Starting in the 1950s, AT&T has been involved in the design, installation, and operation of undersea coaxial cable systems to provide international and inter-island telecommunication services. These systems are analog transmission systems, utilizing frequency division multiplexing to simultaneously transmit multiple channels over a single cable. With the passage of time, and in response to an ever growing demand for services, the frequency bandwidths of successive systems have been increased to accommodate the need for increased traffic density. The increases in bandwidth have been accompanied by increases in copper ohmic losses, brought about by the skin effect phenomenon, mandating ever shorter spacing between repeaters, and consequently larger numbers of repeaters for a given system length. The reliability outlook for extending coaxial cable technology beyond its present capacity, with a decrease in repeater spacing below the current value of about 9 km, is not favorable.Fortunately, we now have available optical fibers for transmission media. Unlike coaxial cable, the fiber medium is not limited by the skin effect phenomenon. Using fiber technology, we can transmit large amounts of traffic through a very small cross-sectional areas, using repeaters at infrequent intervals. Moreover, undersea fiber optical systems utilize digital (as opposed to analog) transmission, a format extremely advantageous in terms of transmission quality and the types of services that can be offered.
Synthesis-Distortion-Aware Hybrid Digital Analog Transmission for 3D Videos
