Identifying the unknown tags in a large RFID system

Radio frequency identification (RFID) technology has been extensively used in various practical applications, such as inventory management and logistics control, with its outstanding features (e.g. non-line-of-sight reading and fast identification). And in a large RFID system, unknown tag identification uses total execution time as the performance criterion. However, the performance of existing protocols in terms of execution time is not ideal. To get better time efficiency, a novel unknown tag identification protocol (NUTIP) is proposed. The novelty of NUTIP is demonstrated mainly in two aspects: i) NUTIP deactivates some known tags and identifies or labels some unknown tags during its first phase to prevent these tags from interfering unknown tag identification. ii) We optimize the parameter settings to minimize the total execution time. Simulation experiments show that the proposed protocol is far superior to other relevant protocols and suitable for both sparse unknown tags environment and dense unknown tags environment.