CN106131859A - The deployment restorative procedure of wireless sensor network node and system - Google Patents

Abstract

The invention discloses deployment restorative procedure and the system of a kind of wireless sensor network node, including: between wireless sensor network sub-block, generate minimum spanning tree；Minimum spanning tree obtains stainer point, and is connected with node, formed and dispose limit；Via node is disposed on limit, it is achieved network connects to be repaired disposing.By the way, the present invention has the most only effectively saved rehabilitation cost, and the network topology constructed by the method has higher average node degree so that the network after reparation has preferable performance.

Description

Deployment repair method and system for wireless sensor network node

Technical Field

The invention relates to the technical field of wireless sensing, in particular to a deployment and repair method and system of a wireless sensor network node.

Background

When a single node of the wireless sensor network fails, the wireless sensor network can be repaired by adopting the method of other nodes in the mobile network. However, when the network is broken in a large scale and is divided into a plurality of sub-blocks, and each sub-block is far apart from the other sub-block, the repair is generally performed by deploying a new node. When a repair algorithm is formulated, each sub-block which cannot communicate is generally regarded as a node. The goal of the repair algorithm is to achieve the repair by establishing communication paths between the nodes. In the case of not considering the fault tolerance of the network, when establishing a connected path, a repair algorithm is generally designed by combining the steiner tree principle.

Lin et al demonstrate that the SMT-MSP problem is an NP-hard problem, and a simple minimum spanning tree algorithm is proposed to repair network connections. Lloyd et al propose the MST _1TRNP algorithm that first generates a minimum spanning tree by Kruskal algorithm or Prim algorithm, and secondly repairs the network connection by deploying a certain number of relay nodes at each edge of the minimum spanning tree. However, the MST _1TRNP algorithm is not an optimal algorithm, and the number of relay nodes used in the algorithm is relatively large. Senel et al propose a fessta algorithm that treats each sub-block in the network as a node. First all triangles in the plane are found and the perimeters of these triangles are arranged from small to large. Second, the algorithm starts with the triangle with the smallest perimeter and determines if the 3 points that make up this triangle already have an edge. If at least 2 points of the 3 points have no edge, judging whether the triangle formed by the 3 points has a Steiner point. If so, connecting the 3 points with the Stanner points; if not, the 3 points are connected according to the minimum spanning tree mode. After all triangles are judged, the whole network is possibly still in a block state, and each block is connected with the nearest block, so that the whole network forms a whole. When the network has no blocks, the algorithm traverses the whole network to judge whether a path needing to be optimized exists in the network. If so, the path of the minimum spanning tree mode connection is changed into the Steiner tree mode connection. The algorithm is better than other algorithms in the aspects of the required number of relay nodes, the average node degree after repair and the like, but the time complexity of the algorithm is higher.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for deploying and repairing the wireless sensor network nodes is provided, so that the energy consumption of the nodes is balanced, and the life cycle of the network is prolonged.

In order to solve the technical problems, the invention adopts the technical scheme that: a deployment repair method for a wireless sensor network node is provided, which comprises the following steps:

generating a minimum spanning tree among the wireless sensor network subblocks;

obtaining Steiner points on the minimum spanning tree, and connecting the Steiner points with nodes to form deployment edges;

and deploying the relay nodes on the deployment edge to realize network connection repair.

In order to solve the above problem, the present invention further provides a deployment and repair system for a wireless sensor network node, including:

the spanning tree module is used for generating a minimum spanning tree among the wireless sensor network subblocks;

the deployment edge module is used for acquiring Steiner points on the minimum spanning tree and connecting the Steiner points with the nodes to form deployment edges;

and the deployment module is used for deploying the relay nodes on the deployment edge to realize network connection repair.

The invention has the beneficial effects that: different from the prior art, the minimum spanning tree is generated among the sub-blocks; and obtaining Steiner points from the tree, and connecting the Steiner points with the nodes to form deployment edges for deploying the relay nodes. By the mode, the method not only effectively saves the repair cost, but also has higher average node degree of the network topology constructed by the method, so that the repaired network has better performance.

