy the time slot, the vehicle monitors the next time slot.

304. And if the second busy tone signal and the third busy tone signal sent by other vehicles are not monitored in the third interval of the time slot to be occupied, initiating the second busy tone signal in the third interval of the time slot to be occupied.

Illustratively, if a vehicle which wants to send data does not monitor second busy tone signals and third busy tone signals sent by other vehicles in a random number of micro time slots waiting in a third interval of the time slot to be occupied, initiating second busy tone signals occupying random number of micro time slots in the third interval of the time slot to be occupied, wherein the number of the micro time slots occupied by the second busy tone signals is more than 2, and the sum of the number of the second busy tone signals and the number of the waiting random micro time slots is less than or equal to the total number of the micro time slots in the third interval.

305. If no other second busy tone signal or other third busy tone signal is monitored in the micro-slot other than the second micro-slot after the currently initiated second busy tone signal is determined to be ended, step 306 is executed.

After step 304, if the vehicle wishing to transmit data does not monitor other second busy tone signals and other third busy tone signals in the micro-slots other than the second micro-slot after the second busy tone is initiated in the third interval of the slot to be occupied, the vehicle contends for the slot successfully, and step 306 is executed.

For example, fig. 9 is a schematic diagram of a vehicle time slot contention provided in the embodiment of the present application. In this scenario, the vehicle a, the vehicle B, and the vehicle C are in the same area (area 1), the vehicle B, the vehicle C, and the vehicle D are in the same area (area 2), and the vehicle a and the vehicle D are in adjacent areas. Vehicles a, B contend for the same time slot.

The positional relationship among the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. Fig. 10 is a diagram illustrating a first contention result of time slots of vehicles in the same region according to an embodiment of the present application. As shown in fig. 10, if the time that the vehicle a waits is equal to the vehicle B, both transmit the second busy signal at the same time. But vehicle a sends a second busy tone signal of greater length than vehicle B. The vehicle B monitors the busy tone signal in the time except the second micro time slot after the transmission of the vehicle B is finished, and abandons the contention time slot to monitor the next time slot. Thus, vehicle a successfully accesses the channel to occupy the time slot, avoiding access collisions.

The positional relationship among the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. Fig. 11 is a diagram illustrating a second contention result of the vehicle time slots in the same region according to the embodiment of the present application. As shown in fig. 11, if the time that the vehicle a waits is shorter than the vehicle B, the second busy signal is transmitted first. Vehicle B monitors the busy tone signal before transmitting, does not transmit the second busy tone signal, and abandons the contention slot to monitor the next slot. Thus, vehicle a successfully accesses the channel to occupy the time slot, avoiding access collisions.

The positional relationship among the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. Fig. 12 is a diagram illustrating a third contention result of the vehicle time slots in the same region according to the embodiment of the present application. As shown in fig. 12, if the time for which the vehicle a waits is equal to the vehicle B, the length of the transmitted second busy tone signal is also equal to the vehicle B. In this case, both the vehicles a and B consider themselves as successful contenders, and an access collision occurs.

For example, the positional relationship of the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. When vehicles a and D in different areas contend for the same time slot, there are five contention results:

fig. 13 is a diagram illustrating a first result of contention for time slots of vehicles in different areas according to an embodiment of the present application. As shown in fig. 13, the end point of the waiting time of the vehicle a is earlier than that of the vehicle B by 2 minislots, and therefore, the second busy tone signal is transmitted first. And after monitoring that the vehicle A sends busy tone signals in two continuous time slots, the vehicles B and C confirm that the vehicle A sends the second busy tone signal, and then send the busy tone signal in the third micro time slot. And after monitoring busy tone signals sent by the vehicle B and the vehicle C, the vehicle D gives up the contention time slot and monitors the next time slot. Thus, vehicle a successfully accesses the channel to occupy the time slot, avoiding access collisions.

Fig. 14 is a diagram illustrating a second result of time slot contention for vehicles in different regions according to an embodiment of the present application. As shown in fig. 14, the end point of the waiting time of the vehicle a is earlier than that of the vehicle B by 2 minislots, and B, C transmits the busy signal in the third minislot where a transmits the second busy signal, and at this time, the vehicle D also starts transmitting the second busy signal. However, since the transmission end point of the second busy signal of the vehicle D is later than that of the vehicle a, the vehicles B and C transmit the busy signals in the second micro-slot after the transmission end of the vehicle D. The vehicle A monitors the busy tone signal in the time except the second micro time slot after the transmission of the vehicle A is finished, abandons the contention time slot and monitors the next time slot. Thus, vehicle D successfully accesses the channel to occupy the time slot, avoiding access collisions.

