DTV Primer

Chris Llana, Editor



July 1 -- a Milestone in the Transition to Digital TV

June 24, 2005

A number of important FCC regulations that will advance the DTV transition go into effect on July 1, just one week from today. Consumers, broadcasters, TV manufacturers and retailers will all be affected.

More new TV sets will be equipped with digital tuners, enabling them to receive digital over-the-air broadcasts. At the same time, many more TV stations will have to increase their digital signal strength, giving those digital tuners something to work with. Cable customers will also see changes in new high-definition set-top boxes and TVs.

Digital Tuners

In the past, most of the widescreen "digital" TVs you saw in the stores were "HD-Ready," which meant they only had the old NTSC/analog channel tuners built-in. TV stations are now broadcasting two separate channels--the old analog one and a new digital one, both with the same programs. Because the analog channels will be permanently shut down at the end of 2008, the FCC is requiring that digital tuners be installed in new TV sets, enabling them to receive those new digital channels (important when analog is gone).

The FCC is phasing in these requirements. On July 1, 2005:

  • All TV sets 36" and larger must have an integral digital tuner. Stores may sell out their existing stock of sets without the digital tuner, but can't bring in any more after July 1.

  • 50% of TV sets from 25" to 35" must have an integral digital tuner. There does not seem to be strict enforcement of these 50% requirements, so if you're looking for one of these mid-size sets, make sure it has a digital tuner before buying. 100% of these mid-size sets must have digital tuners after March 1, 2006.

  • Any set labeled "Digital Cable Ready" must also include an integrated over-the-air digital tuner.

Digital Interfaces

Interfaces are the jacks on the backs of TVs and set-top boxes that you plug cables into to connect your TV, set-top box, DVD player, etc. to each other. Digital interfaces permit the connections to pass digital data instead of analog signals. Keeping these video and audio signals in digital form instead of converting them to analog is important for two reasons: 1) you get a better picture, and 2) it allows anti-piracy (copyright-protection) systems to work. Having digital interfaces means you will be able to see all movies and programming in their most pristine high-definition form.

The most common digital interfaces are Firewire, DVI, and HDMI. The new FCC requirements concern DVI (Digital Visual Interface) and the newer HDMI (High-Definition Multimedia Interface). DVI carries only the video signal; HDMI carries both video and audio. DVI-to-HDMI converter cables are available.

After July 1:

  • All new high-definition cable set-top boxes must have either DVI or HDMI connections.

  • All new TVs 36" or larger that are labeled "Digital Cable Ready" must have DVI or HDMI interfaces using HDCP (High-bandwidth Digital Content Protection) technology.

TV Broadcasts

Beginning July 1, 2005, the top four networks (ABC, CBS, NBC, Fox) in the 100 largest TV markets must bring their digital channel signal up to full strength. Remember that they are also broadcasting on their other old analog channel; that one is already at full power.

The general intent of this requirement is for TV stations' digital channel coverage to extend to everyone who can tune-in their analog channels. Most stations have been operating their digital channels at a reduced power level, sufficient to reach their core audiences, but perhaps not suburban viewers.

This July 1 deadline is not an absolute. It is called the "use-it-or lose-it" deadline and the "replication and maximization" deadline (maximize authorized signal strength, replicate analog channel coverage). If stations don't reach full signal coverage, it means they may not be entitled to later increase power to cover unserved viewers (they would lose interference protection), if in the meantime another transmitter has spread its signal to that area.

There are also caveats for stations that are not yet operating on their final digital channel (the FCC channel assignment process is still underway).

Stations not affiliated with the top four networks and stations not in the top 100 TV markets have another year (until July 1, 2006) to "maximize and replicate."