Adaptive Frame Length Selection Scheme for RFID Object Identification

The frame length is a significant factor which affects the performance of the framed ALOHA-based anti-collision protocols for RFID systems. Using a large frame length can reduce the number of collision slots. However, it also increases the number of wasteful slots. In order to optimize the performance, the frame length must be chosen carefully. In this paper, we present an optimal frame length selection scheme, which maximizes the system throughput. Our scheme requires only minimal information obtained from the tags´ responses in the current frame, as opposed to relying on the past information collected in the previous frames. It is shown that the performance of our scheme is close to that of the ideal best-case scheme where the reader has completely accurate knowledge of the number of tags transmitting in each frame.