Drawings

FIG. 1 is a schematic flow chart of a first embodiment of the method of the present invention;

FIG. 2 is a comparison histogram of total moving distance of the IMST algorithm and the existing MST _1TRNP algorithm and FeSTA algorithm according to an embodiment of the present invention;

fig. 3 is a comparison histogram of the number of relay nodes of the IMST algorithm and the existing MST _1TRNP algorithm and fessta algorithm in the embodiment of the present invention;

fig. 4 is a comparison histogram of the number of relay nodes of the IMST algorithm and the existing MST _1TRNP algorithm and fessta algorithm in the embodiment of the present invention;

FIG. 5 is a histogram of average node contrast for all nodes of the IMST algorithm and the existing MST _1TRNP algorithm and FeSTA algorithm according to an embodiment of the present invention;

fig. 6 is an average node contrast histogram of the IMST algorithm and the internal relay nodes of the existing MST _1TRNP algorithm and fessta algorithm in the embodiment of the present invention;

FIG. 7 is a histogram of average node contrast for all nodes of the IMST algorithm and the existing MST _1TRNP algorithm and FeSTA algorithm according to an embodiment of the present invention;

fig. 8 is an average node contrast histogram of the IMST algorithm and the internal relay nodes of the existing MST _1TRNP algorithm and fessta algorithm in the embodiment of the present invention.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

The most key concept of the invention is as follows: and generating a minimum spanning tree in each sub-block, acquiring Steiner points from the minimum spanning tree, and connecting the nodes to be used as edges needing to deploy the relay nodes.

Referring to fig. 1, an embodiment of the present invention provides a method for deploying and repairing a wireless sensor network node, including:

s1: generating a minimum spanning tree among the wireless sensor network subblocks;

s2: obtaining Steiner points on the minimum spanning tree, and connecting the Steiner points with nodes to form deployment edges;

s3: and deploying the relay nodes on the deployment edge to realize network connection repair.

Different from the prior art, the minimum spanning tree is generated among the sub-blocks; and obtaining Steiner points from the tree, and connecting the Steiner points with the nodes to form deployment edges for deploying the relay nodes. By the mode, the method not only effectively saves the repair cost, but also has higher average node degree of the network topology constructed by the method, so that the repaired network has better performance.

The present invention views each sub-block as a single independent node. Because a certain cost is required to repair a failed network, the more nodes deployed, the higher the cost required. Thus, the present invention contemplates: how to minimize the number of nodes used while accomplishing the goal of network connection repair.

The relevant terms to which the invention relates are first defined:

definition 1, steiner point: given Δ ABC, if the internal angles of Δ ABC are not greater than 120 °, then there is a point P within the triangle_sThe sum of the distances to the three points A, B and C is not more than the sum of the distances from other points to the three points, and then the point P_sReferred to as Steiner points. Suppose P_sThe distances from the three points A, B and C are | | | P_sA||、||P_sB||、||P_sC | |, then there are

||P_sA||+||P_sB||+||P_sC | | < min { | | | AB | + | | | AC |, | | AB | + | | BC |, | AC | + | | BC | }; namely, the path length formed by connecting the Steiner point and the three points is less than or equal to the total path length formed by connecting the three points in a minimum spanning tree mode.

Definition 2, the number of relay nodes to be deployed between two sub-blocks: given two points A and B, the coordinates are (x) respectively₁,y₁)、(x₂,y₂) If relay nodes with communication radius R are deployed between A and B, the number of required deployments isThe specific calculation method comprises the following steps:wherein

Is the Euclidean distance between A and B.

Definition 3, the number of relay nodes required between three sub-blocks connected in a steiner tree manner: three points A, B and C are given, and the coordinates are respectively (x)₁,y₁)、(x₂,y₂)、(x₃,y₃) And a Stanner point P is present in Δ ABC consisting of three points_sCoordinates (x, y) are at A, B, C and P_sRelay to be deployed betweenThe number of the nodes is respectivelyAndthe total number of the relay nodes deployed among the four points is

The specific calculation method is

$\begin{array}{c}\left(\frac{\sqrt{{(x_1-x)}^2+{(y_1-y)}^2}}{R}-1\right)+\left(\frac{\sqrt{{(x_2-x)}^2+{(y_2-y)}^2}}{R}-1\right)+\left(\frac{\sqrt{{(x_3-x)}^2+{(y_3-y)}^2}}{R}-1\right)+1\\ =\frac{\sqrt{{(x_1-x)}^2+{(y_1-y)}^2}}{R}+\frac{\sqrt{{(x_2-x)}^2+{(y_2-y)}^2}}{R}\frac{\sqrt{{(x_3-x)}^2+{(y_3-y)}^2}}{R}-2\end{array}$

Wherein,represents upper rounding, if N is 16, then Meaning lower rounded, e.g. when N is 16, then

In practical operation, the method comprises the following steps:

step 1, initialization. Assuming that there are n nodes (sub-blocks) on the plane, the coordinates of all nodes and the communication radius of the nodes to be deployed are known.

