A linear network-based end-to-end throughput maximization method

Abstract

The application provides a linear network-based end-to-end throughput maximization method, and relates to the technical field of wireless sensor networks. The method first linearly deploys sensor nodes in the network, and completes in-group and inter-group division of the sensor nodes. Then, according to a transmission and reception energy consumption model of the nodes, energy consumption of each node is calculated, and residual energy of the node is obtained. According to the residual energy of the node, a priority of the node in the group is calculated, and different backoff window waiting time lengths are allocated to the nodes in the group according to the priority. When an edge uplink node in the group has data ready to be transmitted, the edge uplink node will enter inter-group transmission competition. Whether the data transmission is within a data transmission interference range is determined through an inter-group interference model. After the backoff time ends, the source node will retransmit the data, a retransmission mechanism is executed, and the reliability and transmission success rate of the data are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless sensor networks, and in particular to a method for maximizing end-to-end throughput based on a linear network. Background Art

[0002] Existing solutions to improve the end-to-end throughput of linear sensor networks include time slot scheduling optimization, dynamic adjustment of node transmit power, multi-channel communication, and network topology optimization. However, time slot scheduling optimization requires strict synchronization of all nodes, and each node must wait for its time slot before sending data. Consequently, in high-traffic or emergency communication scenarios, transmission latency increases, failing to meet real-time requirements. Dynamic adjustment of node transmit power requires nodes to measure and evaluate channel conditions and neighboring node status in real time, increasing computational and communication overhead. Furthermore, in rapidly changing network environments, frequent transmit power adjustments can lead to unstable communication links. While multi-channel communication provides more transmission channels, effectively allocating and managing multiple channels in a dynamic network is challenging and imposes higher hardware requirements, increasing node cost and complexity. Network topology optimization typically assumes relatively static network conditions. However, in practice, most wireless sensor networks are deployed in environments lacking human supervision, where factors such as node energy depletion and environmental changes necessitate constant topology adjustments. While these approaches are effective in small-scale networks, designing a computationally cost-effective and flexible solution to improve end-to-end throughput in large-scale networks remains a challenge.

[0003] Existing solutions often encounter performance bottlenecks due to unstable network topologies and the cost and complexity of large-scale deployment, resulting in low end-to-end throughput. Because these approaches require the coordination and unification of the entire sensor network, they suffer from low universality and high deployment costs. Therefore, by breaking down the entire network into smaller parts, using scheduled transmission within a group and competitive transmission between groups, we improve end-to-end throughput and avoid the challenge of achieving coordinated and unified sensor node networks in large-scale networks. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an end-to-end throughput maximization method based on a linear network; by real-time monitoring of the status of sensor nodes, the optimal sending node is dynamically selected within the group, and the communication between multiple nodes is effectively coordinated through the CSMA / CA protocol and the RTS / CTS mechanism.

[0005] In one aspect, a method for maximizing end-to-end throughput based on a linear network comprises the following steps:

[0006] Step 1: linearly deploy the sensor nodes in the network, starting from the edge nodes of the network, and divide every four adjacent nodes into a group to complete the intra-group and inter-group division of the sensor nodes;

[0007] Step 2: calculate the energy consumption of each node according to the transmission and reception energy consumption model of the node, and obtain the residual energy of the node; according to the residual energy of the node, the priority of the node in the group is calculated, and the node with higher energy will obtain higher priority;

[0008] The transmission and reception energy consumption model is as follows:

[0009]

[0010] E Rx (k)=k(E elec +E da )

[0011] E remaining =E init -∑(E Tx (k)+E Rx (k))

[0012]

[0013] wherein the energy consumed for transmitting a packet with a length of k bits at a distance of d meters is represented by E Tx (k,d), is a threshold value of the distance, E elec represents the energy consumed for transmitting or receiving 1 bit, ε fs is a coefficient of a free space channel model with d 2 power loss, and ε mp is a coefficient of a multipath fading channel model with d 4 power loss; the energy consumption E R x(k) for receiving a k-bit message, Eda is the energy consumption of data aggregation, Einit is the initial energy of the node, E remaining is the residual energy of the node, and priority is the priority level of the node;

