Enhanced Delivery of Video-on-Demand Streams to Heterogeneous Receivers*

The required real-time and high-rate transfers for multimedia data severely limit the number of requests that can be serviced concurrently by Video-on-Demand (VOD) servers. Resource sharing techniques can be used to address this problem. We study how VOD servers can support heterogeneous receivers while delivering data in a client-pull fashion using enhanced resource sharing. We propose three hybrid solutions. The first solution simply combines existing resource sharing techniques and deals with clients as two bandwidth classes. The other two solutions, however, classify clients into multiple bandwidth classes and service them accordingly by capturing the proposed ideas of Adaptive Stream Merging or Enhanced Adaptive Stream Merging, respectively. We also discuss how scheduling policies can be adapted to the heterogeneous environment so as to exploit the variations in client bandwidth, and we briefly explore the advantages of combining the proposed solutions with Layered Video Coding. We evaluate the effectiveness of the proposed solutions and analyze various scheduling policies through extensive simulation.