And 2, generating a minimum spanning tree. A minimum spanning tree is generated among all points by using a Kruskal algorithm, and all points are marked as not searched.

It should be noted that, at initialization, all nodes are marked as "not searched" because they are not searched (assuming that not searched is marked as 0 and searched is marked as 1).

Search refers to a traversal search of the algorithm. All nodes are stored in an array, and each node can only have one state at a time (e.g., setting the initial state value to 0). When the algorithm starts to execute, traversal is started from the first node, and each time a node is traversed, if the node meets the requirement, the state of the node is changed from 0 to 1. The node whose state becomes 1 is the searched node. The node with the state 0 is an unsearched node.

And 3, searching the Steiner points meeting the conditions. From the point v corresponding to the longest edge of the minimum spanning tree_iInitially, a determination is made as to whether the point has been searched. If the point is not searched, judging whether the point has at least 2 edges. If the number of edges of the point is greater than or equal to 2, finding out the longest two edges in the edges of the pointAnd finding out another two points v corresponding to the two edges_jAnd v_k. Judgment of v_i、v_jAnd v_kWhether all three points have been searched. If at most one of the three points is searched, judging whether the triangle formed by the three points has the Steiner point. If the three points exist, finding the Steiner point, deleting the original edges of the three points, connecting the three points with the Steiner point to form a new edge, and connecting the three points v_i、v_jAnd v_kThe mark is searched. When all the points have been searched, the next step is performed.

The "determination of whether or not searched" in step 3 is explained for the global. It means that each time a node is searched, whether the node is marked as 0 is judged (the nodes searched for the first time are all marked as 0, and the nodes searched for the second time may be marked as 0, or may be marked as 1).

For example: assuming that there are five points A, B, C, D, E, the connection is: A-B-C-D-E. And the length relation of each edge is assumed to be AB edge length > BC edge length > CD edge length > DE edge length. A. B, C, D, E are all labeled 0.

Because the AB side is the longest, the invention starts to search from A, judges whether A is marked as 0, if yes, judges whether A has 2 sides, otherwise, searches B.

At this point B is 0 and B has two edges. The points corresponding to these two edges are a and C, respectively. Judging whether at least 2 of the 3 points A, B, C are 0, if so, judging whether a Steiner point exists in the delta ABC, if so, finding the Steiner point Q, deleting the edge between the AB, deleting the edge between the BC, connecting A, B, C with the Q, and marking the three points ABC as 1.

And if the corresponding edge of the point is less than 2, searching the next point. For B, the vertices A, C of the two corresponding sides can be determined as follows:

assume that, in the five points A, B, C, D, E, the minimum spanning tree is connected in the following manner: A-B-C-D-E. The content stored in the point set of the minimum spanning tree is ABBCCDDE. When B is searched, if B is an even number, the previous point (A) is the point of the corresponding side; if B is odd, the next point (C) is the point of the corresponding side, and then the other two points A and C corresponding to B are found. Therefore, if another two points corresponding to a certain point are determined, the position of the point in the set only needs to be known.

And 4, deploying new nodes along all edges to finish network connection repair.

Specifically, the above steps can be illustrated by the following mathematical principles:

s1, generating a minimum spanning tree and a corresponding point set V_mt，V_mt＝{v₁,v₂,…,v_(n-1)×2}，|V_mtAnd (n-1) × 2, where n represents the number of sub-blocks.

S2, initializing the number m of relay nodes to be 0, and enabling each node s_tAre all marked as not searched, s_t∈ S. each v_i∈V_mtAll correspond to one s_t. Each s_tAll correspond to a plurality of v_i。v_iCorresponding s_tIf not, it indicates v_iHas not been searched. In the present invention, if v_iIs not searched, then represents v_iCorresponding s_tHas not been searched.

