CN117320181A - Channel access method, device, equipment and storage medium - Google Patents

Abstract

The application discloses a channel access method, a device, equipment and a storage medium, wherein the method comprises the following steps: acquiring situation information of surrounding nodes of the target node before the next decision period starts or when a data packet needs to be sent; determining the starting moment of an attempted transmission window in the next decision period according to the situation information of the peripheral nodes; and when the starting time of the attempting to send window is reached, controlling the target node to access a channel. The consensus channel access mechanism based on the local situation information solves the problems of higher node packet loss rate and reduced network throughput in the existing channel access scheme.

Description

Channel access method, device, equipment and storage medium

Technical field

The present application relates to the field of computer technology, and in particular, to a channel access method, device, equipment and storage medium.

Background technique

Wireless ad hoc network (MANET, Mobile Ad Hoc Network) is a multi-point and multi-hop network that shares wireless transmission media. It consists of a group of mobile nodes that can access the network at any time. The nodes do not rely on fixed communication network infrastructure and have unlimited capabilities. Center, self-organization, dynamic changes in network topology and other characteristics. This characteristic leads to shortcomings such as more conflicts in network data packets, lower throughput, larger packet loss rate, and longer end-to-end delay. These shortcomings can be alleviated by improving the network MAC layer channel access protocol. The function of the channel access protocol is to control the occupation of wireless media by message transmission of nodes and solve the problem of wireless channel allocation between competing nodes. Therefore, the rationality of the design of the MAC layer channel access protocol directly affects the overall performance of the network. .

Currently, the most commonly used MAC layer channel access protocols are the competition protocol represented by CSMA/CA and the distribution protocol represented by TDMA. Among them, the IEEE 802.11DCF working mechanism uses the CSMA/CA protocol as the base access method and introduces the RTS/CTS mechanism to further solve the problem of hidden terminals. This working mechanism has good robustness in any network topology and random business scenarios, but its free and flexible characteristics and backoff mechanism also bring obvious flaws. As the number of nodes increases, mutual interference between nodes increases and transmission collisions increase, resulting in a large amount of time wasted in the backoff process, severely limiting the system throughput and delay performance. The TDMA protocol is a MAC method based on time synchronization and can be divided into fixed allocation type and dynamic allocation type. A typical fixed allocation TDMA protocol contains multiple transmission frames. In each transmission frame, each node is assigned a time slot, so there is no threat of node collision. However, due to the centerless characteristics of the MANET network and its delay, Requirements, the fixed allocation TDMA protocol performs poorly in large-scale network systems, and has problems of poor scalability and low channel utilization. The dynamic allocation TDMA protocol represented by the Five-Step Reservation Protocol (FPRP) dynamically allocates time slots through a five-step reservation process, solving the shortcomings of the fixed allocation protocol. However, due to the large control overhead and high implementation complexity of the dynamic allocation TDMA protocol, the node packet loss rate is high and the network throughput is reduced.

Therefore, it is necessary to propose an applicable solution to solve the problems of high node packet loss rate and reduced network throughput in the above channel access scheme.

Contents of the invention

The main purpose of this application is to provide a channel access method, device, equipment and storage medium, aiming to solve the problems of high node packet loss rate and reduced network throughput in existing channel access solutions.

In order to achieve the above purpose, this application provides a channel access method. The channel access method includes:

Before the next decision cycle starts or when a data packet needs to be sent, obtain the surrounding node situation information of the target node;

Determine the starting moment of the attempted transmission window in the next decision cycle based on the surrounding node situation information;

When the starting time of the transmission attempt window is reached, the target node is controlled to access the channel.

Optionally, the step of determining the starting moment of the transmission attempt window in the next decision cycle based on the surrounding node situation information includes:

Get node density degree parameters;

According to the situation information of the surrounding nodes, count the number of nodes in the surrounding nodes with the amount of data to be sent greater than zero, and obtain the current network density;

The starting moment of the transmission attempt window in the next decision cycle is determined according to the current network density and the node density parameters.

Optionally, the step of determining the starting moment of the transmission attempt window in the next decision cycle based on the current network density and the node density parameters includes:

Several decision-making cycles are obtained based on the target timeline division;

Determine the duration of the attempted transmission window according to the decision cycle, the current network density and the node density parameters;

Construct a pseudo-random number interval according to the current network density and the node density parameters;

Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

The starting moment of the attempted sending window is determined based on the starting moment of the next decision cycle, the pseudo-random integer and the duration of the attempted sending window.

Optionally, the step of determining the starting moment of the transmission attempt window in the next decision cycle based on the current network density and the node density parameters includes:

Get the preset time frame length parameters;

Determine the next decision cycle according to the time frame length parameter, the current network density and the node density parameters;

Construct a pseudo-random number interval according to the current network density and the node density parameters;

Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

The starting time of the attempted transmission window is determined based on the starting time of the next decision cycle, the pseudo-random integer and the time frame length parameter.

Optionally, the step of determining the starting moment of the transmission attempt window in the next decision cycle based on the current network density and the node density parameters includes:

Calculate the starting moment probability of the attempted transmission window in the next decision cycle based on the current network density and the node density parameters;

Construct a probability interval, and select any pseudo-random probability for each time frame from the uniform distribution of the probability interval before the start of the next decision-making period or at the beginning of each time frame;

Compare the starting moment probability and the pseudo-random probability;

If the pseudo-random probability is less than or equal to the starting time probability, the starting time of the time frame corresponding to the pseudo-random probability is determined as the starting time of the attempted transmission window.

Optionally, after the step of determining the starting moment of the transmission attempt window in the next decision cycle based on the situation information of the surrounding nodes, the step further includes:

Determine the restricted sending window according to the attempted sending window within the next decision cycle;

When the starting time of the restricted sending window is reached, the target node is controlled to be in a restricted sending state.

Optionally, after the step of controlling the target node to access the channel when the starting time of the transmission attempt window is reached, the step further includes:

When the end time of the attempted sending window is reached, determine the current sending and receiving process status of the target node;

If the target node is in a random fallback state, freeze the rollback count, save the remaining rollback duration, and enter the restricted sending window;

If the target node is in the request sending state, monitor the response result, and control the target node to execute the corresponding processing flow according to the response result;

If the target node is in the data sending state, it will enter the restricted sending window after the data sending is completed;

If the target node is in other states, it enters the restricted sending window, where the other states are non-random fallback, non-requested sending, and non-data sending states.

Optionally, before the step of obtaining the surrounding node situation information of the target node, the step further includes:

The target node is used as a maintenance center to maintain the situation information of surrounding nodes within the preset local situation range of the target node, which specifically includes:

Receive situation information of surrounding nodes within a preset local situation range of the target node;

Generate or update a local network situation information table according to the surrounding node situation information;

The step of obtaining the situation information of surrounding nodes of the target node includes:

Read the local network situation information table and extract situation information of all surrounding nodes within the preset local situation range of the target node.

