A Distance Based RFID Reader Collision Avoidance Protocol for Dense Reader Environments

Radio frequency identification (RFID) technology is considered as one of the most applicable wireless technologies in the present era. Readers and tags are two main components of this technology. Several adjacent readers are used in most cases of implementing RFID systems for commercial, industrial and medicinal applications. Collisions which come from readers’ simultaneous activities lead to a decrease in the performance of RFID systems. Therefore, a suitable solution to avoid collisions and minimize them in order to enhance the performance of these systems is necessary. Nowadays, several researches are done in this field, but most of them do not follow the rules and standards of RFID systems; and don’t use network resources proficiently. In this paper, a solution is provided to avoid collisions and readers’ simultaneous activities in dense passive RFID networks through the use of time division, CSMA techniques and measuring received signal power. The new anti-collision protocol provides higher throughput than other protocols without extra hardware in dense reader environment; in addition, the suggested method conforms to the European standards and rules.