Fig. 15 is a diagram illustrating a third result of time slot contention for vehicles in different areas according to an embodiment of the present application. As shown in fig. 15, the vehicle a waits for the end of the time 2 micro-slots earlier than the vehicle B, and the vehicles B and C transmit the busy tone signal in the third micro-slot in which the vehicle a transmits the second busy tone signal, and at this time, the vehicle D also starts transmitting the second busy tone signal. However, since the transmission end point of the second busy signal of the vehicle a is later than that of the vehicle D, the vehicles B and C transmit the busy signals in the second micro-slot after the transmission end of the vehicle a. The vehicle D monitors the busy tone signal in the time except the second micro time slot after the self transmission is finished, and abandons the contention time slot to monitor the next time slot. Thus, vehicle a successfully accesses the channel to occupy the time slot, avoiding access collisions.

Fig. 16 is a diagram illustrating a fourth result of time slot contention for vehicles in different regions according to an embodiment of the present application. As shown in fig. 16, the waiting time of vehicle a is earlier than that of vehicle B by 2 micro-slots, and vehicles B and C transmit busy tone signals in the third micro-slot after the waiting time of vehicle a is over, and at this time, vehicle D also starts to transmit the second busy tone signal. Although the end point of the transmission of the second busy signal of the vehicle D is different from the vehicle a, the end point is the penultimate minislot of the contention interval of the time slot, so that the vehicles B and C cannot transmit the busy signal after the transmission of the vehicle D is finished. In this case, since both the vehicle a and the vehicle B consider themselves as successful contenders, access collision occurs.

Fig. 17 is a diagram illustrating a fifth result of time slot contention for vehicles in different regions according to an embodiment of the present application. As shown in fig. 17, the end point of the waiting time of the vehicle a is earlier than that of the vehicle D by 2 micro-slots, and the vehicles B and C transmit the busy tone signal in the third micro-slot after the end of the waiting time of the vehicle a, at this time, the vehicle D also starts to transmit the second busy tone signal, and the micro-slot in which the transmission of the second busy tone signal is ended is the same as that of the vehicle a. In the second mini-slot after the transmission of the vehicles a and D is finished, B, C transmits the busy signal, but the busy signal is located in the second mini-slot after the transmission of the vehicles a and D is finished. In this case, both the vehicles a and B consider themselves as successful contenders, and an access collision occurs.

306. And transmitting data through a fourth interval of the time slot to be occupied.

In one example, step 306 includes several implementations:

in the first implementation manner of step 306, when the fourth interval of the timeslot to be occupied can carry data, the data is transmitted through the fourth interval of the timeslot to be occupied.

In the second implementation manner of step 306, when the fourth interval of the timeslot to be occupied cannot carry data, part of the data in the data is transmitted through the fourth interval of the timeslot to be occupied, and the remaining data in the data is transmitted through the next timeslot.

In one example, when the remaining data in the data is transmitted through the next time slot in step 306, the method specifically includes: transmitting a first busy tone signal in a first interval of a next time slot; if the fourth busy tone signals sent by other vehicles are not monitored in the second micro-time slot of the second interval of the next time slot, adopting the third interval and the fourth interval of the next time slot to transmit data; and if the fourth busy tone signals sent by other vehicles are monitored in the second micro-slot of the second interval of the next time slot, adopting a time slot competition mode to compete for the next time slot.

For example, after the vehicle requests to occupy the time slot successfully, when the fourth interval can carry data, the vehicle requests to occupy the fourth interval of the time slot of the successful vehicle to transmit data. When the transmitted data volume is large and the fourth interval of the time slot can not bear data, transmitting partial data in the fourth interval of the time slot, and sending first busy tone signals of two random micro time slots to the first interval of the next time slot to represent that the request occupies the next time slot of the current time slot. If busy tone signals sent by other vehicles are not monitored in the second micro-time slot of the second interval of the next time slot, indicating that no other vehicles are requested to occupy at present, adopting a third interval and a fourth interval of the next time slot to transmit data; and if busy tone signals sent by other vehicles are monitored in the second micro-slot of the second interval of the next time slot, adopting a time slot competition mode to compete for the next time slot.

