CN102395182B - Three-dimensional wireless sensor network topology control method with two-dimensional bounded property - Google Patents

Abstract

The invention relates to a two-dimensional bounded three-dimensional wireless sensor network topology control method, comprising the following steps: 1. For any node u, calculate its neighbor node set N _UBG (u); 2. Use 3DYAO algorithm to calculate N _UBG (u ) to get N _YG (u); three, broadcast N _YG (u) to N _UBG (u); four, calculate the inward neighbor set of node u 5. Use the same 3DYAO algorithm in step 2 to

processed, get

Six, put

Broadcast to all neighbors in N _UBG (u); 7. For all nodes v in N _YG (u), if u is also

, then add v to N _YYG (u); 8. Output the two-dimensional bounded three-dimensional wireless sensor network topology N _YYG (u) of node u, adjust the transmission power to reach the farthest in N _YYG (u) location of neighbors. The present invention has the characteristics of two-dimensional boundedness and high efficiency and energy saving, and can be implemented in local distribution, so as to prolong the network life cycle, reduce network interference, and improve network throughput.

Description

Topology control method for 3D wireless sensor networks with bidirectional boundedness

technical field

The invention relates to a three-dimensional wireless sensor network topology control method, in particular to a two-dimensional bounded, high-efficiency, energy-saving, and distributed topology control method proposed for a three-dimensional wireless sensor network, which belongs to the field of three-dimensional wireless network topology control and is suitable for use in Wireless sensor networks with large scale, self-organization, random deployment, complex environment and limited node energy.

Background technique

The wireless sensor network is an ad hoc network system composed of a large number of miniature low-power sensor nodes with data acquisition, processing and wireless communication capabilities through multi-hop. Perceived object information. Wireless sensor networks generally have the characteristics of large-scale, self-organization, random deployment, complex environment, limited sensor node resources, and frequent changes in network topology. Sensors, perceptrons and observers constitute the three elements of a wireless sensor network. Early research on sensor networks was almost entirely focused on the ideal two-dimensional plane, and one of its basic assumptions was that the nodes were distributed on the two-dimensional plane. However, this two-dimensional assumption is not suitable for underwater networks, because most underwater sensor network systems require nodes to be distributed in waters of different depths to perform sensing tasks.

A three-dimensional wireless sensor network is a wireless network system composed of sensor nodes deployed in three-dimensional physical space with certain sensing tasks. There are already a large number of applications of 3D wireless networks, such as underwater static sensor networks, mobile underwater equipment networks, space environment monitoring, forest fire prediction, and wireless networks deployed on various floors of buildings. Especially in recent years, the rise of underwater sensor network research has promoted the development of 3D sensor network systems.

The nodes that constitute the three-dimensional wireless sensor network are small in size, with limited computing and communication capabilities. The energy of the nodes is provided by batteries and cannot be supplemented later. Therefore, the energy consumption of sensor nodes in the working process is directly related to the survival time of the entire network. If each node communicates with the maximum power, not only the energy consumption of the nodes is very fast, but also the signal interference between nodes will be aggravated and the communication efficiency will be reduced.

The topology control method is a method of setting the transmission power of each node, that is, the transmission range. Its goal is to ensure the connectivity and coverage of the entire network topology under the premise of reducing system energy consumption by controlling the transmission range of nodes. Topology control is of great significance in the research of wireless sensor networks: firstly, topology control is an important energy-saving technology; secondly, topology control ensures coverage quality and connection quality; thirdly, topology control can reduce communication interference and improve MAC protocol and routing protocol. Efficiency, providing a topology basis for data fusion; in addition, topology control can improve network reliability, scalability and other performance.

