A Protocol For Identifying Unknown Tags In RFID Systems

Radio frequency identification(RFID)technology is a core technology of the Internet of Things and is widely used in warehouse management and supply chain management.In warehouse management,the use of RFID technology can monitor the status of all commodities,avoiding the problems of low efficiency and low accuracy of manual management.In the actual application scenario,there will be some products that have entered a certain area of the warehouse but have not been identified yet.We call these products unknown products.If the merchant fails to identify these unknown products in time,it may cause serious economic losses and personal safety.If a lighter is mistakenly placed in the alcohol area,it may cause safety problems and cause certain economic losses.Therefore,in RFID,it is an important task to effectively identify unknown tags within the coverage of the reader.The unknown tag recognition protocol can quickly identify unknown tags within the coverage of the reader.The existing protocols have low efficiency due to low frame utilization.To improve efficiency,this paper uses two hash function hashing,and adds sampling ideas after the second hash function hashing,proposing a two hash and sample protocol THS(Two Hash and Sample protocol).The protocol is implemented in two phases:the phase of deactivating known tags and the phase of identifying unknown tags.In the phase of deactivating known tags,the reader uses the idea of two hash functions and sample to construct a hash selection vector HSV and a tag vector TV,and sends these two vectors to all tags,according to the time slot in which the tag is located response to deactivate known tags.this phase terminates until all known tags are deactivated;In the phase of identifying unknown tags,all unknown tags's id are collected using the existing TIP protocol.In order to minimize the execution time of the protocol,this paper estimates the number of known tags that have been assigned,and analyzes and optimizes the sampling probability.It also compares the execution time of the THS protocol and existing unknown tag identification protocols through simulation experiments.Experimental results show that the execution time of THS is the smallest and better than other protocols in terms of time performance.