Approaching the limits of fixed-delay broadcasting schemes for Video-on-Demand

This paper studies the lower bound on the start-up delay in periodic video-on-demand broadcasting schemes for given server bandwidth, or equivalently, the lower bound on the server bandwidth required for given start-up delay. Any currently known VoD broadcasting scheme is based on one of the two policies. Under the "fixed-delay" policy, a customer completely downloads each segment before starting its display, and under the "fixed start points" policy, a customer can start display and downloading only at specified points in time. Given startup delay, bandwidth minimization for the fixed-delay schemes can be formulated as a non-linear programming problem. We introduce a family of fixed-delay schemes, each member of which asymptotically achieves the lower bound on sever bandwidth. We then apply the "majorization theory" to find the most bandwidth-efficient scheme in this family.