There are a lot of research results on topological control in two-dimensional plane, but there are few researches on topological control in three-dimensional space at home and abroad. Compared with the two-dimensional wireless sensor network, the three-dimensional wireless sensor network poses many new problems and challenges, such as the difficulty of his problem increases; the computational complexity increases exponentially; the real physical structure is complex. Moreover, the current research on 3D wireless sensor networks mainly focuses on issues such as coverage quality, connectivity quality and routing. After searching the literature of the prior art, it is found that the current topology control methods applicable to the 3D wireless sensor network have the following protocols:

1) LMST (Local Minimum Spanning Tree) protocol. The LMST protocol proposed in the document "Applications of k-localMST for topology control and broadcasting in wireless ad hoc networks" can be extended to three-dimensional networks, which can ensure that the processed network is connected, but it may have a lot of energy Consumption, ie its energy expansion factor is unbounded.

2) CBTC (Cone-Based Distributed Topology Control) protocol. CBTC is a direction-based distributed algorithm that can guarantee network connectivity. It was originally a protocol for two-dimensional wireless sensor networks. Bahramgiri et al. from the Massachusetts Institute of Technology extended it to three-dimensional space in the document "Fault-tolerant and 3-dimensional distributed topology control algorithms in wireless multi-hopnetworks" and proposed a fault-tolerant CBTC protocol. Its core is to check whether there is a communicable neighbor node in every three-dimensional cone with angle α centered on u. They demonstrate that when α ≤ 2π/(3k), 3D CBTC preserves the k-connectivity of the network graph. But this method does not provide a proof of bounded energy and bounded degree, and the direction-based algorithm needs reliable direction information, and the nodes need to be equipped with multiple directional antennas, so higher requirements are put forward for the sensor nodes.

3) XTC protocol. In the document "XTC: A practical topology control algorithm for ad-hoc networks", Wattenhofer et al. proposed a neighbor-based topology control algorithm - the XTC protocol. The calculation of the protocol only depends on local information, and each node only needs to exchange information with its neighbor nodes twice. But they did not do any theoretical and experimental analysis of the topology of XTC in 3D.

4) 3DRNG, 3DGG, and 3DYAO. RNG, GG, and YAO are three topological control algorithms for two-dimensional wireless sensor networks. Yu Wang et al. extended it to three-dimensional space in the document "Energy-efficient topology control forthree-dimensional sensor networks", and proved the topological properties of 3DRNG, 3DGG and 3DYAO. For example, 3DRNG has connectivity, but no energy support; 3DGG has connectivity, but its energy t-Spanner coefficient is 1; 3DYAO has connectivity, energy support, and extroversion boundedness.

In summary, all currently proposed topologies for 3D WSNs do not have bidirectional (inward and outward) degree-bounded properties. Bounded node degree means that the number of neighbors of nodes in the generated topology is less than a constant k. Reducing the degree of nodes can reduce the number of nodes forwarding messages and the complexity of routing calculations, which is important for saving energy and reducing network interference. significance.

Contents of the invention

The object of the present invention is to provide a topology control method for a three-dimensional wireless sensor network to ensure that the topology structure generated by it has the characteristics of bidirectional boundedness, high efficiency and energy saving.

The purpose of the present invention is achieved through the following technical solutions:

A two-dimensional bounded three-dimensional wireless sensor network topology control method, comprising the following steps:

1. For any node u in a given three-dimensional wireless sensor network, calculate its neighbor node set N _UBG (u), that is, the set of nodes that can be covered by the maximum communication distance of u;

2. Taking the neighbor node set N _UBG (u) of node u as input, use the 3DYAO algorithm to process it, and obtain the 3DYAO neighbor node set N _YG (u) processed by node u;

3. Broadcast the 3DYAO neighbor node set N _YG (u) to the neighbor node set N _UBG (u) of u;

中，即

4. Calculate the inward neighbor set of node u If u∈N _YG (v), then add v to the set of inward neighbors of node u

in, namely

为输入，使用与步骤二中相同的3DYAO算法对其进行处理，得到u节点处理后的邻居节点集

5. Take the inward neighbor set of node u

As input, use the same 3DYAO algorithm as in step 2 to process it, and get the set of neighbor nodes processed by u node

向u的邻居节点集N_UBG(u)中所有邻居广播；Six, the node set

Broadcast to all neighbors in u's neighbor node set N _UBG (u);

7. For all nodes v in N _YG (u), if u is also , then add v to N _YYG (u);

8. Output the two-dimensional bounded three-dimensional wireless sensor network topology N _YYG (u) of node u, and adjust the transmission power to reach the farthest neighbor position in N _YYG (u).

