Radio frequency identification multiple tag anti-collision method

Abstract

The present invention relates to a method for multi-tag anti-collision used for radio frequency identification. First, a reader selects a tag needing an access and sends out a command of access. When receiving the command of access, the tags start a random number generator. The tag, which generates 1, causes 1 to be added to the counter, while the tag, which generates 0, has an unchanged counter value and replies to the tag information immediately. The reader, based on the received information replied to by the tag, sends out a confirm command of a successful or a failed access. The tag, which is transmitted and confirmed as a successful access, leaves the process of access, while the tag, which is not confirmed as a successful access, has an unchanged counter value of 0 and replies to the tag information immediately. The tag, which is not transmitted, 1 is subtracted from the counter value. When tags receive a confirm command of a failed access, the tag, of which the counter value is not 0, 1 is added to the counter value, while the tag, of which the counter value is 0, starts the random number generator, wherein, the tag, which generates 1, 1 is added to the counter value, while the tag, which generates 0, replies to the tag information immediately.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to the field of radio frequency identification in wireless communication. Background technique [0002] In the application of radio frequency identification (RFID) technology, usually one reader corresponds to multiple electronic tags. When multiple tags are connected to the reader at the same time, collisions will occur, so the information in the tags cannot be correctly transmitted to the reader. Therefore, certain mechanisms need to be adopted to avoid collisions or reduce collisions. [0003] In the current international standard ISO 18000-6, ALOHA and Binary Tree methods are used to solve collisions. The basic feature of ALOHA is that the system divides the channel where the tags reply by time into several intervals (the intervals are called time slots), and requires the tags to choose one of the replies. In operation, the reader gives each tag a transmission probabilit...

AI Technical Summary

Problems solved by technology

[0004] In the above-mentioned Binary Tree anti-collision method, the number of tag replies is too many, resulting in low efficiency of multi-tag access, and the loss of access tags may occur, resulting in low reliability.

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