I-ALOHA: intelligent ALOHA protocol for efficient RFID tag reading

Abstract

Radio-Frequency Identification (RFID) has made a revolutionary mark in identifying and tracking number of different industry objects, which has reduced the manual tracking to much higher extent. The key problem which is associated with the reading of RFID tags is the collision between tag responses, which makes the reading more difficult and hence requires more time to complete identifying all tags. Collisions also reduce the accuracy of the reader to read tags at any given instant of time. With many RFID readers being portable these days, limited battery power can be an issue, and hence, energy is another metric of interest. The purpose of this thesis was to design a protocol which would be helpful to read RFID tags in more efficient manner in terms of time and energy. A new RFID anti-collision protocol Intelligent ALOHA (I-ALOHA) is proposed that is a combination of two existing approaches: Intelligent Query Tree (IQT) protocol and Abramson’s Logic of Hiring Access (ALOHA) method. I-ALOHA, like IQT, divides the tag IDs into two parts and reads only postfix parts of the tags when the prefixes are common. It uses the basic features of ALOHA time slots to reduce collisions among tag responses. Simulations done on MATLAB indicated that I-ALOHA performs very well in number of different scenarios in terms of energy and time consumption compared to existing anti-collision protocols.