TRACK: A Novel Connected Dominating Set based Sink Mobility Model for WSNs

The core functionality of a wireless sensor network (WSN) is to detect deviations in expected normal behavior and report it to the sink. In this paper, we propose TRACK - a novel sink mobility model exploiting the connected dominating set (CDS) property of a network graph. TRACK, to the best of our knowledge, is the first contemporary sink mobility model to exploit the CDS property for WSN lifetime longevity and secure data aggregation. In TRACK, the CDS of the given network is computed and then the minimum spanning tree (MST) of the CDS is constructed. Using the CDS-MST as the underlying framework, a Hamiltonian circuit (HC) is constructed, along which the sink is mobilized to traverse the network. Since TRACK, by the very definition of CDS, passes through the transmission range of every node in the network, data can be relayed directly from the source node to the sink, eliminating the need for multi-hop routing. By virtue of this property, nodes in the WSN are discharged from their routing obligations and data aggregation becomes more secure. Additionally, we propose an extended version of TRACK called M-TRACK in this paper. The extended model trades higher fractions of sensor energy with the objective of minimizing the length of sink trajectory. This consequently minimizes the delay between consecutive sink visits, mitigating buffer-overflow of sensors. M-TRACK does necessitate multi-hop routing, but keeps it within a bounded number of hops. We confirm the efficiency and robustness of our models via simulation and analysis, and show that our model can extend the WSN lifetime up to seven times that which can be achieved using a static sink.