S3, from V_mtFor each v, starting with the last node of_i∈V_mtThe following steps are carried out:

if v is_iHas not been searched, and v_iAt least two edges; then find v_iTwo vertexes v corresponding to the two longest edges of_j，v_k；

If v is_i，v_j，v_kAt most one of the three points is searched, and v_i，v_j，v_kTriangle composed of three points has Steiner point P_s(ii) a Then

At v_iAnd P_sBetween deploymentA relay node, each being { p_m+1,p_m+2,…,p_m+m′}，

And updating m ═ m + m';

at v_jAnd P_sBetween deploymentA relay node, each being { p_m+1,p_m+2,…,p_m+m′}，

And updating m ═ m + m';

at v_kAnd P_sBetween deploymentA relay node, each being { p_m+1,p_m+2,…,p_m+m′,P_s}，

And updating m ═ m + m' +1

S4, for each v_i∈V_mtExecuting the following steps:

if v is_iCorresponding s_tIf not searched, find v_iVertex v corresponding to the edge of (1)_j；

And at v_iAnd v_jBetween deploymentA relay node, each being { p_m+1,p_m+2,…,p_m+m′}

And simultaneously updating m to m + m'.

After the steps of S1 to S3 are performed, only the state of the sub-block that meets the requirement changes from 0 to 1, and the state of the sub-block that does not meet the requirement remains 0. So, after all nodes have traversed one pass, there may be a case where the individual subblock state is also 0. Step S4 obtains a sub-block that has not been searched, and deploys relay nodes on the edges of the minimum spanning tree in the sub-block.

To facilitate understanding of the above steps, the following description is aided by specific theorem proving.

Theorem 1: the time complexity of the algorithm is O (n)²) And n is the number of sub-blocks.

And (3) proving that: the worst-case time complexity of generating a minimum spanning tree in Step 1 is O (n)²). Marker s in Step2_tThe time complexity depends on the size of S, and | S | ═ n, so the time complexity of Step2 is o (n). The time complexity of Step 3 depends on V_mtOf (d), and | V_mtSimilarly, the time complexity of Step 4 is O (n), so the time complexity of the IMST algorithm of the present invention is O (n)²). (FeSTA algorithm time complexity of O (n)⁴))

Theorem 2: starting the search with the longest edge, the number of nodes that need to be deployed after repair is less.

And (3) proving that: the existing triangle delta ABC formed by three points A, B, C and A ', B ', C ' 6 points, A, B and C is a triangle with the smallest circumference, the side lengths are respectively | | | AB |, | | | AC |, | | | BC |, A ', B ' and C ' form a triangle delta A ' B ' C ' with the largest circumference, the side lengths are respectively α × | | | AB |, β | | AC |, γ | | | | BC |, wherein α is more than or equal to 1, β is more than or equal to 1, and γ is more than or equal to 1. Let it be assumed that both the minimum triangle Δ ABC and the maximum triangle Δ a ' B ' C ' have steiner points and that the total path length of the steiner tree/the total path length of the minimum spanning tree is 0 ≦ 1. The minimum spanning tree path length of the three points A, B and C is

L＝min{||AB||+||AC||,||AB||+||BC||,||AC||+||BC||} (4-1)

Suppose L_minThe total path length after the formation of the stainer tree is × (| AB | + | AC |), the reduced length being × (| AB | + | AC | |)

(1-)×(||AB||+||AC||) (4-2)

The minimum spanning tree path length of three points A ', B ' and C ' is

L′＝min{α×||AB||+β×||AC||,α×||AB||+γ×||BC||,β×||AC||+γ×||BC||} (4-3)

L 'is assumed'_minα× AB + β× AC, the distance after the Steiner tree is formed is

×(α×||AB||+β×||AC||) (4-4)

Reduced length of

(1-)×(α×||AB||+β×||AC||) (4-5)

Assuming that alpha is less than or equal to beta, then

(1-)×(α×||AB||+β×||AC||)≥α×(1-)×(||AB||+||AC||) (4-6)

Since α ≧ 1, so

(1-)×(α×||AB||+β×||AC||)≥α×(1-)×(||AB||+||AC||)≥(1-)×(||AB||+||AC||) (4-7)

In summary, starting the search from the longest edge can reduce the total path length better than starting the search from the shortest edge. The shorter the total path length, the fewer the number of nodes required for repair.

Theorem 3: the IMST algorithm of the present invention must be convergent, i.e. all sub-blocks can eventually be concatenated.

