The heterogeneity of the Internet’s transmission resources and end system capability makes it difficult to agree on acceptable traffic characteristics among the multiple receivers of a multicast video stream. Three basic approaches have been proposed to deal with this problem: 1) multicasting of replicated video streams at different rates, 2) multicasting the video encoded in cumulative layers, and 3) multicasting the video encoded in non-cumulative layers. Even though there is a common belief that the layering approach is better than the replicated stream approach, there has been no studies that compare these schemes. This paper is devoted to such a systematic comparison. Our starting point is an observation (substantiated by results in the literature) that a bandwidth penalty is incurred by encoding a video stream in layers. We argue that a fair comparison of these schemes needs to take into account this penalty as well as the specifics of the encoding used in each scheme, proto...
Taehyun Kim, Mostafa H. Ammar