AT&T ISB7005 User Manual

Page of 32
26
Frequently Asked Questions
What Is Digital Television?
Digital television (DTV) is a huge leap forward in television technology compared to analog television 
that has been widely available since the 1940s. DTV is delivered and displayed using digital encoding, 
similar to the way a PC operates. By using digital technology, there is no variation in picture and 
sound quality from the origination point until it is displayed on your television. You always receive a 
high-quality picture without the wavy lines or static you might sometimes get from a weak analog 
signal. Another feature of digital television is digital surround sound using Dolby Digital technology, 
which is the same technology used to produce the sound you hear in movie theaters.
What Is Standard-Defi nition Television?
Standard-defi nition television (SDTV) is basic digital television programming delivered by your 
service provider. Typically, the SDTV screen is the same, nearly square shape as an analog 
television screen. Digital images on an SDTV set are crisp and clear—noticeably better than on a 
standard analog television set using an antenna to receive over-the-air signals.
What Is High-Defi nition Television?
High-defi nition television (HDTV) is a completely new way to send and receive television broadcast 
signals. HDTV images are made up of pixels that are much smaller and closer together than those 
used in standard analog television, and there are millions of them. Thus, HDTV can display fi ve to six 
times the detail of analog television to deliver picture quality that is much more realistic, dimensional, 
and precise. SDTV programs can be viewed on an HDTV. 
Are Local TV Stations or Other Programmers Broadcasting in 
HDTV?
Many local TV stations and programmers are transmitting digital signals. However, transmitting 
a digital signal does not mean transmitting an HDTV signal. Some stations are using the new 
bandwidth to broadcast several standard-defi nition channels. Most stations and programmers, once 
they begin broadcasting in digital, are off ering HD content from their parent network (for example, 
CBS, ABC, NBC, Fox, and PBS). Contact your service provider for more information.
Why Aren’t All the Shows I Watch in High-Defi nition?
A high-defi nition program must originate in HD format and be broadcast in HD format. Having an 
HDTV system does not mean that everything you watch will be viewed in high-defi nition. Getting the 
signal from a digital source also does not mean it is high-defi nition.
Why Are Some HDTVs 4:3 Aspect Ratio and Others 16:9?
The aspect ratios diff er because television manufacturers build both standard-screen and wide-
screen HDTVs to appeal to consumer viewing preferences. The two aspect ratios are as follows: 
•  On standard-screen (4:3) HDTVs, the programming is displayed in letterbox format in the middle 
of the screen. There are bars surrounding the picture.
•  On wide-screen (16:9) HDTVs, the programming is displayed on the full screen. 
What Is HDMI and Does it Support Dolby Digital 5.1 Audio?
The High-Defi nition Multimedia Interface (HDMI) is an uncompressed, all-digital audio/video 
interface. The Dolby Digital audio format that provides up to 5.1 separate channels of surround 
sound, and is the standard used for DVD-Video. HDMI supports standard, enhanced, or high-
defi nition video, plus multi-channel digital audio, such as Dolby Digital audio, on a single cable.