LBcast: Load-balanced Broadcast Scheduling for low-duty-cycle Wireless Sensor Networks

Recently, broadcast scheduling for low-duty-cycle WSNs has been extensively studied. However, most of the existing solutions mainly focus on energy efficiency optimization in terms of total energy consumption and very few of them take into account the load balance, which is an important design objective in low-duty-cycle WSNs. In this paper, we propose an energy-efficient broadcasting schedule for low-duty-cycle WSNs, which approximately minimizes the maximum workload of nodes for broadcasting while achieving low total energy consumption. By capturing the spatiotemporal characteristic of broadcasting in low-duty-cycle networks, we first model our scheduling problem as the Directed Minimum Weighted-degree Steiner Tree Problem, which is NP-hard. To solve this problem, we devise the Load-Balanced Broadcasting Schedule (LBcast) algorithm. Further, we introduce how to implement it in a distributed way. Our simulation results reveal that compared with the existing solutions considering the optimization of total energy consumption, LBcast exhibits much better load balance and also achieves low total energy consumption.