Energy Efficient Transmission Scheme for Data-Gathering in Mobile Sensor Networks

Mobile sensor networks are being envisioned for certain applications like habitat monitoring and environmental sensing. For instance, mobile sensor nodes are attached to selected animals to gather data about their behavior. These data are uploaded to stationary units for detailed analysis over wireless ad-hoc networks. Since the mobile sensor nodes are likely to operate on batteries, reducing energy consumption for such data gathering is an important issue. This paper proposes a transmission scheme for power-adjustable radio to optimize transmit energy efficiency subject to given overflow and delay constraints. The energy efficiency is defined as the expected transmit energy to deliver one unit of data from sensor node to stationary unit. An analytical model is developed to estimate the unit energy, data throughput and delay for a sensor node in the single-hop case. Simulation results show that the model achieves very good accuracy. The proposed transmission scheme is then adapted to the multi-hop scenario. Simulations based on radio parameters from a sensor board demonstrate that high energy efficiency can be achieved by the transmission scheme in both single-hop and multi-hop cases