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It has been suggested that this article be merged with digital switchover. (Discuss) Proposed since May 2008.

The DTV transition (or Broadcast Digital Transition) is the switchover from analog (the traditional method of transmitting television signals) to exclusively digital broadcasting of free television programming. The transition from analog to digital television has been described by David Rehr, president and CEO of the National Association of Broadcasters, as representing "the most significant advancement of television technology since color TV was introduced."

United States

The transition from the analog NTSC format to the digital ATSC format will be completed on February 17, 2009, as set by Congress. Congress mandated the conversion to all-digital television broadcasting for full-power broadcasters, also known as the digital television (DTV) transition, because all-digital broadcasting will free up frequencies to be auctioned by the US federal government to the highest bidder. Of the eighteen channels (52 - 69), four (60, 61, 68, 69) will be held for reallocation to public safety communications (such as police, fire, and emergency rescue). In addition, some of the freed up frequencies will be used for advanced commercial wireless services for consumers, such as Qualcomm's planned use of former UHF channel 55 for its MediaFLO service.

Digital TV uses a more efficient transmission technology that allows broadcast stations to offer improved picture and sound quality, as well as offer more programming options through multiple broadcast streams (multicasting). Television stations have been preparing for the transition from analog to DTV since the late 1990s, when they began building digital facilities and airing digital channels alongside regular analog broadcasts. Today, 1,609 out of 1,745 full power television stations nationwide offer digital programming, however, most of the smaller, low-power broadcasters, for whom switching to digital would be cost prohibitive, will still be permitted to transmit in analog for several years to come. Since the majority of US viewership is no longer using over-the-air antennae to receive signals, but has switched to cable and satellite, the impact will be much smaller on current NTSC receivers which will continue to use NTSC content and devices after the cut-off date. Set-top boxes will enable existing over-the-air NTSC only receivers to watch over-the-air ATSC signals.

A major concern is that the broadcast technology used to transmit ATSC signals called 8VSB has problems receiving signal inside buildings and in urban areas, largely due to multipath reception issues which cause annoying ghosting and fading on analogue images, but can lead to intermittent signal or no reception at all on ATSC programs.. DTV broadcasts exhibit a digital cliff effect, by which viewers will receive either a perfect signal or no signal at all with little or no middle ground. Digital transmissions do contain additional data bits to provide error correction for a finite number of bit errors; once signal quality degrades beyond that point, recovery of the original digital signal becomes impossible.

The maximum power for DTV broadcast classes is also substantially lower; one-fifth of the legal limits for the former full-power analogue services. A hundred-kW analogue station on channel 2-6 would therefore be faced with the choice of either lowering its power by 80% (to the twenty kilowatt limit of low-VHF DTV) or abandoning a channel which it occupied since the 1950s in order to transmit more signal power on the less-crowded UHF TV band. Unfortunately, the higher frequencies perform poorly in areas where signals must travel great distances and encounter significant terrestrial obstacles.

The Consumer Electronics Association has set up a website called Antenna Web to identify means to provide the correct signal reception to over-the-air viewers. The TV Fool website provides geographic mapping and signal data to allow viewers to estimate the number of channels which will be gained or lost as a result of digital transition; while it estimates that marginally more stations will be gained than lost by viewers, this varies widely with viewers of low-VHF analogue signals in distant-fringe areas among the most adversely affected. An estimated 1.8 million people will lose the ability to access over-the-air TV entirely as a result of the digital transition.

When the transition is complete, channels 2 through 51 will be used for digital television broadcasts, and channels 52 through 69 will be reclaimed for other uses.

