Parameterized collision tolerant scheduling for broadcast latency minimization in duty-cycled wireless sensor networks

Broadcast latency minimization is one of the most important problems in duty-cycled Wireless Sensor Networks (WSNs). In order to minimize the broadcast latency, recent scheduling schemes prefer to schedule transmissions to nodes along critical paths of a network. Nodes in a critical path are referred as critical nodes and other nodes is referred as non-critical ones. The schemes are typically motivated to find a collision-free broadcast schedule to ensure their completions, i.e. all nodes receive a broadcast message collision-freely. Observing that any delay on transmission to a critical node will result in an increase of the overall broadcast latency, we propose a novel broadcast scheduling, named Parameterized Collision Tolerant Scheduling (PCTS), that allows collision at non-critical nodes to speed up the broadcast process for critical ones. 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.