A Workload-Aware Link Scheduling for Heterogeneous Wireless Sensor Networks

We focus on the problem of links scheduling in heterogeneous wireless sensor networks. Links scheduling becomes more difficult due to the diversity of workload among sensor nodes. An improper links scheduling strategy will lead to high end-to-end delay and then diminish the data availability. We assume the energy cost of state transition cannot be ignored, especially for wireless multimedia sensor node which equips with camera and higher performance processor compared to scalar sensor node. In this paper, we use the conflict graph to model the conflicts among nodes and then propose a workload-aware heuristic scheduling algorithm. In the scheduling, each node can obtain consecutive time-slots to transmit all data at a schedule transmission, and the number of time-slots is calculated based on nodeâs workload. Hence, it is possible for our scheduling to reduce the end-to-end delay and save energy consumed by nodeâs state-switching in heterogeneous wireless sensor networks. In additional, a metric is proposed to measure the frequency of nodeâs state-switching. The numerical results show that our scheduling can reduce the end-to-end delay and meanwhile improve energy efficiency by reducing the energy cost of state-switches.