Data Delivery in Fragmented Wireless Sensor Networks Using Mobile Agents

Due to the wide range of applications in sensors and Wireless Sensor Networks (WSN), research in this area has recently received increasing attention. WSNs rely oil network connectivity to deliver data to a base station through multihop communication. However, connectivity may not be always achievable for a number of reasons. In this paper, we study the problem of data delivery in disconnected WSNs. A special class of disconnected sensor networks called "Fragmented wireless sensor networks (FWSN)" is considered. A FWSN consists of several groups of connected sensors that we call "fragments". To achieve connectivity between these fragments, mobile agents move in the network and act as data relays between fragments, in order to eventually deliver data to the base station. The main contribution of this paper is the modeling of the movement of these mobile relay nodes as a closed queueing network to obtain steady state results of the distribution of the mobile relays in the network. Building on these results, we derive the distributions of the fragment-to-fragment, and fragment-to-sink delays. Comparing these analytical results to results from the TOSSIM simulator, it, is shown that this model accurately captures the system behavior, and call be used to predict data delivery delays.