Underwater acoustic network minimum transmission delay analysis method oriented to multi-link multi-hop transmission task

Abstract

The invention relates to an underwater acoustic network minimum transmission time delay analysis method for a multi-link multi-hop transmission task, which comprises the following steps: step 1, constructing an underwater acoustic communication network, and creating a multi-link multi-hop transmission task in which the number of network nodes is N, the number of links needing to be transmitted is K, and the maximum relay hop number is M; 2, according to the transmission task, constructing a multi-link relay transmission matrix Q, a multi-hop transmission time matrix S and a point-to-point transmission delay matrix Ds, and establishing a transmission task model; and step 3, according to the transmission task, establishing a multi-hop transmission characteristic model and an underwater sound multi-hop network conflict-free transmission model. According to the method, models of underwater acoustic network multi-link multi-hop minimum transmission delay performance and the like can be constructed according to a network real-time transmission scene, minimum delay transmission in a target task scene is realized, and the network transmission efficiency is improved.

Description

Technical field:

[0001] The present invention belongs to the technical field of underwater acoustic networks, and in particular relates to an underwater acoustic network minimum transmission delay analysis method for multi-link multi-hop transmission tasks. Background technology:

[0002] Continuous exploration of the ocean environment requires support from underwater sensor networks. Underwater acoustic communication is currently the primary method for long-distance underwater transmission. Building an underwater acoustic communication network can enable long-distance underwater information transmission. Transmission latency, the time from when data to be sent is generated by a source node to when it is successfully received by the destination node, is a key metric for measuring the transmission performance of underwater acoustic networks.

[0003] In marine environments, point-to-point transmission delay is typically approximated by dividing the operating distance by the speed of sound. The multi-hop transmission delay of a single link can be calculated by summing the transmission delays of each hop. However, for multi-link, multi-hop transmission, multi-link signal interference and conflicts exist within the network, making transmission delay analysis more complex. Currently, research on the minimum transmission delay performance of underwater acoustic networks is largely unresolved. Using the traditional TDMA protocol, each node transmits data sequentially during its own time slot, enabling multi-link, multi-hop transmission in underwater acoustic networks. However, the traditional protocol has a long time slot length—the sum of the packet length, maximum transmission delay, and guard interval—resulting in significant network transmission delays, leaving room for performance optimization and impacting network efficiency. Summary of the invention:

[0004] The technical problem to be solved by the present invention is to provide a method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks. This method can reduce the network transmission delay in multi-link and multi-hop scenarios and improve network transmission efficiency.

[0005] The technical solution of the present invention is to provide a method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link multi-hop transmission tasks, comprising the following steps:

[0006] Step 1: Build an underwater acoustic communication network and create a multi-link multi-hop transmission task, where the number of network nodes is N, the number of links required for transmission is K, and the maximum number of relay hops is M;

[0007] Step 2: Based on the transmission task, construct the multi-link relay transmission matrix Q, the multi-hop transmission time matrix S, and the point-to-point transmission delay matrix Ds to establish the transmission task model;

[0008] Step 3: Based on the transmission task, establish a multi-hop transmission characteristic model and a conflict-free transmission model for underwater acoustic multi-hop networks;

[0009] Step 4: Establish a multi-link and multi-hop minimum transmission delay performance analysis model for underwater acoustic networks;

[0010] Step 5: Solve the minimum transmission delay performance analysis model through optimization theory to obtain a multi-link multi-hop transmission solution, and complete the network multi-link multi-hop minimum delay transmission according to this solution.

[0011] Preferably, in step 2, the transmission task model is used to describe a specific network multi-link relay transmission task, specifically using a multi-link relay transmission matrix Q, a multi-hop transmission time matrix S, and a point-to-point transmission delay matrix Ds. The multi-link relay transmission matrix Q contains three sub-matrices, namely the transmission matrix QS, the reception matrix QR, and the interference matrix QI. The transmission matrix QS and the reception matrix QR are of size K×M, and their internal values ​​correspond to the transmitting or receiving node number. The interference matrix QI is of size N×N, and its internal value is 0 or 1, specifically expressed as

[0012]

[0013] The interference distance indicates that after a network node transmits a signal, it will interfere with the reception of nodes within a specific distance range. This distance corresponds to the interference distance.

[0014] As an example, the multi-hop transmission time matrix S is used to describe the transmission time of multi-link network nodes. The size of S is K×M, S={s ij} K×M , s ij Denotes the transmission time of the j-th relay node in the i-th link, and the point-to-point transmission delay matrix Ds = {ds ij} K×M ,ds ij represents the propagation delay of the j-th hop relay source node on the i-th link.

