An improved dynamic framed slotted aloha algorithm for RFID anti-collision

One of the largest disadvantages in radio frequency identification (RFID) system is its low tag identification efficiency by tag collision. When the number of tags is large, for the conventional RFID anti-collision algorithm the number of slots required to read the tags increases exponentially as the number of tags does. The proposed IDFSA algorithm solved this problem by dividing frequency of tags that is grouping the tags in different frequency channel, reducing the number of slots and saving the communication time of grouping with estimation. The reader requests every frequency in turn to check the tags. In every frequency channel, the optimal frame size was set to enhance the system efficiency. This Algorithm has been used in the 433/868/915 RFID system. The system identification efficiency shows good performance.