Enabling energy-awareness for internet video

Continuous improvements to the state of the art have made it easier to create, send and receive vast quantities of video over the Internet. Catalysed by these developments, video is now the largest, and fastest growing type of traffic on modern IP networks. In 2015, video was responsible for 70% of all traffic on the Internet, with an compound annual growth rate of 27%. On the other hand, concerns about the growing energy consumption of ICT in general, continue to rise. It is not surprising that there is a significant energy cost associated with these extensive video usage patterns. In this thesis, I examine the energy consumption of typical video configurations during decoding (playback) and encoding through empirical measurements on an experimental test-bed. I then make extrapolations to a global scale to show the opportunity for significant energy savings, achievable by simple modifications to these video configurations. Based on insights gained from these measurements, I propose a novel, energy-aware Quality of Experience (QoE) metric for digital video the Energy Video Quality Index (EnVI). Then, I present and evaluate vEQbenchmark, a benchmarking and measurement tool for the purpose of generating EnVI scores. The tool enables fine-grained resource-usage analyses on video playback systems, and facilitates the creation of statistical models of power usage for these systems. I propose GreenDASH, an energy-aware extension of the existing Dynamic Adaptive Streaming over HTTP standard (DASH). GreenDASH incorporates relevant energy-usage and video quality information into the existing standard. It could enable dynamic, energy-aware adaptation for video in response to energy-usage and user ‘green’ preferences. I also evaluate the subjective perception of such energy-aware, adaptive video streaming by means of a user study featuring 36 participants. I examine how video may be adapted to save energy without a significant impact on the Quality of Experience of these users. In summary, this thesis highlights the significant opportunities for energy savings if Internet users gain an awareness about their energy usage, and presents a technical discussion how this can be achieved by straightforward extensions to the current state of the art. Relevant Publications Some of the work presented in this thesis has been published. [1] O. Ejembi and S. N. Bhatti. “Help Save The Planet: Please Do Adjust Your Picture”. In: Proceedings of the 22nd ACM International Conference on Multimedia. MM 2014. Orlando, Florida, USA, Nov. 2014. [2] O. Ejembi and S. N. Bhatti. “Towards Energy Benchmarking For Green Video [Extended Abstract]”. In: Proceedings of the 4th IFIP/IEEE Conference on Sustainable Internet and ICT for Sustainability. SustainIT 2015. Apr. 2015. [3] O. Ejembi and S. N. Bhatti. “The Energy Cost of Your Netflix Habit [Poster]”. In: Proceedings of the 6th ACM International Conference on Future Energy Systems. e-Energy 2015. Bangalore, India, July 2015. [4] O. Ejembi and S. N. Bhatti. “Go Green with EnVI: The EnergyVideo Index”. In: Proceedings of the IEEE International Symposium on Mulitmedia. ISM 2015. Florida, USA, Dec. 2015. [5] O. Ejembi and S. N. Bhatti. “Client-side Energy Costs of Video Streaming”. In: Proceedings of the 11th IEEE International Conference on Green Computing and Communications. GreenCom 2015. Sydney, AUS, Dec 2015.