What Digital Television Means for You
The Timetable
Local broadcasters will be initiating DTV service at different times. A station may begin DTV service as soon as it has received its FCC permit and is ready with equipment and other necessary preparations. The FCC has established a schedule by which broadcasters must begin DTV service (absent extenuating circumstances that may affect individual stations). This schedule required that stations affiliated with the top four networks (ABC, CBS, FOX, and NBC) in the 10 largest markets begin service by May 1, 1999. Stations affiliated with these networks in markets 11-30 must have begun service by November 1, 1999. All commercial stations must begin DTV service by May 1, 2002, and all noncommercial educational stations must start by May 1, 2003. stations are allowed two six-month extensions just by filing a request. Any additional extensions must be granted by the full FCC Commission.
In November 2001, following the World Trade Center disaster and in consideration of the country's economic downturn, the FCC threw a huge bone to broadcasters with a loosening of the DTV deadlines. Commercial broadcasters no longer have to replicate their NTSC service area by the end of 2004 (and non-commercial stations don't have to do it by the end of 2005). They just have to cover their communities of license, and they'll still retain interference protection.
Stations that already have construction permits for maximized coverage no longer face an operation deadline for the maximization. Broadcasters no longer face deadlines (commercial end of 2003, non-commercial end of 2004) for deciding which of their core (channel 2-51) channels they want to keep after the deadline. Except for the NTSC simulcasting requirements that kick in on April Fool's Day of 2003 (50%, then 75% in 2004, and 100% in 2005), DTV stations need no longer operate outside of primetime. "Financial hardship" may now be an acceptable excuse for missing a deadline.
The FCC "said it would defer to a future proceeding technical issues raised in the on-going proceeding, including the issues of receiver performance standards, DTV tuners, the ATSC PSIP standard, and labeling requirements for television receivers": http://www.fcc.gov/Bureaus/Mass_Media/News_Releases/2001/nrmm0114.html.
HDTV:
For the viewer at home, digital television can mean high definition television (HDTV) in a wider 16 by 9 aspect ratio (today's analog TVs have an aspect ratio of 4 by 3) as well as 5.1 channel Dolby Digital surround sound. HDTV pictures are like looking out a window and are better than any picture that today's analog TVs can produce.
SDTV Multicasting:
Digital Television also means muticasting (or more technically correct-multiplexing) where two or more television programs can share the bandwidth normally used by one analog program. It is technically possible to show two HDTV programs at the same time or one HDTV program and two standard definition (SDTV) programs at the same time, or even four to six SDTV programs at the same time each with 5.1 channel Dolby Digital surround sound. The law requires that at least one channel must be free and the same quality as the analog channel-but not the same program.
(At least not until April 1, 2003 when 50 percent of analog programming must be simulcast on one of the DTV channel programs, then 75 percent on April 1, 2004, and finally 100 percent on April 1, 2005. In theory, analog TV will be shut down in 2006, but that depends on how many people still rely on their analog TVs-which can get DTV with a set-top box)
The new (and expensive) HDTV TV sets will be able to figure out how many programs are on a channel and how to display them on the TV screen so they look the best to you. Incredibly, it is in the specification that a single channel of digital television can have as many as 1,024 different programs, but they don't all have to be TV.
Data Broadcasting (Enhanced Television):
A program can also be non-television data. Using "opportunistic" or left over bandwidth, broadcasters can transmit data over the air. What kind of data? Web content, stock reports, electronic coupons that a computer printer could print out, or even the telephone directory. Each 6 MHz DTV channel can transport 19.39 Mbps (2.42 MBps). That data can be television, non- television data, or a combination of both. At that speed (346 times that of a 56k modem), a program like Microsoft Word could be transmitted within five seconds.
The Future:
Only time and technology will tell what happens with digital television. New services are being thought of every day. Widescreen TVs, flat panel TVs, computers capable of HDTV are here now. Television can only get better.