A Query Tree Dynamic Frame Slot ALOHA Collision Resolution Protocol for RFID Tags

One of key issues that affect the universal adoption of the RFID system is the tag collision. The protocols in the frame slot ALOHA and the binary tree families work clumsily in the collision resolution of dense RFID tags. A hybrid protocol, Query Tree Dynamic Frame Slot ALOHA (QTDFSA) is proposed to work in dense tag environment. Based on data gathered and requirement of application system, QTDFSA divides the tags to multiple subgroups using binary suffix strings, and dynamic frame slot ALOHA protocol is employed to resolve tags and collect information in each subgroup. This division and resolution procedure is performed recursively until the required accuracy is satisfied. Numerical simulation shows that this protocol outperforms other frame slot ALOHA protocols and high throughput can be achieved in the identification.