The FCC has set the year 2006 as the deadline for broadcasters to switch from standard definition television (SDTV) to digital television (DTV) and high-definition television (HDTV). Among the many advantages of this transition, transmission distance and repeater (signal regenerators) do not affect the quality of digitized video. A visit to any major broadcast industry trade show, such as those sponsored by the National Association of Broadcasters (NAB) or Society of Motion Pictures and Television Engineers (SMPTE), reveals that cameras, tape decks, mixing boards, matrix switches, effects boxes, etc. operate the digital format.
Fiber optics plays a big part in the move to the new television standards, providing the only viable means of signal transport by offering the bandwidth required for these television standards. Currently, analog video signals can be carried over relatively long lengths of coax cable. With a bandwidth of only 4.5 MHz, analog signals do not tax the limited bandwidth of coax cable, but even so, coax cable introduces a great deal of frequency dependent distortion requiring an equalization network. A digitized video signal's increased bandwidth usurps coax's ability to carry the new signal.
A standard NTSC video signal typically requires a serial bit rate of 143.2 Mb/s. By contrast, high-end HDTV standards require serial bit rates of 1,485 Mb/s. Coax cable can carry such high-speed digital data streams short distances, typically 300-600 meters for NTSC and 30-60 meters for HDTV. Fiber optics, on the other hand, can easily carry the full range of digital signals up to tens of thousands of meters.
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