Impact of Mobility and Heterogeneity on Coverage and Energy Consumption in Wireless Sensor Networks

In this paper, we investigate the coverage of mobile heterogeneous wireless sensor networks (WSNs). By the term heterogeneous, we mean that sensors in the network have various sensing radii, which is an inherent property of many applied WSNs. Two sensor deployment schemes are considered-uniform and Poisson schemes. We study the asymptotic coverage under uniform deployment scheme with i.i.d. and 1-dimensional random walk mobility model, respectively. We propose the equivalent sensing radius (ESR) for both cases and derive the critical ESR correspondingly. From the perspective of critical ESR, we show that 1-dimensional random walk mobility can increase coverage under certain delay tolerance, and thus decreases sensing energy consumption. Also, we characterize the role of heterogeneity in coverage and energy performance of WSNs with these two mobility models, and present the discrepancy of the impact of heterogeneity under different models. Under the Poisson deployment scheme, we investigate dynamic k-coverage of WSNs with 2-dimensional random walk mobility model. There are many reasons for designers to require k-coverage rather than 1-coverage. Both k-coverage at an instant and over a time interval are explored and we derive the expectation of fraction of the whole operational region that is k-covered, which also identifies the coverage improvement brought by mobility.