The Research Of Algorithms To Prolong The Lifetime Of Wireless Sensor Network

Wireless sensor networks(WSN) are composed of a huge number of sensor nodes which have limited energy, resource and computation and communication capabilities. WSN have been widely used in the fields such as military communication,medicine,environment monitoring and agriculture production.Sensor networks are usually close to dangerous environment. Sensor nodes constitute a network by self-organization, and send the information to the base station through a multi-hop transmission. However, the scene of multi-hop transmission will usually produce the problem of energy hole because of the energy imbalance of network, that is, the nodes closer to the base station is easy to die due to its heavy duty of data forwarding task. What's more, the battery of sensor node is limited, if each node transmit data with its maximum power, the energy of nodes will be consumed quickly, reducing the network life cycle. In this paper, we develop new algorithm of energy balance to avoid the energy hole, and raise energy efficiency; we develop the algorithm of power control to optimize the network topology, reducing node energy consumption and prolong the network life cycle. My major work is as follow:1) Analyze the causes of the "energy hole problem" and the current strategies of energy balance.In order to improve energy efficiency, this paper proposed a non-uniform sub-cluster algorithm UCEA, by adjusting the number of cluster to balance the packet number of different clusters, the new algorithm avoid the "energy hole problem" of the cluster's head nodes near the base station and extend the network lifetime.2) Analyze power control algorithms on the influence of network lifetime and problems of power control algorithms. Then, we provide a new power control algorithm (LSPT). The new algorithm can maintain the network connectivity, preserve energy efficiency path between two nodes, and avoid energy hole.Experimental results shows that compared to LMST, CBTC, K-neigh, the proposed algorithm can achieve better performances in terms of transmission power, power stretch factor and network lifetime.