436 research outputs found

    Mobile telecommunication networks and mobile commerce : towards its applications in chinese market

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    La tĂ©lĂ©communication mobile connecte les personnes de n'importe oĂč Ă  tout moment. La transmission de la voix et des donnĂ©es Ă  travers les rĂ©seaux de tĂ©lĂ©communication mobile permet d'envoyer des informations et de diriger des transactions d'une maniĂšre nouvelle. Cela crĂ©e un nouveau domaine d'affaires qui s'appelle du commerce mobile, une affaire Ă©tendue basĂ©e sur l'Internet avec de nombreux des caractĂ©ristiques uniques ajoutĂ©s. Comme un soutien fondamental du plate-forme, les rĂ©seaux de la tĂ©lĂ©communication mobile joue un rĂŽle essentiel dans le commerce mobile. Leurs caractĂ©ristiques techniques et le dĂ©ploiement dĂ©terminent l'essence pour le commerce mobile. Dans cette mĂ©moire, nous Ă©tudions et prĂ©sentons les caractĂ©ristiques techniques des technologies communications mobiles du rĂ©seau 1G Ă  3G et au-delĂ . Nous Ă©tudions Ă©galement les technologies WLAN et WAP qui sont courantes dans le commerce mobile en Chine et dans le monde. Le commerce mobile est en train de se dĂ©velopper, le nombre d'utilisateurs de tĂ©lĂ©phones mobiles sont de plus en plus en Chine et dans ce monde. Les utilisateurs mobiles Ă©normes en Chine ainsi que la maturitĂ© des technologies 3G affichent un fort potentiel pour offrir et d'adopter plus les nouveaux services mobiles. AprĂšs rĂ©viser l'Ă©volution du commerce mobile et l'histoire du succĂšs i-mode au Japon, nous nous concentrons sur le mobile du marchĂ© chinois de maniĂšre Ă  dĂ©couvrir son marchĂ©, l'infrastructure du rĂ©seau mobile, et le modĂšle d'affaires. FondĂ© sur la base de notre enquĂȘte sur le commerce mobile chinois, nous prĂ©sentons, selon notre jugement, les services mobiles et des applications que sont convenables pour la Chine. Parmi eux, nous pensons qu'il y a la tendance sur les services basĂ©s sur la localisation et services orientĂ©es de l'architectures. Cette tendance peut attirer plus d'attention Ă  offrir de nouveaux services. En plus, elle peut offrir des services d'intĂ©gration et de personnalisation qui viennent de fournisseurs de services mobiles et des utilisateurs finaux. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Gestion intĂ©grĂ©e et Ă©cosystĂ©mique, Principe de prĂ©caution, Communication entre acteurs, Risques sur l'environnement et la santĂ©

    Sketch-based Queries in Mobile GIS-Environments

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    Recent achievements in the field of mobile computing and wireless communication promise data retrieval anywhere and anytime. This development provided the basis to expand GIs technology to handheld devices, such as personal digital assistants (PDAs). Although traditional GIs technology is well suited for desktop workstations, it needs to be adapted in order to satisfy the requirements of users using handheld computing devices. This adaptation is necessary because the usability of traditional GISs depends on characteristics of desktop computers, such as their relatively large user interfaces (e.g., displays, keyboards, pointing devices), considerable computing resources (i.e., CPU, memory, storage, operating systems), and high bandwidth network connectivity. Small devices possess few of these characteristics, hence, requiring new and efficient methods for interaction with spatial databases. We propose a concept that supports sketch-based querying in mobile GIs environments. This concept combines newest techniques for spatial querying and mobile technologies. Such a combination is beneficial for users because it allows them to formulate queries by drawing the desired configuration with a pen on the touch-sensitive PDA screen, and consequently avoids typing complex statements in some SQL-like query language. Client-server architectures in mobile environments are characterized by low and fluctuating bandwidth, and by frequent disconnections. We discuss client-server strategies in mobile environments, suggest an adaptive client-server architecture for geomobile querying, and analyze the performance. It is shown that adaptation to the mobile environment is necessary in order to ensure efficiency of geo-mobile queries

