Keynote address: Restoring connectivity of partially damaged wireless sensor networks

Wireless sensor networks (WSN) often operate unattended in harsh and inhospitable environments. While such deployment eliminates/reduces human intervention and provided fully-automated data gathering systems, WSNs are prone to sensors failure which not only can degrade the quality of coverage but also disrupt the data traffic. To address such a problem, most approaches in the literature deploy redundant nodes during network setup and reconfigure the network topology to establish alternate data paths. However, sometimes the network suffers a loss of a critical node or a large scale damage that involves many nodes and would thus create multiple disjoint partitions. For these cases, a provisioned approach for tolerating occasional failures at the network design level will not be effective. This talk analyzes the effect of a node failure on connectivity and explores the different recovery options. A number of schemes for connectivity restoration will be described. A summary of ongoing efforts and open research problems will be also presented.