ASAP: A MAC Protocol for Dense and Time-Constrained RFID Systems

Abstract

We introduce a novel medium access control (MAC) protocol for radio frequency identification (RFID) systems which exploits the statistical information collected at the reader. The protocol, termed adaptive slotted ALOHA protocol (ASAP), is motivated by the need to significantly improve the total read time performance of the currently suggested MAC protocols for RFID systems. In order to accomplish this task, ASAP estimates the dynamic tag population and adapts the frame size in the subsequent round via a simple policy that maximizes an appropriately defined efficiency function. We demonstrate that ASAP provides significant improvement in total read time performance over the current RFID MAC protocols. We next extend the design to accomplish reliable performance of ASAP in realistic scenarios such as the existence of constraints on frame size, and mobile RFID systems where tags move at constant velocity in the reader's field. We also consider the case where tags may fail to respond because of a physical breakdown or a temporary malfunction, and show the robustness in those scenarios as well.

E2MAC : An energy efficient MAC for RFID-enhanced wireless sensor networks

“…The duration of the Reset and Energize command is hardware dependent. In our simulation, we set it to one millisecond according to [31]. Table 4 also defines the slot duration in R frame , B frame and M frame .…”

A Novel Anti-Collision Protocol for Energy Efficient Identification and Monitoring in RFID-Enhanced WSNs

“…The duration of the Reset and Energize command is hardware dependent. In our simulation, we set it to 1 milliseconds according to [15]. Table IV also defines the duration of slots that appear in R frame , B frame and M frame .…”

On the optimal frame-length configuration on real passive RFID systems

“…Other works (Khandelwal et al, 2007;Cha and Kim, 2005;Floerkemeier, 2006;Floerkemeier and Wile, 2006) improve the performance of the RFID systems modifying the procedure of the readers with different variable frame-length procedures. The authors suggest that the reader, at the end of every cycle, runs an algorithm that estimates the number of tags competing.…”

“…Capture effect (CE) is usually neglected in the performance analysis of passive RFID, where it is commonly assumed that transmissions in the same slot are unrecoverable, yielding to invalid conclusions (Myung and Lee, 2006;Vogt, 2002;Khandelwal et al, 2007;Cha and Kim, 2005;Floerkemeier, 2006;Floerkemeier and Wile, 2006). CE is a phenomenon associated with simultaneous transmissions in a shared channel, in which the strongest signal can be successfully demodulated.…”