Beneficial effect

The method proposed in the present invention is a three-dimensional topology control method based on 3DYAO, which has the characteristics of bidirectional boundedness and high efficiency and energy saving, and can be implemented locally, so as to prolong the network life cycle, reduce network interference, and improve network throughput.

At present, there are few researches on the topological control of three-dimensional space at home and abroad, and no topological structure can have the property of two-dimensional boundedness. Reducing the degree of nodes can reduce the number of messages forwarded by nodes and the complexity of routing calculations, so as to reduce network interference and save energy.

The method proposed by the invention also has the property that the energy support factor is bounded. It combines the advantages of two current topology control solutions, degree bounded and energy control, and prolongs the life cycle of the network to a greater extent.

The method proposed by the present invention takes into account the limited computing and communication capabilities of sensor nodes, the complexity of the method and the number of communications are relatively small, and it is distributed control. The nodes in the network only rely on their own constant jump neighbor information, and do not need global information. You can build your own topology locally.

Description of drawings

Fig. 1 is a specific implementation process of a two-dimensional bounded three-dimensional wireless sensor network topology control method.

Figure 2 is a 3DYAO structure using a fixed partition method.

Figure 3 is the 3DYAO structure using the flexible partition method.

Detailed ways

Below in conjunction with accompanying drawing the embodiment of the present invention is described in detail: present embodiment implements under the premise of technical scheme of the present invention, has provided detailed implementation mode and concrete operation process, but protection scope of the present invention is not limited to subordinates the embodiment.

Fig. 1 has provided the detailed process flow of the two-dimensional bounded three-dimensional sensor network topology control method based on 3DYAO according to the present invention, and the specific technical implementation plan is as follows:

Step 1: For any node u in a given wireless sensor network, calculate its neighbor node set N _UBG (u). The specific calculation method is as follows:

Take the node u as the center of the sphere, and take the maximum communication distance R that the wireless sensor node transmit power can reach as the radius to form a sphere. In a given 3D wireless sensor network, if a node v falls within a sphere, then v is a neighbor node of u. All nodes v constitute u's neighbor node set N _UBG (u).

Step 2: Use the 3DYAO algorithm to process the neighbor node set N _UBG (u) of node u, and obtain the neighbor node set N _YG (u) of node u after processing.

As a preferred embodiment of the present invention, the 3DYAO algorithm adopts a fixed division method or a flexible division method. The 3DYAO topological structures of these two division methods are described in detail below.

1) Fixed division method:

In the fixed division method, for any node, the division method of the cone is the same, and the divided cones do not intersect each other. Specifically, there are two methods of division:

The first one: For any node u, first use three orthogonal planes (xy plane, yz plane and xz plane) to divide the transmission range UBG of u into 8 areas, each area is 1/8 of a sphere; secondly, Then use three planes to divide each region into four cones, as shown in Figure 2(a), where c1, c2 and c3 shown in the figure are the midpoints of the arcs they are in respectively. In this way, the transmission range of u is divided into 32 cones that do not intersect each other. Finally, in any cone, for u’s neighbor node set N _UBG (u), node u only selects the edge uv with the shortest length in the cone to keep, and these directed edges uv form the 3DYAO topology N _YG (u). The maximum degree of the 3DYAO structure formed by this division method is 32.

The second type: For any node u, first use three orthogonal planes (xy plane, yz plane and xz plane) to divide the transmission range UBG of u into 8 areas, each area is 1/8 of a sphere; secondly, Use 6 planes to divide each region into 7 cones, as shown in Fig. 2(b), where ci and ci' (i=1, 2, 3) are the trisection points of the arc respectively. In this way, the transmission range of u is divided into 56 cones. Finally, in any cone, for u’s neighbor node set N _UBG (u), node u only selects the edge uv with the shortest length in the cone to keep, and these directed edges uv form the 3DYAO topology N _YG (u). The maximum degree of the 3DYAO structure formed by this division method is 56.

