Using Capture Effect in DFSA Anti-collision Protocol in RFID Systems According to ISO18000-6C Standard

Capture effect happens when signals transmitted simultaneously from multiple transmitters arrive at the receiver with different power levels; the strongest signal can be successfully received in the presence of collision. This effect can have significant impact on the efficiency of tags’ anti-collision protocols in Radio frequency identification (RFID) systems. A very important issue in the use of capture effect is to adjust the size of the frame in the anti-collision protocols as the capture coefficient. The researchers concluded that the capture coefficient less than 0.2 will not increase the protocol efficiency. In this paper, we show that, according to ISO18000-6C standard, if the time interval is empty, successful and collision slots are considered differently; capture effect with coefficient 0.2 can also increase the efficiency of the protocol. We use DFSA (Dynamic Framed Slotted Aloha) anti-collision protocol to evaluate the proposed method. The experimental results show that our proposed method has better performance than other method.