For example, the positional relationship of the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. Fig. 18 is a schematic diagram illustrating a result of a vehicle continuing to occupy a next timeslot in the embodiment of the present application. As shown in fig. 18, in the first interval, vehicle a randomly selects the 2 nd and 4 th minislots to transmit busy tone signals, indicating that it intends to occupy the timeslot. When the vehicle C in the same interval with the vehicle A monitors that the length of the busy tone signal in the interval is equal to the length of two micro time slots, the busy tone signal is sent in the 1 st micro time slot of the second interval of the time slot. If a vehicle B in the same interval with the vehicle A has the intention of accessing a channel to occupy a time slot, and the length of the busy tone signal in the interval is monitored to be equal to the length of two micro time slots, the vehicle B abandons to occupy the time slot and sends the busy tone signal in the 1 st micro time slot in the second interval of the time slot. When a vehicle D in another area adjacent to the vehicle A also has the intention of accessing the channel to occupy the time slot, the busy tone signal is monitored in the 1 st micro-time slot of the second interval of the time slot, and the occupation of the time slot is abandoned. Thus, vehicles that are not accessing the channel in the same area and adjacent areas of vehicle A do not attempt to occupy the time slot, thereby avoiding collisions. And the vehicle A transmits data by adopting the third interval and the fourth interval of the time slot.

The positional relationship among the vehicle a, the vehicle B, the vehicle C, and the vehicle D is as shown in fig. 9. Fig. 19 is a schematic diagram illustrating another result of the vehicle continuing to occupy the next timeslot provided in the embodiment of the present application. As shown in fig. 19, when both the vehicle a and the vehicle D want to request to occupy the current time slot, in the first interval, the vehicle a randomly selects the 2 nd and 4 th micro-slots to transmit the busy tone signal, and the vehicle D randomly selects the 2 nd and 3 rd micro-slots to transmit the busy tone signal. And when the shared vehicles B and C in the areas of the vehicles A and D monitor that the length of the busy tone signal in the interval is greater than the lengths of the two micro time slots, the busy tone signal is sent in the 2 nd micro time slot of the second interval of the time slot. The vehicle A and the vehicle D monitor busy tone signals in the first micro-time slot of the second interval, and start a time slot contention mechanism to avoid the occurrence of collision as much as possible.

307. And if other second busy tone signals and/or other third busy tone signals are monitored in the micro-time slot except the second micro-time slot after the currently initiated second busy tone signal is determined to be finished, monitoring the next time slot.

Illustratively, after step 304, if the vehicle that wants to transmit data monitors other second busy tone signals and other third busy tone signals in the micro-slots other than the second micro-slot after the end of transmitting the second busy tone signal, it indicates that there are other vehicles that want to occupy the slot, and the vehicle that wants to transmit data abandons the current slot to monitor the next slot.

For example, if the vehicle that wants to send data monitors other second busy tone signals or other third busy tone signals in the micro-slot other than the second micro-slot after the end of sending the second busy tone signal, it indicates that there are other vehicles that want to occupy the slot, and the vehicle that wants to send data abandons the occupation of the current slot to monitor the next slot.

In this embodiment, if the first busy tone signal sent by another vehicle is not monitored in the first interval or the second interval of the time slot to be occupied, the channel continues to be monitored. By monitoring the first interval and the second interval, the situation that vehicles in the area and adjacent areas still request access under the condition that the existing vehicles request access can be effectively avoided, and the collision probability is reduced. If the second busy signal is not monitored, the third interval is monitored. And if the second busy tone signals sent by other vehicles are monitored in the third interval of the time slot to be occupied, initiating a third busy tone signal in the third micro-time slot of the second busy tone signals of the time slot to be occupied. And when detecting that the second busy tone signals in the third interval of the time slot to be occupied are all finished, initiating a third busy tone signal to monitor the next time slot. The third busy tone signal can effectively avoid the situation that other vehicles still request to occupy after the existing vehicles send the busy tone signals, and the probability of vehicle conflict is reduced. The priority that the vehicle which is accessed first occupies the time slot is high, and the priority that the vehicle which is late after the second busy tone signal is sent is high. If the second busy tone signals sent by other vehicles are not monitored in the third interval of the time slot to be occupied and the third busy tone signals sent by other vehicles are monitored, the next time slot is monitored, and the collision probability of the vehicles in the adjacent area can be reduced. And when the second busy tone signal exists in the third interval and is not monitored, sending the second busy tone signal with the length of a plurality of micro time slots after randomly waiting for a plurality of micro time slots, and requesting occupation, wherein if the other busy tone signals are not monitored in the intervals except the second micro time slot after the busy tone signal is ended, the requesting occupation is successful. And if the other busy tone signals are monitored in the interval except the second micro time slot after the busy tone signals are ended, monitoring the next time slot. It is guaranteed that the late vehicle at the end of sending the second busy tone signal has a high priority for accessing the channel. And when the vehicle successfully occupies the channel, transmitting data in the fourth interval of the time slot. And if the fourth interval can not bear the data, transmitting part of the data in the data through the fourth interval of the time slot and requesting to transmit the rest of the data through the next time slot. And if the second micro time slot of the second interval of the next time slot does not have the busy tone signal, the vehicle which does not finish sending the data requests to be occupied successfully, and the messages which are not finished sending are sent in the third interval and the fourth interval of the next time slot. By the method, when more data, such as media data, exist in the vehicle, if the data cannot be completely sent in one time slot, the data can be preferentially requested to occupy the next time slot to be sent, so that the timeliness of data transmission is ensured, and the throughput of the network is improved.

