Multipacket reception MAC schemes for the RFID EPC Gen2 protocol

Maximizing the Radio Frequency IDentification (RFID) performance is one of the main challenges for a wide variety of applications, where the overall throughput can be significantly affected by undesired Tag-Tag collision events. The UHF EPC Class-1 Generation-2 (Gen2) protocol only specifies algorithms to avoid the collisions but makes no provision for their resolution. In this paper, performance enhancement of the RFID EPC Gen2 protocol exploiting Tag collision recovery is demonstrated, for the first time, in real time with measurements. Two simple and effective approaches to handle successful Tag acknowledgments of recovered collided packets are proposed and implemented on a software-defined Reader and programmable Tags. The overall throughput per time slot is increased by 72% over the standard Gen2 MAC scheme. The validity of such result is confirmed by the good agreement with simulations reported in the literature.