Mitigating Energy Cost of Connection Reliability in UWSNs Through Nonuniform <i>k</i> -Connectivity

Underwater sensing via networked platforms (i.e., underwater wireless sensor networks – UWSNs) is extremely useful in a plethora of applications such as monitoring underwater assets and surveillance against submerged threats. Maintaining reliable connectivity is of utmost importance in UWSNs, which can be achieved through k-connectivity (i.e., each sensor node maintains at least k node-disjoint paths towards the base station – BS). However, the energy cost of k-connectivity is prohibitively high, especially with large k values. As a tradeoff, it is possible to mitigate the extra energy cost of k-connectivity by employing a non-uniform k assignment strategy in a UWSN (e.g., only the most critical sensors have high k values whereas the rest of the nodes have lower k values). Non-uniform k-connectivity is a novel concept which has never been systematically investigated in the literature, to the best of our knowledge. In this study, we investigate the tradeoff between network lifetime (NetL) and reliability via non-uniform k-connectivity through the use of a novel optimization framework. Our analysis reveal that it is possible to provide strong connection reliability to critical nodes by adopting a non-uniform k-connectivity strategy without deteriorating network lifetime significantly.