There has been much confusion over the many things that are happening with respect to television when it comes to “digital” TV . This is entirely understandable since the word “digital” is being used to mean three different things. Here is a summary of the three meanings.
1. “US Digital Television Transition”: This relates to the way TV signals are broadcast over the air.
The US government decided to switch the way that free, over-the-air TV signals are broadcast from TV stations to TVs that receive their signals via antennas or “rabbit ears”. All TV stations now broadcast these over-the-air signals in a digital format, and the old analog format used for more than 60 years is being discontinued. The date for the government-mandated switchover had been set for February 17, 2009 but was recently extended to June 12, 2009.
a. Despite this date change, some broadcast stations have stuck with the earlier switch over date.
b. Consumers getting their TV signals from cable, satellite or telephone companies are not directly affected by this change. However, those service providers are making other changes that may result in changes in what a consumer receives.
c. Consumers without cable or satellite service can still receive TV over-the-air on their old analog sets by purchasing a converter box, for which the government has been issuing $40 credit coupons. The converter box decodes broadcast digital TV signals and converts them so they can be displayed on an analog TV set.
2. “Digital TV sets & HDTV sets”: This relates to the TV set itself.
“Digital” in front of the word TV (“DTV”) means that the TV set itself can process digital signals (ones and zeros). These sets provide better picture quality and can process additional information contained in the digital TV signal.
Nearly all digital TVs are high definition TVs (HDTVs) which means that they can display the highest-quality digital signals. These sets can display a wider picture (16x9 aspect ratio); all have built-in tuners to receive broadcast digital TV.
Some broadcast digital TV channels are in 16x9 “high definition” (HD) and others are in the familiar 4x3 “standard definition”. Digital TVs can display both types.
3. “Digital Cable Service”: This relates to cable companies using digital technology to provide many more TV channels in additional “digital service” tiers.
Cable companies have been making a gradual transition from analog to digital. Comcast’s “Digital” services currently include many analog channels, including the local broadcast stations that no longer broadcast analog signals. All cable operators have announced their intention to reduce the number of analog channels to make room for more HD channels.
Today’s digital TVs are not equipped to tune digital cable services directly – this requires a converter box from the cable provider. With a converter box, digital cable service can be received on both analog and digital TVs. If a consumer wants HD service from the cable provider, they are provided with a more powerful HDTV converter box and may need to subscribe to additional HDTV channels. Only a digital TV can display HD pictures.