Node placement in linear Wireless Sensor Networks

A Wireless Sensor Network (WSN) for structural health monitoring (SHM) of bridges is considered. SHM applications tend to produce high volume of sensing data and WSNs require considerable amount of energy to transmit them along the length of a bridge, which highly affect the lifetime of battery-run sensor nodes. Moreover, in such multi-hop linear network topologies some sensors have to handle more traffic than others. As a result, their energy may drain out faster, these sensors die and the network become disconnected. In this paper we propose a methodology for optimum placement of sensor nodes in linear network topologies (e.g., along the length of a bridge) that aims to minimize the link connectivity problems and maximize the lifetime of the network. Both simple packet relay and network coding are considered for the routing of the collected data packets towards two sink nodes positioned at both ends of the bridge. Our mathematical analysis, verified by simulation results, shows that the proposed methodology can lead to significant energy saving and prolonged network lifetime.