| Multicast is a new network application in Internet, it can save much of the bandwidth, so it is used to transmit Multimedia Data, and Layered multicast is an efficient approach in multicast communication. However the conventional layered multicast is cumulative, in order to decode the original data stream, he receiver should join the layers gradually, and can not realize fine-grained multicast. A multicast policy using non-cumulative layering is proposed in this article, the multicast policy using non-cumulative layering is realized by MPEG-4 code, we use exponential sequence to allot the rate in the noncumulative layers. First, A receiver-driven TCP-Friendly congestion arithmetic has been proposed as well, the arithmetic expand the RTCP protocol (Real-time Transport Control Protocol), and it can make the receiver get the Round-Trip Tune of link between the sender and itself;second, calculate the TCP-Friendly receive rate, and adjust the layers it should subscribe according to receive-rate of itself. Thus, the receiver can adjust the rate slightly and make the beter of the bandwidth. The arithmetic was being emulated in NS-2 at last, the result show that the arithmetic can make the beter of the bandwidth and scalable. |
