Television and broadcast engineers have always been thinking the best way to transmit media program. In the mid-1980s, television production adopted fiber optic transmission way for the first time. From that time fiber optics are used in all aspects of production and distribution of video and audio signals and find the most suitable encoded way of 10 Bit, for broadcast analog video. The serial digital bit rate can vary from about 144 to 300 Mbps.
With the comeup of digital video in the 1990s, fiber optic transmission systems are used more widely in the broadcast industry. Digital video was encoded into data rates ranging from 144 to 360 Mbps. This way could transmit video upto 300meters over copper, but could be upto 120KM over one fiber.
In modern developpment, HDTV have been the trend and using an SDI interface like SD-SDI, HD-SDI, 3G-SDI which could be upto 2.97G.
In fiber transmission way, many channels of video and audio are trunked together by single fiber. Such system could take advantage of TDM to combine eight channels of video with audio into single wavelengths. The optical multiplexing or CWDM technology is used to combine the wavelengths with eight videos over one fiber. The combined technique of TDM and CWDM provides a fiber transmission capacity of more than 144 video channels over sing fiber.