[0014] Step 3: the nodes in the group assign different backoff window waiting durations according to the priority, and the higher the priority of the node, the shorter the waiting duration; after the end of the backoff window, if the node has data to be transmitted under the condition of meeting the intra-group interference model, a reservation message is sent; after receiving the reservation message, the other nodes in the group enter a silent listening state to avoid conflicts; if the node has no data to be transmitted, it automatically enters the silent listening state and waits to receive the data transmission of other nodes;

[0015] The backoff window is represented as:

[0016] cw init =cw min *priority

[0017] where cw init To initialize the backoff window, cw min is the minimum value of the contention window;

[0018] The intra-group interference model is that the sensor nodes meet the requirement of one-hop transmission and two-hop interference. The nodes in the group obtain their own priorities through the data packet intra-group priority calculation module, set the initial contention window according to the priority, and send the intra-group reservation frame after the contention window ends.

[0019] Step 4: When the edge uplink node in the group has data ready to transmit, it will enter inter-group transmission competition; the inter-group interference model is used to determine whether it is within the data transmission interference range. If it is not within the interference range and the channel is idle, the edge uplink node sends an RTS signal to the destination node, which is a request to send a signal; if the destination node receives the RTS signal and the channel is idle, it will feedback a CTS signal, which means clearing the send signal and preparing to receive the DATA data packet. If the destination node does not receive the RTS signal, or receives it but the channel is busy, it will not send a CTS signal. When the source node does not receive the CTS feedback, execute step 5;

[0020] The inter-group interference model regards inter-group communication as data communication between edge nodes of two groups, that is, the uplink edge node of Group_1 communicates with the downlink edge node of Group_2, and the contention communication between the groups is realized through the CSMA / CA protocol and the RTS / CTS mechanism;

[0021] Step 5: During the transmission process of the competitive channel, when data loss or conflict occurs, the source node will execute the backoff algorithm and enter the backoff window to wait; after the backoff time expires, the source node will retransmit the data and execute the retransmission mechanism to ensure data reliability and transmission success rate.

[0022] The retransmission mechanism uses an optimized binary exponential retransmission algorithm, and the specific steps are as follows:

[0023] Step S1: The source node finishes sending data and enters the channel monitoring state. If a reply frame data is received within the monitoring time slot, it is determined that the destination node has received the data. Otherwise, the data sent by the source node is considered lost.

[0024] Step S2: After determining that the data sent by the source node is lost, the source node enters the backoff window and executes the retransmission mechanism to resend the data packet. The existing backoff window is optimized, and the specific optimization formula is as follows:

[0025]

[0026] where cw max is the maximum value of the contention window, cw is the contention window size; N col Indicates the number of retransmissions during the node transmission process, α and β are cw init Multiplication coefficient, and 1<α<β;

[0027] Step S3: If the current node receives an ACK packet returned by another node, it means that the other node has completed this round of data interaction and will exit the channel competition. In this case, cw is automatically reduced to avoid wasting channel resources. The specific formula is as follows:

[0028] cw=max(cw / ε,cw init ),ε>1

[0029] Where cw is the contention window size and ε is the reduction coefficient.

[0030] On the other hand, the end-to-end throughput maximization method based on a linear network is implemented based on the following system, specifically including: a data packet group priority calculation module, a transmission time slot and backoff window setting module, a data packet group reservation sending module, an inter-data packet group competition module, and a data conflict maintenance mechanism module:

[0031] The data packet group priority calculation module calculates the priority of each node according to the residual energy of the nodes in the group when the residual energy of the node is greater than 20%;

[0032] The transmission time slot and backoff window setting module allocates transmission time slots to different data frames and dynamically sets the initial backoff window based on the priority of the node;

[0033] The data packet group reservation sending module initializes the backoff window according to the priority setting of the nodes, and the nodes with high priority make reservations for data transmission within the group first;

[0034] The packet group reservation sending module adopts a reservation and feedback model. In this reservation and feedback model, one of the four sensor nodes in the group that wants to send data first sends a REV signal, i.e., a reservation signal, to announce its intention to send data to other nodes in the group. After receiving the REV signal, the node in the group immediately sends an ECHO signal, i.e., a feedback signal, to confirm that it has received the reservation request.

[0035] When the channel monitoring is idle, the data packet inter-group competition module sends an RTS frame to the upstream source node at the edge of the group to request the right to use the channel. After receiving the RTS frame of the source node, the downstream destination node at the edge of the next group sends a CTS frame as a response, followed by the transmission of DATA frames between the groups and the reply of ACK frames for successful data reception.

