Abstract: A portable wireless through-the-earth bi-directional communication system for sending and receiving text data using ultra-low-frequency electric current and the earth as the conductive media. A surface controller which executes application software which controls the communication functions of the system. A surface receiver and surface transmitter are connected to sets of electrodes which provide the electric current, and are in communication with the surface controller. Text data are encoded into data packets, modulated onto ultra-low-frequency electric carrier waves, and transmitted through the earth by the surface electrodes to a subsurface transceiver. The subsurface transceiver demodulates, converts and displays incoming signals into text messages. The subsurface transceiver has a user interface to allow subsurface users to submit text data to the surface receiver.

Abstract: A system and method is provided to allow a video conference participant to establish and direct a video conference through a control network separate from the conference network that sustains the conference. A video conference switching system host machine responds to control signals conveyed by a control network to the switching system from a participant-accessible control system. The host machine generates adaptor conference signals that are interpreted to appropriately configure a crosspoint switch in correspondence with the control signals. The switching system may operate in continuous presence or video follows audio modes. In continuous presence mode, the host machine generates adaptor conference signals that are interpreted to convey to the participants a combination video signal composed from the individual video signals. In the video follows audio mode, detected voice signals result in a switch configuration according to a video follows audio protocol or rule set.