Pattern Mutation in Wireless Sensor Deployment

In this paper, we study the optimal deployment pattern problem in wireless sensor networks (WSNs). We propose a new set of patterns, particularly when sensors´ communication range (r_c) is relatively small compared with their sensing range (r_s), and prove their optimality among regular patterns. In this study, we discover a surprising and interesting phenomenon-pattern mutation. This phenomenon contradicts the conjecture presented in a previous work that there exists a universal elemental pattern among optimal pattern evolution and that pattern evolution is continuous. For example, we find mutation happens among the patterns for full-coverage and 3-connectivity when r_c/r_s = 1.0459, among the patterns for full-coverage and 4-connectivity when r_c/r_s = 1.3903, and among the patterns for full-coverage and 5-connectivity when r_c/r_s = 1.0406. To the best of our knowledge, this is the first time that mutation in pattern evolution has been discovered. Also, our work further completes the exploration of optimal patterns in WSNs.