LOSSLESS AGGREGATION - A SCHEME FOR TRANSMITTING MULTIPLE STORED VBR VIDEO STREAMS OVER A SHARED COMMUNICATIONS CHANNEL WITHOUT LOSS OF IMAGE QUALITY

This paper introduces a new concept called lossless aggregation for th e transmission of video information. It is a scheme for the delivery o f variable bit-rate (VBR) video streams from a video server to a group of users over a shared channel. No data are dropped at the source dur ing the adaptation process that reshapes the VBR video traffic to conf orm to the channel bit-rate characteristics. The transmission schedule s of individual video streams evolve in a dynamic way that depends on their relative traffic characteristics. Receiver buffer underflow and overflow are prevented. Therefore, the data delivery process does not cause any loss of image quality. We show that very significant receive r-buffer reduction can be achieved with aggregation compared with the independent transmission of individual video streams over separate cha nnels. Several bandwidth allocation methods for aggregation are studie d extensively. The frame equalization algorithm stands out in terms of its simplicity and optimality.