Probabilistic DCS: An RFID reader-to-reader anti-collision protocol

The wide adoption of radio frequency identification (RFID) for applications requiring a large number of tags and readers makes critical the reader-to-reader collision problem. Various anti-collision protocols have been proposed, but the majority require considerable additional resources and costs. Distributed color system (DCS) is a state-of-the-art protocol based on time division, without noteworthy additional requirements. This paper presents the probabilistic DCS (PDCS) reader-to-reader anti-collision protocol which employs probabilistic collision resolution. Differently from previous time division protocols, PDCS allows multichannel transmissions, according to international RFID regulations. A theoretical analysis is provided in order to clearly identify the behavior of the additional parameter representing the probability. The proposed protocol maintains the features of DCS, achieving more efficiency. Theoretical analysis demonstrates that the number of reader-to-reader collisions after a slot change is decreased by over 30%. The simulation analysis validates the theoretical results, and shows that PDCS reaches better performance than state-of-the-art reader-to-reader anti-collision protocol

Improved RFID Anti-collision Protocol for EPCglobal Class-1 Generation-2

One of the important feature in the RFID technology is its functionality without needs to line of sight which makes it more feasible than other similar technologies. The problem occurs when more than one tag reply to the reader at the same time and collide together. To resolve the mentioned issue an anti-collision algorithm has to be used. The anti-collision algorithms are mostly efficient if the number of tags are small and has not been designed for large number of tags. In some applications that the number of tags may be hundreds of tags the existing mechanism may reduce the performance of the system due to delayed algorithms. In this paper an improved anti-collision protocol has been proposed. A modified two-parameter step size method for Q algorithm is also used to increase the efficiency of reading. The step sizes are adjusted depending on collisions in previous round. The number of slots in each round is also adjusted to prevent collisions in next rounds. The performance of proposed protocol has been evaluated using RFID module that implements EPCglobal C1G2 and designed especially for IoT environment and find the proposed protocol effective. Keywords: RFID, Anti-collision, EPCglobal, Q algorithm, DFSA

Energy efficient anti-collision algorithm for the RFID networks

Energy efficiency is crucial for radio frequency identification (RFID) systems as the readers are often battery operated. The main source of the energy wastage is the collision which happens when tags access the communication medium at the same time. Thus, an efficient anti-collision protocol could minimize the energy wastage and prolong the lifetime of the RFID systems. In this regard, EPCGlobal-Class1-Generation2 (EPC-C1G2) protocol is currently being used in the commercial RFID readers to provide fast tag identification through efficient collision arbitration using the Q algorithm. However, this protocol requires a lot of control message overheads for its operation. Thus, a reinforcement learning based anti-collision protocol (RL-DFSA) is proposed to provide better time system efficiency while being energy efficient through the minimization of control message overheads. The proposed RL-DFSA was evaluated through extensive simulations and compared with the variants of EPC-Class 1 Generation 2 algorithms that are currently being used in the commercial readers. The results show conclusively that the proposed RL-DFSA performs identically to the very efficient EPC-C1G2 protocol in terms of time system efficiency but readily outperforms the compared protocol in the number of control message overhead required for the operation

Evaluation Criteria for Reader-to-Reader Anti-collision Protocols

Technical Repor

Performance evaluation of non-persistent CSMA as anti-collision protocol for active RFID tags.

In this paper we propose the use of non-persistent CSMA as an anti-collision procedure for RFID active tags. Current proposals for both passive and active tags are based on the framed slotted ALOHA protocol, which does not scale well requiring additional procedures for frame length adaptation. However, active RFID devices already include carrier sense capabilities with no additional cost and, thus, CSMA may be employed seamlessly. Nevertheless, selecting the contention micro-slots of CSMA in the classical way (i.e., with a uniform distribution and an exponential back-off algorithm) does not result in an efficient identification process, as we will demonstrate. Fortunately, better choices can be found. Recently, an optimal distribution for the selection of micro-slots for event-driven sensor networks has been computed, as well as a practical implementation: the Sift distribution. In this work we propose the application of the quasi-optimal Sift distribution along with CSMA for active tag identification. By means of an analytical study, we evaluate the average time needed for identification with this mechanism and compare it with the current ISO 18000-7 and EPC “Gen 2” standard. The results reveal that the Sift-based non-persistent CSMA outperforms both of them. Moreover, it also scales much better, without the need for further adaptation mechanismsThis work has been funded by the Spanish Ministerio de Educación y Ciencia with the projects DEP2006-56158-C03-03/EQUI and m:ciudad (FIT-330503- 2006-2, partially funded by ERDF) and by the Spanish Research Council with the ARPaq project (TEC2004-05622-C04-02/TCM)

Analysis of BFSA Based Anti-Collision Protocol in LF, HF, and UHF RFID Environments

Over the years, RFID (radio frequency identification) technology has gained popularity in a number of applications. The decreased cost of hardware components along with the recognition and implementation of international RFID standards have led to the rise of this technology. One of the major factors associated with the implementation of RFID infrastructure is the cost of tags. Low frequency (LF) RFID tags are widely used because they are the least expensive. The drawbacks of LF RFID tags include low data rate and low range. Most studies that have been carried out focus on one frequency band only. This thesis presents an analysis of RFID tags across low frequency (LF), high frequency (HF), and ultra-high frequency (UHF) environments. Analysis was carried out using a simulation model created using OPNET Modeler 17. The simulation model is based on the Basic Frame Slotted ALOHA (BFSA) protocol for non-unique tags. As this is a theoretical study, environmental disturbances have been assumed to be null. The total census delay and the network throughput have been measure for tags ranging from 0 to 1500 for each environment. A statistical analysis has been conducted in order to compare the results obtained for the three different sets

A collision resolution algorithm for RFID using modified dynamic tree with Bayesian tag estimation

© 1997-2012 IEEE. A new tree-based anti-collision protocol for radio-frequency identification systems is proposed to achieve a very high tag identification efficiency. The proposed algorithm works in two phases. In the first phase, the number of competing tags is estimated through the proposed Bayesian estimation technique, while in the second phase, tags are identified using our modified dynamic tree algorithm. The system efficiency is mathematically derived and verified through simulation. Numerical results show that the proposed algorithm achieves a tag identification system efficiency of 45% and a time system efficiency of 78.5%, thus outperforming any existing collision resolution algorithms