And (3) proving that: the IMST algorithm of the invention firstly generates a minimum spanning tree and stores a point set V corresponding to the minimum spanning tree_mt＝{v₁,v₂,…,v_(n-1)×2Set corresponding to subblockIs S ═ S₁,s₂,…,s_nN is the number of sub-blocks, the edge set corresponding to the minimum spanning tree is

$E_{mt}=\left\{\begin{array}{c}\{v_i,v_{i+1}\},i\mathrm{mod}2=1\\ \{v_i,v_{i-1}\},i\mathrm{mod}2=0\end{array}\right.,v_i,v_{i+1},v_{i-1}\&Element;V_{mt}---(4-8)$

After all sub-blocks are connected by the generated minimum spanning tree, firstly judging v by the algorithm in the process of searching the Steiner point_i,v_i+1,v_j(i +1 ≠ j, imod2 ═ 1) (similarly for imod2 ═ 0) whether or not a stainer point exists in a triangle composed of three points, and if so, whether or not a stainer point P exists_sThen the existing connection is deleted

E′_mt＝E_mt-{v_i,v_i+1}-{v_i,v_j} (4-9)

V is to be_i,v_i+1,v_jThree points and P_sConnected in a manner of being modified

$E_{mt}=\{\begin{array}{c}\left\{v_i,P_s\right\},\left\{v_{i+1},P_s\right\},\left\{v_j,P_s\right\}\\ E_{mt}^{\&prime;}\end{array},v_i,v_{i+1},v_j\&Element;V_{mt}---\left(4-10\right)$

At this time v_i,v_i+1,v_jThe three points are still connected except v_i,v_i+1,v_jThe connections of other points than the three points are not affected, i.e. the IMST algorithm of the present invention does not affect the connectivity of all nodes. Therefore, all sub-blocks are still connected after the algorithm runs are finished.

Theorem 4: under the condition that the number n of the sub-blocks is constant, the smaller the number m of the deployed relay nodes (or the larger the communication radius R of the relay nodes), the average node degree D of all the nodes is_all-nodesThe smaller the average node degree D of relay nodes within the network_{inter-relay-nodes}The larger, and satisfy2≤D_{inter-relay-nodes}≤3。

And (3) proving that: (1) n subblocks before repair, average nodal degree D of all points after repair_all-nodesIs composed of

$D_{all-nodes}=\frac{2(m+n-1)}{m+n}=2-\frac{2}{m+n}---(4-11)$

Therefore, when the value of n is fixed, the smaller m,the larger the size of the tube is,the smaller, i.e. D_all-nodesThe smaller. Because of the fact thatL is the total path length after repair, so when the distribution of the sub-blocks is given (i.e. the value of n is fixed), the total path length after repair L is determined immediately, in this case, if R is larger, m is smaller, and D is smaller_all-nodesThe smaller.

(2) There are n subblocks before repair, assuming m in the network after repair_sThe average node degree D of all internal nodes after the repair of the single Steiner point_{inter-relay-nodes}Is composed of

$D_{\mathrm{int}er-relay-nodes}=\frac{3\&times;m_s+2\&times;(m-m_s)}{m}=\frac{m_s+2\&times;m}{m}=2+\frac{m_s}{m}---(4-12)$

Because 0. ltoreq.m_sNot more than m, so that

I.e. 2. ltoreq. D_{inter-relay-nodes}≤3

Wherein m is_sSatisfy the requirement of

When the distribution of the sub-blocks is given (the value of n is fixed), m_sAnd the total path length L is also fixed immediately, if the coverage radius R of the relay node is larger, the number m of the relay nodes used for repairing is smaller, and then

The larger.

From the perspective of simulation analysis, the IMST algorithm of the present invention is compared and analyzed with the existing MST _1TRNP algorithm and FeSTA algorithm in terms of total path length after repair, number of nodes required for repair, and average node degree.

1. Total path and total node number

Fig. 2 is a comparison of the total path length of the topology for the three algorithms with different numbers of partitions. The total path length of all three algorithms, viewed in the lateral direction, generally increases as the number of partitions increases. This is because, as the number of blocks in the area increases, the edges connecting the respective blocks increase, the sum of all the edges added becomes large, and thus the total path becomes long. Viewed longitudinally, the IMST algorithm of the present invention is shorter than the total path of the other two algorithms, regardless of the number of partitions in the region. This is because the MST _1TRNP algorithm directly generates the minimum spanning tree, and the total path length of the minimum spanning tree is greater than the steiner tree, so the total path length of the MST _1TRNP algorithm is greater than the FeSTA algorithm and the IMST algorithm. And because the FeSTA algorithm starts with the smallest perimeter triangle to find the steiner point, theorem 2 has demonstrated that starting with the longest edge, there will be a shorter path length. Thus, the IMST algorithm of the present invention is superior to the other two algorithms.

