|What is Needed to get HDTV
Televisions /Set-Top Boxes
Televisions for HDTV are offered in three generic
(a) Integrated HD televisions contain a tuner, High Definition display
and multi-channel sound system, similar to conventional televisions. These integrated
digital televisions can receive DTV/HDTV signals directly with an over-the-air antenna, if
the local stations in your city are offering this service. Receiving DTV or HDTV content
from a cable or satellite company requires the use of their set-top box, which is then
connected to the external video/audio inputs of the television.
(b) Cable Ready HD Televisions contain a tuner, capable of receiving both
cable channels and over-the-air channels, a High Definition display and multi-channel
sound system, as well as the decoder for the encryption used to protect cable channels.
The television includes a slot for the CableCard, provided by the cable company,
containing the keys for the decoding.
(c) HD Ready televisions (or stand alone displays) do not have a built-in
tuner and will require a set-top box (STB) to receive and display DTV or HDTV services.
Some HD Ready televisions may also require an external sound system, providing only video
Set Top Boxes (STBs) Set Top Boxes for
HDTV are offered in two generic types:
(a) Basic unit capable only of receiving the HDTV signal
and accompanying sound and data services;
(b) Advanced unit, termed Personal Video Recorder or PVR,
that not only receives the signals but also includes storage to record and playback
programs and to select the material to be recorded based on a number of criteria. The PVR
may include multiple tuners to enable recording, playback and direct viewing
simultaneously. Depending upon the kind of service delivery chosen, a different STB or PVR
will be selected (i.e. over-the-air reception, cable or satellite), as these boxes are not
Some STB's and PVR's are only capable of operation with
SDTV signals and of no use for HDTV reception. The set-top box includes the tuner to
receive the DTV signal and the processing electronics to provide audio and video signals
for connection to the display. The set-top box may convert the scanning format (# of lines
and # of pixels per picture) received to one or more of the other formats needed by some
displays. The set-top box typically decodes the multi-channel audio into separate left and
right channels ready for simple connection to a sound system, as well as passing the audio
data stream through an optical fiber or RCA jack connector that can be connected to an
external decoder in the display or associated sound system. Set-top boxes for cable and
satellite reception also include the decoding for the encryption used to protect the
program channels, using a key provided by the company. Specialized knowledge may be needed
to connect up the set-top box to the display and sound system. (See Connecting HDTV).