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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analytical modeling of HSUPA-enabled UMTS networks for capacity planning

Liu, Tuo January 2009 (has links)
PhD / In recent years, mobile communication networks have experienced significant evolution. The 3G mobile communication system, UMTS, employs WCDMA as the air interface standard, which leads to quite different mobile network planning and dimensioning processes compared with 2G systems. The UMTS system capacity is limited by the received interference at NodeBs due to the unique features of WCDMA, which is denoted as `soft capacity'. Consequently, the key challenge in UMTS radio network planning has been shifted from channel allocation in the channelized 2G systems to blocking and outage probabilities computation under the `cell breathing' effects which are due to the relationship between network coverage and capacity. The interference characterization, especially for the other-cell interference, is one of the most important components in 3G mobile networks planning. This monograph firstly investigates the system behavior in the operation of UMTS uplink, and develops the analytic techniques to model interference and system load as fully-characterized random variables, which can be directly applicable to the performance modeling of such networks. When the analysis progresses from single-cell scenario to multi-cell scenario, as the target SIR oriented power control mechanism is employed for maximum capacity, more sophisticated system operation, `feedback behavior', has emerged, as the interference levels at different cells depend on each other. Such behaviors are also captured into the constructed interference model by iterative and approximation approaches. The models are then extended to cater for the features of the newly introduced HSUPA, which provides enhanced dedicated channels for the packet switched data services such that much higher bandwidth can be achieved for best-effort elastic traffic, which allows network operators to cope with the coexistence of both circuit-switched and packet-switched traffic and guarantee the QoS requirements. During the derivation, we consider various propagation models, traffic models, resource allocation schemes for many possible scenarios, each of which may lead to different analytical models. All the suggested models are validated with either Monte-Carlo simulations or discrete event simulations, where excellent matches between results are always achieved. Furthermore, this monograph studies the optimization-based resource allocation strategies in the UMTS uplink with integrated QoS/best-effort traffic. Optimization techniques, both linear-programming based and non-linear-programming based, are used to determine how much resource should be assigned to each enhanced uplink user in the multi-cell environment where each NodeB possesses full knowledge of the whole network. The system performance under such resource allocation schemes are analyzed and compared via Monte-Carlo simulations, which verifies that the proposed framework may serve as a good estimation and optimal reference to study how systems perform for network operators.
2

Analytical modeling of HSUPA-enabled UMTS networks for capacity planning

Liu, Tuo January 2009 (has links)
PhD / In recent years, mobile communication networks have experienced significant evolution. The 3G mobile communication system, UMTS, employs WCDMA as the air interface standard, which leads to quite different mobile network planning and dimensioning processes compared with 2G systems. The UMTS system capacity is limited by the received interference at NodeBs due to the unique features of WCDMA, which is denoted as `soft capacity'. Consequently, the key challenge in UMTS radio network planning has been shifted from channel allocation in the channelized 2G systems to blocking and outage probabilities computation under the `cell breathing' effects which are due to the relationship between network coverage and capacity. The interference characterization, especially for the other-cell interference, is one of the most important components in 3G mobile networks planning. This monograph firstly investigates the system behavior in the operation of UMTS uplink, and develops the analytic techniques to model interference and system load as fully-characterized random variables, which can be directly applicable to the performance modeling of such networks. When the analysis progresses from single-cell scenario to multi-cell scenario, as the target SIR oriented power control mechanism is employed for maximum capacity, more sophisticated system operation, `feedback behavior', has emerged, as the interference levels at different cells depend on each other. Such behaviors are also captured into the constructed interference model by iterative and approximation approaches. The models are then extended to cater for the features of the newly introduced HSUPA, which provides enhanced dedicated channels for the packet switched data services such that much higher bandwidth can be achieved for best-effort elastic traffic, which allows network operators to cope with the coexistence of both circuit-switched and packet-switched traffic and guarantee the QoS requirements. During the derivation, we consider various propagation models, traffic models, resource allocation schemes for many possible scenarios, each of which may lead to different analytical models. All the suggested models are validated with either Monte-Carlo simulations or discrete event simulations, where excellent matches between results are always achieved. Furthermore, this monograph studies the optimization-based resource allocation strategies in the UMTS uplink with integrated QoS/best-effort traffic. Optimization techniques, both linear-programming based and non-linear-programming based, are used to determine how much resource should be assigned to each enhanced uplink user in the multi-cell environment where each NodeB possesses full knowledge of the whole network. The system performance under such resource allocation schemes are analyzed and compared via Monte-Carlo simulations, which verifies that the proposed framework may serve as a good estimation and optimal reference to study how systems perform for network operators.
3

