The Evolution
of
Interactive Teletext
by Ken
Freed.
.
While
America missed the boat, the world has enjoyed smooth
sailing on plain old teletext.
Terrestrial
broadcast television was invented as a one-way medium, a
tube atop a hilltop tower pulsing signals to home
antennas. Broadcasters today are inviting consumers to
adopt digital boxes with phone line return paths, but the
lack of any return has not kept broadcasters from
expanding into one-way interactivity by carrying enhanced
content with viewer appeal, especially lots of free
information, available on demand.
One of the most
effective and enduring methods of enhancing plain old TV
is using the black vertical blanking interval (VBI)
between lines of video to transmit data, displayed on the
screen as a page of text. This concept of television
text, or "teletext," is unfamiliar to Americans, who only
know of "closed captioning." But in the UK and around the
world, teletext is a major business sector of
broadcasting, supported by advertising.
Because rapid
information-on-demand is a primary function of
interactive TV, let's appreciate its valuable place in
the world.
What makes teletext
so compelling and enduring as a business is the volume of
information that can be transmitted within a video frame.
A ream of teletext pages arrives within minutes. People
value having so much useful information at their
fingertips. Teletext falters compared to broadband
information-on-demand, where streaming multimedia
technologies can pour out whole libraries in seconds.
Compared to the current Internet, on the other hand,
teletext fares better in the debates on speed versus
utility when compared to the narrowband World Wide
Wait.
More than a dozen
countries have teletext systems based on the UK model.
The French developed the Antiope information and
subtitling system, a national treasure. The French Mintel
system echoes Ceefax in its boxy format, but text arrives
on phonelines. And in the UK, BBC Ceefax endures as a
public service, free to anyone within broadcasting range.
(Free after one buys a teletext TV set, of course, free
after proper TV set registration, free after paying the
annual TV license fee to the government).
The United States
missed the boat on teletext. As with interactive TV, the
UK and Europe beat America into port. Anybody in the US
television industry who visited Britain or western
Europe, if they entered any homes at all, could not miss
the popularity of Ceefax and kindred teletext services.
One would expect the Americans to follow suit, but that's
not what happened.
.
American
Know-How?
The US tale tracks
to 1984-85 and President Ronald Reagan.
According to
researcher John Carey, "The FCC in the Eighties began
going though a rulemaking process on teletext. When it
came to the fact there were no US teletext standards in
place, the FCC chose not to set any standard, to let the
marketplace decide. In the absence of any standard, TV
set manufacturers were not willing to build a decoder
chip into their TV receivers. The US teletext attempt
shows how politics influences the process. The best idea
was building functionality into the TV set, but the next
idea was placing the teletext functions into a separate
box that sits atop the set,, The venders priced hardware
and assembly at variable costs, projected an initial
ticket for a teletext decoding box at nearly $800 dollars
pet household. " There was never a business case for
teletext, so it faded quickly, Using the VBI only
recently has come back in the form of Wink and others who
call themselves "enhanced television.'"
About the only
thing in common among early American teletext efforts was
a consensus to carry the data in the vertical blanking
interval (VBI) among lines 16 to 20 near the top of a
screen with 525 NTSC standard lines of video. How to
standardize teletext encoding and decoding was an issue,
as in any communication, and the determined attempts were
innately proprietary.
Time magazine
tested a Time teletext service over cable with a 6 MHz
channel sending data at the rate of 5,000 frames or pages
of information every five seconds. Conceived to be
robust, The Time teletext cable tested plants were mostly
around Orlando, Florida, where Time-Warner later tested
their broadband hybrid fiber coaxial cable Full Service
Network. "Although it was very attractive to consumers,
"said Carey, "it was not a business."
Yet a natural
desire persisted to do something useful with the VBI
lines. Said Carey, "the 'Closed Captioning' mechanism
eventually came about in the Eighties through political
pressure from the deaf organisations, and the CC system
has never been developed much beyond the job of producing
subtitles for the deaf. A few local TV stations have
adopted BBC-style teletext, however, and a few
manufacturers, like Zenith, fit text decoders into their
TV sets. Using the VBI to deliver data services is not
unknown in America, but teletext is mostly unknown here.
