Anti‐Collision of Multiple‐Tag RFID Systems

This chapter examines the collision problem from the view of MAC layer, where the collisions are resolved based on several rounds of communications between the reader and RFID tags. Basic anti-collision protocols, which can be broadly categorized into Aloha-based algorithms and tree-splitting based algorithms, have been recommended in RFID standards and implemented in practical RFID systems. The chapter discusses some basic Aloha-based and tree-splitting (TS)-based anti-collision algorithms and presents some analytical tools to analyse the performance of the algorithms. It explains two simple adaptive Aloha algorithms, which can greatly reduce the tag's mean identification delay or inventory time. For tree-splitting based anti-collision algorithms, a fair realization approach has been proposed, the analytical result for the mean identification delay has been obtained and an analytical approach for analysing the expected total transmission time has been presented.