Energy-efficient platform designed for SDMA applications in mobile wireless sensor networks

Although advance network planning and dense node deployment, wireless sensor networks (WSNs) may achieve the required performance, it still face the fundamental challenge of meeting stringent power and time requirements using nodes with limited sensing capacities. To better cope with the power consumption problem, mobile sensor nodes can be introduced to dynamically reconfigure the sensor network capacity in an on-demand manner. Through data gathering and relaying, mobile nodes can reduce the amount of data transmitting between the static nodes then conserve the power of these nodes to prolong the lifetime of network. In this paper we describe the DataTruck, a new open-source sensing platform specifically designed to support our experimental research in mobile sensor networks, which is used to collect or relay data from static sensors. The DataTruck node is designed around the S3C2440A ARM920T RISC microprocessor and the IEEE 802.15.4 compliant CC2431 radio from Chipcon. Mobility is enabled with an additional accessory board that allows the node to drive its 4 linear motion actuators. To reduce power consumption, a long term sleep mode is supported through different power supplying methods for main board and clock. Furthermore, we integrated a smart antenna system to gather the data from multiple static nodes concurrently which transmitting data using the same frequency of channel. The experiments show that DataTruck collects data efficiently to reduce the average data transmission delay by using SDMA technology.