Zugl.: Berlin, Humboldt-Univ., Diss., 2005

No description available.

This research considered the efficient transmission of data within a wireless local area network (WLAN) system. A simulation model was developed to study the performance of our protocol, AGG-MAC (aggregated medium access control). AGG-MAC is a simple and elegant medium access control (MAC) protocol designed to improve performance by transmitting a maximal quantity of data with minimal overhead. Our enhancement to IEEE 802.11, AGG-MAC yields dramatic improvements in both local and global throughput. It furthermore reduces jitter in support of real time communications requirements such as voice over IP (VoIP). In support of heterogeneous roaming between Third Generation (3G) Wideband CDMA (WCDMA), specifically Universal Mobile Telecommunications System (UMTS) and WLAN systems, we constructed a simulation environment which allowed the evaluation of AGG-MAC in such a system. We further demonstrated the suitability of AGG-MAC throughout a range of infrastructure and ad hoc based WLAN scenarios. The AGG-MAC protocol enhancement provides significant performance improvements across a range of wireless applications, while interoperating with standard IEEE 802.11 stations. Performance is commensurate to original WLAN MAC performance for applications that do not benefit from packet level aggregation. The key contributions of this research were two-fold. First was the development of an OPNET simulation environment suitable for evaluation of future protocols supporting tightly coupled, heterogeneous WLAN and 3G systems. Secondly was the implementation and testing of the AGG-MAC protocol which aggregates suboptimal size packets together into a single frame, thereby amortizing the overhead. / Ph. D.

The aim of this dissertation thesis is an optimization of access to CDMA networks. To be more specific, this thesis deals with an optimization of admission control in UMTS network. The first part of the thesis deals with the present progress of the particular topic. Thereinafter there is an analysis of admission control in UMTS system. An own UMTS simulation program was created in MATLAB. This program enables implementation and simulation of the selected admission control algorithms. The thesis is focused on load factor based, fuzzy logic based and genetic algorithms. The created UMTS simulator was used for the mutual comparison of all algorithms. The aims of this thesis are the suitable UMTS model design, evaluation and possible optimization of selected algorithms.

No description available.

El presente proyecto de tesis consiste en realizar el diseño de una red de tercera generación para la ciudad de Arequipa; para esto se ha decidido utilizar la tecnología HSDPA que evoluciona a partir de la tecnología UMTS. Durante el desarrollo de este proyecto veremos el porqué de la elección de dicha tecnología y analizaremos el mercado de dicha ciudad para ver si es que requiere de la implementación de una red de tercera generación y la rentabilidad de dicha inversión. / Tesis

Tese de mestrado. Faculdade de Engenharia. Universidade do Porto. 1998

none

Thèse de doctorat--Signal et images--Paris--ENST, 2005. / Bibliogr. p. 175-180. Résumé en français et en anglais.

Zugl.: Kassel, Univ., Diss., 2008