Achieving adaptive broadcasting performance tradeoff for energy-critical sensor networks: A bottom-up approach

Low-duty-cycle mode is widely adopted in energy-critical wireless sensor networks (WSNs). Such mode greatly reduces the energy waste caused by idle listening. However, it brings many new challenges for broadcasting. This paper mainly focuses on the minimum cost broadcast problem for low-duty-cycle WSNs. We propose a novel opportunistic broadcasting transmission model, which makes full use of the broadcast nature of wireless media to reduce the total energy consumption for broadcasting. The key idea is to allow nodes to defer their wake-up slots to opportunistically overhear the broadcasting messages sent by their neighbors, which could reduce the total energy consumption for broadcasting but increase the average end-to-end broadcasting delay. In this paper, we define a generalized broadcasting cost function, which can make a flexible tradeoff between average end-to-end broadcasting delay and total energy consumption for broadcasting, to adaptively meet various broadcasting performance requirements. Our target is to utilize the opportunistic broadcasting transmission model to design an efficient broadcasting schedule for low-duty-cycle WSNs, so that the broadcasting cost function is minimized. First, we define the Receiver-Constrained Minimum Cost Single-hop Broadcast Problem (RC-MCSB) and propose an optimal solution with a polynomial running time. Next, we extend the solution of RC-MCSB problem to our target problem and present a novel and efficient bottom-up solution. The simulation results have verified the significant performance advantage of our proposed bottom-up solution over the existing top-down solutions and the other solutions.