An embodiment of the present application also proposes a channel access device. The channel access device includes:

The acquisition module is used to obtain the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent;

A determination module, configured to determine the starting time of the attempted transmission window in the next decision cycle based on the situation information of the surrounding nodes;

An access module, configured to control the target node to access the channel when the starting time of the transmission attempt window is reached.

An embodiment of the present application also proposes a channel access device. The channel access device includes a memory, a processor, and a channel access program stored in the memory and capable of running on the processor. The channel access device When the input program is executed by the processor, the steps of the channel access method as described above are implemented.

Embodiments of the present application also provide a computer-readable storage medium. A channel access program is stored on the computer-readable storage medium. When the channel access program is executed by a processor, the channel access method as described above is implemented. step.

In the channel access method, device, equipment and storage medium proposed by the embodiments of this application, the channel access method obtains the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent; according to the surrounding The node situation information determines the starting time of the attempted transmission window in the next decision cycle; when the starting time of the attempted transmission window is reached, the target node is controlled to access the channel. Based on the solution of this application, by obtaining the situation information of surrounding nodes perceived by the target node itself, and determining the starting time of the transmission attempt window in the next decision cycle based on the situation information of surrounding nodes, decisions can be made based on the communication situation of the surrounding environment of the target node. Determine the starting time of the transmission attempt window that the target node can actively access to avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the target node to actively access the channel at the beginning of the transmission attempt window, data processing Packet sending and receiving can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

Description of drawings

Figure 1 is a schematic diagram of the functional modules of the equipment belonging to the channel access device of the present application;

Figure 2 is a schematic flow chart of an exemplary embodiment of the channel access method of the present application;

Figure 3 is a schematic flow chart of another exemplary embodiment of the channel access method of the present application;

Figure 4 is a schematic flow chart of the third exemplary embodiment of the channel access method of the present application;

Figure 5 is a schematic flow chart of the fourth exemplary embodiment of the channel access method of the present application;

Figure 6 is a schematic flow chart of the fifth exemplary embodiment of the channel access method of the present application;

Figure 7 is a schematic diagram of the decision-making cycle involved in an exemplary embodiment of the channel access method of this application;

Figure 8 is a schematic flow chart of the sixth exemplary embodiment of the channel access method of the present application;

Figure 9 is a schematic diagram of a network topology of an example of the present invention;

Figure 10a is a schematic diagram comparing the packet loss rate between the example of the present invention and the DCF mechanism;

Figure 10b is a schematic diagram comparing the saturated throughput of the network between the example of the present invention and the DCF mechanism;

Figure 11 is a schematic diagram of the node network movement trajectory topology according to an example of the present invention;

Figure 12a is a schematic diagram comparing the packet loss rate between the example of the present invention and the DCF mechanism in a mobile scenario;

Figure 12b is a schematic diagram comparing network saturation throughput in mobile scenarios between the example of the present invention and the DCF mechanism;

Figure 13a is a schematic diagram comparing the packet loss rate between the example of the present invention and the DCF mechanism under unsaturated business load conditions;

Figure 13b is a schematic diagram comparing network throughput between the example of the present invention and the DCF mechanism under unsaturated business load conditions.

The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings.

Detailed ways

It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

The main solution of the embodiment of this application is: before the next decision cycle starts or when a data packet needs to be sent, obtain the surrounding node situation information of the target node; determine the attempted transmission window in the next decision cycle based on the surrounding node situation information. Starting time: when the starting time of the attempted transmission window is reached, control the target node to access the channel. Based on the solution of this application, by obtaining the situation information of surrounding nodes perceived by the target node itself, and determining the starting time of the transmission attempt window in the next decision cycle based on the situation information of surrounding nodes, decisions can be made based on the communication situation of the surrounding environment of the target node. Determine the starting time of the transmission attempt window that the target node can actively access to avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the target node to actively access the channel at the beginning of the transmission attempt window, data processing Packet sending and receiving can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

Specifically, refer to Figure 1, which is a schematic diagram of the functional modules of the equipment to which the channel access device of the present application belongs. The channel access device may be a device independent of the device, capable of data collection and channel access, and may be carried on the device in the form of hardware or software. The device can be a smart terminal with data processing functions such as a mobile phone or a computer, or a fixed device or server with data processing functions.

In this embodiment, the device to which the channel access device belongs includes at least an output module 110, a processor 120, a memory 130 and a communication module 140.

The memory 130 stores an operating system and a channel access program. The channel access device can determine the starting time of the attempted transmission window in the next decision cycle based on the obtained peripheral node situation information of the target node. , as well as information such as data packets to be sent and received are stored in the memory 130; the output module 110 can be a display screen, etc. The communication module 140 may include a WIFI module, a mobile communication module, a Bluetooth module, etc., and communicates with external devices or servers through the communication module 140 .

Among them, when the channel access program in the memory 130 is executed by the processor, the following steps are implemented:

Before the next decision cycle starts or when a data packet needs to be sent, obtain the surrounding node situation information of the target node;

Determine the starting moment of the attempted transmission window in the next decision cycle based on the surrounding node situation information;

When the starting time of the transmission attempt window is reached, the target node is controlled to access the channel.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

Get node density degree parameters;

According to the situation information of the surrounding nodes, count the number of nodes in the surrounding nodes with the amount of data to be sent greater than zero, and obtain the current network density;

The starting moment of the transmission attempt window in the next decision cycle is determined according to the current network density and the node density parameters.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

Several decision-making cycles are obtained based on the target timeline division;

Determine the duration of the attempted transmission window according to the decision cycle, the current network density and the node density parameters;

Construct a pseudo-random number interval according to the current network density and the node density parameters;

Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

The starting moment of the attempted sending window is determined based on the starting moment of the next decision cycle, the pseudo-random integer and the duration of the attempted sending window.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

Get the preset time frame length parameters;

Determine the next decision cycle according to the time frame length parameter, the current network density and the node density parameters;

Construct a pseudo-random number interval according to the current network density and the node density parameters;

Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

The starting time of the attempted transmission window is determined based on the starting time of the next decision cycle, the pseudo-random integer and the time frame length parameter.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

Calculate the starting moment probability of the attempted transmission window in the next decision cycle based on the current network density and the node density parameters;

Construct a probability interval, and select any pseudo-random probability for each time frame from the uniform distribution of the probability interval before the start of the next decision-making period or at the beginning of each time frame;

Compare the starting moment probability and the pseudo-random probability;

If the pseudo-random probability is less than or equal to the starting time probability, the starting time of the time frame corresponding to the pseudo-random probability is determined as the starting time of the attempted transmission window.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

Determine the restricted sending window according to the attempted sending window within the next decision cycle;

When the starting time of the restricted sending window is reached, the target node is controlled to be in a restricted sending state.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

When the end time of the attempted sending window is reached, determine the current sending and receiving process status of the target node;

If the target node is in a random fallback state, freeze the rollback count, save the remaining rollback duration, and enter the restricted sending window;

If the target node is in the request sending state, monitor the response result, and control the target node to execute the corresponding processing flow according to the response result;

If the target node is in the data sending state, it will enter the restricted sending window after the data sending is completed;

If the target node is in other states, it enters the restricted sending window, where the other states are non-random fallback, non-requested sending, and non-data sending states.

