Decentralized Synchronization forZigbee wireless sensor networks inMulti-Hop Topology

The most effective solution for energy saving in low-rate wireless sensor networksis maintaining each node in a doze state as long as possible. In order to guarantee networkconnectivity, the intervals at which the network sensors are turned on and off have to becoordinated. We analyze the Zigbee MAC performance in sensor networks deployed in multi-hop topologies. For this networks, critical inefficiencies can arise due to transmissions performedby hidden nodes. We evaluate the impact of different synchronization schemes on the networkperformance, both in terms of network capacity and in terms of energy consumption. We showhow the synchronization function can be opportunistically configured in order to emulate atoken-like access mechanism, able to significantly improve the network performance.