The analog form of Wink offers text-only "virtual
channels" that are virtually the same as UK teletext
pages, but with better graphics
Americans have not
yet adopted an open standard for multimedia, like
DVB-MHP, the multimedia home platform for the Digital
Video Broadcasting system developed by Europe and adopted
everywhere but America and a few friends. An American
plan is Advanced Television Enhancement Forum (ATVEF) as
a move to make interactive TV become computer-centric and
Microsoft friendly. Windows does not support teletext,
although Windows 98 initiated support for Web access via
the VBI on a PC board for TV reception. However, for iTV
to reach potential, methods of multimedia hyperlinking
must be standardized on a global basis. Such a move has
not progressed beyond mere talk.
.
Teletext
Genesis
American VBI
capabilities have little application in the UK and the
rest of the world where teletext is long established as
the main source of information on television, not talking
heads.
Where did teletext
begin? According to teletext enthusiast and historian
Alan Pemberton, in the early Seventies, the BBC was
experimenting with subtitles while the Independent
Broadcasting Authority (IBA) was exploring programme
source identification, both concerns saw value in the
using the VBI to carry news and helpful information. Thus
public and private teletext was born.
American journalism
and communications professor David Carlson at the
University of Florida found a different genesis after
conducting anecdotal research in the UK. "It apparently
was invented by some still anonymous technicians at the
BBC who used VBI to send notes among themselves at the
transmitter sites around Britain." Carlson located what
could be the first written mention of producing
alphanumeric characters on the TV screen, storing lines
of script in the VBI. This was in a note attached to a
facsimile memorandum in December 1970 from BBC designs
department head, one "P. Rainger," to the chief engineer
for R&D. The note proposed creating a 30-page
"magazine" to be stored magnetically in a home receiver
set and continuously updated. A formal BBC patent
application for a "Teledata" service was filed in
February 1972 under the broad title, "The Transmission of
Alphanumeric Data by Television." The term Teledata gave
way to "Ceefax," announced in October 1972 and
demonstrated in January 1973. With a pre-launch test in
October 1975, Ceefax development culminated in January
1976 when the ready-for-market service was demonstrated
at an important teletext conference.
Yet Ceefax could
not hog the spotlight. At the same event was a teletext
service from the British Post Office called "Viewdata."
Adding fun to fray, the Independent Broadcasting
Authority (IBA) announced there that they would launch a
commercial teletext system named "Oracle." Three teams
with substantial resources were poised to play three-way
football.
Panic was quelled
among the contenders and reason prevailed. Influenced by
the TV set manufacturers association BREMA, the three
players negotiated a common protocol. They faced the job
and got it done. The 1974 "Broadcast Teletext
Specification" adopted in March 1976 established a level
technological playing field. From there, success depended
on the quality and reliability of competing services.
Terrestrial TV was ubiquitous in the UK by then.
Standardization let teletext become ubiquitous,
too
A teletext "page"
is transported in the VBI amid the top lines of each
video frame, encoded with a character generator. To
decode and display teletext pages on the screen, a home
viewers needs a teletext-enabled TV receiver set, or any
computer with a teletext board installed. The teletext
decoder memory stores page data, and viewers can "call
up" selected pages at will. "Text" users enter page
numbers using the keypad on a remote control. With
hundreds of pages being downloaded in a rotation in the
VBI, individual pages may load slowly when selected, but
teletext is information-on-demand, and there's nothing
like it in America.
Using the VBI to
transmit data is the same principle applied in the analog
form of Wink and ACTV, but the "look and feel" of
teletext is not like the multimedia graphics we associate
with the interactive TV or the Web. Teletext is
sans-serif block lettering in rows of words on the video
screen. Vivid colors help. But people love the "text"
despite its boxy look because it's useful, simple and
affordable. Where available, people take text for
granted.
.
The
UK Teletext Market
The United Kingdom
leads the world in teletext services. Scant households in
Britain are without a teletext-enabled TV set. All
analogue terrestrial channels in the UK broadcast,
satellite and cable service carry daily teletext content.
Commercial teletext ventures in the UK are licensed by
the Independent Television Commission (ITC) to meet a
national public service code, People routinely call up
favorite page numbers, like the morning news.
