A distributed collision-free low-latency link scheduling scheme in wireless sensor networks

In order to guarantee collision-free transmissions in TDMA-based wireless sensor networks, a substantial amount of work in literature has been done by modeling the problem into minimum graph coloring. However, our observation reveals that such approach is not effective towards low-latency transmissions due to the inherent principle of the graph coloring. This paper introduces DCLS, a distributed collision-free low-latency link scheduling scheme. The scheme considers the network snapshot at each time slot, and determines a set of collision-free transmission pairs on each snapshot. With DCLS, the delay is asymptotically smaller than that with the graph coloring model, and the running time complexity on each snapshot is O(diam), where diam is the diameter of the network graph. From the simulation result, the delay is significantly reduced in the network of maximum degree Δ ranged from 6 to 18, and the duty cycle is 0.23 in average.