Further, when the channel access program in the memory 130 is executed by the processor, the following steps are also implemented:

The target node is used as a maintenance center to maintain the situation information of surrounding nodes within the preset local situation range of the target node, which specifically includes:

Receive situation information of surrounding nodes within a preset local situation range of the target node;

Generate or update a local network situation information table according to the surrounding node situation information;

Read the local network situation information table and extract situation information of all surrounding nodes within the preset local situation range of the target node.

This embodiment uses the above solution, specifically by obtaining the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent; and determines the start of the transmission attempt window in the next decision cycle based on the surrounding node situation information. When the starting time of the attempted transmission window is reached, the target node is controlled to access the channel. Based on the solution of this application, by obtaining the situation information of surrounding nodes perceived by the target node itself, and determining the starting time of the transmission attempt window in the next decision cycle based on the situation information of surrounding nodes, decisions can be made based on the communication situation of the surrounding environment of the target node. Determine the starting time of the transmission attempt window that the target node can actively access to avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the target node to actively access the channel at the beginning of the transmission attempt window, data processing Packet sending and receiving can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

Based on the above device architecture but not limited to the above architecture, method embodiments of the present application are proposed.

The method embodiment of this application proposes a consensus channel access method based on local situation information for the MAC layer channel access protocol of wireless ad hoc networks. This method draws on the characteristics of TDMA and CSMA/CA protocols and innovatively adds The consensus access idea integrates the two protocols, which not only avoids the control information overhead caused by dynamic time slots between nodes, but also solves the problem of performance degradation caused by excessive collision rates in dense networking. Compared with IEEE 802.11DCF technology, this method greatly reduces node packet loss rate and improves network throughput. Especially in large-scale dense networking scenarios, the performance improvement is more prominent.

In the embodiment of this application, the execution subject of the consensus channel access method based on local situation information can be a channel access device, or a channel access device or server. In this embodiment, the channel access device For example, the channel access device can be integrated on terminal equipment, computers and other equipment with data processing functions.

After the target node is powered on through the channel access device, the local situation maintenance module deployed by it processes the received situation information broadcast by other nodes, that is, the situation information of surrounding nodes. At the same time, the local situation maintenance module is responsible for periodically triggering during the network period. The target node broadcasts its own situation information.

Referring to Figure 2, Figure 2 is a schematic flow chart of an exemplary embodiment of the channel access method of the present application. The channel access method includes:

Step S10: Obtain the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent.

Specifically, the entire target timeline is divided into multiple decision-making cycles in advance. Before the next decision cycle starts, or when the target node needs to send a data packet, the target node's surrounding node situation information is obtained. The peripheral node situation information may be the target node maintained in real time by the local situation maintenance module of the channel access device and situation information broadcast by other nodes outside the target node. The situation information may include but is not limited to information such as network topology relationships, network node identifiers, the amount of data to be sent by the node, the activity level of surrounding nodes, and data sending frequency.

In this embodiment, the local situation range maintained by the local situation maintenance module can be set according to actual needs. For example, when setting the local situation range N ≥ 2, the local situation maintenance module of the channel access device maintains the situation information of N hops (more than or equal to two hops) of surrounding nodes centered on the target node in real time.

In this embodiment, by obtaining the situation information of the surrounding nodes of the target node, the communication situation of the surrounding nodes of the target node can be analyzed and understood.

Step S20: Determine the starting time of the transmission attempt window in the next decision cycle based on the situation information of the surrounding nodes.

Specifically, based on the obtained situation information of surrounding nodes, the time period and its starting time during which the target node can actively access the channel in the next decision cycle are determined, that is, the starting time of the transmission attempt window in the next decision cycle.

More specifically, based on the obtained peripheral node situation information, the network node identification, the amount of data to be sent by the node and other information in the peripheral node situation information are counted, and the target node in the next decision cycle is calculated based on the statistical results of the peripheral node situation information. The time period during which the channel can be actively accessed. Among them, during this time period, the target node is always trying to send data packets. When the sendable conditions are met, the target node is controlled to occupy the channel and start the process of sending data packets. In this embodiment, the time period in which the target node can actively access the channel is defined as the transmission attempt window, and the node status in this time period is defined as the transmission attempt state. Afterwards, based on the calculated time period during which the target node can actively access the channel in the next decision cycle, that is, the attempted transmission window in the next decision cycle, the starting time of the attempted transmission window is determined.

This embodiment determines the time period during which the target node can actively access the channel in the next decision-making cycle according to certain rules based on the situation information of surrounding nodes perceived by the target node itself, so that the time period for nodes in the dense transmission area to actively access the channel is shorter. , nodes in the sparse sending area can actively access for a longer time, thereby avoiding collisions between nodes and improving network performance.

Step S30: When the starting time of the transmission attempt window is reached, control the target node to access the channel.

Specifically, when the starting time of the transmission attempt window in the next decision cycle is reached, the target node is controlled to access the channel and send and receive data packets.

More specifically, when the target node accesses the channel at the beginning of the transmission attempt window, it will determine the busy and idle status of the channel through carrier sensing, and use the IEEE 802.11DCF working mechanism to send and receive data packets.

This embodiment uses the above solution, specifically by obtaining the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent; and determines the start of the transmission attempt window in the next decision cycle based on the surrounding node situation information. When the starting time of the attempted transmission window is reached, the target node is controlled to access the channel. Based on the solution of this embodiment, by obtaining the situation information of surrounding nodes perceived by the target node itself, and determining the starting time of the transmission attempt window in the next decision cycle based on the situation information of surrounding nodes, decisions can be made based on the communication situation of the surrounding environment of the target node. , determine the starting time of the transmission attempt window that the target node can actively access, and avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the target node to actively access the channel at the beginning of the transmission attempt window, The sending and receiving of data packets can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

Further, as an embodiment, refer to Figure 3, which is a schematic flow chart of another exemplary embodiment of the channel access method of the present application. In the above step S20, after determining the starting time of the transmission attempt window in the next decision cycle based on the surrounding node situation information, it may also include:

Step S40: Determine the restricted sending window based on the attempted sending window in the next decision cycle.

Specifically, after determining the transmission attempt window in the next decision cycle, the period occupied by the non-attempt transmission window in the next decision cycle is determined as the restricted transmission window based on the overall duration of the next decision cycle. Among them, within the restricted sending window, the target node, as the called party, is in a restricted sending state. In this restricted sending state, the target node does not need physical carrier sensing and will not try to send data packets. However, in this restricted sending state, The target node will still passively send response frames, such as CTS, ACK, etc.