[0036] The data conflict maintenance mechanism module is used to determine whether data conflict loss and data reception failure occur, and to ensure transmission reliability by executing the data conflict maintenance mechanism.

[0037] The data conflict maintenance mechanism determines whether the current node has received the reply frame data. If the reply frame data is not received, it means that the data was lost in the transmission process. When the channel is detected to be idle, the sender will enter the backoff window to execute the retransmission mechanism and resend the data packet.

[0038] The beneficial effects of adopting the above technical solution are:

[0039] The present invention provides a method for maximizing end-to-end throughput based on a linear network, which has the following beneficial effects:

[0040] 1. The present invention breaks the linear sensor network into parts, and nodes within the group schedule transmission while nodes between groups compete for transmission. It proposes a competitive MAC method based on maximizing end-to-end throughput in a linear multi-hop backhaul network, which effectively improves the network throughput and transmission reliability.

[0041] 2. For different linear wireless sensor networks, only the sensor node grouping in the data packet group priority calculation module needs to be adjusted to achieve better data transmission effects, which has good adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a linear wireless sensor node distribution diagram of the present invention;

[0043] Figure 2 is the intra-group transmission interference model of the present invention;

[0044] Figure 3 This is a timing diagram of intra-group reservations of the present invention;

[0045] Figure 4 is the inter-group transmission interference model of the present invention;

[0046] Figure 5 This is a timing diagram of inter-group contention transmission according to the present invention;

[0047] Figure 6 This is a timing diagram of data conflict retransmission according to the present invention. DETAILED DESCRIPTION

[0048] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0049] Figure 1 The figure shows the linear wireless sensor node distribution diagram of the present invention, assuming a wide linear area with dimensions of 1100 meters wide and 150 meters long (i.e., W x H). Within this area, a network topology consisting of N sensor nodes and one sink node is deployed. These sensor nodes are linearly distributed throughout the area, each responsible for processing its own data and forwarding data from other nodes. The red sensor node on the left is the sink node, whose primary responsibility is to collect and aggregate data from all nodes in the coarse linear sensor network and transmit it to its final destination.

[0050] Figure 2 The figure shows the intra-group transmission interference model of the present invention. The sensor node meets the requirements of one-hop transmission and two-hop interference. The node in the group obtains its own priority through the data packet group priority calculation module, sets the initial contention window according to the priority, and sends the reservation frame in the group after the contention window ends. Figure 3 As shown in the intra-group reservation sequence diagram, when node S detects channel idleness and waits for a DIFS time slot and the initial contention window, it sends a REV frame to request a reservation. When adjacent nodes within the group receive the REV frame and send an ECHO frame back to the source node, the hidden node within the group also receives interference from the ECHO frame. The hidden node enters a silent state and waits for the next cycle to transmit frame data. Node S waits for a SIFS time slot before sending a DATA frame. After receiving the DATA frame, node R1 responds with an ACK frame a SIFS time slot later. Similarly, node R1 transmits data to upstream node R2 in the same manner, and node R2 transmits data to upstream node R3 in the same manner, thus achieving data transmission among nodes within the group.

[0051] Figure 4 The figure shows the inter-group transmission interference model of the present invention. Inter-group communication can be regarded as data communication between edge nodes of two groups, that is, the uplink edge node of Group_1 and the downlink edge node of Group_2. We use the CSMA / CA protocol and RTS / CTS mechanism to realize the contention communication between groups. Figure 5As shown in the inter-group contention transmission timing diagram, when node S in Group_1 listens for idleness on the channel and waits for a DIFS time slot and the initial contention window, it sends a REV frame to request a scheduled transmission, notifying the nodes in the group to prepare for data transmission. After waiting for a period of time, node S in Group_1 sends an RTS (Request to Send) frame to request channel usage. After receiving the RTS frame from node S, node R1 in Group_2 responds with a CTS (Clear to Send) frame. This is followed by inter-group DATA frame transmission and an ACK frame reply indicating successful data reception. To reduce the impact of transmission delay on data loss, each node has a queue to cache local and received data.

