Anticollision algorithm for radio frequency identification system with low memory requirements

Abstract

AbstractRadio Frequency Identification (RFID) is recognized as an essential technology for the development of the Internet of Things (IoT) concept. This is due to the possibility of object identification using passive tags which do not require batteries for their operation. Instead, tags are powered by the electromagnetic waves emitted from the reader and then the same electromagnetic wave is used as a carrier to reflect the modulated information about their unique serial number back to the reader. According to the EPCglobal Class‐1 Generation‐2 RFID standard, Dynamic frame slotted ALOHA procedure is used to solve the anticollision problem. Basically, a reader adjusts the frame length for the next reading round based on the estimated number of unread tags. To achieve high reading efficiency, an algorithm with accurate estimation of the remaining number of tags is required. The article shows that for the adjustment of the next frame length, only the number of collisions is relevant. A simple estimator for the frames with 64 slots is designed, and generalized for the frames of any length provided within the EPCglobal Class‐1 Generation‐2 standard. Contrary to existing solutions, which use more tables for storage of the estimated values depending on the frame length, proposed approach requires just one table. Also, the problem of estimation is reduced to dependence on the number of collisions only, while conventional approaches use the number of collisions and successful slots.