Rate control for replicated video streams

Video simulcasting enables a sender to generate multiple streams for the same video program but at different rates, targeting receivers of different capacities. Each stream is then distributed to the target receivers via broadcast or multicast channels. A key design issue of video simulcasting is how to strike a balance between bandwidth economy (as stream replication introduces redundancy) and user satisfaction (as there is a mismatch between a receiver´s capacity and the limited choice of the stream rates). This paper presents a formal study on the above problem in a rate-limited network; specifically, given a session bandwidth budget, what is the optimal number of streams that should be generated and what is the optimal rate that should be allocated to each stream? We also derive efficient algorithms to solve these two problems with the objective of minimizing the expected bandwidth mismatch for all the receivers.