A pipeline transmission method for two adjacent jumps of underwater acoustic links driven by routing

Abstract

The present invention discloses a pipeline transmission method for two adjacent hop underwater acoustic links driven by routing, comprising the following steps: S1: Node A1 initiates an RTS channel access request to Node B; S2: After receiving the RTS channel access request, Node B responds with a CTS message to all downstream neighboring nodes and an upstream neighboring node C; S3: After receiving the CTS message from Node B, each Node A sends data to Node B according to the command; S4: After receiving the data, Node B generates a new data packet and sends it to the upstream neighboring node C and all downstream neighboring nodes A; S5: Node C opportunistically receives the data packet from Node B, while neighboring node A also receives the data packet, performs ACK / NAK determination, and completes channel error control. The present invention reduces the number of channel reservations in the network, reduces the end-to-end delay and energy consumption of the underwater acoustic sensor network, and can improve the overall performance of the underwater acoustic sensor network.

Description

Technical Field

[0001] The present invention belongs to the field of underwater acoustic sensor network data transmission, and in particular relates to a pipeline transmission method of two adjacent jump underwater acoustic links driven by routing. Background Art

[0002] The media access control (MAC) protocols of underwater acoustic sensor networks can be roughly divided into the following four types:

[0003] 1) Contention-free MAC protocols. These include underwater acoustic network protocols designed based on time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA). While these protocols offer collision-free data transmission, they are challenging to implement underwater. For example, TDMA requires strict underwater clock synchronization, while CDMA also presents a challenge in ensuring codeword orthogonality under large clock offsets. Overall, contention-free MAC protocols for underwater acoustic networks are more suitable for static networks.

[0004] 2) Random Contention-Based MAC Protocols. To overcome the long propagation delay of underwater acoustic channels, random contention-based underwater acoustic MAC protocols typically initiate multiple concurrent transmissions to improve channel utilization. To prevent collisions, guard time is often required, sacrificing bandwidth utilization. This makes them suitable for smaller networks.

[0005] 3) Cross-layer-based MAC protocol: Currently, the cross-layer-based MAC protocol for underwater acoustic networks is more suitable for small-scale, static networks.

[0006] 4) Reservation-based MAC protocol. The reservation-based competition-based underwater acoustic MAC protocol is suitable for dynamic underwater acoustic environments and has good scalability. Data reception scheduled by the receiver effectively solves the hidden terminal problem, because only the receiver knows when the data will arrive to avoid conflicts. However, traditional MAC protocols require an independent RTS / CTS channel reservation process for data transmission on each link. Data transmission can only proceed after the channel reservation is successful. This significantly restricts the network's throughput, latency, and energy performance, which is the main drawback of traditional reservation-based MAC protocols. Summary of the Invention

[0007] To address the deficiencies in the prior art, the present invention provides a routing-driven pipeline transmission method for two adjacent underwater acoustic links. After a link makes a channel reservation, pipeline transmission between two adjacent links can be opportunistically performed. This not only saves the number of channel reservations in the network, but also reduces the end-to-end latency and energy consumption of the underwater acoustic sensor network.

[0008] The technical solutions mainly adopted in the present invention are:

[0009] A routing-driven pipeline transmission method for two adjacent water-jumping acoustic links is proposed. Assuming that there are several nodes A, denoted as Ai, where i is the number of each node A, and each node Ai has node B as its upstream neighbor, and node C is the upstream neighbor of node B, the specific transmission steps are as follows:

[0010] Step S1: When node A1 among several nodes A needs to upload data, node A1 initiates an RTS channel access request to node B;

[0011] Step S2: After receiving the RTS channel access request from node A1, node B sends a CTS message to all downlink neighboring nodes and uplink neighboring node C. The CTS message specifies the amount of data to be sent by each node Ai and the time of sending.

[0012] Step S3: After receiving the CTS message from node B, each node Ai sends a specified amount of data to node B at the specified time according to the command;

[0013] Step S4: After receiving the data from all downstream neighbor nodes A, node B regenerates a new data packet and then sends the newly generated data packet to the upstream neighbor node C and all downstream neighbor nodes A respectively;

[0014] Step S5: Node C opportunistically receives data packets from node B, and all downlink neighboring nodes A of node B also receive data packets from node B at the same time. They perform ACK / NAK determination on the data transmitted by each node A to node B based on the received data packets, thus completing channel error control.

[0015] Preferably, the specific implementation method of step S1 is as follows: when the data volume of node A1 among several nodes A reaches a preset threshold value and the channel is detected to be in an idle state, an RTS channel access request is sent to the upstream neighboring node B, and the RTS channel access request includes the identification ID of the source node A1, the identification ID of the destination node B, and the amount of data that node A1 expects to transmit.

[0016] Preferably, the specific steps of step S2 are as follows:

[0017] S2-1: Node B checks and determines its downlink neighboring node;

[0018] S2-2: Node B allocates the amount of transmission data dAi to all downlink neighboring nodes in the CTS message, where the transmission data dAi represents the data transmitted by the i-th node A, and i represents the number of each node A;

[0019] S2-3: Based on the propagation delay between node B and each node Ai and the transmission time of the transmitted data dAi, the specific time when each node Ai transmits data is specified in the CTS message to ensure that there is no collision when the stage data of each node Ai reaches node B. Among them, the propagation delay from node B to each node Ai is obtained through message interaction between adjacent nodes.

