An encoding-aware bitrate adaptation mechanism for video streaming over HTTP

The great interest in flix-like services has amplified multimedia traffic over the Internet. Recently released traffic forecasting predicts that video-related traffic will be responsible for the majority of Internet traffic by 2022. Such traffic will come in a wide range of duration and in the two modes of live and on-demand. Additionally, it is expected to scale and deliver a smoothed experience to an already fragmented audience. The adaptive bitrate over Hypertext Transfer Protocol (HTTP) has emerged as the top technology for multimedia content transport and delivery. Despite the large amount of work in this area, running streaming applications on overload channels still demands the development of effective strategies. In this work, a video bitrate adaptation mechanism deployed in an overloaded channel of an access network is proposed and evaluated under live and on-demand service modes. This mechanism makes decisions regarding bitrate switching based on the Quality of Experience (QoE)-related parameters to accommodate conflicting variables of its design space, namely, image quality, session continuity and short play time. To evaluate this mechanism, a multifactor QoE metric is proposed based on session parameters such as stalls, startup delay, image quality and the mechanism bitrate misalignment. Moreover, in the numerical studies for the evaluation of the effectiveness of the proposed mechanism, the average video bitrate, instability and fairness are measured. Overall, the proposed mechanism was able to improve the session QoE for both live and on-demand modes.