Synchronization of RFID readers for dense RFID reader environments

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.For a dense RFID reader deployment, such as in warehouse RFID deployment, where hundreds of antennas are positioned in a building, the interference between all these readers must be studied carefully to avoid severe reader collisions. Strict RFID regulations and standards have been imposed, trying to address the problem of reader collision and also the problem of RFID devices interfering with other devices operating in nearby frequency bands. However, these guidelines and regulations are not entirely friendly for dense RFID reader deployment, in some cases it is not possible to have a feasible RFID system while adhering to these regulations. Hence, this paper proposes the synchronization of RFID readers, to enable successful dense RFID reader deployment. A case study targeted at European operations is presented in this paper to visualise the actual synchronization of RFID readers in real life applications. Some fine-tuning methods are also suggested to further improve the performance of readers in a high reader density population area.Kin Seong Leong, Mun Leng Ng, Alfio R. Grasso, Peter H. Col

Dense RFID reader deployment in Europe using synchronization

For a dense RFID reader deployment, such as in a warehouse, where hundreds of readers will be positioned in a building, the interference between all these readers must be studied carefully to avoid disruption of operations. Strict RFID regulations and standards have been imposed, trying to address the problem of reader collision and also the problem of RFID devices interfering with other devices operating in the same and nearby frequency bands. However, these guidelines and regulations are not entirely friendly for dense RFID reader deployment; in some cases it is not possible to have a feasible RFID system while adhering to these regulations. Hence, this paper proposes the synchronization of RFID readers to enable successful dense RFID reader deployment. A case study targeted at European operations is presented in this paper to illustrate the actual synchronization of RFID readers in real applications. Some fine-tuning methods are also suggested to further improve the performance of readers in a high reader density population area.Kin Seong Leong, Mun Leng Ng, Alfio R. Grasso, and Peter H. Col

An Approach for Removing Redundant Data from RFID Data Streams

Radio frequency identification (RFID) systems are emerging as the primary object identification mechanism, especially in supply chain management. However, RFID naturally generates a large amount of duplicate readings. Removing these duplicates from the RFID data stream is paramount as it does not contribute new information to the system and wastes system resources. Existing approaches to deal with this problem cannot fulfill the real time demands to process the massive RFID data stream. We propose a data filtering approach that efficiently detects and removes duplicate readings from RFID data streams. Experimental results show that the proposed approach offers a significant improvement as compared to the existing approaches

Improving Reader Performance of an UHF RFID System Using Frequency Hopping Techniques

Computer Science Departmen

RFID in the warehouse:a literature analysis (1995-2010) of its applications, benefits, challenges and future trends

Radio Frequency Identification (RFID) has been identified as a crucial technology for the modern 21st century knowledge-based economy. Some businesses have realised benefits of RFID adoption through improvements in operational efficiency, additional cost savings, and opportunities for higher revenues. RFID research in warehousing operations has been less prominent than in other application domains. To investigate how RFID technology has had an impact in warehousing, a comprehensive analysis of research findings available from articles through leading scientific article databases has been conducted. Articles from years 1995 to 2010 have been reviewed and analysed with respect to warehouse operations, RFID application domains, benefits achieved and obstacles encountered. Four discussion topics are presented covering RFID in warehousing focusing on its applications, perceived benefits, obstacles to its adoption and future trends. This is aimed at elucidating the current state of RFID in the warehouse and providing insights for researchers to establish new research agendas and for practitioners to consider and assess the adoption of RFID in warehousing functions

Batch study on COD and ammonia nitrogen removal using granular activated carbon and cockle shells

Landfills generate leachate that contains elevated concentration of contaminants and is hazardous to human health and the ecosystem. In this study, the mixture of granular activated carbon and cockle shells was investigated for remediation of COD and ammonia from stabilized landfill leachate. All adsorbent media were sieved to a particle size between 2.00 and 3.35 mm. The optimum mixing ratio, shaking speed, shaking time, pH, and dosage were determined. Characterization results show that the leachate had a high concentration of COD (1763 mg/L), ammonia nitrogen (573 mg/L), and BOD5/COD ratio (0.09). The optimum mixing ratio of granular activated carbon and cockle shells was 20:20, shaking speed 150 rpm, pH level 6, shaking time 120 min, and dosage 32 g. The adsorption isotherm analysis reveals that the Langmuir isotherm yielded the best fit to experimental data as compared with the Freundlich isotherm. The media produce encouraging results and can be used as a good and economical adsorbent