Radio frequency identification (RFID) is a technology for identifying objects by radio signal. The reader collision problem is caused by the interrogation zones overlap of multiple readers, and leading to incorrect and unreliable data. This study proposes an array‐based reader anti‐collision scheme (ARCS) for solving the reader‐to‐tag interference problem. This mechanism uses array and grouping techniques to schedule the active readers to reduce the read cycle (RC) time. The ‘RC’ and ‘collision ratio (CR)’ measures serve as performance indexes in the proposed scheme. From ‘RC’ comparison, the ARCS mechanism has the maximum improvement of 55 per cent as compared with the existing mechanisms. Furthermore, take ‘CR’ index, ARCS has the maximum improvement of 42 per cent as compared to the others. Copyright © 2008 John Wiley & Sons, Ltd.

Positioning accuracy is an essential factor for many location-aware applications. This study designs an RFID-based positioning system for telematics location-aware applications. If a passenger in a vehicle loses a wallet with an RFID tag attached, then an RFID reader can be adopted to detect the tag, and thus find the wallet. Performance analysis results indicate that the proposed RFID-based positioning system has a distance error of less than 1.64 m, and an accuracy rate at least 13.24% higher than the common LANDMARC approach. These results indicate that the RFID operations in telematics positioning applications have high-accuracy location-awareness.

Multi-functional and high-quality services are indispensable for providing responsive information services in a highly interactive e-learning system. This work presents a problem-solving mechanism using closed-loop scheduling discipline to achieve QoS e-learning applications. In the closed-loop schedule, the feedback mechanism supports wireless mobile communications services with dynamic QoS requirements. This work presents a closed-loop architecture by cascading the open-loop schedule, the QoS probe, the Proportional-IntegralDerivative (PID) controller and the feedback mechanism. In this architecture, the relationship between input and output is defined using a Lagrange λ-calculus module. The module estimates the future QoS according to the current scheduling, while the controller parameters are tuned according to the system status to achieve dynamic scheduling. Simulation results with e-learning activities demonstrate that the closed-loop schedule outperforms existing disciplines in terms of service delay and system utilization.

No abstract