[0015] As a preference, in step 3, the multi-hop transmission characteristic refers to the same transmission link. The transmission process with the later hops must be performed after the previous transmission process is completed. The multi-hop transmission characteristic model is described by the point-to-point transmission delay matrix Ds and the transmission time matrix S, as follows:

[0016]

[0017] Where L is the packet length, ds ij is the propagation delay of the j-th relay node in the i-th link.

[0018] Preferably, in step 3, the conflict-free transmission model of the underwater acoustic network refers to a model that ensures that there is no signal overlapping interference at the receiving node or the transmitting node. The interference conflicts of the signals sent and received by the nodes in the network include four categories, namely, transmit-transmit conflict, transmit-receive conflict, receive-receive conflict, and interference-receive conflict. These four types of conflicts are described by the multi-link relay transmission matrix Q, the transmission time matrix S, and the point-to-point transmission delay matrix Ds. The description process is as follows:

[0019] Transmit-transmit conflict means that a node cannot send data packets to two or more nodes at the same time. To avoid this type of conflict, the following model can be used

[0020]

[0021] Where b is a random binary parameter, which ranges from 0 to 1. The value corresponding to each constraint is relatively independent. C is a large constant. QS ij =QS mn Indicates that the j-hop relay source node of the i-th link and the n-hop relay source node of the m-th link are the same, which may cause transmission conflict; in formula (3), when b=0, it means that the node QS ij First transmit the data of the jth hop of the i-th link, and then transmit the data of the nth hop of the m-th link after the transmission is completed; when b=1, it means that the node QS ij First transmit the data of the nth hop of the mth link, and then transmit the data of the jth hop of the ith link after the transmission is completed;

[0022] Transmit-receive conflict means that a node cannot send and receive data packets at the same time. To avoid this type of conflict, the following model can be used

[0023]

[0024] Where b is a random binary parameter, QS ij =QR mn Indicates that the j-hop relay source node of the i-th link and the n-hop relay receiving node of the m-th link are the same, which may cause a transmit-receive conflict; in the above formula, when b=0, it means that the node QS ij First transmit the data of the jth hop of the i-th link, and then receive the data of the nth hop of the m-th link after the transmission is completed; when b=1, it means that the node QS ij First receive the n-hop data of the m-th link, and then transmit the j-hop data of the ith link after receiving it;

[0025] Receive-receive conflict means that a node cannot receive data packets from two or more nodes at the same time. To avoid this type of conflict, the following model can be used

[0026]

[0027] Where b is a random binary parameter, QR ij =QR mn Indicates that the j-hop receiving node of the i-th link and the n-hop relay receiving node of the m-th link are the same, which may cause a receiving conflict; in the above formula, when b=0, it means that the node QR ij First receive the data of the jth hop of the i-th link, and then receive the data of the nth hop of the m-th link after receiving it; when b=1, it means that the node QSij First receive the data of the nth hop of the mth link, and then receive the data of the jth hop of the ith link after receiving it;

[0028] Interference-reception conflict means that an active communication signal in the network interferes with the reception of signals from other nodes. To avoid this type of conflict, the following model can be used

[0029]

[0030] Where b is a random binary parameter, is the propagation delay of the signal transmitted from the n-hop source node of the m-th link to the j-hop receiving node of the ith link, QI(QS mn ,QR ij )=1 means that the signal transmitted by the n-hop source node of the m-th link may affect the signal reception of the j-hop receiving node of the ith link. When b=0, it means that the node completes the reception of the j-hop signal of the ith link before the arrival of the n-hop interference signal of the m-th link. When b=1, it means that the reception of the j-hop signal of the ith link is completed before the arrival of the n-hop interference signal of the m-th link.

[0031] As a preference, in step 4, the minimum transmission delay performance analysis model aims to complete the multi-link multi-hop transmission task in the minimum time, with the multi-hop transmission characteristics and the avoidance of four types of interference conflicts as constraints. The model is established as follows:

[0032]

[0033] where b i1 、b i2 、b i3 and b i4 is a random binary parameter, and T is the total time to complete the multi-link multi-hop transmission task.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] The present invention proposes concepts such as multi-link relay matrix and multi-hop transmission time matrix, and establishes models such as multi-hop transmission characteristics, multi-hop network conflict-free transmission and minimum transmission delay performance. It can reduce the delay transmission of underwater acoustic networks in multi-link multi-hop mission scenarios and improve network transmission efficiency. Description of the drawings:

[0036] Figure 1 Flow chart of the implementation of the method proposed in the present invention;

[0037] Figure 2 A simulation network scene diagram of an embodiment;

[0038] Figure 3This is the minimum delay transmission solution when the data packet length is 3s;

[0039] Figure 4 for Figure 2 In the scenario, the total transmission delay of the method of the present invention and the traditional TDMA method at different data packet lengths. Specific implementation method:

[0040] The present invention will be further described below with reference to the accompanying drawings:

[0041] The present invention discloses a method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link multi-hop transmission tasks, comprising the following steps:

[0042] Step 1: Build an underwater acoustic communication network and create a multi-link multi-hop transmission task, where the number of network nodes is N, the number of links required for transmission is K, and the maximum number of relay hops is M;

[0043] Step 2: Based on the transmission task, construct the multi-link relay transmission matrix Q, the multi-hop transmission time matrix S, and the point-to-point transmission delay matrix Ds to establish the transmission task model;

[0044] Step 3: Based on the transmission task, establish a multi-hop transmission characteristic model and a conflict-free transmission model for underwater acoustic multi-hop networks;

[0045] Step 4: Establish a multi-link and multi-hop minimum transmission delay performance analysis model for underwater acoustic networks;

[0046] Step 5: Solve the minimum transmission delay performance analysis model through optimization theory to obtain a multi-link multi-hop transmission solution, and complete the network multi-link multi-hop minimum delay transmission according to this solution.

[0047] For details, see Figure 1 and Figure 2 , Figure 1 This is the implementation process of the method proposed in the present invention. Figure 2 This is a schematic diagram of a simulation scenario. This network is a six-node network, expanded from an equilateral triangle. The triangle has a side length of R = 1.5 km, the transmission distance between network nodes is 2.25 km, and the network interference distance (RI) is 3 km. The network has three pending transmission links, all two-hop: 1→2→4; 1→3→6; and 5→3→4. The data packets transmitted by each node are identical, 3 seconds in length. The speed of sound is 1500 m / s.

[0048] The multi-link multi-hop transmission matrix Q established at this time is as follows

[0049]

[0050] The point-to-point transmission delay matrix Ds is as follows

[0051]

[0052] The performance analysis model of underwater acoustic network multi-link multi-hop minimum transmission delay established at this time is:

[0053]

[0054] The results obtained by solving the above model using the optimization method are as follows Figure 3 As shown in Figure 2, the transmission time to complete all tasks is 19.72s. Figure 3 It can be seen from the figure that the sending and receiving processes of each participating node in the transmission process are very close, and there is no room for optimization, thus achieving the optimal transmission in the current task scenario.

[0055] If the traditional TDMA method is used and the guard interval is 1s, the TDMA time slot length is the packet length (3s). The sum of the maximum transmission delay (1s) and the guard interval (1s) is 5s, and a TDMA transmission cycle is 30s. The time slots are divided according to the node number, that is, node i sends a data packet in the i-th time slot of the current cycle. The specific transmission time for each hop of the three links under the method of the present invention and the traditional TDMA method is shown in Table 1. It can be seen that the traditional TDMA method requires 3 cycles to complete the network transmission task, and the total transmission time is 80s, which is much longer than the 19.72s corresponding to the method proposed in the present invention. This verifies the effectiveness of the proposed method.

[0056] Table 1: Comparison of the transmission scheme of this method and the traditional TDMA method when the data packet length is 3s

[0057]

[0058] Figure 4 In order to change the data packet length, the total transmission delay results of the method of the present invention and the traditional TDMA method are compared in the current transmission scenario. It can be seen that for the task data packet length, the transmission delay of the method of the present invention is better than that of the traditional TDMA method.

[0059] It can be seen that the present invention can construct models such as the multi-link and multi-hop minimum transmission delay performance of underwater acoustic networks according to the real-time network transmission scenario, achieve minimum delay transmission in the target mission scenario, and improve network transmission efficiency.

[0060] The above description is only for the preferred embodiment of the present invention, which should not be understood as limiting the claims. Any equivalent process changes made using the present invention description are included in the patent protection scope of the present invention.

Claims

1. A method for analyzing the minimum transmission delay of underwater acoustic networks for multi-link and multi-hop transmission tasks, characterized by: The following steps are included: Step 1: Build an underwater acoustic communication network and create a multi-link multi-hop transmission task, where the number of network nodes is N, the number of links required for transmission is K, and the maximum number of relay hops is M; Step 2: Based on the transmission task, construct the multi-link relay transmission matrix Q, the multi-hop transmission time matrix S, and the point-to-point transmission delay matrix Ds to establish the transmission task model; Step 3: Based on the transmission task, establish a multi-hop transmission characteristic model and a conflict-free transmission model for underwater acoustic multi-hop networks; Step 4: Establish a multi-link and multi-hop minimum transmission delay performance analysis model for underwater acoustic networks; Step 5: Solve the minimum transmission delay performance analysis model through optimization theory to obtain a multi-link multi-hop transmission solution, and complete the network multi-link multi-hop minimum delay transmission according to this solution.

