A Novel Anti-Collision Algorithm with Optimal Frame Size for RFID System

The most important research in the world in these days, research that looking at the internet of thing's (IoT) topics and their applications. Most of these applications depend on RFID system, which includes RFID readers and tags. The important issues in RFID system or network are how we can reduce anti-collision between readers to identify and read tags data. In these paper, we suggest an Improved anti-collision protocol, which can be used to connect RFID readers with RFID tags and reduce the number of RFID tag's collisions. The simulation shows that an Improved Class-1 Generation 2 algorithm is better than Slotted Aloha, Class-1 Generation-2 (Number of Tags Known), Class-1 Generation-2 (Number of Tags Unknown) algorithms.

Under-determined blind separation becomes poorer with increasing number of tags, to the point where it cannot separate source tag signals, reducing overall system performance. This paper proposes a parallelizable identification anti-collision algorithm based on non-negative matrix factorization and adaptive ID sequence grouping of binary tree slots. The number of tags in each group can be controlled within the optimum range by selecting a reasonable number to retained source signal separation in the RFID system, which will greatly improve system performance. With the Matlab software numerical calculation and simulation, the results show that tag identification rate improves from 152.8% to 359.2% compared with the blind separation and dynamic bit-slot group algorithm using the same multi-antenna technology for 4–16 antennas, while increasing tag identification speed from 60% to 78.4%. Thus, the proposed algorithm provides high efficiency and low cost and will have very good application for fast identification of large numbers of tags.

International audience

Dynamic time slot frame ALOHA algorithm is currently the most widely used anti-collision technology in radio frequency identification (RFID) system. Based on the traditional ALOHA algorithm analysis, we propose an improved algorithm. The algorithm is based on a packet adaptive ALOHA anti-collision algorithm (PA-ALOHA). First, the reader scans and counts the time slots which are randomly selected by tags, and sends it to each tag. The tags, then, adjust accordingly the time slot that enable the reader to skip idle slots and collision slots, adaptively allocate effective slots, and then identify tags rapidly. The algorithm employs packet and dynamically adjusts the frame size and other strategies, in order to reduce the time of processing slots. Simulation results show that PA-ALOHA algorithm improves the efficiency and stability of the system and reduce the transmission overhead. Especially, when the number of tags is over 1000, the algorithm throughput is still above 70% that has been greatly improved system efficiency than conventional ALOHA algorithm.

Passive UHF RFID systems using Dynamic Frame-Slotted ALOHA (DFSA) adjust the frame size according to the number of tags, but frame size N is equals to 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</sup> and cannot be adjusted exactly to the number of tags to be identified. In this paper, we propose an optimal Aloha algorithm (ODFSA), which uses probabilistic approach for tags to access the frame. The Query or Query Adjust packet contains both the parameter Q and P called frame access probability, which represents the ratio of number of active tags in the current frame to the estimated total number of tags which remain to be identified in the system. Estimation of number of unread tags is updated after end of each frame; parameters Q and P are calculated and informed at the beginning of each frame. Mathematical analysis and computer simulations show that the proposed Aloha achieves maximum system efficiency, utilizes less number of slots compared with other algorithms and also takes less identification time.

Anti-collision protocols for radio frequency identification (RFID) tag reading processes are designed to reduce the frequency of collisions and to quickly identify all RFID tags during a tag reading collision process. In this paper, we propose a tree-based anti-collision algorithm using a bit change sensing unit (TABCS) based on the bi-slotted collision tracking tree algorithm (BSCTTA) algorithm. The proposed algorithm can identify bits returned from tags using a bit change sensing unit, even in the event of multiple collisions. The algorithm rapidly generates a unique prefix that identifies each tag and reduces the total number of bits. Simulation results show that the proposed algorithm reduces the cost of tag identification compared with legacy algorithms, such as the query tree algorithm with a bit change sensing unit (QT-BCS) or BSCTTA. When the number of tags is 10000, the average number of tags identified per second in TABCS is improved by 4%, and TABCS requires 28% fewer steps to successfully identify one tag compared to BSCTTA.