    Using mobile computing for construction site information management

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    PhD ThesisIn recent years, construction information management has greatly benefited from advancesin Information and Communication Technology (ICT) increasing the speed of information flow, enhancing the efficiency and effectiveness of information communication, and reducing the cost of information transfer. Current ICT support has been extended to construction site offices. However, construction projects typically take place in the field where construction personnel have difficulty in gaining access to conventional information systems for their information requirements. The advances in affordable mobile devices, increases in wireless network transfer speeds and enhancements in mobile application performance, give mobile computing a powerful potential to improve on-site construction information management. This research project aims to explore how mobile computing can be implemented to manage information on construction sites through the development of a framework. Various research methods and strategies were adopted to achieve the defined aim of this research. These methods include an extensive literature review in both areas of construction information management and mobile computing; case studies that investigate construction information management on construction sites; a web-based survey for the investigation of the existing mechanism for on-site information retrieval and transfer; and a case study of the validation of the framework. Based on the results obtained from the literature review, case studies and the survey,the developed framework identifies the primary factors that influence the implementation of mobile computing in construction site information management, and the inter relationships between those factors. Each of these primary factors is further divided into sub-factors that describe the detailed features of relevant primary factors. In order to explore links between sub-factors, the top-level framework is broken down into different sub-frameworks, each of which presents the specific links between two primary factors. One of the applications for the developed framework is the selection of a mobile computing strategy for managing on-site construction information. The overall selection procedure has three major steps: the definition of on-site information management objectives; the identification of mobile computing strategy; and the selection of appropriate mobile computing technologies. The evaluation and validity of the selection procedure is demonstrated through an illustrative constructions cenario

    Survey on Wi-Fi and Cellular Communication Technology for Advanced Metering Infrastructure (AMI) in a Developing Economy

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    Traditional energy meters have suffered from a lack of automated analysis and inaccuracy in reading energy consumption, which has brought about smart metering systems. Developing economies such as in Africa. still experience a setback in electricity monitoring and load distribution because of existing traditional meter systems in use. Communication technologies play an important role to improve the monitoring of energy consumption and ensure a road map toward a smart grid. This paper reviews communication technologies used for Advanced Metering Infrastructure (AMI) emphasizing Wi-Fi and Cellular technologies. Metrics used to evaluate their performance include cost, energy efficiency, coverage, deployment, latency, payload, and scalability. The review presents a benchmark for research on AMI communication technologies in developing economies. When adopted, the expected AMI benefits are reduced energy theft, cost efficiency, real-time analysis, security, and safety of energy supply in developing economies

