Energy-Efficient Topology Control Method for Heterogeneous Wireless Sensor Networks Based on Blockchain

Abstract

The present invention discloses an energy-efficient topology control method for heterogeneous wireless sensor networks based on blockchain. First, this method uses an improved DPC-MND clustering method to complete clustering. At the same time, sensor nodes are divided into three categories, namely ordinary nodes, cluster head nodes, and pseudo-base station nodes, and the three types of nodes perform their respective functions. Then, a routing path is constructed through blockchain shared routing or the Dijkstra method. Finally, the sensed data is transmitted to the base station based on the form of multi-hop forwarding. The present invention aims at large-scale heterogeneous wireless sensor networks, minimizing the overall network energy consumption as much as possible, improving the energy utilization efficiency, prolonging the survival time of each sensor node, thereby extending the network survival duration, and having better comprehensive performance in terms of energy consumption and stability and other aspects.

Description

Technical Field

[0001] The present invention belongs to the field of computer software development, and particularly relates to an efficient topology control method for heterogeneous wireless sensor networks. Background Art

[0002] As an important communication technology in the Internet of Things, Wireless Sensor Networks (WSN) are widely used in many scenarios such as intrusion detection, meteorological monitoring, security, and tactical reconnaissance. WSN consists of a large number of stationary or mobile sensors that form a network in an ad-hoc and multi-hop manner, and perceive, collect, process, and transmit information about the perceived objects in the network coverage area in a collaborative manner, and finally send this information to the owner of the network. Generally speaking, sensor nodes are essentially energy-constrained, so reasonably and efficiently utilizing node energy through a suitable routing protocol will significantly improve the network performance of WSN.

[0003] Currently, most methods in this field focus on optimizing the energy consumption, security, QoS, etc. of routing methods, and thus derive technologies such as low-energy routing, data aggregation, energy harvesting, and secure routing. However, with the rapid development of microelectronics technology, the functions of wireless sensor devices are becoming more powerful, the degree of integration is significantly improved, the scale of WSN is also becoming larger, and the structure is more complex. Due to factors such as uneven distribution of sensor nodes and continuous expansion of the network scale, most methods have certain gaps and deficiencies in application.

[0004] In summary, how to meet the needs of heterogeneous large-scale WSN, minimize network energy consumption as much as possible, efficiently utilize the remaining energy, and thus extend the network lifetime has become an urgent problem in this field. Summary of the Invention

[0005] To solve the technical problems mentioned in the above background art, the present invention proposes an energy-efficient topology control method for heterogeneous wireless sensor networks based on blockchain.

[0006] The technical solution of the present invention is as follows: For large-scale heterogeneous wireless sensor networks, an improved DPC-MND clustering method is used to complete clustering. At the same time, sensor nodes are divided into three categories, namely ordinary nodes, cluster head nodes, and pseudo base station nodes. The three types of nodes each perform their own functions. Then, a routing path is constructed through blockchain sharing routing or the Dijkstra method, and the sensed data is transmitted to the base station based on the form of multi-hop forwarding.

[0007] The improvement of the DPC-MND clustering method includes the following steps:

[0008] (1) For each sensor node node i calculate its local density ρi :

[0009]

[0010] Among them, knn(i) represents the set of k nearest neighbors of node i , and d ij is the Euclidean distance from node i to node j ;

[0011] (2) Calculate the relative distance δ i from node i to other nodes according to the local density ρ i . The relative distance of node i is defined as the distance to the node with the largest local density among its nearest neighbors:

[0012]

[0013] If the local density of node i is the largest, that is, there is no node with a local density greater than node i , then the relative distance of node i is set to the maximum value of the Euclidean distance between it and other nodes:

[0014]

[0015] (3) Calculate the decision value γ i , as an index to judge whether a node can be used as a density peak. In the present invention, the decision value is determined by the local density ρ i , the relative distance δ i and the distance d tos between the node and the base station:

[0016]

[0017] (4) Select the pseudo base station. First, the network area is evenly divided into multiple small areas, and in each area, the node with the largest pseudo base station decision value pγ i becomes the pseudo base station in that area. The definition of the pseudo base station decision value pγ i is as follows:

[0018]

[0019] Among them, e i is the remaining energy of node i , and d toc is the distance from node i to the center of the area.

[0020] (5) Arrange the decision values γ of all nodes in descending order, and select the largest M peak nodes as the final density peak set C. n Calculate the proximity A of the remaining nodes to all nodes in C. n as follows: i,j :

[0021] A i,j = deg i→j · deg j→i

[0022]

[0023] (6) For each node, select the peak node with the largest proximity and add it to form a cluster.

[0024] The present invention constructs a routing path by combining blockchain shared routing and the Dijkstra method, and transmits sensed data to the base station based on multi-hop forwarding, thereby achieving load balancing within the WSN. The specific steps are as follows:

[0025] (1) Divide the nodes in the WSN into three categories through the above clustering method, namely ordinary nodes (normal node), cluster head nodes (cluster head, CH), and pseudo base station nodes (pseudo base station, PBS). Ordinary nodes transmit sensed data to the cluster head nodes to which they belong. The cluster head nodes fuse the sensed data collected and form data packets of a fixed size and transmit them to the pseudo base station nodes. The pseudo base station nodes are responsible for transmitting the data packets to the base station through the routing path.