Step S50: When the starting time of the restricted sending window is reached, control the target node to be in a restricted sending state.

Specifically, when the starting time of the restricted sending window in the next decision cycle is reached, the target node is controlled to be in the restricted sending state. That is, the target node in the restricted sending state serves as the called party and retains the passive reception or response function. In this state, the target node will still passively send response frames, but does not require physical carrier sensing and will not attempt to send data packets. .

In the solution of this embodiment, in the restricted sending state, the target node does not need to perform physical carrier sensing and attempt to send data packets, thereby reducing energy consumption. This is particularly important for energy-constrained nodes such as mobile devices. By controlling the target node to be in a restricted sending state within the restricted sending window, the target node only passively receives or responds and does not actively send data packets, thus avoiding collisions between nodes and thus improving network capacity.

Further, refer to Figure 4, which is a schematic flow chart of a third exemplary embodiment of the channel access method of the present application. Based on the embodiment shown above, in this embodiment, the above-mentioned step S20, determining the starting time of the transmission attempt window in the next decision cycle according to the situation information of the surrounding nodes may include:

Step S21: Obtain node density degree parameters.

Specifically, the node density level parameter is obtained through the channel access device, where the node density level parameter is a parameter indicating the node density level of the entire network. The node density parameter may be a preset fixed node density parameter of the entire network, or may be a node density parameter of the entire network that changes dynamically according to a specific rule. Wherein, the range of the node density degree parameter is at least greater than zero.

Step S22: Count the number of nodes in the surrounding nodes whose data volume to be sent is greater than zero according to the situation information of the surrounding nodes, and obtain the current network density.

Specifically, the number of nodes with a data volume to be sent greater than zero among the surrounding nodes of the target node is counted according to the obtained situation information of the surrounding nodes, and the current network density is determined based on the counted number of nodes with a data volume to be sent greater than zero among the surrounding nodes. .

Step S23: Determine the starting time of the transmission attempt window in the next decision cycle based on the current network density and the node density parameters.

Specifically, the starting time of the transmission attempt window in the next decision cycle is determined based on the current network density statistics and the obtained node density parameters.

In one embodiment, a method of determining the starting time of the transmission attempt window in the next decision cycle based on current network density and node density parameters may include: presetting the cycle length and starting time of the next decision cycle; According to the method for determining the duration of the attempt to send window, determine the duration of the attempt to send window in the next decision cycle based on the current network density and node density parameters; then, based on the preset cycle length and starting time of the next decision cycle , and the length of the attempted sending window in the next decision cycle, determine the starting moment of the attempted sending window in the next decision cycle. Among them, the cycle length of the next decision cycle is greater than or equal to the attempt sending window length in the next decision cycle.

In another embodiment, the method of determining the starting moment of the attempt to send window in the next decision cycle based on the parameters of the current network density and node density may also include: setting the length of the attempt to send window in advance; and determining the method according to the decision cycle , determine the next decision cycle based on the parameters of the current network density and node density; then, determine the attempted transmission in the next decision cycle based on the preset attempt transmission window length and the cycle length of the next decision cycle and its starting time The starting time of the window.

In other embodiments, the method of determining the starting moment of the transmission attempt window in the next decision cycle based on the current network density and node density parameters may also include: determining the next decision based on the current network density and node density parameters. The period and the transmission attempt window duration. Based on the transmission attempt window duration and the cycle length and starting time of the next decision cycle, the starting time of the transmission attempt window in the next decision cycle is determined.

In yet another embodiment, the method of determining the starting moment of the transmission attempt window in the next decision cycle based on the current network density and node density parameters may also include: determining the transmission attempt based on the current network density and node density parameters. The starting time probability of the window, based on which the starting time of the attempted transmission window in the next decision cycle is determined. Among them, the number of windows of the transmission attempt window in the next decision cycle can be determined by the probability of the starting time, and the total duration of the transmission attempt window is also determined by the probability of the starting time.

Through the above solution, this embodiment dynamically determines the starting time of the transmission attempt window in the next decision-making cycle according to the current network density and node density parameters, and can adjust the channel access time according to the current network communication situation. Avoid collisions between nodes and control information overhead, and improve network performance and efficiency.

Further, refer to FIG. 5 , which is a schematic flowchart of a fourth exemplary embodiment of the channel access method of the present application. Based on the above embodiment shown in Figure 4, in this embodiment, the above step S23 determines the starting time of the attempted transmission window in the next decision cycle according to the current network density and the node density parameters. Can include:

Step S2310: Divide several decision-making cycles based on the target timeline;

Step S2311, determine the duration of the attempted transmission window according to the decision-making period, the current network density and the node density parameters;

Specifically, the target timeline is obtained and divided into multiple decision cycles, and the cycle length and starting time of each decision cycle are obtained. Among them, the cycle duration of each decision-making cycle can be a unified fixed duration, or it can be divided into different durations according to different decision-making cycles. Based on each decision cycle and the determined current network density and node density parameters, the length of the attempted sending window in the next decision cycle is determined.

For example, the entire target timeline is divided into multiple decision cycles of equal length, and the cycle length of the decision cycle is the unified fixed parameter DecisionCycle of all network nodes. Obtain the situation information of surrounding nodes of the target node, and obtain SendNodeNum, the number of nodes in the surrounding nodes with the amount of data to be sent greater than zero, based on statistics of the situation information of surrounding nodes, to represent the current network density. Obtain the node density parameter SubNodeNum>0, and determine the send window duration SendWindow in the next decision cycle based on the decision cycle, current network density, and node density parameters according to the method for determining the send window duration. Among them, the method for determining the duration of the attempted sending window can be as shown in the following formula 1:

Among them, SendWindow is the try sending window duration in the next decision cycle, DecisionCycle is the cycle duration of the next decision cycle, SendNodeNum is the current network density, SubNodeNum is the node density parameter, is the rounding down operator.

Step S2312: Construct a pseudo-random number interval based on the current network density and the node density parameters;

Step S2313, select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

Step S2314: Determine the starting time of the attempted sending window based on the starting time of the next decision cycle, the pseudo-random integer, and the attempted sending window duration.

Specifically, a pseudo-random number interval is constructed based on the determined current network density and node density parameters. Select any pseudo-random integer from the uniform distribution of the constructed pseudo-random number interval, and determine the period within the next decision-making period based on the starting time of the next decision-making period, the selected pseudo-random integer and the length of the attempted transmission window in the next decision-making period. The starting time of the attempt to send window.