[0052] In one aspect, a method for maximizing end-to-end throughput based on a linear network comprises the following steps:

[0053] Step 1: Deploy the sensor nodes in the network linearly, starting from the edge node of the network. Every four adjacent nodes are divided into a small group, completing the intra-group and inter-group division of the sensor nodes; this ensures the hierarchical structure of the network and facilitates subsequent communication and energy management.

[0054] Step 2: Based on the node's transmission and reception energy consumption model, calculate the energy consumption of each node and obtain the node's remaining energy; based on the node's remaining energy, calculate its priority within the group, and nodes with higher energy will receive higher priority; then, the node prepares to send data based on the priority.

[0055] The transmission and reception energy consumption model is as follows:

[0056]

[0057] E Rx (k) = k(E elec +E da )

[0058] E remaining =E init -∑(E Tx (k)+E Rx (k))

[0059]

[0060] The energy consumed by sending a packet of length k bits over a distance of d meters is given by E Tx (k,d) means, is the distance threshold, E elec represents the energy consumed to send or receive 1 bit, ε fs Is with d 2Coefficients of the free-space channel model for power loss, ε mp Is with d 4 The coefficients of the multipath fading channel model for power loss; the energy consumption E for receiving a k-bit message R x(k), Eda is the energy consumption of data aggregation, Einit is the initial energy of the node, E remaining is the remaining energy of the node, priority is the priority level of the node;

[0061] Step 3: Nodes in the group are assigned different backoff window waiting times based on their priority. Nodes with higher priorities have shorter waiting times. After the backoff window ends, if a node has data to transmit, it sends a reservation message. Other nodes in the group enter a silent listening state after receiving the reservation message to avoid conflicts. If a node has no data to transmit, it automatically enters a silent listening state, waiting to receive data transmissions from other nodes.

[0062] The backoff window is expressed as:

[0063] cw init =cw min *priority

[0064] where cw init To initialize the backoff window, cw min is the minimum value of the contention window;

[0065] Step 4: When an edge uplink node in a group has data ready to transmit, it enters inter-group transmission contention. First, the edge uplink node sends an RTS signal to the destination node, requesting to send. If the destination node receives the RTS signal and the channel is idle, it sends back a CTS signal, clearing the send signal and preparing to receive the DATA packet. If the destination node does not receive the RTS signal, or receives it but the channel is busy, it does not send a CTS signal. If the source node does not receive the CTS feedback, it proceeds to step 5.

[0066] Step 5: During the transmission process on the competitive channel, data collisions may occur, resulting in transmission failure. When data loss or collision occurs, the source node will execute the backoff algorithm and enter the backoff window to wait. After the backoff time expires, the source node will retransmit the data and execute the retransmission mechanism to ensure data reliability and transmission success rate.

[0067] The retransmission mechanism uses an optimized binary exponential retransmission algorithm, such as Figure 6 The following is a timing diagram of data conflict retransmission. The specific steps are as follows:

[0068] Step S1: the source node sends data end into the channel listening state, if the reply frame data is received in the listening time slot, it is determined that the destination node receives the data, otherwise the data sent by the source node is determined to be lost;

[0069] Step S2: after judging the loss of data sent by the source node, the source node enters the backoff window to perform the retransmission mechanism and retransmits the data packet. The existing backoff window is optimized, and the specific optimization formula is as follows:

[0070]

[0071] Wherein, cw max is the maximum value of the contention window, cw is the contention window size; N c ol represents the number of retransmissions in the transmission process of the node, and a and b are the multiplication coefficients of cw init , and 1 < a < b;

[0072] Step S3: if the current node receives the ACK packet returned by other nodes, it means that another node has completed the data interaction in this round and will exit the channel competition, and the degree of channel competition is relieved, so the cw is automatically reduced to avoid waste of channel resources, and the specific formula is as follows:

[0073] cw=max(cw / ε,cw init ),ε>1

[0074] Wherein, cw is the contention window size, and e is the reduction coefficient.

[0075] On the other hand, the end-to-end throughput maximization method based on linear network is based on the following system implementation, specifically including: data packet group priority calculation module, transmission time slot and backoff window setting module, data packet group reservation sending module, data packet group competition module and data conflict maintenance mechanism module:

[0076] The data packet group priority calculation module calculates the priority of each node through the remaining energy of the nodes in the group when the remaining energy of the node is greater than 20%; if the remaining energy is less than 20%, it will cause negative effects on the communication quality of data transmission. In this case, the corresponding sensor node will be regarded as unable to continue to perform the task of data receiving and transmission, that is, it is determined to be "dead".