US markets which have presented unique problems for digital transition include:

• New York City-Newark - one of the early US terrestrial digital television pioneers with state-of-the-art ATSC facilities installed atop the World Trade Center as early as 1998, currently lacks one single point of sufficient height from which to cover the entire region without severe multipath interference issues in downtown Manhattan, New York. The 1776-foot Freedom Tower, proposed to replace the former World Trade Center, will not be completed in time for 2009's DTV transition, requiring the use of multiple booster transmitters to fill gaps in coverage from the Empire State Building. The Metropolitan TV Alliance, a group of eleven rival New York and New Jersey broadcasters, proposes to deploy twenty transmitters across the city to provide adequate quality signal.
• New Orleans, Louisiana and portions of Mississippi were operating some digital transmitters from temporary locations or from towers belonging to other stations due to damage done during Hurricane Katrina and Hurricane Rita in 2005. While stations are now back on-air, the coverage area often does not match that specified on the station licences due to the change in antenna locations.
• Denver, Colorado faces unique multipath interference problems largely due to its mountainous location; its antennas on Lookout Mountain will need to increase in height to overcome obstacles to digital reception, but attempts to get local zoning approval have met with strong opposition.

The rules requiring digital must-carry access on cable and satellite systems are still being worked out by the FCC and Congress due to technical issues with available channel capacity and replacement of analog/SD signals with Digital/HDTV signals.

Coupon program

The Department of Commerce's National Telecommunications and Information Administration (NTIA) has launched the Digital-to-Analog Converter Box Coupon Program, as authorized in the Digital Television Transition and Public Safety Act of 2005.

Beginning January 1, 2008, all U.S. households will be eligible for two $40 USD coupons to be used toward the purchase of two digital-to-analog converter boxes..

These coupons may be redeemed toward the purchase of a digital-to-analog converter at brick and mortar, on-line, and telephone retailers that have completed the NTIA certification process. Retail prices for the boxes range from $40 to $70 (plus tax and/or shipping); after applying the coupons, the price to the consumer should be between $5 and $40 per box.

Be Mindful of the implications

An aditional note: Now the government will be able to see what people are tuning into on a much more fine grain scale. No longer will they need to use samples to guestimate potential viewers. Just another way for big brother to stick their noses into your life.

United Kingdom

The DTV transition began in the United Kingdom as FreeView broadcasting additional standard definition programming using DVB-T. The United Kingdom has a phased switchover based upon region, with the last analogue signals to be shut down in 2012.

Digital-to-analog converters

After the switch from analog to digital broadcasts is complete, analog TVs will be incapable of receiving over-the-air broadcasts without the addition of a set-top converter box. Consequently, a digital-to-analog converter, an electronic device that connects to an analog television, must be used in order to allow the television to receive digital broadcasts. The box may also be called a "set-top" converter, "digital TV adapter" (DTA), or "digital set-top box" (DSTB).

References and notes

1. "Broadcasters Prepare For DTV Transition". TWICE. January 7, 2008. Retrieved 2008-03-23.
2. ^ "All-Digital Television Is Coming (And Sooner Than You Think!)". Retrieved 2008-03-23.
3. What is Digital Television? for the public, by DTV Answers. Accessed 11 May 2007.
4. http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/reports/dtvreprt.pdf
5. http://www.antennaweb.org Antenna Web
6. TV fool
7. http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-275789A1.pdf
8. The BRIDGE
9. TV Converter Box Coupon Program Website - Frequently Asked Questions (FAQs)
10. "Digital-to-Analog Converter Box Coupon Program". NTIA.gov. Retrieved 2008-02-15.
11. TV Converter Box Coupon Program Website
12. TV Converter Box Coupon Program Website - Locate a Converter Box Retailer near you
13. "Digital - Switchover". BBC. March 23, 2008. Retrieved 2008-03-23.
14. A television commercial shown on American television featuring This Old House announces that this is true.
15. "What is a set-top converter box?". Digital TV Facts. 2007. Retrieved 2008-03-23.

External links

• DTVAnswers.com: What you need to know about the February 17, 2009 switch to DTV.
• National Association of Broadcasters
• DTVRedAlert.org
• DTV Transition
• Consumer oriented FCC site
• FCC regulatory information on the DTV transition
• Federal Coupon Program

• Articles to be merged from May 2008
• Digital television
• History of television