2) Flexible division method:

In this division method, for different nodes, the cones are divided in different ways, and the divided cones can intersect each other. Specifically, there are two division methods:

The first:

1a) For any node u, first calculate its neighbor node set;

1b) For any neighbor node v in the neighbor node set of node u, set PROCESSED(v)=0;

1c) For any neighbor node v, and PROCESSED(v)=0, perform the following steps:

①Construct a cone with uv as the axis and an angle θ less than π/3 as the apex angle;

②The node u selects the shortest edge uw in the cone to keep, and for all the neighbor nodes x in the cone, set PROCESSED(x)=1;

1d) These directed edges uw form the 3DYAO topology N _YG (u).

As shown in Figure 3(a).

The second type:

2a) For any node u, first calculate its neighbor node set;

2b) Sort u v _i according to the length from node u to neighbor node v _i from small to large, that is ||u v _i ||≤||uv _i+1 ||(i from 1 to m, m is the number of neighbor nodes number));

2c) For all neighbor nodes v _i (i from 1 to m), set PROCESSED(v _i )=0;

2d) For neighbor node v _i (i from 1 to m), if PROCESSED(v _i )=0, perform the following steps:

① Construct a cone with u v _i as the axis and an angle θ less than 2π/3 as the apex angle;

② Node u chooses edge u v _i to keep, and for all neighbor nodes w in the cone, set PROCESSED(w) = 1;

2e) These directed edges u v _i form the 3DYAO topology N _YG (u).

As shown in Figure 3(b).

After the processing in step 2, it can be guaranteed that the processed network outgoing degree is a constant.

Step 3: Broadcast the 3DYAO neighbor node set N _YG (u) to all neighbors in u's neighbor node set N _UBG (u).

如果u∈N_YG(v)，那么把v加入节点u的内向邻居集

中，即

Step 4: Calculate the inward neighbor set of node u

If u∈N _YG (v), then add v to the set of inward neighbors of node u

in, namely

为输入，选取和步骤二中相同的3DYAO算法对其进行处理，得到u节点处理后的邻居节点集

Step 5: Take the inward neighbor set of node u

As the input, select the same 3DYAO algorithm as in step 2 to process it, and obtain the neighbor node set processed by u node

After step five is processed, it can be guaranteed that the processed network introversion degree is a constant.

向u的邻居节点集N_UBG(u)中所有邻居广播。Step 6: Put the node set

Broadcast to all neighbors in u's neighbor node set N _UBG (u).

中，那么就把v加入N_YYG(u)中。Step 7: For all nodes v in N _YG (u), if u is also

, then add v to N _YYG (u).

Step 8: Output the two-dimensional bounded three-dimensional wireless sensor network topology N _YYG (u) of node u, and adjust the transmission power to reach the farthest neighbor position in N _YYG (u).

The present invention uses the 3DYAO algorithm to process the neighbor node set and the inward neighbor set respectively. Since the 3DYAO algorithm has connectivity, energy support, and extroversion boundedness, the topology structure of the three-dimensional wireless sensor network constructed by the present invention has the characteristic of bidirectional boundedness. Reducing the degree of nodes can reduce the number of messages forwarded by nodes and the complexity of routing calculations, so as to reduce network interference and save energy.

The above is only a preferred embodiment of the present invention. It should be pointed out that the two-dimensional bounded three-dimensional wireless sensor network topology control method proposed by the present invention can save energy by performing two operations on any different algorithm that satisfies the 3DYAO structure. The two-way dimension is bounded, prolonging the survival time of the network and reducing network interference. For those of ordinary skill in the art, without departing from the principle of the present invention, some improvements can be made, or equivalent replacements can be made to some of the technical features, and these improvements and replacements should also be regarded as protection of the present invention scope.

