Relative density based anti-collision algorithm in RFID networks with dense readers

In radio frequency identification (RFID) networks with dense readers, reader collision yields low transmission efficiency, characterized by the number of concurrent operating readers per millisecond in a network. In this paper, a novel anticollision algorithm with high transmission efficiency is proposed by accounting for readers' relative densities in practice. To this end, a sub-frame with variable time length is designed and inserted into the transmission frame of classic neighbour-friendly reader anti-collision (NFRA) algorithm. Moreover, a backoff mechanism is exploited to further enhance the transmission efficiency of the proposed algorithm. Simulation results demonstrate the superiority of the proposed algorithm over NFRA with respect to the transmission efficiency.