Probabilistic Coverage and Connectivity in Wireless Sensor Networks

Several empirical studies have shown that sensing and communication ranges of sensors are not regular disks. Rather, they follow probabilistic models. Yet, many current coverage and connectivity protocols continue to assume the disk model for ease of analysis, which may lead to incorrect operation of these protocols in real environments. We propose a distributed coverage and connectivity maintenance protocol that explicitly accounts for the probabilistic nature of communication and sensing ranges. Through analytical analysis, we show that our protocol guarantees a target packet delivery rate in the network, while ensuring the monitored area is covered with a probability exceeding a given threshold. Using large-scale simulations, we compare our protocol against others in the literature and show that it activates fewer nodes, consumes much less energy, and significantly prolongs the network lifetime. We also demonstrate the robustness of our protocol against random node failures, node location inaccuracy, and imperfect time synchronization.