    INTELLIGENTE TRANSPORT SYSTEMEN ITS EN VERKEERSVEILIGHEID

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    This report discusses Intelligent Transport Systems (ITS). This generic term is used for a broad range of information-, control- and electronic technology that can be integrated in the road infrastructure and the vehicles themselves, saving lives, time and money bymonitoring and managing traffic flows, reducing conges-tion, avoiding accidents, etc. Because this report was written in the scope of the Policy Research Centre Mobility & Public Works, track Traffic Safety, it focuses on ITS systems from the traffic safety point of view. Within the whole range of ITS systems, two categories can be distinguished: autonomous and cooperative systems. Autonomous systems are all forms of ITS which operate by itself, and do not depend on the cooperation with other vehicles or supporting infrastructure. Example applications are blind spot detection using radar, electronic stability control, dynamic traffic management using variable road signs, emergency call, etc. Cooperative systems are ITS systems based on communication and cooperation, both between vehicles as between vehicles and infrastructure. Example applications are alerting vehicles approaching a traffic jam, exchanging data regarding hazardous road conditions, extended electronic brake light, etc. In some cases, autonomous systems can evolve to autonomous cooperative systems. ISA (Intelligent Speed Adaptation) is an example of this: the dynamic aspect as well as communication with infrastructure (eg Traffic lights, Variable Message Sign (VMS)...) can provide additional road safety. This is the clear link between the two parts of this report. The many ITS applications are an indicator of the high expectations from the government, the academic world and the industry regarding the possibilities made possible by both categories of ITS systems. Therefore, the comprehensive discussion of both of them is the core of this report. The first part of the report covering the autonomous systems treats two aspects: 1. Overview of European projects related to mobility and in particular to road safety 2. Overview for guidelines for the evaluation of ITS projects. Out of the wide range of diverse (autonomous) ITS applications a selection is made; this selection is focused on E Safety Forum and PreVENT. Especially the PreVent research project is interesting because ITS-applications have led to a number of concrete demonstration vehicles that showed - in protected and unprotected surroundings- that these ITS-applications are already technically useful or could be developed into useful products. The component “guidelines for the evaluation of ITS projects” outlines that the government has to have specific evaluation tools if the government has the ambition of using ITS-applications for road safety. Two projects -guidelines for the evaluation of ITS projects- are examined; a third evaluation method is only mentioned because this description shows that a specific targeting of the government can be desirable : 1. TRACE describes the guidelines for the evaluation of ITS projects which are useful for the evaluation of specific ITS-applications. 2. FITS contains Finnish guidelines for the evaluation of ITS project; FIS is an adaptation of methods used for evaluation of transport projects. 3. The third evaluation method for the evaluation of ITS projects is developed in an ongoing European research project, eImpact. eImpact is important because, a specific consultation of stake holders shows that the social importance of some techniques is underestimated. These preliminary results show that an appropriate guiding role for the government could be important. In the second part of this document the cooperative systems are discussed in depth. These systems enable a large number of applications with an important social relevance, both on the level of the environment, mobility and traffic safety. Cooperative systems make it possible to warn drivers in time to avoid collisions (e.g. when approaching the tail of a traffic jam, or when a ghost driver is detected). Hazardous road conditions can be automatically communicated to other drivers (e.g. after the detection of black ice or an oil trail by the ESP). Navigation systems can receive detailed real-time up-dates about the current traffic situation and can take this into account when calculating their routes. When a traffic distortion occurs, traffic centers can immediately take action and can actively influence the way that the traffic will be diverted. Drivers can be notified well in advance about approaching emergency vehicles, and can be directed to yield way in a uniform manner. This is just a small selection from the large number of applications that are made possible because of cooperative ITS systems, but it is very obvious that these systems can make a significant positive contribution to traffic safety. In literature it is estimated that the decrease of accidents with injuries of fatalities will be between 20% and 50% . It is not suprising that ITS systems receive a lot of attention for the moment. On an international level, a number of standards are being established regarding this topic. The International Telecommunications Uniont (ITU), Institute for Electrical and Electronics Engineers (IEEE), International Organization for Standardization (ISO), Association of Radio Industries and Business (ARIB) and European committee for standardization (CEN) are currently defining standards that describe different aspects of ITS systems. One of the names that is mostly mentioned in literature is the ISO TC204/WG16 Communications Architecture for Land Mobile environment (CALM) standard. It describes a framework that enables transparent (both for the application and the user) continuous communication through different communication media. Besides the innumerable standardization activities, there is a great number of active research projects. On European level, the most important are the i2010 Intelligent Car Initiative, the eSafety Forum, and the COMeSafety, the CVIS, the SAFESPOT, the COOPERS and the SEVECOM project. The i2010 Intelligent Car Initiative is an European initiative with the goal to halve the number of traffic casualties by 2010. The eSafety Forum is an initiative of the European Commission, industry and other stakeholders and targets the acceleration of development and deployment of safety-related ITS systems. The COMeSafety project supports the eSafety Forum on the field of vehicle-to-vehicle and vehicle-to-infrastructure communication. In the CVIS project, attention is given to both technical and non-technical issues, with the main goal to develop the first free and open reference implementation of the CALM architecture. The SAFEST project investigates which data is important for safety applications, and with which algorithmsthis data can be extracted from vehicles and infrastructure. The COOPERS project mainly targets communication between vehicles and dedicated roadside infrastructure. Finally, the SEVECOM project researches security and privacy issues. Besides the European projects, research is also conducted in the United States of America (CICAS and VII projects) and in Japan (AHSRA, VICS, Smartway, internetITS). Besides standardization bodies and governmental organizations, also the industry has a considerable interest in ITS systems. In the scope of their ITS activities, a number of companies are united in national and international organizations. On an international level, the best known names are the Car 2 Car Communication Consortium, and Ertico. The C2C CC unites the large European car manufacturers, and focuses on the development of an open standard for vehicle-to-vehicle and vehicle-to-infrastructure communications based on the already well established IEEE 802.11 WLAN standard. Ertico is an European multi-sector, public/private partnership with the intended purpose of the development and introduction of ITS systems. On a national level, FlandersDrive and The Telematics Cluster / ITS Belgium are the best known organizations. Despite the worldwide activities regarding (cooperative) ITS systems, there still is no consensus about the wireless technology to be used in such systems. This can be put down to the fact that a large number of suitable technologies exist or are under development. Each technology has its specific advantages and disadvantages, but no single technology is the ideal solution for every ITS application. However, the different candidates can be classified in three distinct categories. The first group contains solutions for Dedicated Short Range Communication (DSRC), such as the WAVE technology. The second group is made up of several cellular communication networks providing coverage over wide areas. Examples are GPRS (data communication using the GSM network), UMTS (faster then GPRS), WiMAX (even faster then UMTS) and MBWA (similar to WiMAX). The third group consists of digital data broadcast technologies such as RDS (via the current FM radio transmissions, slow), DAB and DMB (via current digital radio transmissions, quicker) and DVB-H (via future digital television transmissions for mobiledevices, quickest). The previous makes it clear that ITS systems are a hot topic right now, and they receive a lot of attention from the academic world, the standardization bodies and the industry. Therefore, it seems like that it is just a matter of time before ITS systems will find their way into the daily live. Due to the large number of suitable technologies for the implementation of cooperative ITS systems, it is very hard to define which role the government has to play in these developments, and which are the next steps to take. These issues were addressed in reports produced by the i2010 Intelligent Car Initiative and the CVIS project. Their state of the art overview revealed that until now, no country has successfully deployed a fully operational ITS system yet. Seven EU countries are the furthest and are already in the deployment phase: Sweden, Germany, the Netherlands, the United Kingdom, Finland, Spain and France. These countries are trailed by eight countries which are in the promotion phase: Denmark, Greece, Italy, Austria, Belgium,Norway, the Czech Republic and Poland. Finally, the last ten countries find themselves in the start-up phase: Estonia, Lithuania, Latvia, Slovenia, Slovakia, Hungary, Portugal, Switzerland, Ireland and Luxembourg. These European reports produced by the i2010 Intelligent Car Initiative and the CVIS project have defined a few policy recommendations which are very relevant for the Belgian and Flemish government. The most important recommendations for the Flemish government are: ‱ Support awareness: research revealed that civilians consider ITS applications useful, but they are not really willing to pay for this technology. Therefore, it is important to convince the general public of the usefulness and the importance of ITS systems. ‱ Fill the gaps: Belgium is situated in the promotion phase. This means that it should focus at identifying the missing stakeholders, and coordinating national and regional ITS activities. Here it is important that the research activities are coordinated in a national and international context to allow transfer of knowledge from one study to the next, as well as the results to be comparable. ‱ Develop a vision: in the scope of ITS systems policies have to be defined regarding a large number of issues. For instance there is the question if ITS users should be educated, meaning that the use of ITS systems should be the subject of the drivers license exam. How will the regulations be for the technical inspection of vehicles equipped with ITS technology? Will ITS systems be deployed on a voluntary base, or will they e.g. be obliged in every new car? Will the services be offered by private companies, by the public authorities, or by a combination of them? Which technology will be used to implement ITS systems? These are just a few of the many questions where the government will have to develop a point of view for. ‱ Policy coordination: ITS systems are a policy subject on an international, national and regional level. It is very important that these policy organizations can collaborate in a coordinated manner. ‱ Iterative approach to policy development: developing policies for this complex matter is not a simple task. This asks for an iterative approach, where policy decisions are continuously refined and adjusted

