Videoconferencing

As has been discussed, ACTS has participated in a number of satellite/terrestrial interoperability trials and demonstrations. A satellite hop, a skip underneath the ocean on fiber, and finally a jump to the final destination via satellite describe the next demonstration in which ACTS was involved. On September 17, 1997, ACTS and Italsat-2 (the second operational Italian Ka-band satellite serving Italy and Europe), were used in the first two Ka-band satellite link connecting attendees at the third Ka-band Utilization Conference in Sorrento, Italy with participants in Canada and the United States. The network consisted of an ACTS link from Cleveland to the Canadian Research Centre in Ottawa, Canada, and a fiber link across the Atlantic and through Europe to the Telecom Italia CSELT laboratory in Turin, Italy. From Turin, the network was connected via Italsat-2 to Sorrento. Full duplex, 2:048 Mbps (E1, a European telephony standard analogous to T1) traffic was routed over the network using the ATM protocol. The live, multi-cast videoconference (at 128 Kbps video data rate per link) enabled sites in the United States, Canada, and Italy to interact simultaneously. Workstations using multiple windows displayed the speakers as well as the charts used in their presentations.

The overall quality of the video and audio was excellent. The content of the slides was clearly visible in the windows, while the small video of the speakers was enough to observe hand gesture, voice inflections, and general body motions. The delay of the double hop link...