Trial experiment of distance learning with the links of satellite communications, ISDN and the internet

As communication media for distance learning, satellite communications, ISDN and the Internet are generally used, we have held experiments on the distribution of events with these media. These experiments have three features. First, we connected two satellite communication systems. Second, we received a distribution of an event with two kinds of links, a satellite link and an ISDN link, and compared the quality of distributed picture and sound. Last, we received a distribution of an event with two Internet video distribution's application by two kinds of links, the Internet and ISDN, and compared the quality of distributed picture and sound. From the experience of these experiments on distribution, we show some prospects about distance learning in the case of these media.