HDTV Issues
Ever since the first form of HDTV was introduced in the United States, there
have been groups who have taken issue with this new form of technology.
Courting Controversy
In the 1980s, the National Association of Broadcasters in the United States
invited NHK, Japan’s public network, to present their HDTV system, MUSE,
to the Federal Communications Commission. From the time that the U.S. got
wind of this new technology there were issues. In the beginning there were two
groups that were adamantly against the introduction of HDTV in the U.S: terrestrial
television broadcasters and the U.S. Congress.
Broadcasters were scared by the possibility of being excluded from the HDTV
market because HDTV required more bandwidth (the amount of information sent
through a channel or connection) than standard TV. These broadcasters worried
because the channels that they already had license to would not be able to handle
the bandwidth of this new form of television. They were also concerned because,
with new channels being provided for HDTV, there would be less opportunity for
those channels to be taken by new stations and therefore there would be less
career opportunity.
U.S. Congress was concerned with the idea of HDTV for a different reason. They
saw this Japanese innovation as a threat and were concerned that Japanese companies
would make millions of dollars from U.S. consumers just as they did after the
VCR was introduced.
Avoiding Trouble
Both of these initial problems were addressed after the U.S. Federal Communications
Commission united a group of American researchers and manufacturers, called the
Grand Alliance, to design a completely digital form of HDTV. This not only helped
Americans to profit from HDTV, but the digital format allowed HDTV to be transmitted
using existing channels that were already used by broadcasters.
With these problems solved, HDTV gained momentum and popularity. But with this
popularity, more HDTV issues were brought to light.
Existing HDTV Issues
Unfortunately, there are still some unresolved issues with HDTV today. These problems include:
- Cost
- Bandwidth Limitations
- Broadcasting Distribution
- Compression
- Interlacing problems
Money, Money, Money
Cost is a major HDTV issue for both broadcasters and consumers. In switching
to HDTV, broadcasters are usually required to purchase new cameras and editing
equipment. Broadcasters also have to build new towers to broadcast their signals
and rebuild control rooms with new equipment that is compatible with HDTV systems.
The transition is one that few broadcasters feel they can afford and consumers
usually have the same complaint.
Purchasing a new HDTV system can cost a consumer thousands of dollars, especially
when combined with the necessary equipment. To get HDTV, you need either an antenna, satellite or cable service to receive HD signals.
Getting the Clear Picture
Bandwidth limitations are also a concern. Conventional bandwidth allocations
are 6MHz per channel and in most cases this is not sufficient for transmitting
HDTV signals. Images that are transmitted for standard analog TVs typically
have 525 lines scanned at 29.97 Hz with a horizontal resolution of 427 pixels.
But many HD images have 1050 lines with 600 pixels and therefore a bandwidth
of 18 MHz which obviously won’t fit on a 6MHz channel. One solution is to transmit
HD signals on new 20MHz channels. But terrestrial broadcasters will likely have
a problem with this because it revisits the issue they were concerned with
in the 1980s with the introduction of HDTV.
Getting It
Broadcasting distribution is at the top of the list of HDTV issues because
many stations haven’t adopted this new technology yet. The fact that HDTV is
not yet widely available has become an issue for consumers. Although the FCC
has mandated that analog television be phased out by 2006, to be replaced by
HDTV, many consumers are still not convinced.
In many areas, local cable companies
do not yet offer HDTV service. So people who want HD have to invest in either
a satellite or an antenna and sometimes both, which can be extremely expensive.
Squishing it Down
Compression is another concern. Even if more channels with increased bandwidth
become available, many HD signals are still too large to be transmitted via these
channels without being compressed.
The software used to compress HD images is
called MPEG-2. This software is responsible for recording just enough of each
image without making them look like they have elements missing. Many people
frown upon this method of compression because it lessens picture quality. However,
others argue that, even with degraded quality, the HD image is far superior to
the average analog image.
Intricate Lacing
Interlacing can also cause HDTV issues. Interlacing is used with HDTV to conserve
transmission bandwidth and involves dividing a frame into two fields: one of
odd-numbered horizontal lines and the other with even-numbered horizontal lines.
The problem with interlaced images is that there can be errors when the two
fields are recombined back into one frame. Many people don’t like the jagged
visual effect that interlacing produces and the effect often worsens the bigger
the HDTV screen or monitor is.
Even with issues like high cost and distribution problems, many people still
argue that HDTV is here to stay and that many of the problems will be overcome
in the near future. HDTV supporters say that it is just a matter of time before
all of the technical glitches are worked out of HDTV and that, as high definition
becomes more popular, HDTV systems will become more affordable and service will
eventually be available from all local cable companies and satellite providers.