Teletext is
ubiquitous on terrestrial TV channel in the UK. Text is
found on the public BBC and the private commercial
networks (Channel 4, Channel 5, and ITV) all carry
teletext under the 1990 Broadcasting Act. The smaller
local and regional services carry some kind of text
because its routine in the marketplace.
The most evolved
teletext system in the UK, developed in the late
Seventies for the BBC is called Ceefax, sounds like "See
Facts." Produced by the BBC news and current affairs
divisions, Ceefax is a daily teletext magazine offering
TV program schedules, news headlines, sports scores,
weather, financial news and stock prices, airport and
train schedules, the local entertainment listings with
reviews, lottery results, recipes, special sections for
children, all manner of other useful information. Ceefax
reserves pages for BBC programs, e.g., background for a
documentary. Teletext news flashes overlaying the picture
may appear at the bottom of the screen. Ceefax use that
same area to display "subtitles," the service for the
hearing impaired also called "closed captioning" .
The Viewdata
teletext service from the Post Office was launched in
1979 as a trial service, "Prestel.' Rather than transmit
the signals within the VBI, however, Prestel presaged
modern online services because the data was transported
over plain old copper telephone wires. An adapter linked
the home phone to a decoder terminal attached to the TV.
Prestel may be the first real convergence of the
telephone and the television. Two problems plagues
Prestel. TV sets were not designed as display devices for
text. And most UK. households kept the phone in a
different room than the TV, for quiet, and the phone was
hard-wired to the wall outlet, Prestel customers had to
install wiring, damaging the value proposition.
Eventually, the Prestel was improved so it could be
accessed by home computers, but it was too little, too
late. Prestel had some usage in businesses, but it was
never widely adopted in homes. The Post Office had to
withdraw from the teletext business.
Ceefax and Oracle
teletext services were cost-effective for both
broadcasters and viewers, so their services survived. A
million teletext TV receivers were sold by 1984. The
Oracle text service endured into the Nineties on ITV and
Channel 4, and many fans would argue is virtues over
Ceefax in the local pub. Oracle had regional pages from
the outset, for instance, but Ceefax did not add regional
pages until the Nineties. Critics claim Oracle was a
victim of its own success, that internal politics and
management upheavals cost Oracle its ITV and C4
franchises.
Replacing Oracle
was a new commercial service, Teletext UK Limited,
co-opting the word as its brand. Conceived in 1991 to
take advantage of the apparent weakness at Oracle,
Teletext Ltd. was founded in 1992 by Media Ventures and
principal owner Associated Newspapers (Evening Standard
and Daily Mail). Philips had a stake, but sold out by
1998. Through intense and some say sly lobbying, Teletext
Ltd. won the ITC Public Teletext Service license and
commenced broadcasting on 1 January 1993, putting Oracle
out of business. ITC does not require Channel 4 to carry
text on its satellite signal, so Teletext is not
satellite C4, which instead carries its own branded
"4-Tel" teletext service. In contrast, Channel 5
broadcasts it main and ancillary text services on
satellite, despite no ITC satellite requirement. These
carriage choices can be debated. To carry or not to
carry? That is the question at the heart of the
business.
The BSkyB satellite
system, for instance, offers "SkyText" on the Sky One
channels with enhanced teletext variations on Sky News as
well as Sky's sports and movie channels. SkyDigital
delivers an expanded version of SkyText with more depth
in areas like sports and financial programming. Don't
seek TV schedules on SkyDigital, however, since such
content is in the electronic program guide (EPG) of the
"Open..." interactive TV service from OpenTV. Instead of
static TV listings on a screen, the EPG lets you preview
a show and go there with one click.
Some teletext
products and services are superior to others, as is true
in any trade, but text stays popular, and advertising
pays the bills. Flitting through pages of "text" is
routine around the globe, except America. Individual
teletext rituals are ingrained into the daily fabric of
millions of lives. 'The service is so popular, in fact,
that analog teletext-on-demand will not easily be
replaced by the new form of digital information-on-demand
over interactive TV.
.
Digital
Teletext
Because digital
television is being adopted worldwide, because lines of
video are about to be replaced by high-speed streams of
compressed video, voice and data. Teletext fans worldwide
must accept that the text they've known is doomed to
obsolescence.
