Case for caching and Model Predictive Control quality decision algorithm for HTTP Adaptive Streaming: is cache-awareness actually needed?

摘要

Presence of in-network opportunistic cache is known to cause undesirable effects on Quality of Experience when using HTTP Adaptive Streaming (HAS). While these effects on rate-based and buffer-based HAS algorithms have been studied, the recent near-optimal Model Predictive Control (MPC) has not yet been considered. We evaluate the impact of cache presence on MPC and show that caches may cause instabilities in common set-ups. To tackle this issue, we consider an idealized cache-aware extension to MPC and discuss its implementation. Our simulations show that overall cacheunaware MPC benefits from in-network caching with only video quality instability being increased, while cache-awareness brings noticeable improvement in this regard.