Patent ID: 7383346

Claim:
A computer-implemented process for providing progressively higher quality versions of an audio-only program, video-only program, or audio and video program over a client-server based network, comprising a server computer performing the process actions of: providing a base quality version of the program to the client over the network, wherein the base quality version of the program comprises layer data of a layered unicast having hierarchically related layers in that the lowest level layer is a base layer and each subsequently higher level layer adds enhancing information for enhancing the quality of the program that can be rendered from the layers preceding it in the hierarchy, and wherein requesting a base quality version of the program from a server over the network comprises requesting as many layers, in the order of their position in the hierarchy starting with the base layer, as can be transmitted from the server to the client without exceeding the available bandwidth of the network; and providing at least one enhancement layer of the layered unicast to the client over the network without also providing any layer of the base quality version of the program.