Home page logo
/

interesting-people logo Interesting People mailing list archives

IP: Brazilian story getting cleaned up
From: Dave Farber <farber () cis upenn edu>
Date: Tue, 30 May 2000 06:30:59 -0400



From: Janos_Gereben <janos () netcom com>
Subject: Brazilian story getting cleaned up
To: farber () cis upenn edu
Date: Mon, 29 May 2000 22:18:49 -0700 (PDT)

Brazil favors Japanese digital TV standard
Janos Gereben - the451.com

[Tests place Japan ahead of American and European competitors in a country
where only 20 percent of the population owns a TV.]

Anatel, Brazil's federal communications agency, has just received the
result of tests that compared the three major globally competing
digital-television standards. Japan's system received the top
recommendation in this country of 150m people with 30m TV sets. The low
ratio of saturation indicates the importance of future TV technology in
Brazil if a "leapfrog model" becomes the tool to catch up with
technologically more advanced countries. (The U.S. population of 273m and
Japan's 127m have close to 100 percent TV ownership. The American
switchover to digital TV has a deadline of 2006, with a projected 6bn
income to the government in licenses.)

The three tested standards were Japan's ISDB (Integrated Services Digital
Broadcasting), ATSC (Advanced Television System Committee) from the U.S.,
and DVB (Digital Video Broadcasting) from Europe. Renato Cruz, of Brazil's
National Telecommunications Magazine, told the451.com that ISDB gave
"better results" over COFDM (Coded Orthogonal Frequency Division
Multiplexing) modulation, which is expected to serve as the basis of
service there.

Recommendations from the Set/Abert Group favoring the Japanese model will
be subject to public consultations between the government, the industry and
the general public before a final decision is made by September, after
consultation with Argentina, which is coordinating its DTV plans with
Brazil. Two other members of the regional group, Uruguay and Paraguay, are
not choosing their digital TV standard yet. Brazilian regulators said final
decisions depend on economic issues as well as on technical considerations.
The Set/Abert Group, making the recommendation, consists of television
engineers and members of the Brazilian Radio and Television Association.

According to Cruz, there is opposition in Brazil to the ISDB standard
because it's commercially still unproven. Also, in the SET/Abert tests, the
European DVB results were very close to the Japanese system's performance.

Although public discussion seldom differentiates between HDTV and DTV, they
are distinct. High-definition TV works in the analog mode as well - the
Japanese have been broadcasting in that format - but digital HDTV has many
advantages and is to be used by the Japanese despite their headstart in the
other format. DTV allows full exploitation of the capabilities of HDTV, but
it can also be used to carry multiple channels of conventional video and
assorted digital signals.

The Japanese digital TV model was developed by NHK, the Japan Broadcasting
Corporation, beginning in 1968, proposed as a worldwide standard in 1983,
and then vetoed by the U.S. and Europe in 1986. A year later, work began in
the U.S., leading to FCC adoption in 1996 of ATSC. The European platform,
DVB, is from the same time period; it was adopted by Australia as well in
1998.

Regular broadcasting of HDTV programs began in Japan in 1989, based on
NHK's hybrid analog-digital Hi-Vision format, which is just moving to full
digital broadcasting this year. Programs have been processed digitally, and
then broadcast in an analog mode, creating a situation in which sets were
very expensive and technology fell behind others going to the full digital
broadcasting system.

One of the leading digital models, the Digital Terrestrial Television
Broadcasting (DTTB) system uses advanced digital techniques to convert
analog to digital signals, which are then compressed, along with other
signals, before being broadcast from a transmitter. With digital
transmission, sound and pictures are processed electronically and converted
into binary digits. This code is then transmitted as a bit stream and the
receiver converts the digital transmissions back to graphics, text, and
sound.

HDTV, enabled by digital TV, offers approximately twice the vertical and
horizontal resolution of a PAL signal, providing a picture close to 35mm
film and a sound quality approaching that of a compact disc. It is
particularly suited to large-screen television display, with an aspect
ratio of 16:9 (1.78 to 1) and at least 1,000 lines making up the picture.
Currently, the U.S. National Television Standards Committee, or NTSC,
standard has a 4:3 aspect ratio (1.33 to 1) and 525 lines.)

DTTB systems can accommodate 6, 7 and 8 MHz channel spacing, with minimal
or no apparent cost disadvantage. Australia uses 7 MHz channel spacing for
analog services, the USA uses 6 MHz, and Europe usually uses 8 MHz.


  By Date           By Thread  

Current thread:
  • IP: Brazilian story getting cleaned up Dave Farber (May 30)
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]