Self-adapting binary tree multi- label collision intermediation method for RFID system

Abstract

The invention discloses a self-adaptive binary tree multi-label conflict arbitration method used for a RFID system comprising a reader and at least two labels in the coverage area of the reader. The reader sends out an instruction and the labels execute corresponding operation after receiving the instruction. The labels are provided with four states, i.e. close, ready, ID and data exchanging and can adopt a counter and a random number generator to execute the state shifting according to the present time slot state to realize the binary tree method so as to avoid the conflict between labels. The storage of each label stores a priority number which can determine when the label can be communicated with the reader in a reading circle and the priority number in each reading circle can make self-adaptive adjustment according to the present time slot state so as to reduce conflict and idle time slot. The application of the invention to the RFID multi-label conflict can largely reduce conflictarbitration time and avoid the problems of label reading leakage and unlimited extension of the reading circle.

Description

technical field [0001] The invention relates to a method for conflict arbitration of an adaptive binary tree, in particular to a method for multi-label conflict arbitration in an RFID system. Background technique [0002] The communication between RFID multi-tags and readers is essentially a multi-access problem. Tags and readers use a shared wireless channel to communicate. Therefore, the communication between multiple tags and readers will inevitably cause channel contention, resulting in tag conflicts. At present, the arbitration methods of RFID tag conflicts can be roughly divided into random type and deterministic type according to the type of system model. The ALOHA type is the most important type in the random type. It is based on the probability theory and time division multiple access principle, and sends signals of multiple tags in multiple time slots or frames. However, when there are a large number of tags in the system, the tags cannot be read out for a long ti...

AI Technical Summary

Problems solved by technology

However, the adaptive ABS can only reduce the conflict arbitration time when the label changes little. When the label changes greatly, the arbitration time of ABS even exceeds that of BTree and RS.

In particular, ABS also needs to predict the number of tags. When the change of the number of tags is unknown, the tag will be missed or the reading cycle will be extended indefinitely. These factors greatly limit the application of ABS.

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