Analysis and Assessments of Time Delay Constrains for Passive RFID Tag-Sensor Communication Link: Application for Rotation Speed Sensing

Radio frequency identification (RFID) sensors are increasingly recognized as the way for achieving smart environment monitoring. Real world industrial applications, such as multiobjects orientation detection, motion sensing as well as monitoring in harsh environment require real-time operation and fast responses for control decisions. This paper examines the timing analysis of UHF networked RFID sensors tag system and the factors influencing time latency. Time constrains in RFID communication channel, such as the minimum detection time of the reader in the vicinity of the RFID tag and the effect of protocol requirements are examined experimentally for commercial tags in compliance with the European Telecommunications Standards Institute (ETSI) regulations. This assessment has the objective to analyze the RFID tag for instance as a motion sensor. In order to illustrate the interest of the presented delay analysis, a method to measure the response time due to rotation speed is introduced. A case study using two commercial RFID tags under rotation is presented and analyzed in terms of delays.