Algorithm For Wireless Sensor Network Topology Cluster-based Control

With the rapid development of wireless communication technology, embedded technology and sensor technology, wireless sensor network is becoming the one of the hot spots and tendency in modern wireless communication researches. Wireless sensor network is an intelligent monitoring and controlling system composed of large scale of micro-sensor nodes which have certain wireless communication capabilities, processing capabilities and wireless sensing abilities deployed in certain areas to monitor and control certain targets. The micro-sensor nodes are self-organized or organized by certain control algorithms; they communicate and cooperate with each other.Wireless sensor networks usually have a series of characteristics such as large scale of nodes, random distribution, intelligent organization and monitoring, and some other characteristics to adapt to different environments. According to these characteristics, wireless sensor networks can be used in military, agriculture production, automation monitor, medical, family and some high-risk environments that are beyond the human abilities.Topology control is one of the most important research directions in wireless sensor networks; it is also a key to user node energy efficiently, improve network connectivity and robustness, increase network throughput and extend lifetime of the whole network. Based on research and analysis of existing topology control algorithms for wireless sensor networks, this paper proposes topology control algorithm for wireless sensor networks based on virtual grids.The first algorithm is a periodical algorithm which divides the entire network area into several virtual grids, processing clustering-based algorithm and selecting a cluster head in each grid. Cluster head in each grid communicates with Sink node in single-hop or multi-hop. The algotithm decreases the energy consumption of establishing cluster and selecting cluster heads, and balances the energy consumption of all nodes, accordingly extends the lifetime of all nodes.The second algorithm is the improvement and expands of the first algorithm. In this algorithm, all nodes are homogeneous and have the same initial state; they are distributed according to certain rules in the monitoring area. The same as former algorithm, this algorithm also divides the entire network into several virtual grids. The topology generation process uses the lowest communicating cost path. When finishing the topology generation, the entire network becomes a spanning tree with lowest consumption. Using non-uniform distribution of sensors solves the hot spot problem efficiently, ensures the network connectivity, and finally achieves an efficient topology control.