[0077] The transmission time slot and backoff window setting module, since the network data packet is sent in the form of wave, there may be problems such as node packet loss and congestion, therefore, when the network node transmits data, transmission time slots are allocated for different data frames, and the initialization backoff window is dynamically set based on the priority of the node;

[0078] The embodiment designs the transmission time slot of the node:

[0079] SIFS=0.5*Slot Time

[0080] DIFS=SIFS+2*Slot Time

[0081] SIFS ensures that high-priority short frames (such as ACK, CTS, DATA) can be sent in the shortest time possible. DIFS adds extra waiting time before sending general data frames (such as RTS, REV).

[0082] The data packet group reservation sending module initializes the backoff window according to the priority setting of the nodes, and the nodes with high priority make reservations for data transmission within the group first;

[0083] The data packet group reservation sending module adopts a reservation and feedback model; in the reservation and feedback model, the node that wants to send data among the four sensor nodes in the group will first send a REV signal, that is, a reservation signal, to announce its sending intention to other nodes in the group; after receiving the REV signal, the node in the group will immediately send an ECHO signal, that is, a feedback signal, to confirm that it has received the reservation request; at the same time, the feedback signal can solve the hidden node problem in the group and reduce data conflicts.

[0084] When the channel monitoring is idle, the data packet inter-group competition module sends an RTS frame to the upstream source node at the edge of the group to request the right to use the channel. After receiving the RTS frame of the source node, the downstream destination node at the edge of the next group sends a CTS frame as a response, followed by the transmission of DATA frames between the groups and the reply of ACK frames for successful data reception.

[0085] The data conflict maintenance mechanism module is used to determine whether data conflict loss and data reception failure occur, and to ensure transmission reliability by executing the data conflict maintenance mechanism.

[0086] The data conflict maintenance mechanism determines whether the current node has received the reply frame data. If the reply frame data is not received, it means that the data was lost in the transmission process. When the channel is detected to be idle, the sender will enter the backoff window to execute the retransmission mechanism and resend the data packet.

[0087] The above description is merely that of the preferred embodiments of the present disclosure and a description of the technical principles of the present disclosure. It should be understood by those skilled in the art that the inventive scope of the embodiments of the present disclosure is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by the combinations of the above technical features or equivalent features without departing from the above inventive concept. For example, the technical solutions formed by the mutual replacement of the above features and the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) form the technical solutions.

Claims

1. A method for maximizing end-to-end throughput based on a linear network, characterized in that: The following steps are involved: Step 1: Deploy the sensor nodes in the network linearly, starting from the edge node of the network, and divide every four adjacent nodes into a group, completing the intra-group and inter-group division of the sensor nodes; Step 2: Based on the node's transmission and reception energy consumption model, calculate the energy consumption of each node and obtain the node's remaining energy. Based on the node's remaining energy, calculate its priority within the group. Nodes with higher energy will receive higher priority. Step 3: Nodes within the group are assigned different backoff window waiting times based on their priorities. Nodes with higher priorities have shorter waiting times. After the backoff window expires and the intra-group interference model is met, if the node has data to transmit, it sends a reservation message. After receiving the reservation message, other nodes in the group enter the silent listening state to avoid conflicts. If the node has no data to be transmitted, it automatically enters the silent listening state and waits to receive data transmission from other nodes. The backoff window in step 3 is expressed as: ； in To initialize the backoff window, is the minimum value of the contention window, is the priority level of the node; The intra-group interference model is that the sensor nodes meet the requirement of one-hop transmission and two-hop interference. The nodes in the group obtain their own priorities through the data packet intra-group priority calculation module, set the initial contention window according to the priority, and send the intra-group reservation frame after the contention window ends. Step 4: When an edge uplink node in a group has data to transmit, it enters inter-group transmission contention. The inter-group interference model is used to determine whether it is within the data transmission interference range. If it is not within the interference range and the channel is idle, the edge uplink node sends an RTS signal to the destination node, which is a request to send signal. If the destination node receives the RTS signal and the channel is idle, it will feedback the CTS signal, that is, clear the send signal and prepare to receive the DATA data packet; If the destination node does not receive the RTS signal, or receives it but the channel is busy, it will not send the CTS signal; when the source node does not receive the CTS feedback, it will execute step 5; Step 5: During the transmission process of the contention channel, when data loss or collision occurs, the source node will execute the backoff algorithm and enter the backoff window to wait; After the backoff time ends, the source node will retransmit the data and execute the retransmission mechanism to ensure the reliability and transmission success rate of the data.