CELLULAR BROADBAND TELEMETRY OPTIONS FOR THE 21st CENTURY: Looking at broadband cellular from a telemetry perspective

Smith, Brian J. 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / With the recent broadband upgrades to various cellular infrastructures and the myriad new emerging wireless broadband standards and services offered by carriers, it is often difficult to navigate this sea of technology. In deciding the best choice for broadband telemetry applications, one must look not only at the technology, but also at the economics, market timing, bandwidths, legacy issues, future expandability and coverage, security, protocols, and the requirements of the specific application. This paper reviews the technology roadmap of cellular providers keeping these issues in perspective as they apply to TCP/IP data for images, audio, video, and other broadband telemetry data using CDMA 1xRTT, EV-DO, and EV-DO Rev A systems as well as GSM GPRS/EDGE, UMTS/W-CDMA, HSDPA, and HSUPA networks. Lastly, issues seen by system integrators when using cellular channels for telemetry applications are examined, and a case is presented for overcoming many of these issues through the use of cellular routers.
4

Vývoj a výhled mobilního připojení v ČR / Development and Future Prospects of Mobile Internet Connection in the Czech Republic

Bičík, Petr January 2008 (has links)
Mobile telecommunications belong to one of the fields which still evolves and it is expected that in the future they are going to offer great benefit to the whole world. This work focuses on current and future development of mobile Internet connection in the Czech Republic. At first the technologies used to provide mobile Internet connection are described and compared and then the situation (in terms of technologies and mobile operators) in the Czech market is outlined and its possible evolution in the near future is presented. Furthermore, the tarifs of mobile operators are compared with those in place two years ago. The strengths and weaknesses of the current mobile Internet connection are evaluated based on the conducted questionnaire survey. The latest results are then analyzed and compared with the results from a previous survey conducted in 2007 as part of a bachelor's thesis, which has been further extended in this mater's thesis.
5

Základy mobilního internetu / Mobile internet principles

Jehličková, Lenka January 2011 (has links)
Thesis concerns with mobile communications theory with focus on data transfer. In the introduction the history, the origin and individual mobile systems generations are described. It is followed by detailed description of second, third and fourth generation mobile systems. Frequency band allocation, signal processing, the system architecture itself, security management and basic features are also discussed. The GSM system is described together with individual data transmission types based on circuit switching – CSD and HSCSD and packet switching – GPRS and EDGE. For UMTS, FDD and TDD modes are listed as well as changes in individual releases, corresponding technologies and provided services. Next, there is the description of LTE and WiMAX systems, together with their improvements whose are part of the fourth generation of mobile systems. Last of the described systems is the still work in progress HAPS, also known as the system of stratospheric platforms. In the end important parameters are summarized and systems are compared with each other.
6

Architectures matérielles pour la technologie WCDMA étendue aux systèmes mulit-antennes

