In the1940's, analog television technology was introduced and the NTSC broadcast standard was initiated. Although this analog standard has been enhanced over the years, with the addition of color and stereo sound, it continues to fall far short of today's demand for larger screens, better picture quality and better sound. With the advancements in digital electronics and transmission capabilities, we are now able to upgrade our television system.
Also, bandwidth is an issue. Bandwidth is the range within a band of wavelengths over which an analog signal can travel. Currently, the broadcaster can only show one program per channel with an analog (NTSC) signal. This is a very inefficient use of channel bandwidth and power.
You see, bandwidth is limited, there is only so much space we can use. All of our TV, radio, cell phones, etc. all use up precious space. With digital (ATSC) the broadcaster can simultaneously transmit between 1 and 4 programs, depending on the format of the material, for a much more efficient use of bandwidth and power. The digital signal only uses about 10% of the power it takes to broadcast the analog signal over the same distance. Therefore, DTV will reduce energy consumption.
The bandwidth which is freed up by DTV will be turned back over to the FCC. They, in turn, will dedicate new channels and space for wideband data transmissions, emergency broadcasts, military use, government broadcasting, etc. Or, they may sell it to companies for commercial use, time will tell.