Adaptive Distributed Reader Activation Approach for Large-Scale RFID Systems

In recent decades, a growing number of large-scale RFID systems are used in various applications. In such a system, it is not uncommon that multiple concurrent radio communications among RFID readers and tags cause serious inference (called collision in the RFID field). One important kind of method to achieve collision-free communication is to activate RFID readers in different time slots. Existing activation approaches for solving this problem are mainly centralized, which is impractical due to the lack of central server, one-point failure risk, and performance bottleneck. Some distributed algorithms are proposed recently, but failed to consider the adaptiveness of the identification, where all of the RFID readers need to participate in the coordination control even if they do not have communication requirements any more. As a result, the optimal identification performance cannot be achieved. In this paper, we propose an adaptive distributed reader activation approach called ADRA for large-scale RFID systems. We build a fine-grained conflict graph for different kinds of collisions. And then a shared permission based distributed approach is adopted to eliminate those collisions. We guarantee that the RFID readers that do not need to communicate any more are suspended and excluded from the execution of coordination eventually. Extensive simulation results show that our approach outperforms existing approaches in terms of execution time and message overhead.