Making Aggregation Scheduling Usable in Wireless Sensor Networks: An Opportunistic Approach

The problem of aggregation scheduling in wireless sensor networks is widely studied in order to minimize aggregation latency and prevent collisions. Many aggregation scheduling algorithms have been designed for time-critical applications. However, all of the existing work on aggregation scheduling suffers from packet losses due to the lossy links in wireless sensor networks. We observe that high data loss rates of over 90% often occur using existing scheduling algorithms when the link qualities are poor. This makes the aggregation scheduling algorithms impractical in real applications. This paper makes aggregation scheduling usable by proposing an opportunistic approach to improve the delivery rate by elaborately selecting opportunistic links for sensor nodes. Simulation results verify the efficiency of our approach. One of our methods can achieve delivery rates of close to 100% in various network conditions.