FIG. 3 is substantially similar to FIG. 2 in that the number of nodes required per edge is equal to the number of nodes required per edgeThat is, fig. 3 is substantially proportional to fig. 2. FIG. 3 is not exactly the same as FIG. 2, since 1 needs to be subtracted when calculating the number of nodes that need to be deployed per edge. As can be seen from fig. 3, as the number of blocks increases, the number of relay nodes required for repair also increases. Compared with the other two algorithms, the IMST algorithm of the invention uses less relay nodes under the condition of different block numbers, so the IMST algorithm of the invention is superior to the other two algorithms in the aspect of the required relay node number.

Fig. 4 is a comparison of the communication radius with the required number of relay nodes. When the distance between two points is fixed, the larger the communication radius is, the smaller the number of relay nodes is required. Therefore, as can be seen from fig. 4, when the communication radius of the relay node increases, the number of relay nodes required for all of the three algorithms decreases. In the vertical view, the IMST algorithm of the invention needs less relay nodes than other two algorithms along with the increase of the communication radius.

In conclusion, in any aspect, the comparison shows that the IMST algorithm of the invention uses fewer nodes than other algorithms, and can save the fault repairing cost.

2. Average degree of node

The average node degree may reflect the survivability of the network topology. When the average node degree of the topology is larger, the number of edges of each node is larger, and the robustness of the topology is better. Therefore, the proposed algorithm is evaluated in terms of average node degree in this section, and the topology formed by the IMST algorithm of the present invention is proved to be more robust by comparison with the other two algorithms. The communication radius of the relay node in fig. 5 and 6 is a fixed value.

As can be seen from fig. 5 and 6, as the number of partitions increases, the average node degree also increases. This is because the network topology becomes complex as the number of partitions increases, and the average number of nodes increases as the number of partitions increases, since each node has more edges on average. Under the condition that the number of the partitions is the same, the IMST algorithm has larger average node degree than other algorithms, and the network topology robustness formed by the IMST algorithm is better.

Fig. 7 and 8 illustrate the relationship between the communication radius and the average node degree. It can be seen that, when the number of partitions is constant, the average node degrees of all the nodes decrease with an increase in the communication radius (fig. 7), while the average node degrees of the internal relay nodes increase (fig. 8), which is consistent with the proof result of theorem 4. Compared with the average node degree of all the nodes or the average node degree of the internal nodes, the IMST algorithm is obviously superior to the average node degrees of the other two algorithms, and the IMST algorithm has better robustness under the condition of different communication radiuses.

Correspondingly, a second embodiment of the present invention further provides a deployment repair system for a wireless sensor network node, including:

the spanning tree module is used for generating a minimum spanning tree among the wireless sensor network subblocks;

the deployment edge module is used for acquiring Steiner points on the minimum spanning tree and connecting the Steiner points with the nodes to form deployment edges;

and the deployment module is used for deploying the relay nodes on the deployment edge to realize network connection repair.

Wherein the system further comprises an initialization module for:

acquiring a wireless sensor node, coordinates thereof and a communication radius of a relay node;

marking all wireless sensor nodes as not searched;

and dividing the wireless sensor network into a plurality of sub-blocks according to the node coordinates.

The sub-block comprises at least one node, and when the sub-block is not searched, the node contained in the sub-block is marked as not searched.

The deployment edge module is specifically configured to:

obtaining the edges of the minimum spanning tree and sorting according to the edge length

Sequentially selecting nodes at one end of the longest edge from the longest edge;

it is determined whether the node has been searched for,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, judging whether the edges passing through the node are less than 2,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, selecting two nodes passing through the longest two edges of the node;

judging whether at least two nodes of the three nodes are searched,

if yes, neglecting the node and selecting the node at the other end of the longest edge

Otherwise, judging whether the triangle formed by the three nodes has Steiner points or not,

if so, removing the original edge of the triangle, connecting the three nodes with the Steiner point to generate a deployment edge, and marking the three nodes as searched nodes;

otherwise, the node is ignored, and the node at the other end of the longest edge is selected.