Claims (7)

1. a 3-D wireless sensor network topology control method for two-way degree bounded, comprises following steps:

One,, for the arbitrary node u in given 3-D wireless sensor network, calculate its neighbor node collection N _uBG(u) set of node that, the maximum communication distance of u can cover;

Two, with the neighbor node collection N of node u _uBG(u) be input, use 3DYAO algorithm to process it, obtain the 3DYAO neighbor node collection N after u node processing _yG(u);

Three, 3DYAO neighbor node collection N _yG(u) to the neighbor node collection N of u _uBG(u) broadcast;

Four, the interior of computing node u collects to neighbours

if u ∈ is N _yG(v), so v being added to the interior of ingress u collects to neighbours in,

n wherein _yG(v) refer to the 3DYAO neighbor node collection after v node processing;

Five, with the interior of node u, to neighbours, collect

for input, use and with 3DYAO algorithm identical in step 2, it is processed, obtain the neighbor node collection after u node processing

Six, set of node

neighbor node collection N to u _uBG(u) all neighbours' broadcast in;

Seven, for N _yG(u) all node v in, if u also exists

in, so just v is added to N _yYG(u) in; Wherein

refer to the neighbor node collection after v node processing;

Eight, the 3-D wireless sensor network topology N of the two-way degree bounded of output node u _yYG(u), adjust transmitting power for can reach N _yYG(u) neighbor location farthest in.

2. a kind of network topology control method according to claim 1, is characterized in that, the 3DYAO algorithm adopting in step 2 is fixed partition method.

3. a kind of network topology control method according to claim 2, is characterized in that, described fixed partition method is: to arbitrary node u, first use three orthogonal planes that the transmission range UBG of u is divided into 8 regions, each region is 1/8 spheroid; Secondly, re-use three each regions of bundle of planes and be divided into 4 cones, like this transmission range of u has been divided into 32 cones that mutually disjoint; Finally, in any centrum, for the neighbor node collection N of u _uBG(u), node u only selects the shortest limit uv of length in cone to retain; These directed edges uv has formed 3DYAO topological structure N _yG(u) number of degrees of the 3DYAO structure that, this partitioning forms are 32 to the maximum.

4. a kind of network topology control method according to claim 2, is characterized in that, described fixed partition method is: to arbitrary node u, first use three orthogonal planes that the transmission range UBG of u is divided into 8 regions, each region is 1/8 spheroid; Secondly, use 6 each regions of bundle of planes to be divided into 7 cones, like this transmission range of u has been divided into 56 cones; Finally, in any centrum, for the neighbor node collection N of u _uBG(u), node u only selects the shortest limit uv of length in cone to retain, and these directed edges uv has formed 3DYAO topological structure N _yG(u) number of degrees of the 3DYAO structure that, this partitioning forms are 56 to the maximum.

5. a kind of network topology control method according to claim 1, is characterized in that, the 3DYAO algorithm adopting in step 2 is flexible partitioning.

6. a kind of network topology control method according to claim 5, is characterized in that, described flexible partitioning is:

1a) to arbitrary node u, first calculate its neighbor node collection;

Arbitrary neighbor node v 1b) neighbor node of node u being concentrated, establishes PROCESSED (v)=0;

1c) to arbitrary neighbor node v, and there is PROCESSED (v)=0, carry out following steps:

1. take uv as axle, the angle θ who is less than π/3 of take is drift angle, builds a cone;

2. node u selects limit uw the shortest in cone to retain, and to all neighbor node x in cone, establishes PROCESSED (x)=1;

1d) these directed edges uw has formed 3DYAO topological structure N _yG(u).

7. a kind of network topology control method according to claim 5, is characterized in that, described flexible partitioning is:

2a) to arbitrary node u, first calculate its neighbor node collection;

2b) according to node u to neighbor node v _ilength ascending to u v _isort, || uv _i||≤|| uv _i+1||, i is by 1 to m, and m is neighbor node number;

2c) to all neighbor node v _i, i to m, establishes PROCESSED (v by 1 _i)=0;

2d) to neighbor node v _i, i by 1 to m, if PROCESSED (v _i)=0, carry out following steps:

1. with uv _ifor axle, the angle θ who is less than 2 π/3 of take is drift angle, builds a cone;

2. node u selects limit uv _iretain, and to all neighbor node w in cone, establish PROCESSED (w)=1;

2e) these directed edges u v _iformed 3DYAO topological structure N _yG(u).

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