A Time and Capture Probability Aware Closed Form Frame Slotted ALOHA Frame Length Optimization

摘要

Minimizing the reading time in dense radio-frequency identification (RFID) networks is a critical issue. Commonly used RFID systems are based on frame alotted ALOHA (FSA) for tag anti-collision management. The usual approach for improved reading times with large tag populations is the optimization of the number of slots per frame. In real RFID systems, the slot duration depends on the slot type (i.e. idle, successful, or collided). In addition, collided slots might be converted to successful slots by capturing the strongest transponder, i.e. the so-called capture effect. Recent publications have proposed numerical solutions for obtaining the optimum frame length under these assumptions. The authors employ numerical solutions that require Multi-dimensional look-up tables for obtaining the optimum frame length. In this letter, we propose a closed form solution for the analytical calculation of the optimum frame length. The proposed solution gives a novel closed form equation for the frame length considering the different slot durations and the capture effect. Moreover, this letter presents a new method to calculate the capture probability per frame. Simulations indicate that the proposed solution gives accurate results for all relevant parameter configurations without any need for multi-dimensional look-up tables.