Understanding performance limits in wireless sensor networks

In this PhD thesis, we study the fundamental limits of the network performance with respect to coverage, connectivity, lifetime, power, energy, and capacity in wireless sensor networks. An interesting finding is that most of the performance limits are linked at heart by the power consumption of sensor nodes and sensor networks.; We first address the problem of maintaining sensing coverage and connectivity in large scale wireless sensor networks. We prove a necessary and sufficient condition under which coverage infers connectivity: the radio range is at least twice the sensing range. We then devise a localized algorithm OGDC that can form a connected coverage set of sensors using a small number of sensors.; We next analyze the lifetime upper bounds for a wide class of algorithms that maintain coverage and connectivity in sensor networks. Based on the theory of coverage processes, we derive the asymptotic lifetime upper bound in an infinitely large region under several different model assumptions and several different types of node deployment methods. In addition, we investigate the lifetime upper bound for which only alpha portion of the area is covered and also devise an algorithm that can approach the derived lifetime upper bound.; We also study the minimum total power (termed as critical total power) required for maintaining k-connectivity. We prove both an upper bound and a lower bound of the critical total power. We find that by allowing each node to choose different transmission ranges, the average power consumption can be reduced by an order of theta((log lambda) c/2), compared with the case when all nodes choose a common minimum power to ensure k-connectivity.; Finally, we study the minimum energy required for transporting packets between two arbitrarily chosen source and destination in a random wireless network. We prove both an upper bound and a lower bound of the minimum transporting energy. We also show several results of network transport capacity based on the findings.