Modeling of On-line Traffic Control and Management Network for Operational and Communication Performance Evaluation

Communication systems are the backbone of every effective and reliable traffic control and management application. While traditional fiber optics and telephone communications have long been used in managing and controlling highway traffic, wireless communication technology shows great promise as an alternative solution in traffic management applications due to their suitability for deployment in rural areas, and their flexibility and cost-effectiveness for system expansion. However, the detailed characteristics of various wireless communication technologies and real performance in the field have not been systematically studied. To augment this existing knowledge so that traffic professionals may better utilize these technologies to improve traffic safety, mobility and efficiency, this study aims to 1) identify existing wireless communication technologies used in ITS, and potential wireless communication alternatives that can be widely used in ITS, 2) evaluate the performance, cost and reliability of existing and potential wireless communication technologies in supporting on-line traffic control and management functions, and 3) apply benefit-cost analysis to identify the impacts of using these wireless technologies to support on-line traffic management. To achieve these research objectives, the author first conducted an interview to discover the specifications of existing communication infrastructures deployed for various ITS related applications and the usage of wireless technologies in different states. Moreover, the author proposed a network design process that considered wireless coverage range and network topology, followed with case studies utilizing Wireless Fidelity (WiFi) and Worldwide Interoperability for Microwave Access (WiMAX) technologies to support a traffic surveillance system in seven metropolitan areas throughout South Carolina. Field tests were conducted to evaluate the performance and reliability of wireless transmissions between adjacent sensor nodes. After that, the author applied a communication simulator, ns-2, to compare the communication performance of a traffic sensor network with WiFi and WiMAX technologies under infrastructure and mesh topologies, and environmental conditions. Based on these simulation results, the author conducted performance-cost analysis for these selected technologies and topologies. The WiFi field test results indicated that wireless communication performance between two traffic sensors significantly degrades after 300 ft; this distance, however, may vary with the modulation rates and transmission power upon which the system operates. WiMAX nomadic test suggested that line-of-sight (LOS) greatly affects the connectivity level. Moreover, the capabilities and the performance of the WiMAX network are sometimes affected by the characteristics of the client radio. The simulation analysis and benefit-cost analysis indicated a WiFi mesh network solution has the highest throughput-cost ratio, 109 bits/dollar for supporting traffic surveillance systems, while the WiMAX infrastructure option provides the greatest amount of excess bandwidth, 9.15Mbps per device, which benefits the system\u27s future expansion. This dissertation provides an important foundation for further investigation of the performance and reliability of different wireless technologies. In addition, research results presented in this dissertation will benefit transportation agencies and other stakeholders in evaluating and selecting wireless communication options for different traffic control and management applications

Design of an All-In-One Embedded Flight Control System

This thesis describes an all-in-one flight control system (FCS) that was designed for unmanned aerial vehicles (UAVs). The project focuses on the embedded hardware aspect of a stand-alone system with low-cost and reliability in mind

Modeling the Use of an Airborne Platform for Cellular Communications Following Disruptions

In the wake of a disaster, infrastructure can be severely damaged, hampering telecommunications. An Airborne Communications Network (ACN) allows for rapid and accurate information exchange that is essential for the disaster response period. Access to information for survivors is the start of returning to self-sufficiency, regaining dignity, and maintaining hope. Real-world testing has proven that such a system can be built, leading to possible future expansion of features and functionality of an emergency communications system. Currently, there are no airborne civilian communications systems designed to meet the demands of the public following a natural disaster. A system allowing even a limited amount of communications post-disaster is a great improvement on the current situation, where telecommunications are frequently not available. It is technically feasible to use an airborne, wireless, cellular system quickly deployable to disaster areas and configured to restore some of the functions of damaged terrestrial telecommunications networks. The system requirements were presented, leading to the next stage of the planned research, where a range of possible solutions were examined. The best solution was selected based on the earlier, predefined criteria. The system was modeled, and a test ii system built. The system was tested and redesigned when necessary, to meet the requirements. The research has shown how the combination of technology, especially the recent miniaturizations and move to open source software for cellular network components can allow sophisticated cellular networks to be implemented. The ACN system proposed could enable connectivity and reduce the communications problems that were experienced following Hurricane Sandy and Katrina. Experience with both natural and man-made disasters highlights the fact that communications are useful only to the extent that they are accessible and useable by the population

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities.Postprint (published version

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Ground plane booster antenna technology for wireless handheld devices

This thesis is framed in the field of mobile communications and more particularly in handset antennas. The wireless industry is constantly growing, which entails challenging handset antenna specifications. Handset antennas not only have to be multi-band for satisfying the great number of communication services, but also sufficiently small as for fitting in the reduced space imposed by the handset platforms. The appearance of the MIMO (Multiple Input Multiple Output) technology, further exacerbates these challenges. In order to satisfy these requirements, this thesis proposes the use of the ground plane, inherently present in any handset platform, as the main radiator. Electrically small nonresonant elements, called along this thesis as ground plane boosters, are used to transfer energy to this ground plane. The solution removes the need of including a dedicated antenna featured by considerable dimensions, thus releasing space to integrate other antennas, as well as, other handset components, services and functionalities

Design, Fabrication and Veri cation of a Mixed-Signal XY Zone Monitoring Circuit and its Application to a Phase Lock Loop Circuit