[0020] Preferably, the specific steps of step S3 are as follows:

[0021] S3-1: Node A1 sends the agreed transmission data dA1 according to the time agreed in the CTS message;

[0022] S3-2: After receiving the CTS message from node B, other nodes Ai continue to back off if a neighboring node is accessing the channel and needs to back off. Otherwise, they send the agreed amount of data according to the time agreed in the CTS message.

[0023] Beneficial Effects: This invention provides a routing-driven pipeline transmission method for two adjacent hops of underwater acoustic links. This method reduces the number of channel reservations in the network, lowers the end-to-end latency and energy consumption of the underwater acoustic sensor network, and improves the overall performance of the underwater acoustic sensor network. Furthermore, it can opportunistically transmit received data directly to the upstream node C, eliminating the need for channel reservations between nodes B and C. This significantly improves network throughput and latency, effectively increasing the network's energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of the pipeline transmission method of the present invention. DETAILED DESCRIPTION

[0025] In order to help those skilled in the art better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0026] Example 1

[0027] A routing-driven pipeline transmission method for two adjacent water-jumping acoustic links is proposed. Assuming that nodes A1, A2, and A3 all have node B as their upstream neighbor, and node C is the upstream neighbor of node B, the specific transmission steps are as follows:

[0028] Step S1: When node A1 needs to upload data, it first initiates an RTS channel access request to node B. Driven and constrained by routing, nodes A1, A2, and A3 all use node B as their uplink neighbor. The specific implementation method is as follows: When the data volume of node A1 reaches a preset threshold and the channel is detected to be idle, an RTS channel access request is sent to the uplink neighbor node B. The RTS channel access request contains the identification ID of the source node A1, the identification ID of the destination node B, and the amount of data that node A1 expects to transmit.

[0029] Step S2: After receiving the RTS channel access request from node A1, node B responds with a CTS message to its downstream neighbor nodes A1, A2, and A3 and its upstream neighbor node C. The CTS message specifies the amount of data to be sent by nodes A1, A2, and A3 and the time of sending the data. The details are as follows:

[0030] S2-1: Node B checks and determines that its downlink neighbor nodes include nodes A1, A2, and A3;

[0031] S2-2: Node B allocates the transmission data amounts dA1, dA2, and dA3 to downlink neighboring nodes A1, A2, and A3 in the CTS message, respectively. The transmission data amount dA1 of node A1 is primarily determined because it is deterministic. The transmission data amounts dA2 and dA3 allocated to nodes A2 and A3 are allocated by node B based on the network's service load and in combination with network fairness. In this implementation 1, dA1, dA2, and dA3 are represented as frames of data at the link layer. Each frame contains fields such as a frame header, the MAC address of the sending node, the MAC address of the receiving node, information bits, a check bit, and a frame trailer. The information bits are the actual data to be transmitted, and the other fields are necessary overhead.

[0032] S2-3: Based on the propagation delay between node B and nodes A1, A2 and A3 respectively and the transmission time of the transmission data volume dA1, dA2 and dA3, the specific time when nodes A1, A2 and A3 transmit data is specified in CTS to ensure that there is no collision when the stage data of nodes A1, A2 and A3 arrives at node B. Among them, the propagation delay from node B to nodes A1, A2 and A3 respectively can be obtained through message interaction between adjacent nodes.

[0033] Step S3: After receiving the CTS message from node B, nodes A1, A2, and A3 send a specified amount of data to node B at a specified time according to the command. The details are as follows:

[0034] S3-1: Node A1 sends the agreed data dA1 according to the time agreed in CTS;

[0035] S3-2: After nodes A2 and A3 receive the CTS from node B, if a neighboring node is accessing the channel and needs to back off, they continue to back off. Otherwise, they send the agreed amount of data according to the time agreed in the CTS.

[0036] Step S4: After receiving data from all downstream neighboring nodes, Node B regenerates a new data packet containing the data just received from all downstream neighboring nodes. It then sends the generated data packet to Node B's upstream neighbor, Node C. Because Node C had previously received a CTS message from Node B, it should be in a listening or backoff state. In this first embodiment, Node A1 originally initiated a handshake request to transmit data to Node B. However, Node B learned that its downstream nodes, A2 and A3, also wanted to transmit data. Therefore, it also allocated channels for A2 and A3 to transmit data, effectively using a piggyback technique.

[0037] Step S5: Node C opportunistically receives the data packet from Node B, and Node B's downlink neighbor node performs ACK / NAK determination on the data just sent based on the received data packet, completing channel error control. The specific steps are as follows:

[0038] S5-1: Node C opportunistically receives data packets forwarded by its downstream neighbor node B, unless the data packets are collided with messages arriving from other neighboring nodes of node C when they arrive at node C.