2. The method for maximizing end-to-end throughput based on a linear network according to claim 1, characterized in that: The transmission and reception energy consumption model in step 2 is as follows: ； ； ； ； Among them The length of the transmission is The energy consumed by the bit grouping is given by express, is the distance threshold, Indicates the energy consumed to send or receive 1 bit, Is a The coefficients of the free space channel model for power loss, Is a Coefficients of the multipath fading channel model for power loss; receiving Energy consumption of bit message , is the energy consumption of data aggregation, is the initial energy of the node, is the residual energy of the node, The priority level of the node.

3. The method for maximizing end-to-end throughput based on a linear network according to claim 1, wherein: The inter-group interference model in step 4 is to regard inter-group communication as data communication between edge nodes of two groups, that is, the uplink edge node of Group_1 and the downlink edge node of Group_2 communicate, and the contention communication between the groups is realized through the CSMA / CA protocol and RTS / CTS mechanism.

4. The method for maximizing end-to-end throughput based on a linear network according to claim 1, characterized in that: The retransmission mechanism described in step 5 uses an optimized binary exponential retransmission algorithm. The specific steps are as follows: Step S1: The source node finishes sending data and enters the channel monitoring state. If a reply frame data is received within the monitoring time slot, it is determined that the destination node has received the data. Otherwise, the data sent by the source node is considered lost. Step S2: After determining that the data sent by the source node is lost, the source node enters the backoff window and executes the retransmission mechanism to resend the data packet; the existing backoff window is optimized, and the specific optimization formula is as follows: ； in is the maximum value of the contention window, is the contention window size; Indicates the number of retransmissions during the node transmission process, and for Multiplication factor, and 1< < ; Step S3: If the current node receives an ACK packet returned by another node, it means that the other node has completed this round of data interaction and will exit the channel competition, and the current node will automatically reduce the current node. To avoid wasting channel resources, the specific formula is as follows: ； in is the contention window size and ε is the reduction factor.

5. The method for maximizing end-to-end throughput based on a linear network as claimed in claim 1 is implemented based on the following system, characterized in that: Specifically include: Priority calculation module within the data packet group, setting module for transmission time slot and backoff window, reservation sending module within the data packet group, competition module between data packet groups and data conflict maintenance mechanism module: The data packet group priority calculation module calculates the priority of each node according to the residual energy of the nodes in the group when the residual energy of the node is greater than 20%; The transmission time slot and backoff window setting module allocates transmission time slots to different data frames and dynamically sets the initial backoff window based on the priority of the node; The data packet group reservation sending module initializes the backoff window according to the priority setting of the nodes, and the nodes with high priority make reservations for data transmission within the group first; The packet group reservation sending module adopts a reservation and feedback model; in the reservation and feedback model, the node that wants to send data among the four sensor nodes in the group will first send a REV signal, i.e., a reservation signal, to announce its sending intention to other nodes in the group; After receiving the REV signal, the nodes in the group will immediately send an ECHO signal, which is a feedback signal, to confirm that the reservation request has been received; When the channel monitoring is idle, the data packet inter-group competition module sends an RTS frame to the upstream source node at the edge of the group to request the right to use the channel. After receiving the RTS frame of the source node, the downstream destination node at the edge of the next group sends a CTS frame as a response, followed by the transmission of DATA frames between the groups and the reply of ACK frames for successful data reception. The data conflict maintenance mechanism module is used to determine whether data conflict loss and data reception failure occur, and to ensure transmission reliability by executing the data conflict maintenance mechanism; The data conflict maintenance mechanism determines whether the current node has received the reply frame data. If the reply frame data is not received, it means that the data was lost in the transmission process. When the channel is detected to be idle, the sender will enter the backoff window to execute the retransmission mechanism and resend the data packet.

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