A CONTRIBUTION TO VIDEO STREAMING QUALITY AND ENERGY EFFICIENCY IN OPTICAL AND ETHERNET NETWORKS
Tito Raúl Vargas Hernández
Multimedia content distribution, both over the Internet and over managed networks dedicated exclusively for this purpose, is having a greater share of total traffic and it is raising every day, especially the video streaming service. Therefore, research interest has arisen to maintain and improve the Quality of Service (QoS) in access and backbone networks, and to offer Quality of Experience (QoE) to end users, by adjusting parameters, configurations, protocols and algorithms to the network requirements regarding the video traffic high demand. The latter is carried out taking full advantage of the network resources at core and access networks such as bandwidth and total installed capacity, and at the same time, proposing efficient transportation alternatives for the aggregated video traffic without increasing services costs and alternatives to reduce operational and maintenance expenditures in an efficient manner, such as reducing the energy consumption.
In the first place, this thesis deals with the study of optical switching proposals in backbone networks regarding multimedia content distribution, particularly studying the Optical Bursts Switching (OBS) Networks proposal from the Telematics Engineering point of view. Therefore, architecture, protocols and algorithms of these networks are studied to make contributions to the video traffic evaluation and alternatives to offer QoS and QoE for multimedia traffic. In this sense, this work contributes with proposals for the evaluation of quality through simulation using traces of real video transmissions, and optical burst assembly and scheduling algorithms proposals to offer QoS and QoE to video traffic in the OBS networks.
Secondly, video traffic patterns at the application and network level are studied to characterize them and carry out studies on energy efficiency and energy consumption savings in the network cards used by streaming video servers and clients that implement the IEEE 802.3az Energy Efficient Ethernet (EEE) standard, both in managed networks, such as IPTV that implements RTP video streaming, and unmanaged networks, such as Internet which implements Dynamic Adaptive Streaming over HTTP (DASH) standard for Over The Top (OTT) services. To reach this goal, testbeds are implemented, and experiments are carried out to conclude how video traffic could benefit from the energy efficiency and achieve a large-scale reduction in energy consumption if the EEE standard is implemented word wide in the Ethernet cards of devices involved in video distribution.
The integrating subject that is addressed in this thesis is the distribution of digital video. Therefore, this work also presents a study on the IP networks video transmission encoding and adaptation, presenting aspects regard the video quality evaluation and the network transmission quality assessment. Therefore, methodologies and testbeds are proposed and implemented that involves programming and execution of simulators, scripts, algorithms, software and, in general, frameworks to carry out studies for video transmissions in telecommunications networks, covering the broad spectrum of Multimedia Communications. This study could be useful to undertake other necessary studies in the rapid evolution of both, multimedia services demand and new content distribution techniques proposals.