Centralized connectivity restoration in multichannel wireless sensor networks

Wireless sensor networks (WSNs) are widely used in various domains. In general, the applications, in which the WSN is deployed, require that this network presents a minimum degree of reliability, effectiveness and robustness. However, the specificity of the nodes deployed in this kind of networks makes them prone to failures. One of the important problems caused by a sensor node failure is the loss of the network connectivity, which means that some network parts become isolated and hence, the nodes cannot reach the sink. In addition to the initial nodes' deployment that ensures the connectivity, other connectivity restoration mechanisms must be integrated to overcome the problem of WSN partition after a node failure. In this paper, we propose two centralized approaches for the connectivity restoration in a multichannel WSN. The first approach Preventive Failure Recovery (PFR) performs just before the partition of the network while the second approach Rotating Nodes based Failure Recovery approach (RNFR) is a reactive approach that intervenes after the failure occurrence. The main task of these two approaches targets the reorganization of the network in the failed nodes' vicinity to restore the connectivity and hence ensure an optimal channel allocation as for the initial configuration. We prove the performance of the two proposed approaches by evaluating them through simulation and comparing them to each other and to another existing approach.