¡¡	Chinese Journal of Computers   Full Text
Title	Topology Evolution of Wireless Sensor Networks among Cluster Heads by Random Walkers
Authors	CHEN Li-Jun1£©,2£© LIU Ming3£© CHEN Dao-Xu1£©,2£© XIE Li1£©,2£©
Address	1£©(State Key Laboratory for Novel Software Technology, Nanjing University, Nanjing 210093) 2£©(Cooperative Laboratory for Mobile and Wireless Sensor Networks of Nanjing University and Hong Kong Polytechnic University, Nanjing 210093) 3)(School of Computer Science and Engineering, University of Electronic Science and Technology, Chengdu 610054)
Year	2009
Issue	No.1(69¡ª76)
Abstract &   Background	Abstract Fault-tolerance mechanisms are needed to protect wireless sensor networks from various faults such as node failure due to loss of power and link failure due to network intrusion. A number of fault-tolerance techniques have been developed specifically for wireless sensor networks. One of the major fault-tolerance techniques is the exploitation of redundancy. In this paper, an evolving network model based on the random walkers among the cluster heads is proposed. The analysis of growth dynamic demonstrates that such network exhibits a power-law distribution of node degree. Mangy research work has demonstrated that the fault tolerance is not only shared by all redundant systems, but also it is displayed in scale-free networks. Keywords complex networks; wireless sensor networks; random walkers; topology evolution Background Fault-tolerance mechanisms are needed to protect wireless sensor networks from various faults such as battery running out, etc and node failure due to loss of power, compromise, etc and link failure due to network intrusion, etc. A wireless sensor network that is not prepared to deal with such situations may suffer a reduction in overall lifetime, or lead to dangerous consequences in critical application contexts. A number of fault-tolerance techniques have been developed specifically for wireless sensor networks. One of the major fault-tolerance techniques is the exploitation of redundancy, which is often a default condition in wireless sensor networks. Many properties of complex networks have currently been reported in the literatures. A significant discovery is the observation that many large-scale complex networks are scale-free. People found that scale-free networks display an unexpected degree of robustness, the ability of their nodes to communicate being unaffected by even unrealistically high failure rates. The robustness of scale-free networks is rooted in their redundancy, which for networks represents the existence of many alternative paths that can preserve communication between nodes even if some nodes are absent. With the help of the theory of complex networks, we propose an evolving network model of wireless sensor networks among the cluster heads by random walkers. The analysis of growth dynamic demonstrates that the network topology of evolving has power-law distribution of the connectivities, and Barab¢~si-Albert scale-free model is only one of its special cases. This work has been supported in part by the National Natural Science Foundation of China under Grant No.60573132, ¡°Topology control based on the theory of complex networks in wireless sensor networks¡±.