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FREQUENTLY ASKED QUESTIONS - FAQ'S

 

What Is Digital Television?

 

How Is DTV Different From What We Have Today?

Why Would I Want To Buy An HDTV?

Is DTV The Same As High-Definition Television?

What Does “HDTV Ready” Mean?

What Are The Minimum Features A TV Must Have To Qualify As A
High Definition TV (HDTV)?

Why Are There Different Forms Of DTV?

Why So Many Formats Within DTV?

The ATSC Table 3 Shows Many Formats For HDTV And SDTV Transmission.
How Will My HDTV Be Able To Display All These Formats?

How Will I Receive HDTV?

Who Is Broadcasting HDTV?

When Broadcasters Begin Transmitting HDTV Signals,
What Happens To Current Analogue Televisions?

How Long Will Conventional Analogue TV Signals Be Available?

Am I Getting DTV From My “Digital“ Cable, Satellite, Or MMDS Service Provider?

What About The TV I Own Now And The Next TV I Buy?

What Features are Important When Buying an HD Set?

When Should I Buy An HDTV?

 

What Is Digital Television?

 

Digital Television (DTV) is a new standard established in both Canada and the U.S.A. for the broadcast of television pictures, sound, and data.

 

In November 1997, Industry Canada adopted the Advanced Television Systems Committee (ATSC) standard for DTV. The ATSC standard includes 18 DTV broadcast formats, all of which fall under one of two categories: High-Definition Television (HDTV) or Standard-Definition Television (SDTV). In the Fall of 2000, the U.S. Consumer Electronics Association issued more detailed terminology for the various classes of reception and display for digital televisions, and introduced a third category, “Enhanced Definition Television”, (EDTV), which fits in between SDTV and HDTV. These definitions also apply to the Canadian market.

 

It is very important to recognize the differences between the two sets of standards. The ATSC’s 12 Standard Definition and 6 High Definition formats relate to the broadcast of Digital TV.  The CEA terminology for Standard Definition, Enhanced Definition and High Definition relate specifically to hardware reception and display capabilities.

 

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How Is DTV Different From What We Have Today?

For the past 40 years televisions signals have employed a standard known as NTSC (National Television Systems Committee) for production, transmission and display. The NTSC standard is known as analogue signal in that it is created with continuously varying voltage levels or electrical waves, which may be adversely affected by every step in the production -distribution process. To conserve the limited transmission spectrum, the color portion of the signal and the luminance (black and white image) are combined in the production stage and retained in this composite form until separated at the television receiver into the primary components of red, green and blue  (R,G,B) at the picture tube. 

DTV is the new generation of television. DTV signals are generally recorded, distributed and transmitted in a digital component format. Being digital, the signal generally experiences minimal loss of quality from the studio or mobile cameras to the homes. The color is more faithfully reproduced through the entire process from the originating R,G,B components in the camera to our home television displays. This ensures sharper pictures, and greater color fidelity. Potentially studio origination quality can be delivered to the home without transmission or distribution losses. And this can be done at varying levels of picture detail depending on the content needs, broadly described as Standard Definition television (SDTV), Enhanced Definition television (EDTV), and High Definition. 

The North American DTV standard known as ATSC (Advanced Television Systems Committee) is basically a highly compressed stream of 1’s and 0’s, known as bits, which represent the pictures, sound and data associated with the television signal. These bits are then converted into pixels (short for Picture Elements), which can be thought of as a single dot of light on the TV screen. The greater the number of pixels, the sharper or better defined the picture will be. In its “finest” form HDTV can display up to 10 times as many pixels as most analogue televisions.

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Why Would I Want To Buy An HDTV?

There is no question that HDTV is much better than the analogue system we've been used to.

Vastly Superior Picture Performance. Broadcasters are now be able to transmit pictures with a quality far superior to today’s NTSC television system or any other picture source currently available (e.g. VCR, DVD and Laser Disc).

New Wide screen Format. HDTV provides for a wide screen presentation similar to what you see in movie theatres. The new screen has a width-to-height (or aspect) ratio of 16:9 compared to today’s 4:3 width-to-height ratio on conventional television sets.

Wider Aspect Ratio. See the illustration below.

aspects-en.jpg (19377 bytes)

Clearer Pictures. HDTV eliminates “snow” and ghosting.

Better Color. HDTV delivers exceptionally vivid colors – including subtle purples and reds – and  eliminates any bleeding of colors at the edges...

