Optimal power stationary policies for synchronous queued RFID networks

Abstract

RFID networks are subject to interferences caused by simultaneous readers’ operation, and different arbitration mechanisms have been proposed to deal with this issue. If the network is synchronized, it is possible to implement schedulers which decide, at each particular timeslot, which set of readers operates, thus reducing or eliminating interferences. In this paper, we analyze the performance of an optimal scheduler, which controls the transmission power in the RFID cells using a policy which is randomized and stationary, and which aims at maximizing the joint incoming traffic for a given set of readers subject to attain a stable network operation. We have studied two families of policies: (i) the on/off power policy where all active readers operate with the same transmission power, and (ii) an independent power policy where the transmission powers can be different. Additionally, we have compared the performance against a purely on/off policy where readers use a nominal transmission power of 1 W. Results highlight that on/off power policies are only marginally worse than independent power policies, despite the higher flexibility of the latter ones. Thus, a network designer may rely on/off policies. Finally, we have also shown that arbitration mechanisms between readers are required even for networks operating with the DRE masking mode.