Design And Implementation Of The Relay Node Placement Algorithm In Wireless Sensor Networks

In wireless sensor networks, the key factors restricting the networks developmentis the limited battery power of nodes. And it is impossible to change the batteryespecially in the complex geographical environment. The study found that datatransmission path of sensor node takes multi-hop can effectively reduce the wholeenergy consumption of networks. Therefore, it is significant to adopt an effective relaynode layout algorithm and reasonable decorate relay node position for the robustnessand service life of wireless sensor networks.At present, the scholars at home and abroad have put forward many kinds of relaynode layout algorithm, but it is less about the algorithm validity evaluation and practicalapplication research. And the typical existing algorithms do not involve the constraints.Focusing on the problems, the paper verifies and analyzes four kinds of greedy criterion.Aiming at search the optimal algorithm, the paper also puts forward the performancestandards to evaluate the effectiveness of greedy criterion. We complete the design ofrelay node layout system. The article main research content is as follows:1. In the paper, according to the problem of relay node layout, in order to limit andoptimize the path selection, we introduce constraints such as data flow restrictions,communication setting and the biggest capacity constraints of data forwarding number.In the article, we respectively analyze the nearest greedy criterion, nearest neighborgreedy criterion, directional greedy criterion and angle least greedy criterion. Weanalyze and compare the effectiveness of the algorithms in many aspects. Studies showthat the nearest neighbor greedy criterion do not meet the demand and the nearestgreedy criterion has the best effect.2. As the fault tolerance ability of networks is limited, we put forward the disjointfault-tolerant communication path algorithm based on the nearest greedy criterion. Thealgorithm selects two paths for each sensor node. When the main path cannot runnormally produced by fault, the secondary path starts to work. According to the theoryof combinatorial optimization problems, we also set up a mathematical model. And thenwe come up with the energy consumption balanced rate, scalability and relay nodenumber to evaluate the feasibility of the algorithm. Studies show the algorithm ofdisjoint fault-tolerant communication path algorithm based on the nearest greedycriterion greatly prolong the lifetime of the networks by the least energy consumption.3. We design a relay node layout system which adopts the VC++software based onnearest greedy criterion. The system can intuitively display relay node layout positionthrough the network topology or routing tables. After the test, the system hascharacteristic of simple operation and strong scalability. Experimental verification shows that the relay node layout position the system displays and calculates correspondswith the theoretical analysis results.Theoretical analysis and experimental verification shows the relay node layoutsystem based on nearest greedy criterion can reasonable display the relay node layoutposition to achieve the purpose of prolonging the service life of wireless sensornetworks.