Optimal Topology Design of the Integrated Telecommunication and Broadcast Network

Various kinds of broadcast services, such as TV distribution and Near Video-On-Demand, will be introduced into the B{ISDN tra c. These services need wide bandwidth since they have moving images. Therefore, broadcast services will occupy a large part of the B{ISDN tra c. However, the nationwide topologies of the conventional telecommunication network are designed for point-to-point (P-P) services such as telephone, facsimile and data. Since broadcast services are quite di erent from P-P services, new nationwide topologies must be designed for B{ISDN which will be the integrated telecommunication and broadcast network. The results of our past studies showed that Star and Ring topologies were suitable for P-P services and broadcast services, respectively. In this paper, the new basic topology which combines Ring topology with Star topology is proposed, and the hierarchical network topology is optimized. The result is that the proposed topology is especially suited to achieving low switch cost.