Fast Identification of Mobile RFID Tags

We consider the problem of efficient and fast identification of mobile tags in RFID networks. So far only a few works have addressed identification of mobile tags, and in very specific scenarios (i.e., tags placed on a moving conveyor). In this paper we address more general scenarios, involving tags that are free to move and may stay in the reader range for very short time (e.g., a few seconds), making their identification a real challenge for the reader. We propose a protocol, called PrIME (for Priority-based tag Identification in Mobile Environments), that is based on a probabilistic model and performs continuous reading cycles during which tags may enter and leave the system at any time. Through extensive ns2-based simulations we show that PrIME is very efficient, as it is able to identify 98-99% of mobile tags and to reduce the identification delay drastically with respect to other protocols.