[0026] (2) There are two ways to establish a routing path: namely, select the shared routing in the blockchain and establish a routing using the Dijkstra method.

[0027] a) Blockchain shared routing: After calculating the shortest path path from the pseudo base station PBS i to the base station each time, record path i in the blockchain. When establishing a routing next time, check whether there is already a path from PBS i to the base station in the blockchain. If it exists, directly select this path. i to the base station. If it exists, directly select this path.

[0028] b) Establish a routing using the Dijkstra method: Use the Dijkstra method to calculate the shortest path. The weight influencing factors include the remaining energy of the next-hop candidate node, the distance from the current node, the direction to the next-hop candidate node, and the number of times the next-hop candidate node participates in the routing. The weight calculation formula is set as follows:

[0029]

[0030] A high-efficiency topology control method for heterogeneous wireless sensor networks based on blockchain. The specific process is as follows:

[0031] (1) The improved DPC-MND clustering method is used to cluster the sensor nodes within a fixed network period, and the pseudo base station nodes (PBS) are selected.

[0032] (2) In each network cycle, a cluster head node (CH) is selected in each cluster according to the cluster head election factor. The cluster head election factor formula is as follows:

[0033]

[0034] Among them, E res is the average value of the residual energy in the network, e is the residual energy of the node; D res is the average distance from the remaining nodes in the network to the base station, d is the distance from the node to the base station; c is the number of times the node is elected as the cluster head, r is the number of current network cycles; u, v, γ are weight parameters (u+v+γ=1).

[0035] (3) Nodes in the network include ordinary nodes, CHs, and PBSs. Ordinary nodes are responsible for sensing data in each network cycle and transmitting the sensed data to their CHs. CHs fuse the collected sensing data into fixed-size data packets and transmit them to PBSs.

[0036] (4) After receiving the data packet, PBS first checks whether there is a path to the base station in the blockchain. If so, it directly selects the path as the routing path; otherwise, it calculates the shortest path as the routing path through the Dijkstra method and records the routing path in the blockchain.

[0037] (5) PBS transmits the data packet to the base station hop by hop according to the routing path.

[0038] The beneficial effects brought about by adopting the above technical solution are:

[0039] (1) The present invention improves the DPC-MND clustering method to make it suitable for WSN environments. The clustering method achieves an efficient clustering process while avoiding the recursion in the original clustering method, greatly improving the efficiency of node energy utilization in WSNs.

[0040] (2) This invention introduces blockchain shared routing to optimize the data transmission process. Through blockchain shared routing, routes can be quickly established when necessary. Furthermore, the number of times a node participates in important tasks within the WSN is counted to balance the energy consumption of each node. Furthermore, due to the immutability of blockchain data, it is also possible to track and detect abnormal WSN nodes, thereby improving the security of the WSN.

[0041] (3) The energy - efficient topology control method for heterogeneous wireless sensor networks based on blockchain designed by the present invention, aiming at large - scale heterogeneous wireless sensor networks, reduces the overall network energy consumption through the mutual influence of multiple factors at each stage of the WSN routing protocol, improves the energy utilization efficiency, extends the survival time of each sensor node and the network lifetime, and has better comprehensive performance in terms of energy consumption and stability than traditional routing protocols. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is the flowchart of the method of the present invention;

[0043] Figure 2 is the flowchart of the improved DPC - MND clustering method in the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0044] The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] The basic idea of the present invention is that, aiming at large - scale heterogeneous wireless sensor networks, the improved DPC - MND clustering method is used to complete clustering. At the same time, the sensor nodes are divided into three categories, namely ordinary nodes, cluster - head nodes and pseudo - base - station nodes. The three types of nodes perform their respective functions. Then, a routing path is constructed through blockchain - shared routing or the Dijkstra method, and the sensed data is transmitted to the base station based on the form of multi - hop forwarding.

[0046] As Figure 1 shown, the energy - efficient topology control method for heterogeneous wireless sensor networks based on blockchain proposed by the present invention is as follows:

[0047] (1) Determine whether re - clustering is required in the current period according to the fixed network period set by the user. If re - clustering is required, use the improved DPC - MND clustering method to cluster the sensor nodes and select the PBS; otherwise, go to step (2).

[0048] (2) Select the CH according to the cluster - head election factor λ in each cluster, and divide the nodes in the network into ordinary nodes, CHs and PBSs.

[0049] (3) Ordinary nodes transmit the sensed data to the CH, and the CH fuses the collected sensed data and forms a data packet of a fixed size and transmits it to the PBS.

[0050] (4) The PBS checks whether there is already a routing path to the base station in the blockchain. If so, directly go to step (6); otherwise, go to step (5).

[0051] (5) Calculate the shortest path as the routing path through the Dijkstra method and record this routing path in the blockchain.

[0052] (6) The PBS transmits the data packets hop by hop according to the routing path to the base station.

