On Minimizing Broadcast Latency in Duty-cycled Wireless Sensor Networks

Minimizing broadcast latency is one of the most important issues for broadcasting in duty-cycled wireless sensor networks. The existing broadcast schemes do not allow any collision in a schedule to ensure its completion, i.e. all nodes receive a broadcast message collision-freely. A delay of transmission caused by the collision-prevention may increase the broadcast latency if the delay occurs along a critical path of the network. In order to minimize broadcast latency, the paper proposes a broadcast scheduling scheme that provides preference to nodes along critical paths of a network. The proposed scheme allows collision at noncritical nodes to speed up the broadcast process for critical ones. It ensures the completion of a broadcast scheduling by retransmission. Simulation results show that the proposed scheme significantly reduces broadcast latency compared with the existing schemes, and slightly increases the number of transmissions due to retransmission.