Research On User-Oriented Missing Tag Identification In RFID System

Radio Frequency Identification(RFID),as a technology with excellent advantages in modern automatic identification,is widely used in the Internet of Things,such as monitoring logistics and managing inventory.It is a noncontact automatic identification technology by attaching RFID tags to items and using radio frequency to communicate.According to the actual application requirements,identifying the missing tags to determine which goods is missing plays an important role in many practical RFID applications.At present,most existing methods can only work in a relative static scenario where without unknown tags in the system.However,the actual environment is usually dynamic RFID system where the tags move in and out of the system frequently.The missing and unknown tags usually exist concurrently.In this case,identifying the missing tags becomes more challenge due to the unknown tags interference but most existing missing tag identification work can not identify the missing tags accurately with the presence of unknown tags and the efficiency and safety are not guaranteed.Therefore,for the actual dynamic environment,this paper studies the user-oriented missing tag identification method to meet different user environment needs.This paper designs a protocol DMI for single user to identify missing tags efficiently and a multi-user parallel missing tag identification MUMI to identify missing tags safely and efficiently for multiple users.The specific contributions in this paper are as follows:In this paper,a protocol DMI is designed for single user to identify missing tags efficiently in dynamic RFID system.DMI utilizes both slot position and reply Key to maximize slot utilization.With the presence of unknown tags,DMI can identify the missing tags correctly and efficiently.This paper also gives an analysis of the optimal Key length and frame size settings,so that the DMI can be efficient.Then,this paper also designs a multi-user parallel missing tag identification MUMI,which uses the user-separation filter to separate the tags of several users from all the tags and identifies the missing tag for each user.It not only reduces identification time,but also ensures the security of theidentification process.The length of user separation filter and frame size in missing tag identification of each user are optimized as well.In this paper,the effectiveness and efficiency of the DMI and MUMI are also confirmed by simulation experiments.The experimental results show that DMI can identify missing tags in a dynamic environment efficiently and accurately.In the best case,DMI can reduce the execution time by 86% of the latest work ERMI.At the same time,the MUMI can also identify missing tags accurately and achieve good efficiency when multiple users jointly apply for missing tag identification.