A CacheAware Approach for Dynamic Adaptive Video Streaming over HTTP More and more CDN (Content Delivery Network) or video content providers are deploying their cache nodes at the edge of networks in order to improve user perceived QoE (Quality of Experience). However, stateoftheart ABR (Adaptive Bitrate) algorithms do not take into account the presence of a cache on video delivery path. In this paper, we firstly investigate how these ABR algorithms behave in the context of edge caching system and how caching factors such as hit ratio and access bandwidth impact on the performance of ABR algorithms. Extensive analysis results show introducing an edge cache on video delivery path cannot necessarily improve the performance of ABR algorithms in terms of average QoE. Furthermore, we propose a cacheaware ABR approach taking into account caching information including a cache hit indicator for the past chunks and the availability of the next video chunk on the cache. Experimental results validate the significant benefits of the approach which helps to make a more accurate throughput estimation and is more likely to select the video chunks stored in the cache to increase cache utilization.

A novel framework for improving bandwidth utilization for VBR video delivery over widearea networks There are great challenges in streaming variablebitrate video over widearea networks due to the significant variation of network conditions. The utilization of the precious bandwidth of widearea networks is often low in such streaming systems. In this paper, we propose a novel framework to improve the bandwidth utilization from a new perspective. Instead of focusing on the performance of each single media stream, we aim to improve the overall bandwidth utilization for video streaming systems. We try to exploit the unoccupied bandwidth in ongoing streams and using it to deliver some prefetched data which can be used to facilitate future streaming. Preliminary results show that our mechanism has great potential to improve both the overall bandwidth utilization and the caching performance of the proxy servers in the streaming systems.