Author : Ujwal G. Shirwadkar
Publisher :
Page : 164 pages
File Size : 41,29 MB
Release : 2006
Category : Computer network architectures
ISBN :
The diverse and changing nature of the service requirements among emerging Internet application calls for network architecture that is both flexible and able to distinguish among the needs of the application. In this thesis a new framework has been proposed which focuses on achieving an End-to-End Quality of Service for video traffic in a heterogeneous network. The core components of the framework are state-of-art H.264 codec, Differentiated network model and IEEE 802.lle protocol. H.264 standard was chosen due to its intrinsic ability to adapt to network delays and its average reduction in bit rate by up to 50% for similar encoders. DiffServ architecture provides mechanism for aggregate traffic and prioritized individual flow, that together can be used to build service with varying delay and loss behavior. The newly introduced IEEE 802.11e being the only protocol to support QoS in wireless was chosen to provide the mobile receivers with higher quality of delivered video. To construct this framework modification to functioning of ingress router is proposed since IP packets were assigned drop probabilities by ETBMS. The source marker marked the packets containing video slices (I,-P, B) and also assigned priorities to the packets. The framework also describes a Video Differentiator present in the access point which identifies and maps the video packets to corresponding IEEE 802.1 le prioritized video service queues. Using simulation, the proposed framework is verified by examining QoS parameters like peak signal to noise ratio, mean square error, end-to-end delay and Video quality metric (VQM). The results obtained from various simulations thus illustrate that the framework achieves its goal of guarantying endlto end QoS in a heterogeneous network.