Selecting back off algorithm in active RFID CSMA/CA based medium-access protocols

Abstract

Active radio frequency identification (A-RFID) is a technology where the tags (transponders) carry an on board energy source for powering the radio, processor circuits, and sensors. Besides offering longer working distance between RFID-reader and tag than passive RFID, this also enables the tags to do sensor measurements, calculations and storage even when no RFID-reader is in the vicinity of the tags. In this paper we study the effect on tag energy cost and read out delay incurred by some typical back-off algorithms (constant, linear, and exponential) used in a contention based CSMA/CA (carrier sense multiple access/collision avoidance) protocol for A-RFID communication.