For example, the method of determining the starting time SendWindowStart of the attempted sending window in the next decision cycle is:

Construct a pseudo-random number interval based on the determined current network density and node density parameters. Select a pseudo-random integer mw from the uniform distribution in this interval, and calculate it from the beginning of the next decision cycle. After mw×SendWindow time, where SendWindow is the length of the attempt to send window, the target node enters the attempt to send window, that is The start time of the attempted sending window SendWindowStart is the time after mw×SendWindow duration has elapsed from the start time of the next decision cycle.

This embodiment adopts a fixed and unified decision-making cycle length. In each decision-making cycle, the attempt-to-send window duration will be dynamically adjusted according to the current network density and node density parameters. That is, the attempt-to-send window length will change with the density. It changes based on the characterization to flexibly control the duration of the attempt to send window, which improves channel utilization and network performance.

Further, referring to Figure 6, Figure 6 is a schematic flow chart of the fifth exemplary embodiment of the channel access method of the present application. Based on the embodiment shown in Figure 4, in this embodiment, the above step S23 is based on the current The network density and the node density parameters determine the starting moment of the transmission attempt window in the next decision cycle, which may include:

Step S2320, obtain the preset time frame length parameter;

Step S2321: Determine the next decision cycle based on the time frame length parameter, the current network density level, and node density level parameters.

In this embodiment, each decision cycle may be composed of multiple time frames. Obtain the preset time frame length parameter, where the time frame length parameter is a unified fixed time frame length parameter for the entire network node. The next decision cycle is determined based on the preset time frame length parameters, current network density and node density parameters.

In this embodiment, the time frame in which the channel can be actively accessed within the decision-making period is defined as the transmission attempt window, and the node status in this time frame period is defined as the transmission attempt state. Therefore, the transmission attempt window duration in this embodiment can be set correspondingly to the length of the time frame in which the channel can be actively accessed.

For example, as shown in Figure 7, the length of each time frame is set to the unified fixed parameter Slot of the entire network node, and the duration of the attempt to send window is 1 time frame length. First, the surrounding node situation information of the target node is obtained, and based on the statistics of the surrounding node situation information, the number SendNodeNum of nodes in the surrounding nodes whose data volume is greater than zero is obtained to represent the current network density. Get the node density parameter SubNodeNum>0. Assume that the decision-making cycle consists of M time frames, and all time frames are numbered {0, 1,...,M-1} in chronological order. Among them, the m-th time frame in the decision-making cycle is the attempt to send time frame, and other time frames It is defined as a restricted sending time frame, and a restricted sending window is composed of a restricted sending time frame. The status of the node in this window period is defined as a restricted sending state. According to the determination method of the decision cycle, the next decision cycle DecisionCycle is determined based on the time frame length parameter Slot, the current network density and the node density parameters. Among them, the confirmation method for the next decision-making cycle can refer to the following formulas 2 and 3:

DecisionCycle＝M×Slot (3)

Among them, M is the number of time frames occupied by the next decision cycle, DecisionCycle is the next decision cycle, SendNodeNum is the current network density, SubNodeNum is the node density parameter, is the rounding down operator, and Slot is the time frame length parameter.

Step S2322: Construct a pseudo-random number interval based on the current network density and the node density parameters;

Step S2323: Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval;

Step S2324: Determine the starting time of the attempted transmission window based on the starting time of the next decision cycle, the pseudo-random integer and the time frame length parameter;

Specifically, a pseudo-random number interval is constructed based on the determined current network density and node density parameters. Select any pseudo-random integer from the uniform distribution of the constructed pseudo-random number interval, and determine the start of the attempted transmission window in the next decision-making period based on the starting time of the next decision-making period, the selected pseudo-random integer and the time frame length parameter. starting moment.

For example, the method of determining the starting time SendWindowStart of the attempted sending window in the next decision cycle is:

Construct a pseudo-random number interval based on the determined current network density and node density parameters. Select a pseudo-random integer mw from the uniform distribution in this interval, and calculate it from the beginning of the next decision cycle. After mw The attempt to send window, that is, the start time of the attempt to send window SendWindowStart is the time after mw×Slot duration has elapsed from the start of the next decision cycle.

In this embodiment, the try-to-send window length remains unchanged in each decision-making cycle, and the decision-making cycle length is dynamically adjusted according to the time frame length parameters, current network density, and node density parameters to achieve flexibility based on the actual situation of the network. Control the length of the decision-making cycle to improve channel utilization and network performance.

Further, referring to Figure 8, Figure 8 is a schematic flow chart of the sixth exemplary embodiment of the channel access method of the present application. Based on the embodiment shown in Figure 4, in this embodiment, the above step S23 is based on the current The network density and the node density parameters determine the starting moment of the transmission attempt window in the next decision cycle, which may include:

Step S2330: Calculate the starting moment probability of the attempted transmission window in the next decision cycle based on the current network density and the node density parameters.

Specifically, based on the statistics of the current network density and the preset node density parameters, the starting time probability of the attempted sending window in the next decision cycle is calculated, where the starting time probability refers to the start of the attempted sending window The probability that a moment occurs at the beginning of any time frame in the next decision cycle.

Step S2331, construct a probability interval, and select any pseudo-random probability for each time frame from the uniform distribution of the probability interval before the start of the next decision-making cycle or at the beginning of each time frame;

Step S2332, compare the starting time probability and the pseudo-random probability;

Step S2333: If the pseudo-random probability is less than or equal to the starting time probability, determine the starting time of the time frame corresponding to the pseudo-random probability as the starting time of the attempted transmission window.

Specifically, in order to determine whether a certain time frame in the next decision cycle is the starting time frame of the attempt to send the window, a probability interval of 0-1 is constructed before the start of the next decision cycle, or at each time frame in the next decision cycle At the starting moment of , select any pseudo-random probability from the uniform distribution of the constructed probability interval. Then, compare the calculated probability of the starting moment of the attempted transmission window in the next decision cycle with the selected pseudo-random probability. If the pseudo-random probability is less than or equal to the probability of the starting moment of the attempted transmission window in the next decision cycle, the time frame corresponding to the current pseudo-random probability is considered to be the starting time frame of the attempted transmission window, and the time frame corresponding to the pseudo-random probability is The starting time of is determined as the starting time of the attempted sending window in the next decision cycle.

It should be noted that in this embodiment, each decision cycle duration is composed of several time frames. In the next decision cycle duration, there are several time frames with the probability of being defined as the attempt to send window, wherein these several time frames The time frames defined as the attempt window may be concatenated together, or they may be scattered across time frames in the next decision cycle. Therefore, the method of this embodiment makes the total duration of the transmission attempt window and its relative starting time determined by probability.

For example, based on the parameters of the current network density and node density, the starting moment probability P ₀ of the attempted transmission window in the next decision cycle is calculated. The method of calculating the starting moment probability can refer to the following formula 4:

Among them, P ₀ is the probability of the starting moment of the attempted sending window in the next decision cycle, SendNodeNum is the current network density, SubNOdeNum is the node density parameter, is the rounding down operator.

