Coverage and Connectivity Issues in Wireless Sensor Networks
Amitabha Ghosh, Sajal Kumar Das · 2005
Area coverage and node connectivity are two of the most fundamental problems in ad hoc wireless sensor networks because they are directly related to optimization of resources in a sensing field. Since in most practical scenarios sensors are randomly distributed, finding an optimal deployment strategy that would minimize cost, reduce computation and communication, be resilient to node failures and provide a high degree of area coverage is extremely challenging. Coverage and connectivity together can be considered as a measure of quality of service (QoS) in a sensor network, for it means how well each point in the sensing field is covered while at the same time satisfying the criterion that each node is within the communication neighborhood of at least one other node. Therefore, maximizing coverage as well as maintaining node connectivity in a severely resource constrained environment is a non-trivial optimization problem. In this chapter, we first briefly introduce the notion of coverage and connectivity in a sensor network. Then we provide a mathematical framework and formalize the coverage-connectivity problem. In the subsequent sections, we describe the several approaches that have been taken in the past to find out optimal sensor deployment strategies for static, mobile as well as in mixed sensor networks keeping the resource constraints in mind. We also compare these approaches and algorithms based on their goals, assumptions, complexities and usefulness in practical scenarios. Lastly, we discuss the open problems and research challenges with respect to deployment issues in sensor networks.