Design and experimental evaluation of long-distance and high-mobility ZigBee transceivers for WSNs

With the rapid development of wireless sensor networks and Internet of Things (IoT), ZigBee has attracted increasing attention from both the academia and industry due to its advantages of low cost, low power consumption and easy networking configuration. However, as originally defined for Personal Area Networks (PANs), a typical transmission distance of a ZigBee device is only 10100m. Such short distance limits the applications of ZigBee such as for the large-scale sparse wireless sensor networks and long-distance low data-rate transmission. In this paper, we propose a simple and robust ZigBee transceiver design that supports the transmission distance of 1.2km and moving speed of 60km/h. Such capacity is achieved by two mechanisms, i.e., using the power amplifier and Low-Noise-Amplifier (LNA) on the transmit and receive path, respectively, and dual directional antennas. Furthermore, an antenna switching MAC protocol is proposed to avoid the deafness problem introduced by using directional antennas. Comprehensive field tests have proven the performance of the designed system. The hardware and protocol design provides a validated, low-cost ZigBee node with the capacity of low data-rate, long distance transmission in high mobility.