Each decision cycle duration consists of multiple time frames. In order to determine whether each time frame in the next decision cycle is a transmission attempt window, first construct a probability interval [0, 1], select any pseudo-random probability p from the uniform distribution of this probability interval, and judge whether the transmission attempt window is in the next The size of the starting moment probability P ₀ and the pseudo-random probability p in the decision-making cycle. If p ≤ P ₀ , then the time frame corresponding to the current pseudo-random probability is considered to be the starting time frame of the attempted transmission window, and the pseudo-random probability is corresponding to The starting moment of the time frame is determined as the starting moment of the attempted sending window in the next decision cycle. Otherwise, the time frame corresponding to the current pseudo-random probability is determined as the restricted transmission window.

In this example, the pseudo-random probability p can be selected randomly at the beginning of the next decision period for each time frame in the decision period; it can also be selected at the beginning of each time frame within the decision period. time, randomly selected from the probability interval.

Further, based on the embodiment shown above, in this embodiment, in the above step S30, when the starting time of the attempted transmission window is reached, after controlling the target node to access the channel, it may also include: when When the end time of the transmission attempt window is reached, the current transmission and reception process status of the target node is determined.

Specifically, when the end time of the transmission attempt window in the next decision cycle is reached, the current transceiver process status of the target node is determined, where the transceiver process status may include but is not limited to random fallback status, request transmission status, and data transmission. Status etc.

Optionally, if the target node is in a random backoff state, freeze the backoff count, save the remaining backoff duration, and enter the restricted sending window.

Specifically, if the current target node is in a random backoff state when the end time of the attempted sending window is reached, the backoff count will be frozen, the remaining backoff duration will be saved, and the restricted sending window will begin. Furthermore, if the target node is in a random backoff state when the current attempt to send window is ended, a new random backoff will be started when the next time it enters the attempt to send window, so that the frozen backoff count will continue.

Optionally, if the target node is in the request sending state, the response result is monitored, and the target node is controlled to execute the corresponding processing flow according to the response result.

Specifically, if the current target node is in the requesting RTS sending state when the end time of the sending attempt window is reached, the response result after the request is sent is monitored, and the target node is controlled to execute the corresponding processing flow according to the response result. For example, if a response CTS frame (Clear to Send frame) is received, it indicates that the data packet can be received, and the target node is controlled to continue to complete subsequent processes based on the received response result, such as sending data DATA, waiting for confirmation ACK, etc.; if in the scheduled If no response CTS frame is received within the time, the current response result is empty. At this time, the target node is controlled to enter the restricted sending window based on the timeout non-response result.

Optionally, if the target node is in the data sending state, the restricted sending window will be entered after the data sending is completed.

Specifically, if the current target node is in the data sending state when the end time of the attempted sending window is reached, the data will continue to be sent and after the data sending is completed, the target node will be controlled to enter the restricted sending window.

Optionally, if the target node is in other states, the restricted sending window is entered, where the other states are non-random fallback, non-requested sending, and non-data sending states.

Specifically, if the current target node is in the remaining states when the end time of the attempted sending window is reached, that is, in the non-random fallback, non-requested sending, and non-data sending states, then the target node is controlled to enter the restricted sending window.

For example, at a certain moment before the end of the current decision cycle or when the target node needs to send a data packet, the target node's surrounding node situation information is obtained. Among them, each decision-making cycle is divided according to the set target timeline, and each divided decision-making cycle is composed of multiple time frame Slots. Determine the duration of the attempted sending window SendWindow and the starting time of the attempted sending window SendWindowStart in the next decision cycle based on the acquired situation information of surrounding nodes. At the beginning of the next decision cycle, the target node enters the restricted sending state, turns on the waiting timer TW, and sets the timer duration to mw×SendWindow from the beginning of the next decision cycle to the starting time of the attempt to send window, where mw is Pseudorandom integer.

In the restricted transmission state, the physical layer can receive signals but does not actively sense carriers. The data link layer (MAC layer) can only perform all procedures as the called party in the IEEE 802.11 DCF scheme. For example, when the MAC layer receives an RTS frame, if the destination address is the target node itself, it determines whether a response CTS frame can be sent based on the network allocation vector (NAV); when the MAC layer receives a DATA frame, if the destination address is the target node itself, it will be combined with the network allocation vector (NAV) to determine whether the response ACK frame can be sent; in other cases, if the RTS, CTS, DATA, ACK whose destination address is other nodes is received, it will be based on the "duration" field in the frame. Update the network allocation vector (NAV).

Until the timer TW times out, that is, when it reaches the starting time mw×SendWindow of the attempt to send window in the next decision cycle, the target node is controlled to access the channel and enter the attempt to send state. At the same time, turn on the waiting timer TW again, and set the timer duration to the attempted sending window duration SendWindow. In this attempted transmission state, the physical layer requires carrier sensing and signal reception. The processing flow of the MAC layer is the same as the IEEE 802.11DCF solution.

Until the timer TW times out again, that is, the end time of the transmission attempt window is reached, at this time the target node may be in different states of the data packet sending and receiving process, and the current sending and receiving process status of the target node is determined.

If the current target node is in a random rollback state, the rollback count will be frozen, the remaining rollback duration will be saved, and the restricted sending window will begin. Furthermore, if the target node is in a random backoff state when the current attempt to send window is ended, a new random backoff will be started when the next time it enters the attempt to send window, so that the frozen backoff count will continue.

If the current target node is in the request RTS sending state, monitor the response result after the request is sent, and control the target node to execute the corresponding processing flow based on the response result. For example, if a response CTS frame (Clear to Send frame) is received, it indicates that the data packet can be received, and the target node is controlled to continue to complete subsequent processes based on the received response result, such as sending data DATA, waiting for confirmation ACK, etc.; if in the scheduled If no response CTS frame is received within the time, the current response result is empty. At this time, the target node is controlled to enter the restricted sending window based on the timeout non-response result.

If the current target node is in the data sending state, it will continue to send data and after the data sending is completed, the target node will be controlled to enter the restricted sending window.

If the current target node is in other states, that is, in a non-random fallback, non-requested sending, and non-data sending state, the target node is controlled to immediately enter the restricted sending window.

After that, until the end of this decision cycle, if the target node still has data to send, the attempt to send window and its starting time of the next decision cycle will be recalculated.

The solution of this embodiment performs the corresponding processing process according to the current sending and receiving process status of the target node and enters the restricted sending window. The sending behavior can be flexibly controlled according to the actual status of the target node to improve network performance and efficiency.

Further, based on the above-described embodiment, in this embodiment, before obtaining the surrounding node situation information of the target node in step S10, it may also include:

Step S01: Use the target node as a maintenance center to maintain the situation information of surrounding nodes within the preset local situation range of the target node.

