DOCW: Dynamic overlapping contention window algorithm of wireless sensor networks

Flooding is often used by routing protocol to establish a routing tree. However, the effect of backoff mechanism on routing tree topology is ignored by most of researchers on designing their routing protocols. In addition, the collision is much more fiercely in a flooding procedure. In this paper, the influence of backoff mechanism on establishing routing tree topology and the message collision in flooding are analyzed. Based on the shortest path and congestion degree, a new method to estimate routing tree is developed. Furthermore, The DOCW (dynamic overlapping contention window) algorithm which used in the procedure of establishing routing tree is proposed. By hearing the activity of neighbors, each node can adjust its activity automatically. Simulation results demonstrate that the DOCW performs better than IEEE802.11 and IEEE802.15.4 in message flooding, congestion avoidance and topology control.