US Patent 7690020 Hybrid central/distributed VOD system with tiered content structure

The present invention provides a hybrid central/distributed and tiered video on demand (VOD) service network with tiered content structure. In particular, the present invention uses media servers located in both the headend station and the hub stations. Set-top boxes generally would be supplied VOD services from the high-demand content media servers located in the hub station nearest to the user. The central media server located in the headend would be used as an installed backup to the hub media servers; as the primary source for lower demand VOD services and as the source of the real time, centrally encoded programs with PVR (personal video recorder) capabilities.