Specifically, before obtaining the situation information of surrounding nodes of the target node, after the target node is powered on through the channel access device, the local situation maintenance module deployed by it uses the target node as the maintenance center to maintain the preset local situation range of the target node. Situation information of surrounding nodes within the system.

For example, assuming that the local situation range N ≥ 2, the local situation maintenance module of the channel access device maintains situation information of N hops (more than or equal to two hops) of surrounding nodes centered on the target node.

Further, the above step S01 may specifically include:

Step S011: Receive the situation information of surrounding nodes within the preset local situation range of the target node;

Step S012: Generate or update a local network situation information table according to the situation information of surrounding nodes.

More specifically, the deployed local situation maintenance module receives situation information of surrounding nodes within a preset local situation range of the target node, where the preset local situation range is at least greater than or equal to two hops. Generate or update a local network situation information table based on the received situation information of surrounding nodes.

Further, the above step S10 may include:

Step S11: Read the local network situation information table, and extract situation information of all surrounding nodes within the preset local situation range of the target node.

Specifically, read the pre-generated or updated local situation information table, and extract the situation information of all surrounding nodes within the preset local situation range of the target node, where the situation information of the surrounding nodes is used to statistically obtain the to-be-sent information in the surrounding nodes. The number of nodes with data volume greater than zero represents the current density of the network.

After that, based on the situation information of surrounding nodes and the current network density obtained by statistics, the starting time of the attempted transmission window in the next decision cycle is determined; when the starting time of the attempted transmission window is reached, the target node is controlled to access the channel and perform Sending and receiving of data packets.

Through the above solution, this embodiment maintains the situation information of surrounding nodes within the local situation range perceived by the target node itself, and determines the starting time of the attempted transmission window in the next decision cycle based on the situation information of the surrounding nodes, based on the situation around the target node. Decision-making is made based on the communication situation of the environment, and the starting time of the attempt to send window that the target node can actively access is determined to avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the starting time of the target node reaching the attempt to send window Actively accessing the channel to send and receive data packets can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

Illustratively, refer to FIG. 9 , which is a schematic diagram of a network topology according to an example of the present invention. The example of the present invention uses a channel access method based on local situation information to build a large-scale networking simulation environment. The simulation parameters are as shown in Table 1 below:

parameter IEEE 802.11 DCF mechanism Network access mechanism topological area 500m×500m 500m×500m Signal transmission radius (m) 300 300 Data packet length (Byte) 1500 1500 CWMAX 2 ⁵ ~ 2 ¹⁰ 2 ⁵ ~ 2 ¹⁰ Transmission rate (bps) 3.25M 3.25M Number of retransmissions 4 4 SubNodeNumber \ 15 DecisionCycle \ 100ms

Table 1: IEEE 802.11DCF and access mechanism parameter configuration

In the above simulation parameter conditions, the network node positions are randomly distributed, and each node is in a saturated sending state. Figure 9 shows an example network topology of 100 nodes in a 500m×500m area. Compared with the DCF mechanism in the IEEE 802.11n standard, the advantages of this example using the channel access method based on local situation information are as follows:

(1) Comparing the packet loss rate performance, as shown in Figure 10a, it can be seen from the simulation results that the access mechanism proposed in this example greatly reduces the packet loss rate of data sent by the MAC layer. In the simulation experiment, compared with DCF technology, the access mechanism in this example reduced the packet loss rate from 39.3% to 19.0%. The reduction of packet loss rate can not only improve the energy utilization of nodes, but also reduce the retransmission probability of upper layer end-to-end data, thereby reducing the average end-to-end delay of the network.

(2) Comparing the network saturation throughput performance, as shown in Figure 10b, it can be seen from the simulation results that in the case of large-scale dense networking, the access mechanism proposed in this example greatly improves the network saturation throughput. In the simulation experiment, compared with DCF technology, the access mechanism in this example increased the network saturation throughput by 29.7%.

Illustratively, refer to FIG. 11 , which is a schematic diagram of a node network movement trajectory topology according to an example of the present invention. In the example of the present invention, a node movement scenario is constructed. Based on the above example, a node movement model is added. The parameters of the node movement model are as shown in Table 2 below:

parameter value kinematic model Random waypoint model Moving range 1000m×1000m Moving speed (m/s) Uniform(10,20)random selection Movement start time (s) 40 moving time 120s

Table 2: Node mobility model parameters

The simulation results based on the node mobility model are shown in Figure 12a and Figure 12b, where curve ① represents the performance of DCF technology, and curve ② represents the performance of this channel access scheme. Figure 12a is a schematic diagram comparing the packet loss rate between the example of the present invention and the DCF mechanism in the mobile scenario, showing the changing trend of the packet loss rate as the node moves; Figure 12b is the comparison of the network saturation throughput between the example of the present invention and the DCF mechanism in the mobile scenario. Schematic diagram showing the changing trend of network saturation throughput as nodes move. As can be seen from these two figures, the channel access mechanism proposed in this example is also very robust in mobile scenarios and always has better performance than the DCF mechanism.

At the same time, this example solution still has good performance advantages under the condition that the business load is not saturated. In the network topology environment of Figure 9, the business load of the nodes is not saturated, that is, at any time, some nodes have data to send, and the data to be sent by other nodes may be 0. Under this condition of unsaturated business load, the simulation results of packet loss rate and network throughput are shown in Figure 13a and Figure 13b. Among them, curve ① represents the performance of DCF technology, and curve ② represents the performance of the solution of the present invention. As can be seen from the two figures, the packet loss rate of curve ① is significantly higher than that of curve ②, and the network throughput of curve ① is lower than curve ②. That is to say, the channel access mechanism proposed in this example can also be used under the condition that the business load is not saturated. Has better performance. It can be seen that this solution has broad adaptability, reduces the packet loss rate and improves network throughput while ensuring robustness.

In addition, the embodiment of this application also proposes a channel access device. The channel access device includes:

The acquisition module is used to obtain the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent;

A determination module, configured to determine the starting time of the attempted transmission window in the next decision cycle based on the situation information of the surrounding nodes;

An access module, configured to control the target node to access the channel when the starting time of the transmission attempt window is reached.

For the principle and implementation process of channel access in this embodiment, please refer to the above embodiments, which will not be described again one by one.

In addition, the embodiment of the present application also proposes a channel access device. The channel access device includes a memory, a processor, and a channel access program stored on the memory and capable of running on the processor. When the channel access program is executed by the processor, the steps of the channel access method as described above are implemented.

Since this channel access procedure adopts all the technical solutions of all the foregoing embodiments when executed by the processor, it has at least all the beneficial effects brought by all the technical solutions of all the foregoing embodiments, which will not be described again one by one.

In addition, embodiments of the present application also propose a computer-readable storage medium. A channel access program is stored on the computer-readable storage medium. When the channel access program is executed by a processor, the channel access as described above is implemented. Method steps.

