HAR: A Hotspots-based Adaptive Routing in Delay Tolerant Mobile Sensor Networks
Feng Lin, Bai Jun Wu and Ji Liu Zhou
Delay Tolerant Mobile Sensor Networks (DTMSN) is built to provide data delivery service for ubiquitous applications in challenging scenarios, such as battlefield monitoring, disaster areas rescuing and wild environment surveillance. With respect to traditional Wireless Sensor Networks (WSN), DTMSN are much more resilient to sparse connectivity, dynamic topology and long network partitions. Recent research show conventional routing protocols for WSN are not suitable for DTMSN. Since end-to-end connections in DTMSN exist with certain probability, utilizing the knowledge concerning regularity of nodal mobility would play a key role in routing designs. In this work, we propose a new carrier-based routing scheme constructed upon nodal mobility patterns, named HAR (Hotspots-Based Adaptive Routing for DTMSN). In our scheme, the popular areas that nodes visit frequently, called hotspots, are classified dynamically. A mobile-assisted carrier is assigned to each class to transmit data from nodes to sink by visiting hotspots. In this paper, we provide an analysis of nodal mobility by relaying real mobility models. We also study the hotspots selection problem which is NP-hard and give a greedy algorithm to find hotspots. The simulation results show that our scheme performs better than other routing approaches like Message Ferry, and adapts well under different circumstances.
Keywords: Wireless sensor networks (WSN), delay tolerant mobile sensor networks (DTMSN), carrier-based routing, mobility model, set-cover problem, NP-hard