RFID tags have been used by railways for many years, RFID has proven its worth in inventory management, yet this technology is underutilized for enhancing railway operations and health monitoring due to limitations of passive RFID technology. Active RFID provides enhanced capabilities with potential to improve railway operations. Active technology differs from passive RFID by incorporating an onboard power source enabling longer ranges, changeable data fields, and the ability to transmit independently of the reader. This paper compares the advantages and disadvantages of active compared to passive RFID in terms of power requirements, transmission range, and dynamic data. A survey of existing products and vendors is presented. The existing active RFID standards are reviewed and elements of the data tag protocols are detailed as well as protocols for mitigating collisions of data packets. Finally, specific railway applications utilizing active RFID are discussed.
Spatial Signal Attenuation Model of Active RFID Tags
