A holistic sensor network design for energy conservation and efficient data dissemination

One important application of wireless sensor networks is to track mobile elements in the field, where the sensor network generally consists of a large number of sensor nodes deployed in an unattended environment and the sensor nodes are unlikely to be recharged. Redundant sensor nodes are often deployed to increase network robustness and extend network lifetime. There is a big challenge to distribute information and conserve energy in resource-constrained, densely populated sensor networks. Target and inquirer mobility brings further challenges to large-scale sensor networks. Frequent location updates for multiple inquirers and targets can drain the limited on-board energy excessively. We propose a holistic system design across media access control, network and application layers to optimize the performance of large-scale sensor networks by taking into account the interactions and tradeoffs between different design objectives. Our system includes a two-level node activity scheduling scheme for energy conservation and a scenario-aware data dissemination scheme to efficiently distribute query and event data and handle inquirer and target mobility. Furthermore, we analyze the system delay and introduce an adaptive scheduling scheme to reduce the initial sensing delay. The simulation results show that our system can save more than six times of the energy with reduced transmission delay and increased data delivery ratio.