Congestion Control Mechanism For Multimedia Traffic in 3G Mobile Technology

Abstract

newline ABSTRACT newlineWideband-CDMA (W-CDMA) air interface contain by the third generation of GSM technology (3GSM). W-CDMA has a shared high-speed channel for multimedia traffic from the base station to the different mobile users. Congestion control is among the fundamental problems of Internet multimedia traffic and an active research area with many challenges. In 3G cellular internet network Transport control protocol (TCP) is most commonly used transport protocol. Initially TCP is only designed for wired networks in which the random packet losses are negligible. newlineThis thesis first presents a survey about various generations of mobile cellular networks and then presents an introduction to congestion control and a brief literature survey of current congestion control protocols. After that, study performs on universal mobile telecommunication networks (UMTS). To this direction we study about various flavors of Transmission Control Protocol framework in UMTS. Further we studied about various queuing disciplines in UMTS framework. We also study about the QoS framework in UMTS and compare it with non QoS scenario. newlineImplementation is performed for various TCP protocol s versions on UMTS network. TCP is reliable protocol but with a problem of slow start. To provide the effective congestion control in mobile communication networks this research work makes few modifications in the Transmission Control Protocol s (TCP) Tahoe flavor. Modifications in TCP Tahoe shows that when changes performs in TCP Tahoe algorithm, TCP Tahoe can shows better results on the wireless links, and at the same time it also contain all the advantages of the wired networks. This is very advantageous feature because in almost all cases conventional TCP contradicts to the demands of the wireless links of communication network. Finally we design a modified TCP Tahoe for reduce the congestion in the network. newlineFour Service Classes are defined for universal mobile telecommunication networks (UMTS) to get Quality of Service (QoS) requirements from d