Saïdi, Taofik 08 July 2008 (has links) (PDF)
Depuis une dizaine d'années, l'avènement des techniques multi-antennes (ou MIMO) pour les communications sans fil, mobiles ou fixes, a révolutionné les possibilités offertes pour de nombreux domaines d'application des télécommunications. La disposition de plusieurs antennes de part et d'autre du lien augmente considérablement la capacité des systèmes sans fil. Cependant, les al- gorithmes numériques à mettre en œuvre pour réaliser ces systèmes sont autrement complexes et constituent un challenge quant à la définition d'architectures matérielles performantes. L'objectif du travail présent repose précisément sur la définition optimale de solutions architecturales, dans un contexte CDMA, pour contrer cette problématique. Le premier aspect de ce travail porte sur une étude approfondie des algorithmes spatio- temporels et des méthodes de conception en vue d'une implantation matérielle efficace. De nom- breux schémas de détection sont proposés dans la littérature et sont applicables suivant trois critères qui sont : la qualité de service, le débit binaire et la complexité algorithmique. Cette dernière constitue une contrainte forte pour une mise en application à faible coût de terminaux mobiles intégrant ces applications. Aussi, il est nécessaire de disposer d'outils performants pour simuler, évaluer et affiner (prototypage rapide) ces nouveaux systèmes, candidats probables pour les télécommunications de quatrième génération. Le second aspect concerne la réalisation d'un transcepteur multi-antennes sans codage de ca- nal, intégrant la technologie d'accès multiple par répartition de codes dans le cas d'un canal large bande. Un système mono-antenne WCDMA, généralisable à un nombre quelconque d'antennes, a été intégré et simulé au sein de la plate-forme de prototypage rapide Lyrtech. L'architecture développée intègre les principaux modules du traitement en bande de base, à savoir le filtrage de Nyquist, la détection des multiples trajets suivie de l'étape de détection. Le prototype MIMO- WCDMA développé est caractérisé par sa flexibilité suivant le nombre de voies entrantes, le for- mat d'entrée des échantillons, les caractéristiques du canal sans fil et la technologie ciblée (ASIC, FPGA). Le troisième aspect se veut plus prospectif en détaillant de nouveaux mécanismes pour réduire le coût matériel des systèmes multi-antennes. Le principe d'allocation adaptative de la virgule fixe est présenté dans le but d'adapter le codage des données suivant les caractéristiques du canal sans fil et de minimiser en conséquence la complexité du circuit. D'autre part, le concept d'ar- chitectures adaptatives est proposé afin de minimiser l'énergie consommée au sein d'un système embarqué suivant le contexte d'application.
7

Optimization of Remote ServiceSolution for large installations : Wireless LAN and WAN for ABB Robotics

Stenbom, Håkan January 2011 (has links)
This report describes a thesis work carried out at ABB Robotics in Västerås. The objective of this thesis is to find technologies  and equipments  for wireless data transfer  suitable for the present and future needs of ABB Robotics Remote Service for large installations in industrial environments. ABB Robotics has a Remote Service solution to securely gather information from robots, manage alarms and potentially execute remote commands by ABB Robotics. This solution consists of an intelligent Service  Box plugged to the robot. This  Service Box is also connected through GPRS or directly through Internet to create a secure VPN connection to a central Remote Service  server. The Remote Service Box is well  suited  for small customers with  1-10 robots with plug  and play installation, but show limitations at a larger scale of deployment  due to equipment costs,  network and installation complexity. A new Service Box is planned that will accommodate future added functionality to Remote Service. This Service Box will require new network solutions as the added functionality  is depending on a higher bandwidth than the GPRS networks can deliver. I have surveyed most existing  wireless  networking technologies  and  analyzed  them  withrespect  to function, cost and availability which provide a knowledge base that makes it possible to find  suitable  solutions. When the most suitable technologies are identified a survey was performed to find equipments that meet the requirements at the lowest cost. A new hierarchical network topology is proposed  that will lead to cost savings by replacing multiple WAN connections in the present solution with  a network switch and  single WAN connection to Internet. As manufacturers of network equipments for industrial environments are relatively few, alternative solutions were also investigated in order to find the most cost effective solutions. The  proposed  network topology together with the data from the surveys lead to recommendations on using Wi-Fi  in the wireless LAN and  a  3G mobile  network for the WAN connection to Internet, as well as recommendations on alternative network equipments that  potentially  can  lead to substantial savings when the new network solutions are implemented.

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