Mobile relays based federation of multiple wireless sensor network segments with reduced-latency

Wireless sensor networks are used to continuously monitor certain area of interest and send data to a base station for processing. In many applications, WSN serve in inhospitable environments where multiple nodes may simultaneously fail causing the network to be divided into disjoint segments. Restoring connectivity in this case would be necessary for the WSN to become fully functional again. A similar scenario is when multiple standalone WSNs may need to be federated to collectively handle an important event that requires data sharing among these networks. A viable approach for establishing connectivity among these network segments is by employing mobile data collectors (MDCs). Few MDCs can be used to create intermittent links among the segments by touring and carrying data. Obviously, the travel path of the MDCs will affect the date delivery latency. We present two algorithms for finding optimized travel routes for the MDCs so that the average and maximum delay for delivering the inter-segment traffic is minimized. The algorithms deal with two variants of the federation problem that differ in the available MDC count. The first algorithm handles the case when the number of available MDCs is more than the number of segments, while the second tackles the problem when the MDC count is significantly less. The performance of the algorithm is validated through simulation.