Modeling anti-collision protocols for RFID Systems with multiple access interference

Passive tags based on backscattered signals yield low energy consumption and enable a rich set of applications. In this paper, the performance of the dynamic framed ALOHA of the ISO/IEC 18000-6C standard is investigated. A Markov chain model of the protocol is developed by including the effects of the channel under different propagation scenarios. Depending on the air interface parameters and the fading components, it is shown that multiple access interference determines complex and unexpected effects on the system performance. An explicit analysis of the successful interrogation probability is obtained with respect to the number of tags, number of interrogation rounds and fading severity. It is shown that channel statistics may induce significant degradation, although a moderate spread of the fading can be beneficial especially for those contexts that include time-varying conditions.