Research Of Topology Control In Wireless Sensor Networks

Sensor network is regarded as one of the four new technologies in the 21st century, which will make great sense to people's lives. In wireless sensor networks, the sensor nodes, whose power is supplied by batteries, are small embedded systems. Every node has limited power to compute and communicate. That's why optimized topology control algorithm is needed, besides for energy-efficient protocols for MAC, routing and application. Topology control has vital influence on the performance of the network. A good topology is a firm foundation of time synchronization, location and so on, which results in a longer lifetime.Topology control algorithms are investigated here. Main research directions are discussed and analyzed here. As for clustering, representative algorithms are summarized in this paper. Comparison is made between clustering and planar topology control algorithm.Power control is an important direction of topology control in wireless sensor networks. Besides for representative power control algorithms , an energy model and the ratio of transmission range and energy is also analyzed in this paper. We come up with the existence of an optimized transmission range, which is then proved by the results of the emulation.Two means of topology control are combined to create an energy-aware hybrid topology control algorithm-EAHTC. First, clustering is carried through, which results in IS as the cluster heads. Then each node adjust its transmission range, which leads to a better topology. The results of emulation prove that the node set of the cluster heads are symmetrical and overlays the whole net. What's more, the topology is optimized, which is a subnet of the original graphics. This paper also takes into consideration the asymmetry between the inside and outside. The algorithm is carried on periodically, which prolongs the lifetime of the network effectively.