Multi-Channel Digital Sound Quality. HDTV provides highly advanced Dolby® Digital Audio, also known as AC3, with 5.1 discrete audio channels.

Future Possibilities. HDTV uses a high bit-rate channel, which will mean broadcasters will be capable of transmitting new value-added services, such as Interactive TV,  to consumers in the near future.

 

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Is DTV the Same as High-Definition Television?

HDTV is DTV at it’s finest. HDTV is the best option in the range of DTV transmission formats.

 

Each of the eighteen possible broadcast formats within the ATSC standard has a specified number of active horizontal scanning lines used to create a TV picture. The greater the number of these scanning lines, the greater the level of vertical detail, in either progressive or interlaced mode. Six of ATSC’s eighteen transmission formats use 1080 or 720 active scanning lines, in either “p”-progressive, or “i”-interlaced display. This is true HDTV. The remaining twelve transmission formats use 480 active scanning lines, and are classified as Standard Definition. TV set manufacturers may also use the term Enhanced Definition (EDTV) to define the display of an SD broadcast in a 480 line progressive format. Thus Standard Definition Television (SDTV) would be any display of digital transmission, down converted to 480 line interlaced format (480i).

 

The following comparison chart indicates attributes of the various formats. Note that the SD, ED, and HD formats all require either an ATSC compliant built in tuner or an add-on ATSC set top box. Also remember that an ATSC compliant tuner or set top box must be able to receive and decode all 18 broadcast formats, and allow for a usable display of the picture. 

Analogue

SDTV

EDTV

HDTV

Aspect Ratio

4:3

4:3 or 16:9

4:3 or 16:9

16:9

Pixels per line

450 (equiv.)

708 - 720

708 - 720

1280 (720p)

1920 (1080i)

Active lines/picture

480i

480i

480p

720p or 1080i

Total number of pixels

253,000 +/-

<480,000

>480,000

921,600 (720p) 2,073,600 (1080i)

Progressive Scan

No

No

Yes

Yes

Interlaced Scan

Yes

Yes

Yes

Yes

Pictures/sec.

30

30

60

60 (720p)

30 (1080i)

Audio

2 channel - stereo

2 channel digital

Dolby Digital

Dolby Digital

Broadcast Formats

1 Analogue

12 Digital formats

12 Digital formats

6Digital formats

 

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What Does “HDTV Ready” Mean?

All televisions are Digital TV-Ready when connected to a DTV set-top box. This will produce an NTSC (analogue) quality picture. As a result, it is important to understand the different terms used to describe your televisions capabilities. 

  • An INTEGRATED Digital Television, be it SD, ED, or HD, must meet the specific display and audio criteria for its class, utilizing an ATSC compliant BUILT IN tuner.
  • A DIGITAL READY Television, whether SD, ED, or HD, must also meet the specific display and audio characteristics of its class, utilizing an add-on DTV set-top box (STB) to decode the signals.
  • HDTV-READY means the TV has a designated HDTV input, but does not have an ATSC tuner built in. These TVs require a DTV converter box that will allow the TV to display a HDTV program in its native 720p or 1080i transmission format, as well as reproducing or passing through Dolby Digital audio, which may include up to 5.1 discrete audio signals. The image on-screen must be in a 16:9 aspect ratio. Most HD sets are built with a screen in that aspect ratio, however, letterboxing a 720p or 1080i broadcast on a 4:3 display will still qualify as High Definition. Your set manufacturer will identify the number of active scanning lines in these cases. 

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What are the Minimum Features a TV Must Have to Qualify as a High Definition TV (HDTV)?

The minimum performance attributes for HDTV are: 

  • Picture Quality: vertical display resolution of 720p,resulting in 921,600 pixels per frame, or 1080i or higher delivering a picture of over 2,000,000 pixels.
  • Aspect Ratio: capable of displaying a 16:9 image at the minimum resolution level. Should your HD set be a 4:3 natural display, the HD signal will be letter-boxed to a 16:9 aspect ratio, and the set manufacturer will identify the number of active scan lines: 540 in progressive or 810 for interlaced formats.
  • Audio: receives, reproduces, and/or outputs Dolby Digital audio.
  • Tuner: receives all ATSC Table 3 formats and displays them.

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Why Are There Different Forms of DTV?

