Framework Quick Rfid Tag Reading in Dense Environments

Abstract

Radio Frequency Identification (RFID) systems provide a mechanism to automatically identify the objects and collect information about them. The main objective of RFID Medium Access Control (MAC) protocols is to provide an opportunity to RFID readers in identifying multiple tags successfully and efficiently. Several variants of ALOHA and Binary Tree Search protocols are being proposed in this area but they show acceptable performances only if limited number of tags are present in the RFID reader region as fairly low amount of data is going to be exchanged. Their performances degrade when large numbers of tags are present in the region because if multiple tags try to communicate with the reader at the same time, it leads to collisions. This problem becomes more complex in the case of mobile tags because of their limited time presence in the reader's region. In this research, we develop a framework which can be used in conjunction with most of the Framed Slotted ALOHA protocols. A new protocol, Accelerated Framed Slotted ALOHA (AFSA), which is a result of application of the framework with Enhanced Dynamic Frame Slotted ALOHA, not only tries to minimize the number of collisions but also minimizes the total wastage of bandwidth due to collisions and unoccupied slots. We show, through analysis and simulations, our approach gives better average tag reading time over existing models. We further extend our approach to mobile RFID systems where the tags move with a constant velocity in the reader's vicinity.