PSR: A Novel High-Efficiency and Easy-to-Implement Parallel Algorithm for Anticollision in RFID Systems

Tag anticollision is critical to the performance of many radio frequency identification systems in industrial applications. Tree-based schemes are popular arbitration algorithms for tag collision, as they are scalable and easy to implement. In these schemes, collided tags are recursively divided into two groups until each group contains only one tag. However, we have determined that previous pure tree-based schemes do not fully utilize the information that can be collected; they allow only the responding tags to be involved in the splitting process. In this paper, we propose a novel pure tree-based method that we named parallel splitting with retrieve (PSR), which allows both the nonresponding and unidentified tags to also be involved in the splitting process. PSR consists of two mechanisms: parallel splitting (PS) and retrieve. The PS mechanism can reduce the total number of tag collisions and the retrieve mechanism can reduce the extra idle slots caused by PS. In comparison with conventional pure tree-based schemes, the proposed PSR algorithm achieves higher efficiency without the need to estimate the number of tags; simulation results indicate an efficiency level of 0.41. The PSR algorithm also has similar performance to state-of-the-art algorithms that do not need to estimate the number of tags, but it is simpler to implement and is thus preferred for resource constrained systems.