Analytical Computation of the Mean Number of Tag Identifications During a Time Interval in FSA

We analytically compute the mean number of identifications when N tags contend in a bounded time interval of T seconds in RFID systems using framed slotted aloha. Usually, performance is described in terms of identifications per time-slot. However, slot duration notably varies depending on the event (identification, collision, or empty slot). Moreover, during the reading process, the number of tags contending dynamically changes since identified tags withdraw from the process, and the frame length may vary dynamically as well. These conditions have been included in the model and lead to an accurate analysis of real RFID systems.