Fig. 20 is a schematic structural diagram of a collision-free multiple access device suitable for media applications in car networking according to an embodiment of the present application. As shown in fig. 20, the apparatus includes:

a first monitoring unit 41, configured to not monitor a first busy tone signal sent by another vehicle in a first interval or a second interval of a time slot to be occupied, where the time slot includes a first interval, a second interval, a third interval, and a fourth interval having a time sequence relationship, the first interval, the second interval, the third interval, and the fourth interval respectively occupy multiple micro time slots, and the first busy tone signal is used to indicate that the time slot to be occupied is requested to be occupied, and continue to monitor a channel;

the second monitoring unit 42 is configured to transmit data through a fourth interval of the time slot to be occupied if a second busy tone signal and a third busy tone signal sent by another vehicle are not monitored in a third interval of the time slot to be occupied, where the second busy tone signal is used to indicate that a vehicle located in the same area as the current vehicle requests to occupy the time slot to be occupied, and the third busy tone signal is used to indicate that a vehicle in an adjacent area adjacent to the current vehicle has the vehicle that requests to occupy the time slot to be occupied.

The apparatus provided in this embodiment is used to implement the technical solution provided by the above method, and the implementation principle and the technical effect are similar and will not be described again.

Fig. 21 is a schematic structural diagram of another collision-free multiple access device suitable for media applications in car networking according to an embodiment of the present application. On the basis of fig. 20, as shown in fig. 21, the apparatus provided in this embodiment further includes:

the third monitoring unit 51 is configured to initiate a fourth busy tone signal in a second interval of the time slot to be occupied if a first busy tone signal sent by another vehicle is monitored in the first interval of the time slot to be occupied, where the fourth busy tone signal is used to indicate that the time slot is requested to be occupied.

In one example, when the number of minislots occupied by the first busy tone signal is equal to a first preset number, the fourth busy tone signal is carried on the first minislot of the second interval of the time slot to be occupied. And when the number of the micro time slots occupied by the first busy tone signal is larger than the first preset number, the fourth busy tone signal is borne on the second micro time slot of the second interval of the time slot to be occupied.

In one example, the first preset number is 2.

In an example, the apparatus provided in this embodiment further includes:

the fourth monitoring unit 52 is configured to initiate a third busy tone signal in a third interval of the time slot to be occupied if a second busy tone signal sent by another vehicle is monitored in the third interval of the time slot to be occupied.

The sending unit 53 is configured to initiate a third busy tone signal when it is detected that the second busy tone signals in the third interval of the time slot to be occupied are all ended.

In an example, the apparatus provided in this embodiment further includes:

a fifth monitoring unit 54, configured to monitor a next timeslot if the second busy tone signal sent by another vehicle is not monitored in the third interval of the timeslot to be occupied and the third busy tone signal sent by another vehicle is monitored.

In one example, the second listening unit 42 is further configured to, before transmitting data through the fourth interval of the slot to be occupied: initiating a second busy signal in a third interval; and if other second busy tone signals and other third busy tone signals are not monitored in the micro-slot except the second micro-slot after the currently initiated second busy tone signal is determined to be finished, executing a step of transmitting data through a fourth interval of the to-be-occupied time slot.

In an example, the apparatus provided in this embodiment further includes:

and the sixth monitoring unit is used for monitoring the next time slot if other second busy tone signals and/or other third busy tone signals are monitored in the micro time slots except the second micro time slot after the second busy tone signal initiated currently is determined to be ended.

In one example, when the second listening unit 42 is configured to transmit data through the fourth interval of the timeslot to be occupied, specifically: when the fourth interval of the time slot to be occupied can bear data, transmitting the data through the fourth interval of the time slot to be occupied; and when the fourth interval of the time slot to be occupied can not bear data, transmitting part of data in the data through the fourth interval of the time slot to be occupied, and transmitting the rest data in the data through the next time slot.

