The optimal channel utilization ratio of the pure ALOHA algorithm and the time-gap ALOHA algorithm is 18.4% and 36.8%. As the number of tags increases, their performance deteriorates dramatically. Therefore, binary search algorithm is proposed. Binary anti-collision algorithm is based on the method of polling, and it traverses all possibilities according to the binary tree model and a certain order. Therefore, it is not a probabilistic algorithm, but a deterministic anti-collision algorithm.
The binary tree search algorithm is controlled by the reader. The basic idea is to divide the colliding electronic tags and reduce the number of tags to be searched next step until only one electronic tag responds.
Binary search algorithm, the basic idea is after working field of the multiple tags into the reading and writing, speaking, reading and writing about command to send with constraints, tag answer to meet the constraints, in the event of collision, depending on the errors of a modified constraints, send inquiry command again, until you find a correct answer, and complete the read and write operations on the label. Repeat the above for the remaining tags until you have finished reading and writing all the tags.