A Modified Grouped-Tag TDMA Access Protocol for Radio Frequency Identification Networks

In this paper we describe a new medium access protocol termed as the modified grouped-tag TDMA protocol (MGTDMA) for networking radio frequency identification tags. It is known that the previously proposed grouped-tag TDMA (GTDMA) protocol performs very well under the conditions of uniform destination distribution and not so well for heterogeneous traffic conditions. The MGTDMA differs from GTDMA in the sense that MGTDMA allows groups experiencing high traffic to steal (cooperatively) from low traffic groups at regular time intervals. Performance of an access scheme is assessed in terms of average packet delay and average energy consumption. Approximate analytical equation for average delay is derived. More accurate estimates for delay are obtained through simulation studies. We compare the performances of MGTDMA, GTDMA, and a pseudo random protocol and show the usefulness of the new scheme

Integrating the Supply Chain with RFID: A Technical and Business Analysis

This paper presents an in-depth analysis of the technical and business implications of adopting Radio Frequency Identification (RFID) in organizational settings. The year 2004 marked a significant shift toward adopting RFID because of mandates by large retailers and government organizations. The use of RFID technology is expected to increase rapidly in the next few years. At present, however, initial barriers against widespread adoption include standards, interoperability, costs, forward compatibility, and lack of familiarity. This paper describes basic components of an RFID system including tags, readers, and antennas and how they work together using an integrated supply chain model. Our analysis suggests that business needs to overcome human resource scarcity, security, legal and financial challenges and make informed decision regarding standards and process reengineering. The technology is not fully mature and suffers from issues of attenuation and interference. A laboratory experiment conducted by the authors\u27 shows that the middleware is not yet at a plug-and-play stage, which means that initial adopters need to spend considerable effort to integrate RFID into their existing business processes. Appendices contain a glossary of common RFID terms, a list of RFID vendors and detailed findings of the laboratory experiment. NOTE: BECAUSE OF THE ILLUSTRATIONS USED, THIS ARTICLE IS LONG; APPROXIMATELY 850KB IN BOTH JOURNAL AND ARTICLE VERSIO

Mobile Ad hoc Networking: Imperatives and Challenges

Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future

An energy-efficient communication system for ad hoc wireless and sensor networks

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 76-78).Existing ad hoc wireless and sensor network systems often trade off energy against performance. As such, it is hard to find a single deployable system that supports high data rates while maintaining energy-efficient operation. This research addresses the problem by designing a communication system that achieves high performance and reduces the energy needed for delivering data in multi-hop networks by a factor of 100 or more over IEEE 802.11. The system is composed of a duty cycling and pseudo-random Medium Access Control (MAC) that provides deterministic access to the shared medium. Furthermore, the MAC provides link level QOS to support high data rates required for real-time traffic as well as delay-bounded services such as voice and multi-media streaming.by William Nii Adjetey Tetteh.M.Eng

Sensor-based management systems based on RFID technology

Παρατηρήσεις έκδοσης: λείπουν οι σελίδες 78, 102 από το φυσικό τεκμήριο.In this diploma thesis, the RFID technology is analyzed (operating principles, readers' and tags hardware, coding, modulation, anticollision procedures, frequencies, standards, applications). Moreover, a protocol to synchronize readers working in a multi-reader multi-tag environment is proposed. The protocol is applied to the store shelf scanning application and further refined to meet the requirements of this specific application

Advanced Radio Frequency Identification Design and Applications

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. This book focuses on the advances in RFID tag antenna and ASIC design, novel chipless RFID tag design, security protocol enhancements along with some novel applications of RFID

Energy-Conserving Access Protocols for Identification Networks

A myriad of applications are emerging in which energy conservation is a critical system parameter for communications. Radio Frequency Identification Devices (RFID) networks, smart cards, and even mobile computing devices in general, all need to conserve energy. In RFID systems nodes are small, battery-operated, inexpensive devices with radio receiving /transmitting and processing capabilities, integrated into the size of an ID card or smaller. These identification devices are designed for extremely low-cost, large scale applications such that the replacement of batteries is not feasible. This imposes a critical energy constraint on the communications (access) protocols used in these systems, so that the total time a node needs to be active for transmitting or receiving information should be minimized. Among existing protocols, classical random access protocols are not energy conserving while deterministic protocols lead to unacceptable delays. This paper deals with designing communicat..