Randomized scheduling algorithm for data aggregation in wireless sensor networks

We consider a wireless sensor network in which a routing tree has been established to transmit the information from a set of source nodes to a data sink. The existing algorithms to schedule the transmission slots in a way that allows the data to be compressed as it moves towards the data sink are centralized or rely on interference models that fail occasionally. We propose a distributed TDMA scheduling protocol specifically designed for data aggregation called RandSched. RandSched tests whether the transmissions of different sets of nodes succeed simultaneously and only assigns the same slot to them if they have been proved to tolerate each other's interference. By constructing and testing the schedule incrementally, RandSched is more likely to obtain a collision-free schedule than existing algorithms, which is particularly important in large networks. This is confirmed by our simulations, which also reveal a low scheduling overhead and a reduced transmission latency.