Abstract :
In late 1973 trial television conferences were held between Sydney, Australia, and London, England, using the Intelsat Indian Ocean Region Satellite. Nonswitched voice channels were used in an attempt to obtain a natural conference atmosphere although it was realized that echo would be a problem. Careful attention was paid to the acoustic levels in the system and, for the prevailing conditions, optimum performance was judged to occur at about 52 dB (A). The trials demonstrated the technical feasibility of intercontinental television conferencing, and although there were technical problems which merited further work, it was considered that future trials should primarily explore user requirements.