    Chinese cellular telecommunications in the past and the 21st century

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    Cellular telecommunication technology is one of the hottest topics of the last two decades. The annual rate of user growth is more than 30 percent. It began with the first generation (1G) networks and bloomed with second generation (2G) of cellular technologies. New third generation cellular (3G) technologies aim at offering high-speed, superior-quality information service to mobile subscribers. [2] The Chinese cellular market is developing with unbelievable speed. China launched its first cellular network in 1987. At the end of 2002, it was the biggest wireless market in the world, with more than 200 million subscribers. [56] Technologies used in the migration from the 2G networks to the 3G networks are referred to as 2.5 generation or 2.5G. It is no doubt that the 3G pattern selected in China will deeply affect the competition among the 3G technologies. This thesis will forecast the 3G systems to be selected for use in China. It will begin with the 1G and 2G networks and then look into the 2.5 G and the 3G cellular telecommunication technologies in more detail. Analysis the history, culture and business conditions in China will follow. Finally, this paper will make a prediction of the principal Chinese 3G technologies that will be chosen based on analyzing concrete information. An examination of other Asia markets, such as the 3G markets in Japan, and South Korea will be included. The conclusion of this thesis is that WCDMA (Wideband Code Division Multiple Access), a 3G technology that is developed and supported by European telecommunication manufacturers, will take the lion\u27s share of the Chinese 3G market, about 65% to 70%. Another technology, CDMA2000, will take more than 20% of the Chinese 3G market share. There is also a Chinese oriented 3G technology named TD-SCDMA (Time Division Synchronous Code Division Multiple Access). With the Chinese government\u27s support, it will collect the remaining 10% to 15% market share
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