Radio Frequency IDentification (RFID) systems have rich applications in daily life. A crucial problem in RFID systems is to estimate the cardinality of RFID tags. Most exiting probabilistic RFID cardinality estimation algorithms utilize a certain pattern hidden in the response vector formed by the tag responses to make estimators. In this paper, we argue that finding the patterns is actually not necessary! In this paper, we present a novel approach to RFID cardinality estimation by making the full use of the whole response vector. We characterize the critical relationship between the number of RFID tags and the specific distribution of the bits in the response vector. In this paper, we consider two kinds of responses, i.e., empty / non-empty responses and empty / singleton / collision responses. To cater for RFID systems with a very large number of tags, we also generalize our estimation approach to handle geometrically distributed response vectors. Both rigid theoretical analysis and extensive simulations have been conducted and the conclusive results demonstrate that our approach is more accurate than existing state-of-the-art RFID estimation approaches.

Dynamic frame slotted Aloha (DFSA) has been widely adopted to solve the anticollision problem in a radio frequency identification (RFID) system. In a DFSA procedure, the interrogator needs to continuously estimate tag backlog and select a new frame length for identifying the backlog. Intuitively, the accuracy of the tag estimator will affect the read performance. Hence, a considerable amount of research effort has been invested to improve the accuracy of backlog estimation. The improvement in general comes at the expense of large computation load and may lead to a serious challenge if one needs to implement such a kind of estimators in a real RFID system. This paper analyzes the influence of estimation error on read performance. Based on the analysis, we propose a feasible and easy-to-implement anticollision algorithm. Our proposed algorithm can achieve a normalized throughput of 35% that is very close to the theoretical maximum 36.1% for an EPCglobal UHF Class-1 Generation-2 system. The easy-to-implement advantage of our algorithm comes at the expense of only 1% reduction in normalized throughput as compared with the case where maximum throughput can be obtained. The results obtained are useful in designing fast and efficient interrogators. Note to Practitioners - A fast and efficient anticollision algorithm is required in many applications such as warehouse and supply chain management. Since most RFID interrogators are built with a single-chip microprocessor, whose computation ability or memory is limited. From the implementation point of view, a feasible algorithm should consider the compromise between complexity and performance. In order to easily implement the anticollision algorithm in a real RFID system, the proposed algorithm is based on a simple but sufficiently accurate method rather than complex models. The results obtained can be useful for the industry to develop fast and efficient RFID interrogators.

Collision is a familiar problem in a RFID (radio frequency identification) system. How to solve this problem effectively is very important to the whole RFID system. A RFID system is always made up of two indispensable components: one is the tag, the other is the reader. Collisions occur when there are so many tags within the interrogation zone of a reader communicating with the reader synchronously. Binary search algorithm is an important anti-collision algorithm to solve the collision problems. But the main disadvantage of any existing algorithm based on binary search algorithm is the rate of identifying the identification codes (IDs) of tags is slow. In this paper, an improved anti-collision algorithm is proposed. Using this algorithm will recognize more tags in less time compared with other existing algorithms

The dynamic frame slot ALOHA (DFSA) algorithm is a typical anti-collision. For the shortcomings of DFSA algorithm, this paper presents an improved algorithm - IDFSA. On the one hand, IDFSA algorithm to improve the label estimation algorithm, so as to achieve dynamic adjustment. On the other hand, through the analysis of mathematics, the new grouping of labels is improved, and the phenomenon of landslide is improved. The simulation results show that the throughput of IDFSA algorithm is higher, and the total operations time is less. RFID (radio frequency identification, RFID) is widely used in logistics, identification, anti-theft and other fields. A traditional RFID system mainly includes two parts: the reader and the tag. In the case of the number of tags more dense, the reader must use the anti-collision to identify the individual tags. So, anti collision algorithm is very important in multi label application field. Tag anti-collision protocols (1) can be categorized into two groups: probabilistic anti-collision methods and deterministic anti-collision methods. The probabilistic anti-collision methods are Aloha-based protocols (2) such as pure Aloha protocol, Slotted ALOHA (SA) protocol, Framed Slotted ALOHA (FSA) protocol and Dynamic Framed Slotted ALOHA (DFSA) (3, 4) protocol. In this paper, an improved dynamic frame slot ALOHA (IDFSA) algorithm is proposed. 2. Related work Frame slotted ALOHA algorithm will be a plurality of time slots set as a frame, for a fixed frame length, when the tag number is less than the length of the frame appears waste the time slot, when the frame length is less than or equal to the number of tags conflict too frequent . In view of this situation, according to the number of tags in the reader range, dynamic adjustment of the next frame length, by a decrease or increase the length of the frame, you can solve the slot waste and tag identification time increased, this method is called dynamic frame slotted ALOHA (DFSA). The analysis of DFSA algorithm shows that the throughput of the system is mainly determined by the estimation of the number of tags and the adjustment of the frame length. The estimation of the number of tags plays a key role in the performance of the algorithm. At present, there are three kinds of label estimation algorithms, Vogt, Schoute and Lowbound

