In this research, the authors developed a Gate Sensor System (GSR), which uses the passive-type RFID tags
(to overcome the drawbacks of the active-type sensors) and the Wireless Sensor Network (WSN)
technology based on Zigbee and digital wireless telephony and data network (i.e. the CDMA network). Pilot tests and on-site field tests were conducted for evaluating technical feasibility of our system.