On Feb. 17, 2009, major U.S. television stations will stop broadcasting analog signals and will send only digital transmissions, which take less airspace. Here's how it breaks down for consumers and businesses.

What's happening and why?

Stopping the waveform analog broadcasts will free up a huge amount of airwaves, which the government is auctioning off for use in advanced wireless services. There's also a drive to use some of the spectrum for a network that can be used in emergency situations by public safety officials.

Is this going to affect me?

If you have cable or satellite TV, only extra sets that are not hooked up will be affected. If you get TV only over the air — a situation affecting about 13 million U.S. households — your TV might not work come Feb. 18, 2009. All new TVs sold now have digital tuners, sometimes called "ATSC" tuners after the technical standard they use. "NTSC" is the old standard.

What can I do?

For most people, the cheapest way to handle the transition is to get $40 government coupons to cover most or all the cost of a converter box for each of your older TVs. There is a limit of two coupons per household, available at www.dtv2009.gov or by calling 1-888-DTV-2009 (1-888-388-2009).

Who stands to gain?

Cable and satellite TV companies could get another 1.4 million new subscribers, estimates Sanford C. Bernstein & Co., enough to give the industry a measurable boost the next two years. Another $1.7 billion worth of new TVs could be sold as part of the transition, along with some $1.4 billion in converter boxes.