An energy-efficient self-organizing global extremity reporting scheme for sensor networks

In this paper we propose an energy-efficient self-organizing global extremity reporting scheme for wireless sensor networks. The proposed scheme assists applications of periodic reporting of extreme values (such as maximum or minimum temperature/pressure) across a wireless sensor field, back to the sink. Furthermore, an event-driven counterpart is supplied for individual sensor nodes to supply their instantaneous sensed values back to the sink, once queried. The targeted sensors initially establish their relative distances to the sink in regards to number of hops, whilst the highest hopcount nodes (HHNs) from the sink identify themselves. The broadcast initiation of the HHNs have the ability to penetrate all nodes within the network towards the sink, and hence obtain the extreme value of the entire network in an efficient manner. This is due to the relative position of these special nodes within the network. Furthermore, the scheme does not require nodes to possess location information of themselves or other nodes, avoiding the need for the global positioning system (GPS) or other location-aware methods. Simulation results show the effectiveness of the proposed protocol in its target application. In particular, the advantage of HHN-initiated broadcasting can be seen in both uniformly and randomly distributed topology networks. Copyright # 2008 John Wiley & Sons, Ltd.