Rapid RFID tag collision resolution with the frame slotted ALOHA protocol

RFID holds the promise to provide a bridge between the physical item world and the digital virtual space. One of the key issues that affect this promise to become a reality is the tag collision. When multiple tags try to transmit their digital identifiers simultaneously to the reader, tag collision will occur. In this paper, based on the analysis of the frame slotted ALOHA protocol commonly used for tag collision resolution, the optimal frame size for the protocol to adopt in resolving the collisions caused by different number of tags is calculated, and two enhanced frame slotted ALOHA protocols are proposed for the rapid resolution of collisions caused by a large amount RFID tags. The performances of these protocols are evaluated and it is verified that this protocols outperforms the traditional frame slotted ALOHA protocols.