A New Approach for Boundaryand Holes Detection for Wireless Sensor Networks

Wireless sensor networks (WSNs) comprise a large number of sensor nodes, whichare spread out within a region and communicate using wireless links. In some WSNapplications, recognizing boundary nodes is important for topology discovery, geo­graphic routing and tracking. In this thesis, we study the problem of identifyingthe boundary nodes of WSN. In WSN, close-by nodes can communicate with theirneighbors and have the ability to estimate distances to nearby nodes. Our objectiveis to find the boundary nodes by using the connectivity relation and neighbor dis­tance information without any knowledge of node location. We develop two novelalgorithms that detect the boundary sensor nodes in WSN and connecting them intodifferent subgraphs. where each algorithm works under specific properties of WSN.Moreover, we design distributed algorithms that work in density and sparse network.Management the coverage of the monitoring region is important for both of energyconservation and network lifetime improvement. In addition to boundary detectionproblem, we present an efficient algorithm that discovers overlapping sensing regionsto effectively discovers redundant sensor nodes using virtual distances between sensornodes without any knowledge of node location. Also, we introduce an energy-awarealgorithm which constructs the optimal coverage set of sensor nodes to stand as activesensor nodes in WSN. where these sensor nodes used for nodes schedule, topologycontrol, etc. We design a new distributed algorithm where it prolongs the lifetime ofthe network and reduces the energy consumption of the sensor nodes.