The technology of
analogue teletext does not exist in digital television
(DTV). There are no vertical blanking intervals in a DTV
bitstream, just lines of pixel instructions without
breaks in a multiplexed flow. The receiver decodes the
signal into compact video lines under DVB or ATSC. Those
who got analog teletext can now get digital teletext on
the TV, but the text service looks more like a webpage,
nice text and graphics. Do not expect this overnight.
SkyDigital, for instance, still broadcasts its analog
SkyText text within its digital datastream pending the
launch of "Sky SuperText" at some as yet unspecified
future date.
For analog teletext
providers in the UK and elsewhere wanting to survive, the
core business for teletext remains sound. More than 22
million people now use Teletext Ltd. on a regular basis,
for example, supporting their advertising revenues. But
the playing field has altered, and so have the rules of
the game. There is no VBI in digital TV. Adapt or die.
Consider the
Multimedia Hypermedia Experts Group, which drafted an
open standard for the MHEG-5 language, used for coding
teletext services on DTT platforms. An object-oriented
language permitting pixel-by-pixel positioning of text
boxes and graphics, MHEG-5 works for writing teletext
with hyperlinks or hotspots, like headlines with links to
news stories, or TV listings with links to the show. MHEG
sets functions codes on a remote control, so buttons on
the remote would be standardized, too.
For any text
services going digital, as with the free analog TV
services, the goal of the game is selling advertising
that generates a direct response, best when delivering
emotional satisfaction that promotes brand loyalty.
Look at one market
strategy, Once again co-opting the name of the technology
for its brand name, the "Digital Teletext" service from
Teletext Ltd. is being broadcast on Channel 9 as a DTT
service providing free information 24 hours a day, begun
as a test transmission. Users receive Digital Teletext by
aerial, and they need a digital TV set or a set-top box
for their analog set. Users press "9" and then the "Text"
button on a remote control to access Digital Teletext
content, which includes national and local news, TV
listings, sport, weather, and film listings. Other
content is being added as demand warrants, based on
feedback.
Teletext has built
a profit center around holiday advertising as a popular
UK marketplace for hot travel bargains. Claiming 10
percent of the holidays being sold in the UK, Teletext
hopes to transfer their customer base to DTT and expand
it. With more bandwidth for broadcasting full-colour
graphics, advertisers can trademark their sponsored pages
with more attractive logos, bolstering their brands.
Cleaner lettering, means more room for advertising copy
on digital teletext. In terms of interactive TV, Digital
Teletext can deliver interactive advertising with
hyperlinks to other media. Promises Teletext's
literature, "The enhancements of Digital Teletext will
encourage viewers to not only look at but also respond to
an even greater number of advertisements."
The BBC Ceefax
service is undergoing transformation for digital
television, too. Ceefax initially was to be renamed "BBC
Text," but lately the brand is "BBC Inform." BBC digital
text service sends pictures and graphics using MHEG-5 for
multimedia and hyperlinked content, breaking ground by
mixing still images with video from BBC channels.
Compatibility with the new digital terrestrial television
technology explains why BBC Inform is being launched
first through the ONdigital terrestrial service. Next in
line is BBC Inform on the SkyDigital service, then
digital cable services like NTL. BBC wants to be
ubiquitous.
Critics of BBC
Inform complain current test transmissions are slower
than Ceefax, and accessible only to viewers with Philips
boxes. They especially dislike having to navigate though
a menu because there are no page numbers anymore. This
contrasts with the Digital Teletext test transmissions
with both menu navigation menus and page numbers. BBC
Inform and Digital Teletext both apply MHEG-5 in text
authoring, but there is not yet a universal national or
international standard for a teletext user interface.
The business case
for teletext remains valid. World demand for teletext is
strong is will not fade soon. When text is just another
fish in the broadband stream, though, when information on
a TV or PC screen is a click away, the value proposition
for network operators centers on their choices in content
carriage. (To carry content likely to build reliable
revenues, I say, transport content that grows and matures
the marketplace along the way,)
Just like digital
TV generally, the home equipment needed to receive
digital teletext varies with the local source of the
digital signals. Regardless of the media delivery system
for the digital TV signal, once a digital reception
system is in place, it does not matter whether the
display screen is a cathode ray tube or a flat-panel
plasma monitor. It does not matter whether the DTV source
signal contains video, data or graphics. Bits are bits.
