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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

Radio over fiber for 3G cellular System

Prasad, Saurabh January 2010 (has links)
The demand for bandwidth is increasing vigorously. Thus wired network is using fiber optic telephone line instead of coaxial cable. The concept of Fiber to the Home (FTTH) is really coming into picture. Few countries like Japan, Korea etc are leading in this technology. But now the major challenge is how to provide the high speed internet connection wirelessly. Thus the change is to integrate the wireless and optical fiber communication. / Wireless Optical Communication
2

A distributed, mobile positioning systemfor wireless, handheld devices

Christiansson, Fredrik January 2000 (has links)
This thesis investigates the possibilities of implementing a location awareness mechanism for the so-called lesswire localNavigator. The author claims that it is possible to implement such a mechanism within the given prerequisites and constraints, even though with today’s technology it may not be economically feasible. Due to the lesswire’s constraints: high accuracy (67%), high-resolution (12 m2) and no hardware modification allowed to the mobile device, the suggested scheme uses Time Difference Of Arrival technology (TDOA). The main advantage of TDOA, as stated in this thesis, is the fact that it is almost totally independent of the preferred wireless technology of the mobile device. TDOA technology therefore, can be applied to a wide range of wireless networks (primarily TDMA, CDMA, FDMA – based). A disadvantage of this scheme is the fact that the network infrastructure needs to be extremely well synchronized - which in turn implies higher costs. Depending on how the synchronization problem is solved, the proposed system may well be economically feasible in the near future.
3

Small Cell Wireless Backhaul in Mobile Heterogeneous Networks

Legonkov, Pavel, Prokopov, Vasily January 2012 (has links)
Small cells are deployed in a crowded areas with a high demand for both coverage and capacity. It is hard to address both of these requirements simultaneous with a conventional mobile network architecture based on macro cells. In many case a wire is not available to connect the small cell to the core of the mobile network. Under these circumstances a wireless link could be a convenient solution for the backhaul. In this master’s thesis IEEE 802.11n technology was evaluated to assess its suitability for backhaul from a small wireless cell. The performance of wireless equipment manufactured by several vendors has been measured. The results of these measurements were analyzed and compared to a set of requirements established for small cell backhaul. The analysis has affirmed that IEEE 802.11n is capable of providing sufficient performance to be used for small cell backhaul in various deployment scenarios. Note that in this thesis we include femtocells, picocells, wireless LAN access points, and other technologies in the category of "small cells". Another research questions of this master’s thesis is security of small cell backhaul. In addition to protecting the backhaul link itself, the security research investigated the safety of the whole mobile network architecture remodeled with the introduction of small cells. A mechanism to integrate secure small cells into a mobile network was developed. The results obtained during the project will be used as an input for product development activities in the company hosting the project. The resulting product could become the target of future wireless system performance measurements. / Små celler sätts ut i områden med höga krav på täckning och kapacitet. Det är svårt att adressera båda dessa krav samtidigt med en konventionell mobil nätverksarkitektur baserad på makro-celler. I många fall finns ingen kabel tillgänglig att koppla den lilla cellen till kärnan i det mobila nätverket. Under dessa omständigheter kan en trådlös länk vara en lämplig lösning för backhaul. I denna avhandling utvärderas IEEE 802.11n-teknikens lämplighet för backhaul av små celler. Prestandan hos trådlös utrustning tillverkad av flera olika tillverkare har mätts. Resultaten av dessa mätningar analyserades och jämfördes med en mängd krav uppsatta för backhaul av små celler. Analysen har förankrat att IEEE 802.11n är kapabel till att tillhandahålla tillräcklig prestanda för backhaul av små celler i diverse miljöer. Notera att i denna avhandling så inkluderas femto-celler, pico-celler, Wireless LAN-åtkomstpunkter, och andra teknologier i kategorin små celler". Andra forskningsfrågor berörda i avhandlingen är säkerhet vid backhaul av små celler. Utöver att skydda backhaul-länken själv så undersökte säkerhetsforskningen säkerheten av hela mobilnätsarkitekturen när små celler används i arkitekturen. En mekanism för att integrera säkra små celler i ett mobilnät utvecklades. De resultat som införskaffades under projektets genomförande kommer att användas som input till produktutvecklingsaktiviteter hos företaget som sponsrade projektet. Den resulterande produkten skulle kunna bli mål för framtida prestandamätningar av trådlösa system.

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