Optimized scheduling for data aggregation in wireless sensor networks

The most important issue in wireless sensor networks is energy consumption. To this end, many networking schemes attempt to minimize the amount of data transmitted by using data aggregation. This trades off data freshness for a savings in energy, because reports from sensor nodes that arrive at an aggregating node may have to be held there for some period of time before being reported so that additional reports may reach the aggregator from slower nodes. We propose to use an intelligent timer and some high-level knowledge of the network to implement an efficient aggregation timing control protocol. Our protocol aims to dynamically change the data aggregation period according to the aggregation quality. A request from the data sink will include the maximum latency for a certain number of reports. If this number of reports can be returned in less time than the maximum, then the maximum time will not be reached. If, however, the specified number of responses can be returned in anywhere between zero-time (instantaneous) and the maximum latency, the timing scheme will find the minimum aggregation period that satisfies the sink´s request.