High-definition television (HDTV) is the wave of the future.
HDTV is broadcast using a digital signal, instead of the traditional analog broadcast signal, which means that
HDTV is just one type of digital television. Over time, traditional analog broadcasts will be replaced by digital broadcasts, so you'll eventually need a TV capable of receiving digital broadcasts.
When will your local television stations switch from analog to digital broadcasts? The Federal Communications Commission (FCC) originally mandated that all commercial TV stations begin some form of
HDTV broadcasting by May 1, 2002, offering at least half of their programs in high definition within 12 months of that date. Obviously, those dates have come and gone, which is why you see the "This program available in
HDTV" designation at the start of so many network programs.
More important, the government has legislated that all broadcast TV stations will completely shift to digital broadcast on
February 17, 2009. On that date, your local stations will no longer broadcast analog signals, instead broadcasting their entire schedule of programs in the new digital format.
When this happens, any existing TV that contains an analog tuner will no longer be able to pick up over-the-air television broadcasts. However, if you have a newer TV that contains a digital tuner (like that found in most of today's widescreen
HDTV models), you'll be fine, since the digital tuner will receive the digital TV broadcasts.
But don't throw out that analog TV just yet. If your TV is connected to a cable or satellite provider, your cable or satellite box already functions as a digital-to-analog converter. That is, the set top box converts the incoming digital cable or satellite signal to an analog signal that your older TV has no trouble receiving. You can expect television manufacturers to begin selling similar digital-to-analog conversion boxes for over-the-air broadcasts at some point before the 2009 changeover date. In fact, the government has allocated funds to subsidize the purchase of these converter boxes, so beginning in 2008, each U.S. household will be eligible for a $40 coupon towards the purchase of a digital-to-analog converter box.
That said, if you're buying a new TV set today, make sure that it includes a digital tuner so that you'll be fully prepared for the switch to all-digital programming in 2009.
Michael Miller is a writer and commentator on technology and digital lifestyle topics. 