[0039] S5-2: Node B's downstream neighbors A1, A2, and A3 also receive this newly generated data packet as an ACK / NAK response to the data just transmitted to Node B by these downstream neighbors A1, A2, and A3, thus achieving channel error control. In this first embodiment, the ACK / NAK response from the receiver to the transmitter is not a simple ACK / NAK, but rather a new data packet generated by receiver B. This completes the traditional RTS / CTS / DATA / ACK four-stage handshake process. Furthermore, the new data packet generated by receiver B, acting as an ACK, can be opportunistically received by upstream node C, eliminating the need for a separate channel reservation (i.e., the RTS / CTS process) between nodes B and C and significantly improving the transmission performance of the communication system.

[0040] In this implementation 1, when node A1 successfully reserves the channel with node B (via RTS / CTS), not only can nodes A1, A2, and A3 transmit data to node B, but they can also opportunistically transmit the received data directly to the upstream node C, which is equivalent to saving the channel reservation required between node B and node C, greatly improving the network's throughput performance and latency performance, and effectively improving the network's energy efficiency.

[0041] In the present invention, if data from node B is blocked by messages from other neighboring nodes when it reaches node C, this indicates that node C was unable to successfully receive node B's data. However, the data sent by node B to node C can serve as an ACK confirmation response to the data sent by nodes A1, A2, and A3, and the protocol algorithm remains valid. In many cases, when node B's data reaches node C, it is not blocked by messages from neighboring nodes. This is equivalent to a handshake between A1 and B, completing the data transmission between two adjacent links. Therefore, it is opportunistic and represents a qualitative change from the traditional handshake protocol, because in the traditional handshake protocol, data transmission between two links requires two successful handshakes to complete.

[0042] In the present invention, RTS / CTS stands for Request To Send / Clear To Send, which is a channel handshake mechanism used in wireless local area networks to solve the problem of hidden terminals and exposed terminals, and belongs to the prior art.

[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A pipeline transmission method for two adjacent diving acoustic links driven by routing, characterized in that: Assume that there are several nodes A, denoted as Ai, where i is the number of each node A, and each node Ai has node B as its upstream neighbor, and node C is the upstream neighbor of node B. The specific transmission steps are as follows: Step S1: When node A1 among several nodes A needs to upload data, node A1 initiates an RTS channel access request to node B; Step S2: After receiving the RTS channel access request from node A1, node B sends a CTS message to all downlink neighboring nodes and uplink neighboring node C. The CTS message specifies the amount of data to be sent by each node Ai and the time of sending. Step S3: After receiving the CTS message from node B, each node Ai sends a specified amount of data to node B at the specified time according to the command; Step S4: After receiving the data from all downstream neighbor nodes A, node B regenerates a new data packet and then sends the newly generated data packet to the upstream neighbor node C and all downstream neighbor nodes A respectively; Step S5: Node C opportunistically receives data packets from node B. At the same time, all of node B's downlink neighboring nodes A also receive data packets from node B. Based on the received data packets, node C performs ACK / NAK determination on the data transmitted from each node A to node B, completing channel error control. The specific steps are as follows: S5-1: Node C opportunistically receives data packets forwarded by its downstream neighbor node B, unless the data packets are collided with messages arriving from other neighboring nodes of node C when they arrive at node C. S5-2: Node B's downlink neighboring nodes A1, A2 and A3 also receive the newly generated data packet as an ACK / NAK response to the data just transmitted by each downlink neighboring node A1, A2 and A3 to node B, thereby achieving channel error control.

2. The pipeline transmission method of two adjacent diving acoustic links driven by routing according to claim 1 is characterized in that: The specific implementation method of step S1 is as follows: when the data volume of node A1 among several nodes A reaches a preset threshold value and the channel is detected to be idle, an RTS channel access request is sent to the upstream neighboring node B. The RTS channel access request includes the identification ID of the source node A1, the identification ID of the destination node B, and the amount of data that node A1 expects to transmit.

3. The pipeline transmission method of two adjacent diving acoustic links driven by routing according to claim 1 is characterized in that: The specific steps of step S2 are as follows: S2-1: Node B checks and determines its downlink neighboring node; S2-2: Node B allocates the amount of transmission data dAi to all downlink neighboring nodes in the CTS message, where the transmission data dAi represents the data transmitted by the i-th node A, and i represents the number of each node A; S2-3: Based on the propagation delay between node B and each node Ai and the transmission time of the transmitted data dAi, the specific time when each node Ai transmits data is specified in the CTS message to ensure that there is no collision when the stage data of each node Ai reaches node B. Among them, the propagation delay from node B to each node Ai is obtained through message interaction between adjacent nodes.

4. The pipeline transmission method of two adjacent diving acoustic links driven by routing according to claim 1 is characterized in that: The specific steps of step S3 are as follows: S3-1: Node A1 sends the agreed transmission data dA1 according to the time agreed in the CTS message; S3-2: After receiving the CTS message from node B, other nodes Ai continue to back off if a neighboring node is accessing the channel and needs to back off. Otherwise, they send the agreed amount of data according to the time agreed in the CTS message.

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