Beneficial Limitations: Rate caps for Enhanced Branched Video Streaming Experience

Abstract: The demand for on-demand video streaming has seen an enormous increased usage and is today the main contributor to Internet traffic. Technological developments combined with the accessibility of sufficiently powerful end-user hardware, large bandwidth capacities and significantly reduced storage cost are major contributors to this trend. We have built a simulation environment where multiple clients stream linear and branched video while competing over a shared bottleneck network. We examine how rate caps can be implemented to increase the overall Quality of Experience (QoE). First we present simulation results demonstrating the impact that rate caps have on clients playing linear video and compare and relate the results with prior work. Second we simulate the performance implementation of branched video and consider how its performance is affected by rate caps. Here, we highlight and discuss the trade-off patterns between playback quality and stability observed when a cap is implemented. To derive our conclusions we consider a range of scenarios, in which we vary different variables when a rate cap is set or not and measure the (i) requested encodings, (ii) buffer occupancy, and (iii) the amounts of switches between encodings made by the clients during the playback sequence. The rate cap implementation is shown to generate less switches between encodings, providing an enhanced stability and thus contributing to a better QoE in both the linear and branched environment.