Date Added: Nov 2010
Data aggregation is a critical and widely-used operation in Wireless Sensor Networks (WSNs). Data Aggregation Scheduling (DAS) aims to find an interference-free scheduling for data aggregation with the minimum latency. Most existing algorithms for the DAS problem, unfortunately, assume that nodes are always active, and hence are not suitable for duty-cycled scenarios. In this paper, the authors investigate the DAS problem in Uncoordinated Duty-Cycled WSNs (DAS-UDC problem) under protocol interference model and prove its NP-hardness.