[0053] (7) Repeat a new round of network cycle until the user terminates the WSN.

[0054] 2. Improvement of the DPC-MND clustering method, such as Figure 2 As shown, the clustering process of the above step (1) is as follows:

[0055] (101) Select the set of neighboring points knn(i) for each sensor node node according to the Euclidean distance. i

[0056] (102) Calculate the local density ρ for each sensor node node. i i .

[0057] (103) Calculate the relative distance δ of each node node to other nodes. i i . If the local density of node i is the largest, its relative distance is set to the maximum value of the Euclidean distance to other nodes; otherwise, the relative distance of node i is the distance to the nearest node with a relatively large local density.

[0058] (104) Calculate the density peak decision value γ of each node node. i i

[0059] (105) Select the pseudo base station PBS, divide the network area evenly into multiple small areas, and select the node with the largest PBS decision value pγ in each area as the pseudo base station of that area. i

[0060] (106) Arrange the decision values γ of all nodes in descending order, and select the largest M peak nodes as the final density peak set C. n . Calculate the mutual proximity A of the remaining nodes to all nodes in C. n i,j

[0061] (107) For each node, select the peak node with the largest mutual proximity and add it to form a cluster.

[0062] 3. In this embodiment, the following preferred scheme can be adopted to implement the routing path establishment process, that is, step (4) in the above steps:

[0063] (401) The PBS first checks whether there is a path to the base station in the blockchain. If so, directly select this path as the routing path.​​​​​​

[0064] (402) If there is no routing path from the PBS to the base station in the blockchain, the shortest path is calculated by the Dijkstra method as the routing path. The weight influencing factors during the calculation include the remaining energy of the next-hop candidate node, the distance from the current node, the direction to the next-hop candidate node, and the number of times the next-hop candidate node participates in routing.

[0065] (403) Then, the calculated shortest path path i from the pseudo base station PBS i to the base station is recorded in the blockchain.

[0066] The embodiments are only used to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the present invention.

Claims

1. An energy-efficient topology control method for heterogeneous wireless sensor networks based on blockchain, characterized in that , The specific process is as follows: (101) Select the set of neighboring points knn(i) for each sensor node node according to the Euclidean distance i ; (102) For each sensor node node i calculate its local density ρ i ; Among them, knn(i) represents the set of k nearest neighbor points of node i , and d ij is the Euclidean distance from node i to node j . (103) Calculate the relative distance δ from node i to other nodes according to the local density ρ i . The relative distance of node i is defined as the distance to the node with a larger local density that is closest to it: i ​ If node i has the maximum local density, that is, there is no node with a local density greater than node i , then set the relative distance of node i to the maximum Euclidean distance between other nodes: (104) Calculate the density peak decision value γ of each node i ; The decision value is determined by the local density ρ i , the relative distance δ i , and the distance d between the node and the base station i : tos Decide: (105) Select the pseudo base station PBS, evenly divide the network area into multiple small areas, and select the PBS decision value pγ in each area i The node with the largest value becomes the pseudo base station in that area and is separated from the corresponding cluster; The decision value pγ of the fake base station i is defined as follows: Among them, e i is the remaining energy of node i , and d toc is the distance from node i to the regional center; (106) Arrange the decision values γ of all nodes in descending order, and select the largest M peak nodes as the final density peak set C n ; Calculate the mutual proximity A of the remaining nodes to all nodes in C n ; For each node, select the peak node with the largest mutual proximity and add it to the cluster i,j ​ A i,j = deg i→j ·deg j→i (107) Select the cluster head node. In each network cycle, in each cluster, select the cluster head node CH according to the cluster head election factor. The node with the largest cluster head election factor in each cluster is elected as the cluster head, and the remaining nodes in the cluster are ordinary nodes. The cluster head election factor formula is as follows: Among them, E res is the average value of the remaining energy in the network, and e is the remaining energy of the node; D res is the average value of the distances from the remaining nodes in the network to the base station, and d is the distance from the node to the base station; c is the number of times this node is elected as the cluster head, and r is the current network cycle number; u, v, and γ are weight parameters, and u + v + γ = 1; (108) After the cluster head election is over, the nodes in the network are divided into three categories, namely ordinary nodes, cluster head nodes, and pseudo base station nodes; (109) Ordinary nodes are responsible for sensing data in each network cycle and transmitting the sensed data to the cluster head to which they belong; (110) After the ordinary nodes transmit the sensed data to the CH, the CH fuses the collected sensed data and forms a data packet of a fixed size and transmits it to the PBS; (111) If there is a routing path from the PBS to the base station, directly select this path as the routing path; (112) If there is no routing path from the PBS to the base station in the blockchain, calculate the shortest path as the routing path through the Dijkstra method. The weight influencing factors during the calculation include the remaining energy of the next-hop candidate node, the distance from the current node, the direction to the next-hop candidate node, and the number of times the next-hop candidate node participates in routing; (113) Then, the calculated shortest path path from the pseudo base station PBS i to the base station i is recorded in the blockchain; (114) The PBS transmits the data packet to the base station hop by hop according to the routing path.

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