In order to overcome the low efficiency of traditional binary-tree anti-collision algorithms,an adaptive multi-tree anti-collision algorithm based on heuristic function was presented in the paper.By defining the heuristic function which was computed by the number of collision bits,the new algorithm can estimate the number of tags in the branch effectively.Because the new algorithm can adjust the number of searching fork in different branches and depths dynamically,it improves the searching efficiency.The theoretical analyses and simulation results show that the new algorithm overcomes the deficiency of traditional algorithms.For the large number of tags in particular,it can reduce the searching and recognition time and increase the throughput of Radio Frequency IDentification(RFID) system.

CNCAA: A new anti-collision algorithm using both collided and non-collided parts of information

In recent years, numerous authentication protocols for radio frequency identification (RFID) systems have been proposed to protect privacy. Due to the hardware resource limitation on RFID tags, the majority of these protocols are based on symmetric-key ciphers. However, most of them lack scalability at the reader side as they require a linear or logarithmic search proportional to the number of tags in the system in order to authenticate a tag. Recently proposed scalable protocols require a constant-time search and utilize hash look-up tables. However, the storage requirement of the hash-table in these protocols is very large, therefore not practical. Moreover, previous proposals do not support dynamic resizing where the number of tags changes during the life time of the RFID system. In this paper, a new Re-Hash technique is presented to reduce the hash-table storage in constant-time authentication protocols. To the best of our knowledge, it offers the smallest storage cost in comparison to previous proposals. The Re-Hash technique is also further adapted to support the dynamic scalability for RFID systems.

This paper discusses the separation of signals in multiple-tag radio frequency identification (RFID) systems. First, a model for the RFID system in both single and multiple tag environments is presented. Then, an analytical constant modulus algorithm (ACMA) for the blind source separation problem is reviewed. An alternative approach to the traditional ACMA using joint diagonalization is considered. Finally, both the ACMAs are applied to the multiple-tag RFID environment and performance of the system is studied. Simulations are carried out for 4-QAM and 16-QAM modulations at tag and analyses of the simulation results reveal that the ACMA with joint diagonalization takes lesser CPU time to execute compared to the traditional ACMA, but with higher average modulus error (AME). The variation of system performance with the number of measurements, SNR (signal to noise ratio), number of tags and number of antennas at the reader is also studied. Based on these, some design guidelines are presented. Interestingly both the ACMA algorithms work for the 16-QAM case and yield trends similar to those of 8-PSK and 4-QAM.

Radio Frequency Identification (RFID) system is a new communication technology identifying one or more objects simultaneously in favor of using electromagnetic waves. In RFID systems, tags and readers communicate together over a shared wireless channel, and their signals may collide during transmission process and collision problem may occur in these systems. When two or more tags want to communicate with the reader, this collision problem may occur. This collision problem will waste the time for identification and it is also energy consuming as well and consequently reduces efficiency of the tag identification process. Therefore, it is required to attempt minimizing collision occurrence and decrease possibility of collision by using RFID anti-collision algorithms. In this project a novel Anti-collision Algorithm was suggested, which is called Enhance Dynamic Tree Slotted Aloha (EDTSA) by combining Tree slotted ALOHA and Advance Dynamic Framed Slotted Aloha Anti-Collision Algorithms and using Cubic Spline-based tag estimation technique. We have designed this algorithm by using C# programming language in visual studio 2008. The final results has simulated and compared with other algorithms. Simulated results also have illustrated that proposed algorithm can improve the efficiency of RFID systems.