2. The method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks according to claim 1 is characterized by: In step 2, the transmission task model is used to describe the specific network multi-link relay transmission task. The multi-link relay transmission matrix Q contains three sub-matrices, namely the transmission matrix QS, the receiving matrix QR and the interference matrix QI. The size of the transmission matrix QS and the receiving matrix QR is K×M, and their internal values ​​correspond to the transmitting or receiving node number. The size of the interference matrix QI is N×N, and its internal value is 0 or 1, which is specifically expressed as The interference distance indicates that after a network node transmits a signal, it will interfere with the reception of nodes within a specific distance range. This distance corresponds to the interference distance.

3. The method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks according to claim 2 is characterized by: The multi-hop transmission time matrix S is used to describe the transmission time of multi-link network nodes. The size of S is K×M, S={s ij } K×M , s ij Denotes the transmission time of the j-th relay node in the i-th link, and the point-to-point transmission delay matrix Ds = {ds ij } K×M ,ds ij represents the propagation delay of the j-th hop relay source node on the i-th link.

4. The method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks according to claim 1 is characterized by: In step 3, the multi-hop transmission characteristic refers to the same transmission link. The transmission process with the later hops must be performed after the previous transmission process is completed. The multi-hop transmission characteristic model is described by the point-to-point transmission delay matrix Ds and the transmission time matrix S, as follows: Where L is the packet length, ds ij is the propagation delay of the j-th relay node in the i-th link.

5. The method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks according to claim 1 is characterized by: In step 3, the conflict-free transmission model of the underwater acoustic network is a model that ensures that there is no signal overlap interference at the receiving node or the transmitting node. The interference conflicts between the sending and receiving signals of nodes in the network include four types: transmit-transmit conflicts, transmit-receive conflicts, receive-receive conflicts, and interference-receive conflicts. These four types of conflicts are described by the multi-link relay transmission matrix Q, the transmission time matrix S, and the point-to-point transmission delay matrix Ds. The description process is as follows: Transmit-transmit conflict means that a node cannot send data packets to two or more nodes at the same time, which can be modeled as follows Where b is a random binary parameter, which ranges from 0 to 1. The value corresponding to each constraint is relatively independent. C is a large constant. QS ij =QS mn Indicates that the j-hop relay source node of the i-th link and the n-hop relay source node of the m-th link are the same, which may cause transmission conflict; in formula (3), when b=0, it means that the node QS ij First transmit the data of the jth hop of the i-th link, and then transmit the data of the nth hop of the m-th link after the transmission is completed; when b=1, it means that the node QS ij First transmit the data of the nth hop of the mth link, and then transmit the data of the jth hop of the ith link after the transmission is completed; Transmit-receive conflict means that a node cannot send and receive data packets at the same time, which can be modeled as follows Where b is a random binary parameter, QS ij =QR mn It means that the relay source node of the jth hop of the i-th link and the relay receiving node of the nth hop of the m-th link are the same, which may cause a transmit-receive conflict; In the above formula, when b=0, it means that the node QS ij First transmit the data of the jth hop of the i-th link, and then receive the data of the nth hop of the m-th link after the transmission is completed; when b=1, it means that the node QS ij First receive the n-hop data of the m-th link, and then transmit the j-hop data of the ith link after receiving it; Receive-receive conflict means that a node cannot receive data packets from two or more nodes at the same time, which can be modeled as follows Where b is a random binary parameter, QR ij =QR mn Indicates that the j-hop receiving node of the i-th link and the n-hop relay receiving node of the m-th link are the same, which may cause a receiving conflict; In the above formula, when b=0, it means node QR ij First receive the data of the jth hop of the i-th link, and then receive the data of the nth hop of the m-th link after receiving it; when b=1, it means that the node QS ij First receive the data of the nth hop of the mth link, and then receive the data of the jth hop of the ith link after receiving it; Interference-reception conflict means that an active communication signal in the network interferes with the reception of signals from other nodes. It can be modeled as follows Where b is a random binary parameter, is the propagation delay of the signal transmitted from the n-hop source node of the m-th link to the j-hop receiving node of the ith link, QI(QS mn ,QR ij )=1 means that the signal transmitted by the n-hop source node of the m-th link may affect the signal reception of the j-hop receiving node of the ith link. When b=0, it means that the node completes the reception of the j-hop signal of the ith link before the arrival of the n-hop interference signal of the m-th link. When b=1, it means that the reception of the j-hop signal of the ith link is completed before the arrival of the n-hop interference signal of the m-th link.

6. The method for analyzing the minimum transmission delay of an underwater acoustic network for multi-link and multi-hop transmission tasks according to claim 1 is characterized by: In step 4, the minimum transmission delay performance analysis model aims to complete the multi-link multi-hop transmission task in the minimum time, with the multi-hop transmission characteristics and the avoidance of four types of interference conflicts as constraints. The model is established as follows: where b i1 、b i2 、b i3 and b i4 is a random binary parameter, and T is the total time to complete the multi-link multi-hop transmission task.

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