Optimization on guard time and synchronization cycle for TDMA-based deterministic RFID system

This paper presents optimizations on guard time and synchronization cycle for Time Division Multiple Access (TDMA) based deterministic Radio Frequency Identification (RFID) system. The TDMA scheme can provide guaranteed latency and high throughput for RFID system that includes fixed number of users (tags) and requests long-message transmission. However, collisions due to accumulated clock drifts of the active RFID tags equipped with independent self-clocked microcontrollers are the major challenge. In this work, we model relations between guard time and synchronization cycle used to tolerate the accumulated clock drift and reduce the probability of collisions for an extended-star RFID system. Constraints of safe guard time and synchronization cycle are proposed to consider energy efficiency and time efficiency. Moreover, optimization on guard time and synchronization cycle are explored in terms of transmission time, tag number, energy efficiency and time efficiency. The simulation results indicate that system with long transmission time (around 1 ms) enjoys higher time and energy efficiency under optimal configuration of guard time and synchronization cycle.