Data aggregation scheduling in uncoordinated duty-cycled wireless sensor networks under protocol interference model

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, we investigate the DAS problem in uncoordinated duty-cycled WSNs (DAS-UDC problem) under protocol interference model and prove its NP-hardness. To solve this problem, we propose two novel approximation algorithms called SDAS and CDAS with the data aggregation latency of at most O(Rs+ Δ) and O(R + Δ) respectively, where Rs, Δ and R are the maximum depth of the breadthfirst- search tree rooted at the sink node s, the maximum node degree and the graph-theoretic radius of the network respectively.We conduct extensive simulations to evaluate the performance of our algorithms and report their average performance.