Networks and other over-the-air broadcasters have a specific amount of broadcast capacity, or bandwidth, in which to carry DTV signals. If a broadcaster wants to transmit the best picture quality (HDTV) it will require most of its available broadcast channel capacity. A broadcaster might choose the option to broadcast as many as 6 programs in the same channel at a lower definition (SDTV), or a mix of HDTV and one or two SDTV programs. 

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Why so Many Formats Within DTV?

Analogue broadcasting is a world without choices. Every analogue television uses 480 lines, the same interlaced scanning at 30 frames (complete pictures) per second and the same 4:3 aspect ratio screen. This system is abbreviated as 480i or 480/30i.  

In comparison, the ATSC recommendations give broadcasters and viewers a world of choice. The signal for transmission may be scanned either Interlaced (i) or Progressive (p). Interlaced scanning means that each frame is sent as two “fields” – one with the odd-numbered scanning  lines (A) and the next with even-numbered lines (B), similar to current TVs. In progressive scanning, all lines of the frame are scanned sequentially and sent as a single frame. There’s also a choice of 24, 30 or 60 frames per second and a choice of standard 4:3 or wide-screen 16:9 aspect ratio. In total there are 18 formats, each suited to a specific purpose.

p-i-en.jpg (88849 bytes)

 

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The ATSC Table 3 Formats for HDTV and SDTV Transmission. How will my HDTV be able to display all these formats?

Digital TV broadcasts will be received and decoded by your DTV’s ATSC compliant built-in tuner or set top box. Set manufacturers will design their TV’s so that they will either up-convert or down-convert the broadcast signal to their TV’s “native display format, the format of the screen. As an example, Brand A may have decided that their set will display HD broadcasts in 1080i-30. Therefore the set will include circuitry that will convert any of the other 5 HD broadcast formats, (such as 720p-60) into the set’s “native” display of 1080i-30p. Similarly, that same set manufacturer may have selected 480p-60 as the “native” display for all 12 Standard Definition broadcasts, and will use circuitry to up or down convert all SD broadcasts to that display. 

Remember, as you select your HDTV, that there are 2 different, but related sets of terminology. DTV broadcasts will fall under 2 classifications: High Definition (with 6 formats of transmission), and Standard Definition, with 12 different broadcast formats. DTV reception and display criteria have the same 6 formats for High Definition, and separate the other 12 formats into 2 subsets: Enhanced Definition for 480p,and Standard Definition at 480i. Your HDTV will be able to display all digital TV broadcasts, converted to the sets native display format, as designed by the manufacturer, with the use of it’s ATSC tuner or set top box.

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How will I Receive HDTV?

In the US, digital TV initially arrived through over-the-air (OTA) (terrestrial) broadcasts in previously unused portions of the VHF/UHF spectrum. Standard VHF/UHF antennas will provide reception. In Canada, only 20% of homes receive terrestrial broadcasts in this manner, and this is currently not an economically viable solution for Canadian broadcasters. As a result, initial DTV offerings in Canada were introduced through Cable, and Direct to Home (DTH) satellite distribution rather than over-the-air. However, CityTV has been broadcasting in High Definition since 2003 and OTA HDTV is available in Montreal (CBC, RC, TQS), Toronto (CITY, CBC, RC, OMNI) and Vancouver (CTV) Other broadcasters have their digital licenses applications in place with the CRTC. Up to 42 channels of HDTV are available on DTH and up to 33 channels on Cable. All Canadian DTV services will have to follow Canadian Government procedures, policies, and CRTC regulations.

Different networks may choose different formats. A network might go one way, and some of its affiliates may go another. A single station might broadcast HD (1080 or 720 lines) for prime time and SD (480) at other times. The format you receive will be determined by the content provider, and the signal distributor. Regardless, your HDTV, or set top box, will be able to convert and display any digital signal, and will automatically switch between the different formats.

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Who is broadcasting HDTV?

United States. The major networks, ABC, CBS, NBC, PBS and Fox are broadcasting HD in prime time throughout the US, and currently over 95% of U.S. homes now have access to HDTV signals. By April 2006 over 1550 stations serving 211 US markets were broadcasting DTV, although they must simulcast their programming in NTSC until February 2009.

Canada. At this time (early 2006) HDTV broadcasts are available over-the-air in Montreal, Toronto and Vancouver. In addition, in certain border cities, HDTV broadcasts from the adjacent US cities can be received. The content from Canadian HDTV broadcasters is also available on Cable and DTH in many markets. Contact your service provider for programming and availability information. Digital broadcasting license applications for the other broadcasters and networks are in process before the CRTC and new HDTV stations are expected to be on-air shortly.

