Latency optimization through routing-aware time scheduling protocols for wireless sensor networks

Abstract

Communications in wireless sensor networks are mainly controlled by the temporal decisions of the data link layer and the spatial decisions of the network layer. When taken independently, these decisions may not be correlated which affects the latency metric. To tackle this problem, we propose cross-layer algorithms to define TDMA (Time Division Multiple Access) schedules based on routing information. Two main strategies are applied, based on routing tree traversals or on adapted ones using information from the network’s graph. We also present the Optimal scheduling algorithm which finds the scheduling with the minimal latency; the latter is used to compute the efficiency of our heuristics. Extensive simulations have been performed and show improvement in latency up to 29% compared with existing works. The effect of the heuristics on the duty-cycle is studied in the perspective of energy consumption. The duty-cycle is improved up to 11.54%.