Node failure in Wireless Sensor Networks (WSNs) is a fundamental problem because WSNs operate in hostile environments. The failure of nodes leads to network partitioning that may compromise the basic operation of the sensor network. To deal with such situations, a rapid recovery mechanism is required for restoring inter-node connectivity. Due to the immense importance and need for a recovery mechanism, several different approaches are proposed in the literature. However, the proposed approaches have shortcomings because they do not focus on energy-efficient operation and coverage-aware mechanisms while performing connectivity restoration. Moreover, most of these approaches rely on the excessive mobility of nodes for restoration connectivity that affects both coverage and energy consumption. This paper proposes a novel technique called ECRT (Efficient Connectivity Restoration Technique). This technique is capable of restoring connectivity due to single and multiple node failures. ECRT achieves energy efficiency by transmitting a minimal number of control packets. It is also coverage-aware as it relocates minimal nodes while trying to restore connectivity. With the help of extensive simulations, it is proven that ECRT is effective in connectivity restoration for single and multiple node failures. Results also show that ECRT exchanges a much smaller number of packets than other techniques. Moreover, it also yields the least reduction in field coverage, proving its versatility for connectivity restoration.

Cut-vertex; failure recovery; network connectivity; node relocation; wireless sensor network; node failures