Whatever the signal origination, if the receiver has a
digital teletext decoder, that's all it takes to receive
digital teletext.
.
Teletext
Meets the Web
Notice how teletext
gained popularity throughout the world decades before
anyone had ever heard about the Internet or the World
Wide Web.
People ask Robert
Hardy why they have to wait so long for teletext pages to
load. A teletext enthusiast who works in the iTV
industry, his UK Teletext website independently tracks
teletext industry developments. He champions teletext
over the Web. "Actually, in my experience, it's a lot
faster and cheaper to flick to the football page on
teletext than it is to boot up, log on, open a browser
and load a webpage. I suspect that in the UK, at least,
more people use teletext for fast access to daily
information than use the World Wide Wait."
"I think the
Internet is vastly over-rated in what it offers." Hartly
said. "What annoys me the most is the way some US
companies, notably Microsoft's WebTV, give the impression
they've invented 'interactive TV', when all they're doing
is broadcasting web pages in the VBI instead of teletext
pages. In my view, this is no more interactive than
choosing which page to read in the newspaper."
Yet the public
clamor centers on the Internet. Teletext services have
responded to the Web by upgrading their own look and
feel, making their teletext pages more weblike with
sharper type and some graphic images.. "HighText" level 2
was developed for more colours and smoother graphics.
European broadcasters using High Text include Arte, ARD,
ZDF and 3sat.
"In the UK, TV
manufacturers and teletext providers have both ignored it
[High Text] in a chicken-and-egg scenario. You
see, if the teletext providers used all of its extra
features, it'd slow down the service. The BBC
experimented with High Text level 2.5 a few years ago, he
added, and Teletext Ltd. also flirted with it, but both
services are concentrating on digital teletext instead.
Now that digital terrestrial has launched in the UK, it
looks unlikely that the broadcasters will invest anything
into updating the analogue teletext services."
A technical fix is
to add memory to the text decoder, so more pages may be
cached, making it possible to flick quickly through most
or all of the pages after a minute or two of loading.
Adding memory works best for a computer with a TV tuner
cards. Said Hardy, "I've seen so-called 'instantext' TV
sets advertised, which are teletext TVs with more memory
that claim to cache 100 pages. This is still nothing
compared to a computer."
Another option is
offering teletext on the Web. "It strikes me as strange."
said hardy, "that newspapers are widespread online, but
none of the main UK teletext services, which are
transported in electronic form, are available on the
Web,. You'd be able to save and print pages. A massive
archive of every page ever broadcast could be created.
Technically, putting teletext on the Web is easy,
Conversely, why look for information on a teletext
gateway that is likely to be on the Web in other,
prettier and more accessible forms, such as lottery or
horse racing results, or flight arrivals."
UK teletext
services with websites are wise enough not to let their
content go to waste. The BBC, for instance, repurposes
the Ceefax weather service for BBC Online, but the
popular Ceefax "TV Links" with program details is not
published on the BBC website. There are no Ceefax-branded
webpages at all on BBC Online. The Teletext Ltd. website,
however, has images of the text feeds, ranging from news
headlines to weather to holiday offers, ported to the web
verbatim when possible, but in a nicer
format..
A taste of web-like
interactivity is an individualized teletext page, a
service chiefly from SysMedia as well as SkyText's
interactive sector. Dialing a commercial phone number,
usually a premium toll call, a person is given a personal
teletext page. Afterwards, one can dial in and use the
phone keypad to select teletext pages. This is viable for
games or pay-per-view information resources, such as
locating a new automobile. Bank customers can securely
view their account transactions over teletext. Critics
call it a last-gasp stop-gap.
"The computer press
likes to bash teletext," retorts Hardy. "They like to
brand teletext as 'defunct' because of its looks. This is
in spite of the facts that more than 20 million people
use teletext every week in the UK, that text needs no
technical expertise by the users, that it's free of all
subscription and phone charges. True, it looks like crap.
But the thing is, most people don't care. The majority of
text users just don't notice its limitations." 
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