AnĂ¡lise de desempenho de TCP sobre GPRS em um ambiente fim a fim

by de Oliveira, Jeísa Pereira

Abstract (Summary)
The General Packet Radio Service (GPRS) represents a packet-switched network extension for GSM (Global System for Mobile communications) and aims to provide wireless access to the Internet. For sharing the network structure with GSM, the world?s leading technology in cellular communications system, it has been adopted by many cellular operators, including Brazilian ones.Wireless networks suffer from high packet loss levels due to air interface errors. This results in performance problems for TCP (Transmission Control Protocol), which is used by most application services currently available in the Internet. Packet losses represent an implicit notification of network congestion for a TCP transmitter, which decreases its transmission rate. When using TCP over GPRS, TCP has not enough information to distinguish between packet losses occurred in the wireless link and due to discards in routers queues. Therefore, it is necessary to study carefully TCP behavior over GPRS. Although there have recently been a number of publications on this topic, they present a limited scope in their analysis. This work presents, via simulation results, wider performance issues related to TCP over GPRS. Many scenarios are studied, including different error rates, packet sizes, number of users and downlink timeslots per user. In addition, an innovating aspect is analised: the use of an adaptive model that configures dinamically GPRS coding schemes. Amongst the contributions of this work, it is worth emphasizing the many adjustments and additions made to the used simulator code so it could generate more reliable and correct results
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Judith Kelner

School:Universidade Federal de Pernambuco

School Location:Brazil

Source Type:Master's Thesis

Keywords:TCP Performance analysis


Date of Publication:02/06/2004

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