NBC has been involved in the development of High Definition Television (HDTV) for over 15 years. In the early 1990s, we were part of a research consortium that developed one of the first digital HDTV prototypes. In 1992, we performed the world's first simultaneous transmission of digital HDTV and analog television from our TV station in Washington, D.C. We later participated in establishing the final technical standard, and we hosted an industry testbed for digital HDTV broadcasting, again at our station in Washington.

Today, over 70 NBC owned and affiliated stations are broadcasting digital television. We currently broadcast certain series and movies in the 1080i HD format, providing the highest resolution possible. We plan to increase our HDTV programming to 60 percent of our primetime and late night lineup, plus special events, movies and sports.

Here are some frequently asked questions regarding HDTV:

• Do I need a new television to watch HDTV?
  HDTV is best viewed on a new high-definition television. You can purchase an HD monitor and a separate receiver box, or a fully integrated HDTV set. The HDTV receiver boxes are also digital-to-analog converters that you can connect to your current TV, but you won't get the full benefit of HDTV that way.


• How can I receive HDTV programs?
  HDTV programming from NBC and other major networks is generally available as an over-the-air broadcast signal or via their cable provider. Getting the signals may require the use of an outdoor antenna pointed towards the broadcaster's tower. HDTV channel numbers are different than your analog TV channel numbers; you can click here for more station information.


• What shows does NBC currently broadcast in high-definition?
  30 Rock, Heroes, ER, Friday Night Lights, Las Vegas, Late Night with Conan O'Brien, Law & Order, Law & Order: Criminal Intent, Law & Order: Special Victims Unit, Medium, My Name is Earl, The Office, Saturday Night Live, and The Tonight Show with Jay Leno, are currently broadcast in HDTV. Occasionally, theatrical films and made-for-TV movies are also broadcast in the high-definition format.


• What are the advantages of HDTV?
  
  There are several benefits to viewing programs in high-definition.
  
  
  1. Clarity. The digital signal is crystal clear and noise-free.
  2. Wide-screen picture. Traditional televisions use a 4 by 3 aspect ratio, which means the screens are 4 units wide by 3 units high. However, theatrical films are usually much wider, taking advantage of the actual human field of vision. HDTV uses a wider 16 by 9 aspect ratio, which delivers movies with less "edge cropping" and provides a more intense viewing experience.
  3. Sharpness. In addition to clarity, HDTV provides a much sharper picture than analog television. Just like a digital camera, more pixels means sharper pictures. The highest resolution HDTV format has approximately 2 million pixels compared to about ½ million pixels in analog TV.
  4. Digital sound. HDTV's digital audio sounds better than a standard television's analog sound, just like digital CDs are superior to analog radio. All HDTV programs use Dolby Digital sound, which is also used on DVDs. This format is used to transmit two to six channels of audio depending on the program. NBC's soundtracks are a variety of stereo (2-channel) and surround sound (multi-channel). NBC surround sound programs are four-channel, five-channel or the most advanced, 5.1-channel (the .1 is the subwoofer channel). With these soundtracks driving 6 speakers, NBC and Dolby Digital create a home theater experience rivaling the best cinema sound.


• Aren't there two different HDTV formats (720p and the 1080i)? Which will a new HDTV receive?
  The Digital Television (DTV) standard allows broadcasters to choose among several different formats that they can transmit. There are two high definition formats: 720p and 1080i. NBC broadcasts HDTV in the 1080i format, which provides the highest possible resolution to our audience. But you don't have to worry - any HDTV receiver will receive both formats.


• Why are there two HD formats? What are the technical details of 720p and 1080i?
  Having two HD formats allows broadcasters to choose the format that provides the best technical quality for their particular mix of programming.
  
  The 720p format makes a picture with 720 vertical lines, each with 1280 pixels horizontally -- so in computer display terms, it has a resolution of "1280 x 720". 720p uses progressive scanning, like computers, which sends a complete picture 60 times per second. 720p provides the smoothest possible motion rendition, but it does not have as much resolution as 1080i.
  
  The 1080i format makes a picture with 1080 vertical lines, each with 1920 pixels horizontally -- so in computer display terms, it has a resolution of "1920 x 1080". 1080i uses interlaced scanning, like traditional TV, which alternates sending odd lines and even lines and thus sends a complete picture 30 times per second. 1080i provides the highest possible resolution, but has the same motion rendition as traditional TV.
  
  For those of you are really technically inclined, think about this: movies and many primetime shows that are produced on film are made with only 24 pictures per second, so 1080i actually becomes progressive scan when film-based material is being broadcast!


• What is DTV? Is it different than HDTV?
  In additional to the two HDTV formats, the Digital Television (DTV) standard also includes several Standard Definition Television (SDTV) formats. The two HDTV formats, 1080i and 720p, are described above. The Standard Definition formats provide DVD-quality pictures and sound, in both widescreen 16:9 and traditional 4:3 aspect ratios.


• Is HDTV replacing standard analog television?
  Most broadcasters, including NBC, will continue to provide standard analog transmissions for at least the next several years, while continuing to add more digital broadcasts. However, the federal government is encouraging broadcasters and consumers to adopt HDTV as quickly as possible, so that analog transmissions can be phased out.


• What else does the digital future have in store?
  Digital technology creates the possibility of new programming forms, utilizing accompanying data, graphics and different camera angles to make television a far more interactive and informative experience than it is today. This is similar to the capability that can be found today on some DVDs.


• I just heard about HDTV - when was it developed?
  The earliest work on analog HDTV started in Japan in the late 1960s, and development continued through the 1970s and 1980s. In 1987, US broadcasters petitioned the Federal Communications Commission (FCC) to reserve spectrum for HDTV broadcasting. The FCC formed an industry wide advisory committee to select a standard, and many different analog approaches were considered. In 1991 four competing groups (one of which included NBC) proposed revolutionary digital HDTV approaches, which were extensively tested. In 1993 the FCC encouraged the competing proponents to join forces and develop a "best-of-the-best" digital system. The resulting "Grand Alliance" system was developed, documented as the ATSC (Advanced Television Systems Committee) standard, tested, and recommended to the FCC by the end of 1995. The FCC approved the digital television standard on December 24, 1996. The first HDTV receivers were introduced in 1998, and HDTV broadcasts have been steadily increasing since that time.