Multichannel Slotted-Aloha Anticollision Protocol for Active RFID Systems

We propose a multichannel slotted-aloha anticollision protocol to mitigate the tag collision problem and improve tag collection performance in active RFID systems. In the proposed anticollision protocol, while an RFID reader transmits commands to multiple RFID tags via a common radio channel, it receives multiple tag responses over multiple radio channels simultaneously. We also implemented an active RFID system supporting the proposed anticollision protocol. In experiments with the implemented reader and 60 tags, the average time spent on tag collection using the dual-channel anticollision protocol was 46.5% of that required using the single-channel anticollision protocol.