In one example, the second listening unit 42, when configured to transmit the remaining data in the data through the next time slot, is specifically configured to: transmitting a first busy tone signal in a first interval of a next time slot; if the fourth busy tone signals sent by other vehicles are not monitored in the second micro-time slot of the second interval of the next time slot, adopting the third interval and the fourth interval of the next time slot to transmit data; and if the fourth busy tone signals sent by other vehicles are monitored in the second micro-slot of the second interval of the next time slot, adopting a time slot competition mode to compete for the next time slot.

Fig. 22 is a schematic structural diagram of a controller provided in an embodiment of the present application, and as shown in fig. 22, the controller includes:

a processor (processor)291, the electronic device further including a memory (memory) 292; a Communication Interface 293 and bus 294 may also be included. The processor 291, the memory 292, and the communication interface 293 may communicate with each other via the bus 294. Communication interface 293 may be used for the transmission of information. Processor 291 may call logic instructions in memory 294 to perform the methods of the embodiments described above.

Further, the logic instructions in the memory 292 may be implemented in software functional units and stored in a computer readable storage medium when sold or used as a stand-alone product.

The memory 292 is a computer-readable storage medium for storing software programs, computer-executable programs, such as program instructions/modules corresponding to the methods in the embodiments of the present application. The processor 291 executes the functional application and data processing by executing the software program, instructions and modules stored in the memory 292, so as to implement the method in the above method embodiments.

The memory 292 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal device, and the like. Further, the memory 292 may include a high speed random access memory and may also include a non-volatile memory.

The embodiment of the application provides a computer-readable storage medium, in which computer-executable instructions are stored, and the computer-executable instructions are executed by a processor to implement the method provided by the above embodiment.

The embodiment of the application provides a conflict-free multiple access system suitable for vehicle networking media application, which comprises at least one vehicle; wherein each vehicle is configured to perform the method provided by the above embodiments.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A collision-free multiple access method for media applications in the internet of vehicles, the method being applied to a current vehicle, the method comprising:

and if a second busy tone signal and a third busy tone signal sent by other vehicles are not monitored in a third interval of the time slot to be occupied, wherein the second busy tone signal is used for indicating a vehicle in the same area as the current vehicle to request to occupy the time slot to be occupied, the third busy tone signal is used for indicating a vehicle in an adjacent area adjacent to the current vehicle, and the existing vehicle requests to occupy the time slot to be occupied, transmitting data through a fourth interval of the time slot to be occupied.

2. The method of claim 1, further comprising:

3. The method according to claim 2, wherein when the number of minislots occupied by the first busy tone signal is equal to a first preset number, the fourth busy tone signal is carried on a first minislot of a second interval of the timeslot to be occupied;

4. The method of claim 2 wherein said first busy tone signal is carried on any two minislots within a first interval of said slot to be occupied.

5. The method of claim 1, further comprising:

6. The method of claim 1, further comprising:

7. The method of claim 1, further comprising, prior to transmitting data through a fourth interval of the slot to be occupied:

8. The method of claim 7, further comprising:

9. The method according to any of claims 1-8, wherein transmitting data through a fourth interval of the slot to be occupied comprises:

when the fourth interval of the time slot to be occupied can not bear the data, transmitting part of data in the data through the fourth interval of the time slot to be occupied, and transmitting the rest data in the data through the next time slot;

wherein the transmitting of the remaining data in the data through the next slot includes: transmitting a first busy tone signal in a first interval of a next time slot; if a fourth busy tone signal sent by other vehicles is not monitored in a second micro time slot of a second interval of the next time slot, adopting a third interval and a fourth interval of the next time slot to transmit data; and if the fourth busy tone signals sent by other vehicles are monitored in the second micro-slot of the second interval of the next time slot, adopting a time slot competition mode to compete for the next time slot.

10. A collision-free multiple access apparatus for media applications in a vehicle network, the apparatus being applied to a current vehicle, the apparatus comprising:

the first monitoring unit is used for not monitoring first busy tone signals sent by other vehicles in a first interval or a second interval of a time slot to be occupied, wherein the time slot comprises a first interval, a second interval, a third interval and a fourth interval which have a time sequence relation, the first interval, the second interval, the third interval and the fourth interval respectively occupy a plurality of micro time slots, and the first busy tone signals are used for indicating that the time slot to be occupied is requested to be occupied and continuing monitoring a channel;

11. A controller, comprising: a memory, a processor;

a memory for storing the processor-executable instructions;

the processor configured to perform the method of any one of claims 1-9 according to the executable instructions.

12. A collision-free multiple access system suitable for media applications in the internet of vehicles, comprising at least one vehicle; wherein each of said vehicles is adapted to perform a method according to any of claims 1-9.