Algorithm for Readers Arrangement without Collision in RFID Networks

Radio Frequency IDentification (RFID) was identified as one of the ten best technologies in the 21st century. This technology is frequently used in different sectors: industrial, agricultural and academic. In RFID networks, readers and tags communicate wirelessly through electromagnetic signals. Due to the optimized tag coverage, multiple readers must be deployed in the same working area, causing reader-to-reader or/and readerto- tag collisions. In addition, the RFID reader is characterized by a maximum number of tags that can read them and a maximum interrogation range. Then the problem of activating the RFID readers and adjusting their interrogation ranges in order to cover the maximum number of tags without collisions is one of hot spot researches in RFID networks. This problem is known as the Reader Coverage Collision Avoidance Arrangement (RCCAA) problem. In the literature, an algorithm called the Maximum-Weight-Independent-Set-Based Algorithm (MWISBA) was put forward to solve the RCCAA problem. In this algorithm, only the interrogation ranges of readers where adjusted. The interference range was not taken into account. Thus, a readerto- reader collision could occur if a reader interrogated a tag located in the overlap area of its interrogation area with the interference area of another reader. To fill in this gap, we propose an improvement of the MWISBA called the MWISBAII which is able to solve the RCCAA problem avoiding all types of collisions. The experimental results show the superiority of our algorithm compared with the state-of-the-art solutions.