SwitchTable: An efficient anti‐collision algorithm for RFID networks

Abstract

Radio frequency IDentification (RFID) applications in the Internet of Things usually use multiple readers to read multiple tags. In such a practice, reader collisions may critically affect the performance. To obtain better reading schedules for the readers in order to enhance the RFID performance, the authors introduce a new and efficient anti-collision algorithm – the SwitchTable algorithm – in this study. The authors build the new algorithm over the concepts of the four-colour theorem and also the switch tables to fix the loopholes in existing algorithms – mainly the practice of variable MaxColor and the broadcast of kick signals. The authors’ SwitchTable algorithm sets MaxColor to four according to the four-colour theorem, to avoid possible collisions and solve the problem of previous dynamic MaxColor change. It meanwhile uses a colour switch mechanism which works by switch tables and unicasting switch signals (not broadcasting kick signals) to remove the impact of sending kick signals and attain more efficient planned colour change. Extended simulation runs are carried out to evaluate the performance of various anti-collision algorithms, including DCS, ColorWave, ColorTable and the authors’ SwitchTable. The results show that, with the new features, the authors’ new algorithm produces constantly better transmission success ratios and throughput, particularly in more complex RFID networks.