Since this channel access procedure adopts all the technical solutions of all the foregoing embodiments when executed by the processor, it has at least all the beneficial effects brought by all the technical solutions of all the foregoing embodiments, which will not be described again one by one.

Compared with the existing technology, the channel access method, device, equipment and storage medium proposed in the embodiments of this application have a channel access method that obtains the surrounding node situation of the target node before the next decision cycle starts or when a data packet needs to be sent. information; determine the starting time of the transmission attempt window in the next decision cycle according to the situation information of the surrounding nodes; when the starting time of the transmission attempt window is reached, control the target node to access the channel. Based on the solution of this application, by obtaining the situation information of surrounding nodes perceived by the target node itself, and determining the starting time of the transmission attempt window in the next decision cycle based on the situation information of surrounding nodes, decisions can be made based on the communication situation of the surrounding environment of the target node. Determine the starting time of the transmission attempt window that the target node can actively access to avoid the control information overhead caused by dynamic time slot allocation between nodes; by controlling the target node to actively access the channel at the beginning of the transmission attempt window, data processing Packet sending and receiving can effectively avoid collisions between nodes, greatly reduce the node packet loss rate, improve network throughput, and make the performance improvement more prominent.

It should be noted that, as used herein, the terms "include", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or system that includes a list of elements not only includes those elements, but It also includes other elements not expressly listed or that are inherent to the process, method, article or system. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

In addition, if there are descriptions involving “first”, “second”, etc. in the embodiments of the present invention, the descriptions of “first”, “second”, etc. are only for descriptive purposes and shall not be understood as indications or implications. Its relative importance or implicit indication of the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions in various embodiments can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist. , nor within the protection scope required by the present invention.

The above serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus the necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is better. implementation. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence or that contributes to the existing technology. The computer software product is stored in one of the above storage media (such as ROM/RAM, magnetic disk, optical disk), including several instructions to cause a device (which can be a mobile phone, a computer, a server, a controlled terminal, or a network device, etc.) to execute the method of each embodiment of the present application.

The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of the present application may be directly or indirectly used in other related technical fields. , are all equally included in the patent protection scope of this application.

Claims (11)

1. A channel access method, characterized in that the channel access method includes: Before the next decision cycle starts or when a data packet needs to be sent, obtain the surrounding node situation information of the target node; Determine the starting moment of the attempted transmission window in the next decision cycle based on the surrounding node situation information; When the starting time of the transmission attempt window is reached, the target node is controlled to access the channel. 2. The channel access method according to claim 1, wherein the step of determining the starting time of the transmission attempt window in the next decision cycle according to the surrounding node situation information includes: Get node density degree parameters; According to the situation information of the surrounding nodes, count the number of nodes in the surrounding nodes with the amount of data to be sent greater than zero, and obtain the current network density; The starting moment of the transmission attempt window in the next decision cycle is determined according to the current network density and the node density parameters. 3. The channel access method according to claim 2, wherein the starting time of the attempted transmission window in the next decision cycle is determined according to the current network density and the node density parameters. The steps include: Several decision-making cycles are obtained based on the target timeline division; Determine the duration of the attempted transmission window according to the decision cycle, the current network density and the node density parameters; Construct a pseudo-random number interval according to the current network density and the node density parameters; Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval; The starting moment of the attempted sending window is determined based on the starting moment of the next decision cycle, the pseudo-random integer and the duration of the attempted sending window. 4. The channel access method according to claim 2, wherein the starting time of the attempted transmission window in the next decision cycle is determined based on the current network density and the node density parameters. The steps include: Get the preset time frame length parameters; Determine the next decision cycle according to the time frame length parameter, the current network density and the node density parameters; Construct a pseudo-random number interval according to the current network density and the node density parameters; Select any pseudo-random integer from the uniform distribution of the pseudo-random number interval; The starting time of the attempted transmission window is determined based on the starting time of the next decision cycle, the pseudo-random integer and the time frame length parameter. 5. The channel access method according to claim 2, wherein the starting time of the attempted transmission window in the next decision cycle is determined based on the current network density and the node density parameters. The steps include: Calculate the starting moment probability of the attempted transmission window in the next decision cycle based on the current network density and the node density parameters; Construct a probability interval, and select any pseudo-random probability for each time frame from the uniform distribution of the probability interval before the start of the next decision-making period or at the beginning of each time frame; Compare the starting moment probability and the pseudo-random probability; If the pseudo-random probability is less than or equal to the starting time probability, the starting time of the time frame corresponding to the pseudo-random probability is determined as the starting time of the attempted transmission window. 6. The channel access method according to claim 1, characterized in that, after the step of determining the starting time of the transmission attempt window in the next decision cycle according to the situation information of the surrounding nodes, it further includes: Determine the restricted sending window according to the attempted sending window within the next decision cycle; When the starting time of the restricted sending window is reached, the target node is controlled to be in a restricted sending state. 7. The channel access method according to claim 1, characterized in that, after the step of controlling the target node to access the channel when the starting time of the attempted transmission window is reached, the method further includes: When the end time of the attempted sending window is reached, determine the current sending and receiving process status of the target node; If the target node is in a random fallback state, freeze the rollback count, save the remaining rollback duration, and enter the restricted sending window; If the target node is in the request sending state, monitor the response result, and control the target node to execute the corresponding processing flow according to the response result; If the target node is in the data sending state, it will enter the restricted sending window after the data sending is completed; If the target node is in other states, it enters the restricted sending window, where the other states are non-random fallback, non-requested sending, and non-data sending states. 8. The channel access method according to claim 1, characterized in that before the step of obtaining the surrounding node situation information of the target node, it further includes: The target node is used as a maintenance center to maintain the situation information of surrounding nodes within the preset local situation range of the target node, which specifically includes: Receive situation information of surrounding nodes within a preset local situation range of the target node; Generate or update a local network situation information table according to the surrounding node situation information; The step of obtaining the situation information of surrounding nodes of the target node includes: Read the local network situation information table and extract situation information of all surrounding nodes within the preset local situation range of the target node. 9. A channel access device, characterized in that the channel access device includes: The acquisition module is used to obtain the surrounding node situation information of the target node before the next decision cycle starts or when a data packet needs to be sent; A determination module, configured to determine the starting time of the attempted transmission window in the next decision cycle based on the situation information of the surrounding nodes; An access module, configured to control the target node to access the channel when the starting time of the transmission attempt window is reached. 10. A channel access device, characterized in that the channel access device includes a memory, a processor, and a channel access program stored in the memory and capable of running on the processor, and the channel access device When the program is executed by the processor, the steps of the channel access method according to any one of claims 1-8 are implemented. 11. A computer-readable storage medium, characterized in that a channel access program is stored on the computer-readable storage medium, and when the channel access program is executed by a processor, it implements any one of claims 1-8 The steps of the channel access method described in the item.