The deployment module is specifically configured to:

deploying relay nodes along deployment edges from the three nodes according to the communication radius of the relay nodes;

and acquiring the sub-blocks which are not searched, and deploying the relay nodes on the edges of the minimum spanning tree in the sub-blocks.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.

Claims (10)

1. A deployment repair method for a wireless sensor network node is characterized by comprising the following steps:

generating a minimum spanning tree among the wireless sensor network subblocks;

obtaining Steiner points on the minimum spanning tree, and connecting the Steiner points with nodes to form deployment edges;

and deploying the relay nodes on the deployment edge to realize network connection repair.

2. The deployment recovery method for the wireless sensor network node according to claim 1, further comprising:

acquiring a wireless sensor node, coordinates thereof and a communication radius of a relay node;

marking all wireless sensor nodes as not searched;

and dividing the wireless sensor network into a plurality of sub-blocks according to the node coordinates.

3. The deployment recovery method for wireless sensor network nodes according to claim 2, wherein the sub-block comprises at least one node, and when the sub-block is not searched, the nodes contained in the sub-block are marked as not searched.

4. The deployment repair method of the wireless sensor network node according to claim 1, wherein the step of obtaining the steiner point on the minimum spanning tree and connecting the steiner point with the node to form the deployment edge specifically comprises:

obtaining the edges of the minimum spanning tree and sorting according to the edge length

Sequentially selecting nodes at one end of the longest edge from the longest edge;

it is determined whether the node has been searched for,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, judging whether the edges passing through the node are less than 2,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, selecting two nodes passing through the longest two edges of the node;

judging whether at least two nodes of the three nodes are searched,

if yes, neglecting the node and selecting the node at the other end of the longest edge

Otherwise, judging whether the triangle formed by the three nodes has Steiner points or not,

if so, removing the original edge of the triangle, connecting the three nodes with the Steiner point to generate a deployment edge, and marking the three nodes as searched nodes;

otherwise, the node is ignored, and the node at the other end of the longest edge is selected.

5. The deployment repair method for the wireless sensor network node according to claim 3, wherein the step of deploying the relay node on the deployment edge specifically includes:

deploying relay nodes along deployment edges from the three nodes according to the communication radius of the relay nodes;

and acquiring the sub-blocks which are not searched, and deploying the relay nodes on the edges of the minimum spanning tree in the sub-blocks.

6. A deployment repair system for a wireless sensor network node, comprising:

the spanning tree module is used for generating a minimum spanning tree among the wireless sensor network subblocks;

the deployment edge module is used for acquiring Steiner points on the minimum spanning tree and connecting the Steiner points with the nodes to form deployment edges;

and the deployment module is used for deploying the relay nodes on the deployment edge to realize network connection repair.

7. The deployment repair system of a wireless sensor network node of claim 6, further comprising an initialization module to:

acquiring a wireless sensor node, coordinates thereof and a communication radius of a relay node;

marking all wireless sensor nodes as not searched;

and dividing the wireless sensor network into a plurality of sub-blocks according to the node coordinates.

8. The deployment recovery system of wireless sensor network nodes of claim 7 wherein the sub-block contains at least one node and when the sub-block is not searched, the nodes contained in the sub-block are marked as not searched.

9. The deployment recovery system of a wireless sensor network node of claim 6, wherein the deployment side module is specifically configured to:

obtaining the edges of the minimum spanning tree and sorting according to the edge length

Sequentially selecting nodes at one end of the longest edge from the longest edge;

it is determined whether the node has been searched for,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, judging whether the edges passing through the node are less than 2,

if yes, ignoring the node, and selecting the node at the other end of the longest edge;

otherwise, selecting two nodes passing through the longest two edges of the node;

judging whether at least two nodes of the three nodes are searched,

if yes, neglecting the node and selecting the node at the other end of the longest edge

Otherwise, judging whether the triangle formed by the three nodes has Steiner points or not,

if so, removing the original edge of the triangle, connecting the three nodes with the Steiner point to generate a deployment edge, and marking the three nodes as searched nodes;

otherwise, the node is ignored, and the node at the other end of the longest edge is selected.

10. The deployment repair system for a wireless sensor network node of claim 8, wherein the deployment module is specifically configured to:

deploying relay nodes along deployment edges from the three nodes according to the communication radius of the relay nodes;

and acquiring the sub-blocks which are not searched, and deploying the relay nodes on the edges of the minimum spanning tree in the sub-blocks.