The Combined Internet and Satellite Communications Networks - IP based satellite networks can bring a fully multicasting Internet

摘要

The general trend in recent satellite communications is IP based network structure for varieties of different application areas. The IP based structure is going to be the dominant trend in terrestrial communication networks, too. The all-IP networks integrating broadcasting and communication are called Next Generation Networks (NGN). Thus the satellite communication networks will form a part of the NGN. The application areas in which the satellite communications can play key roles are broadcasting, multicasting and teleconferences. The broadcasting and multicasting by satellite communications are quite easy because of its one dimensional structure. On the other hand broadcasting is inhibited and multicasting is difficult in the Internet because of its two dimensional structure which can form numerous loops. Tele-conferences of a large scale with a large number of participants existing over wide geographical areas are very difficult as real time multicasting for speakers taking turns almost randomly can be inefficient and cause delays of various values. Those group communications are not quite fit for the Internet which is essentially a point to point uni-casting network. All those difficulties can be solved by including the satellite communication networks, which are essentially Local Area Networks (LAN) in its structure. Direct satellite broadcasting, multicasting and teleconferences can be easily made by the Satellite LAN. The Satellite LAN can be further extended by routers into the Local Internet so the features of the satellite communications can be offered to the users without satellite communication facilities. Thus the proposed combined Internet and satellite communications networks can bring about the Internet capable of broadcasting, multicasting and teleconferences of very large scales which is more than a mere integration of communication and broadcasting.