Data sweeping in deterministic trajectories-covered Wireless Sensor Networks

Mobile Elements (MEs) are widely employed for data collection in Wireless Sensor Networks (WSNs) to balance the energy consumption and prolong the network lifetime. However, the limited travel speed of the MEs causes a large data collection latency, which in turn degrades the performance of the data collection task and weakens the applicability of the data collection schemes. Considering the deterministic concentric circle-like trajectories-covered sensing field, we propose a Low-latency Data Sweeping scheme, LDS, which utilizes the communication opportunities among MEs to shorten the data collection latency. The data are swept by the MEs, which traverse along the trajectories, and are relayed to the adjacent MEs towards the sink node. Besides, the transmission range of sensor nodes is limited to the minimum distance to the nearest trajectory for energy-conservation purposes. The performance of the proposed scheme is first analyzed with probabilistic methods. Extensive simulations further show that our scheme outperforms the well-known heuristic algorithms in terms of the data collection latency, energy dissipation, and network lifetime.