Streaming stored continuous media over fair-share bandwidth

We investigate the impact of the long-term behavior of fair-share bandwidth on transmission schemes for streaming stored Continuous Media (CM). To obtain typical fair-share bandwidth conditions, we perform a series of Internet experiments in which we monitor TCP bulk-data transfers between various sites, and collect average TCP throughput traces. The collected traces exhibit high-variability over a broad range of time scales as well as self-similar scaling behavior over longer time scales. Under fair-share bandwidth conditions, we evaluate the performance of a series of data transmission schemes for non-layered CM, and of several bandwidth allocation schemes for streaming layered CM. Our findings demonstrate that prefetching during playback over intervals of several minutes is necessary for achieving best quality. For layered CM encoded into two layers, we propose a threshold-based inter-layer bandwidth allocation scheme, and a measurement-based heuristic for dynamically computing the threshold. Our empirical results show that, using conservative estimates for future average bandwidth, our heuristic is highly reliable.