This is accomplished through a simplex circuit on the satellite that all Sites can receive and transmit on. It operates like a radio system. One station transmits at a time and all the Users will all hear the voice transmission. There is a protocol for passing the transmission from Site to Site. There are no technical limits to the amount of sites capable of joining a teleconference, however for a practical interactive teleconferencing it is more manageable to have a maximum of approximately 7 sites.
Teleconferences require a minimum of one week to schedule and to confirm participation.
This service is needed for communication between two sites. The audio bride can support up to 12 callers. The user protocol is based on basic radio communications. The full-duplex channels are reserved for facsimile and data communications.