El presente proyecto de final de carrera se centra en el diseño, análisis e implementación en silicio de una metodología de test/diagnosis basada en la comparación de firmas digitales generadas a partir de curvas de Lissajous. Se muestra su aplicación para testar la etapa de filtro de un circuito de bucle de enganche de fase (phase lock loop, PLL), así como los resultados experimentales de su implementación en tecnología CMOS de 65 nm. La obtención de las firmas digitales se consigue mediante el uso de un circuito monitor, el cual, a partir de la composición de dos señales periódicas del circuito a analizar, genera, para cada punto de la curva de Lissajous, un valor digital. La utilización de varios monitores con gurados de la manera adecuada permite una completa teselación del plano en diferentes zonas y por tanto, la generación de distintos códigos digitales (firma) a medida que la curva de Lissajous evoluciona en el tiempo. El test del circuito y/o diagnosis del posible defecto se realiza mediante la comparación de la signatura golden o sin defecto y la signatura generada por el circuito testado. Para la comparación de firmas se emplea el concepto de distancia de Hamming entre códigos a modo de métrica de discrepancia. A partir de los valores precalculados de la métrica para cada posible valor del defecto se consigue realizar la diagnosis de este para el parámetro en estudio. El trabajo se enmarca en el diseño de circuitos integrados de muy alta escala de integración usando una tecnología CMOS de actualidad (65 nm). Es por ello que se requieren técnicas de diseño analógico específicas, como lo son las estrategias centroidales para la elaboración de layouts o el correcto modelado de transistores nanométricos. Para esto último se hace uso del modelo Berkeley, el cual, debidamente ajustado a la tecnología empleada, proporciona aproximaciones muy aceptables y con relativa facilidad de uso. Con el objetivo de verificar la metodología de test/diagnosis propuesta, se hace uso de una aplicación Matlab que permite simular el comportamiento del circuito a testar en diferentes situaciones. Es posible excitar el circuito con distintas entradas, cambiar los parámetros de este, introducir defectos, o emplear distintos conjuntos de curvas para teselar el plano. La aplicación resulta fundamental para efectuar el proceso de diagnosis pues relaciona la cantidad de defecto con los valores de discrepancia obtenidos con la métrica definida. Finalmente, se presentan los resultados experimentales obtenidos con el chip fabricado. Se constata el correcto comportamiento de este y la validez de la metodología de test/diagnosis propuesta

Comparisons of telecommunications markets in regulated and deregulated market environments: case study of cellular phone markets in China and Hong Kong.

by Ng Wing-tim, Daniel, Yeung Siu-ming.Thesis (M.B.A.)--Chinese University of Hong Kong, 1995.Includes bibliographical references (leaves 113).ABSTRACT --- p.iiiTABLE OF CONTENTS --- p.vLIST OF EXHIBITS --- p.viiiChapterChapter I. --- INTRODUCTION --- p.1Economic Background --- p.1PRC --- p.1Hong Kong --- p.3Basic Telecommunications Structure --- p.4PRC --- p.4Hong Kong --- p.8Basic Cellular Environment --- p.8PRC --- p.9Hong Kong --- p.11Comparisons between PRC and Hong Kong --- p.12Characteristics of the Cellular Market --- p.13PRC --- p.13System Summary Table --- p.16Chapter II. --- CELLULAR NETWORKS --- p.17System Growth --- p.19Migration to Digital Era --- p.21GSM --- p.21CDMA --- p.23D-AMPS --- p.24E-TDMA --- p.24Market Analysis in Selected Areas --- p.25Beijing --- p.26Shanghai --- p.29Guangdong Province --- p.31Hong Kong --- p.33Chapter III. --- CELLULAR TERMINAL MARKET --- p.36Market Potential --- p.36PRC --- p.36Hong Kong --- p.37Subscriber Distribution --- p.37PRC --- p.38Hong Kong --- p.38Subscriber Growth --- p.40PRC --- p.41Hong Kong --- p.42Black Market --- p.43PRC --- p.43Hong Kong --- p.44Roaming --- p.45PRC --- p.45Hong Kong --- p.46Chapter IV. --- CUSTOMERS --- p.48Preference --- p.48Consumption Trends --- p.49Segments --- p.50Subscriber Charges --- p.51Chapter V. --- COMPETITORS --- p.52Cellular Infrastructure Suppliers --- p.52PRC --- p.52Hong Kong --- p.56Cellular Terminal Suppliers --- p.57PRC --- p.57Hong Kong --- p.60Product Comparisons --- p.61Market Shares --- p.61PRC --- p.61Hong Kong --- p.62Pricing Trend --- p.63PRC --- p.63Hong Kong --- p.64Competition from CT2 --- p.64PRC --- p.64Hong Kong --- p.65Chapter VI. --- TECHNOLOGY --- p.67Migration to Digital Era --- p.67PRC --- p.67Hong Kong --- p.68New Generation on Mobile Terminal --- p.69PRC --- p.69Hong Kong --- p.70Chapter VII. --- ECONOMIC ENVIRONMENT --- p.71PRC --- p.71Hong Kong --- p.73Chapter VIII. --- LEGAL ENVIRONMENT --- p.75PRC --- p.75Migration into Deregulated Environment --- p.75Government Policy --- p.77Difficulties Encountered in Deregulation --- p.78Hong Kong --- p.80Law in Hong Kong --- p.81Telecom Deregulation --- p.81Mobile Telecommunications Service --- p.82Chapter IX. --- RECOMMENDATIONS FOR A NEW ENTRANT INTO THE MARKET --- p.84PRC --- p.84Type approval --- p.84Import --- p.86Distribution --- p.87Pricing --- p.87Local Production --- p.88Hong Kong --- p.89EXHIBIT --- p.90BIBLIOGRAPHY --- p.11