Distributed connectivity restoration using cognitive relay nodes positioning in damaged wireless sensor network

Natural d isasters such as earthquakes, storms and fire scenes can led to the failure of many nodes simultaneously in wireless sensor network, leaving behind multiple isolated network segments. Establishing connectivity among different segments is possible by deploying relay nodes. There are couples of challenges in the deployments mechanism, i.e., how many relay nodes will be sufficient and where these relay nodes should be placed. For a scenario, with known information about segmented network such as number of segments, number of nodes in each segment and the location of each node, these problems can be solved in a centralized fashion. However, for a damaged network with unknown information, a distributed connectivity establishment mechanism is required. In this paper, a distributed connection restoration algorithm (DCRA) is proposed. In this algorithm, cognitive radio based relays move in the subjected area and try to establish the connection among various segments of the damaged network. The main aim of the DCRA is to establish the connection quickly with less number of possible relay nodes. The results demonstrate the significance of the proposed algorithm.