[Japanese | Thesis | Researches in Minoh Lab | Minoh Lab]
Layered multicast enables us to transmit video streams over heterogeneous IP networks such as the Internet. In previous work on layered multicast, each receiver was supposed to receive only one stream. In our study, we extended the previous work and proposed a method to receive multiple streams and control their bandwidths by negotiation among receivers.
It often happens that a receiver, which receives multiple streams, cannot view them with the highest quality, owing to bandwidth limitations. In this case, the receiver may view the streams with a lower quality by dropping their bandwidths.
In our method, the receiver sets a priority ordering on each stream and manages receiving bandwidths according to the priority and bandwidth limitations. The higher the priority of a stream, the better the receiver get the stream quality. By our method, if there is only one link, where all the streams pass, and a congestion occurs in this link, the receivers negotiate which bandwidth of the stream they would drop according to the current bandwidths and priorities of the streams.
The proposed method has been validated through experiments where receivers obtained as good streams as the receivers' demands after the described procedure of ordering and negotiation has been applied.