“Tag Loss Probability Evaluation for a Continuous Flow of Tags in the EPC-Global standard”

Abstract. This paper addresses the evaluation of a passive RFID system under a continuous flow of tag arrivals and departures, for instance, in a conveyor belt installation. In such configuration, the main operational variable is the Tag Loss Probability (TLP). Since tags stay in the coverage area of the reader for a finite amount of time, it is possible that some tags leave the area unidentified if many tags compete for being simultaneously identified. A suitable configuration of the system (flow speed, tags per block, time between blocks, etc.) must be selected to assure that TLP remains under a given operative threshold. In this paper we focus on the EPCglobal Class-1 Gen-2 standard, which specifies an anti-collision protocol based on Framed Slotted Aloha. Our work is aimed at evaluating the TLP for the different configurations of such protocol, and selecting the right scenario configuration to guarantee a TLP below a given limit. This issue has not been studied yet, despite of its relevance in real-world scenarios based on assembly lines or other dynamic environments. Simulation results show that both anticollision protocol operation mode and flow configuration heavily impacts in the performance. Additionally, real test have been conducted which confirm simulation results.