Design and Application of Enhanced Communication Protocols for Wireless Sensor Networks operating in Environmental Monitoring

The adoption of Wireless Sensor Networks (WSN) for wide area environmental monitoring is currently considered one of the most challenging application scenario for this emerging technology. The promise of an unmanaged, self-configuring and self-powered wireless infrastructure attracts the attention of both final users and system integrators, replacing previously deployed wired solutions and opening new business opportunities. Even if many habitat monitoring applications usually do not provide for strictly real-time performances, however, smart power saving procedures have to be adopted, especially to increase the network lifetime. A common approach is to introduce a low power sleep mode, in which the node's radio section is switched off. In adhoc networking scenarios, this definitely requires the adoption of synchronization procedures, properly scheduling the packet transmission time and avoiding both overhearing effects and collisions. In this paper, a novel class of MAC layer protocols, named STAR MAC, that aims at efficiently managing the node's low power mode, is presented, and properly integrated within a routing scheme, according to the cross-layer design for minimizing the signaling overhead. The proposed solution is applied to a realistic user defined scenario oriented to agro-food production phase monitoring, highlighting remarkable advantages both in terms of cost and complexity reduction and QoS enhancement as well and, consequently, validating the WSN technology adoption.