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When Broadcasters Begin Transmitting HDTV Signals, What Happens to Current Analogue Televisions?

Nothing. The current analogue signals will be broadcast just as they are today until the transition to DTV is complete, at which time they be terminated. In the US this is legislated to occur February 17, 2009. In Canada, the date has yet to be determined, but will certainly be well after the US closure of analogue television. As part of the transition, it is expected that low cost converter boxes will soon be available to allow current analogue receivers to receive the content of DTV signals, but of course, at the lower quality inherent in the analogue receiver. 

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How Long will Conventional Analogue TV Signals Be Available?

Since the transition to digital TV will take a long time to complete, you'll be able to watch analogue broadcasting for years. As a point of reference, it took 13 years for sales of color televisions to surpass black-and-white sales. In comparison, digital television represents a change of even greater complexity. The earliest that Canadian analogue stations may be allowed to shut down has yet to be determined but it is likely to be much beyond the year 2009, when analogue television broadcasting is expected to terminate in the US. Because analogue broadcasting will be with us for some time, current models of HDTV receivers also receive and display analogue TV signals.  

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Am I Getting DTV from my “Digital“ Cable, Satellite, or MMDS Service Provider?

Yes, if the program was recorded in digital form, transmitted in digital form, and received by your TV tuner or set top box in digital form. Once the signal reaches this point, the capabilities of your TV will determine how good a signal you ultimately see. We’re back to whether your set can display signals in the SD, ED, or HD display formats. And, in the case of HD, the original digital signal still has to meet the HD criteria. Currently, the two Canadian satellite companies and many cable companies are providing up to 20 HDTV channels. The majority of the other digital offerings fall into the SD classification, or the programs may only be digital in the transmission process, having been converted from an analogue source. For consumers to receive true HDTV signals, the programs must originate in a digital format, and be digitally transmitted. And remember,  a “digital” set top box does not decode HD signals. You will need to get an HD set top box from your service provider

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What About the TV I Own Now and the Next TV I Buy?

When analogue signals are no longer available will my analogue television become obsolete? No. Consumers will be able to continue watching analogue broadcasts, cable, videocassettes, DVD and satellite as well as watch the new HDTV broadcasts using a DTV-to-NTSC set-top box. The set-top box will deliver many of the benefits of DTV broadcasting including HDTV programming, superior picture and clear sound. However, an analogue television cannot display the full quality of High-Definition images or sound. 

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What Features are Important When Buying an HD Set?

Technological progress never stops, but there are some key things to keep in mind. The picture quality, and display type (LCD, CRT, Plasma, LCOS, DLP and others)  will be a subjective choice. We’d recommend that you look at a 16x9 aspect ratio, in a screen size appropriate for your room. You may decide on a set with a built-in HD tuner, or a set without that, which would be HD Ready, and then would require an HD set-top box to receive and display HD. The other issue is connectivity and many manufacturers are adding digital input connections (DVI and /or HDMI) to their product offerings. Either one is advisable for future connectivity. The other element to consider is the CableCard feature, which is being introduced slowly.  In the future this will enable you to use a Cable Card, (like a PCM-IA card), from your cable/satellite provider, instead of a set top box. All good questions to ask your retailer about. As they say, technology never stops.

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When Should I Buy an HDTV?

HDTV is revolutionizing the TV industry in much the same way that CD’s changed the recorded music business. The end result will be that you will enjoy significantly improved picture and sound quality with HDTV, but the process of recording, delivering and displaying the program is new. Virtually every TV set manufacturer is aggressively marketing HD-Ready or HD sets with built-in ATSC digital tuners. And pricing on these sets has dropped dramatically, as economies of scale unfold. Purchasing an HDTV, or an HD-Ready TV is now no more expensive that regular projection sets were a couple of years ago. The advantage of buying one of these sets now, is that it enables you to enjoy the finest visual and audio experience available, when watching HDTV programming. 

A true HDTV Television will be able to display analogue, SDTV, and HDTV signals, both audio and video, in their optimum format and quality, as intended by the original content provider.

The programmer and the signal provider will determine the kind of signal (SD or HD) you get.

The kind of television you have will determine the quality of picture and sound (SD, ED, or HD) you will enjoy. 

So, the answer is… whenever you are ready enjoy HDTV - the finest quality television content in the world. There is a lot of content available right now, and more being created every day. 

 

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