Efficient mobile sink-based data gathering in wireless sensor networks with guaranteed delay

In this paper, we present a rendezvous-based data gathering protocol for wireless sensor networks employing a mobile sink. For satisfying timely delivery of sensory data to the mobile sink, the mobile sink is forced to visit only an appropriate number of rendezvous nodes while the remaining nodes send their data through multi-hop communication toward the rendezvous nodes. The proposed technique achieves prolonged network lifetime by selecting energy rich paths for this multi-hop communication. Specifically, first the network is partitioned into a number of clusters and then the cluster heads of an appropriate number of energy rich clusters are selected as rendezvous nodes in such a way that (i) the rendezvous nodes are appropriately distributed across the network area to ensure energy efficient data gathering from the other sensor nodes to the rendezvous nodes and (ii) the length of the mobile sink trajectory is below a certain limit. Then, by exploiting the clustering structure, energy efficient routes are determined for all sensor nodes of the network toward the mobile sink trajectory. Experimental results confirm the effectiveness of our approach compared with other competitive approaches from the literature.