Missing Tag Detection With Unknown Tags In Large-Scale RFID Systems

Internet of Things(Io Ts)developed rapidly in recent years.Radio Frequency Identification(RFID)technology,which is one of the core technologies of the Internet of things,has been applied in many fields,such as logistics tracking,warehouse management,transportation,retail industry and so on,generating huge economic benefits.For example,there are some valuable merchandises which need to be monitored in real time in a warehouse management system so as to avoid loss caused by the missing merchandises.Fortunately,the detection of missing merchandises can be achieved by detecting the missing tags in RFID systems.However,there actually are a large number of unknown tags which will disturb the missing tag detection.Therefore,the main research content of this paper is to detect the missing tags with unknown tags in large-scale RFID systems.And we propose three schemes for this problem.Firstly,this paper proposes the TBMD(Two-Phase Bitmap Based Missing Tag Detection with Unknown Tags)scheme,which deploys the Framed Slotted Aloha protocol to improve the communication efficiency.TBMD deactivates unknown tags using expected frame mapped by known tags in the first phase.In the second phase,TBMD detects missing tags by comparing the expected status with actual status of each slot.Secondly,this paper proposes the second scheme SBFMD(Segmented Bloom Filter Based Missing Tag Detection for Large-Scale RFID Systems with Unknown Tags),which deploys segmented Bloom filter to deactivate the unknown tags and detect the missing tags.The core idea of SBFMD is to remove the useless slots so as to improve the execution efficiency both in the first phase and the second phase.Furthermore,we theoretically optimize the parameters in SBFMD and extensive simulations are conducted,the results show that SBFMD scheme can achieve the expected effects.In addition,the execution efficiency of SBFMD can be improved by at least 30% compared to BMTD protocol.Finally,this paper proposes the third scheme EUMD(Efficient Slot Utilization Based Missing Tag Detection with Unknown Tags).EUMD introduces the grid table in the first phase to increase the proportion of empty slots so as to improve the deactivation efficiency.In the second phase,EUMD deploys the Hash function based on ID right shift to increase the proportion of singleton slots in order to improve the detection efficiency.In addition,we theoretically optimize the parameters in EUMD and carry out lots of simulations,the simulation results show that the efficiency of EUMD scheme approximately increases by 30%compared to MDUT.