[opendtv] Multi-band TV receiver and DVB-H
- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
- To: "OpenDTV (E-mail)" <opendtv@xxxxxxxxxxxxx>
- Date: Wed, 26 May 2004 12:05:45 -0400
Interesting article. Since DVB-H is transmitted over separate channels
from DTT, no reason why it can't be deployed here as easily as it can
be in Europe.
BTW, check this out too:
http://www.xceive.com/products.html
A startup produces a single-chip receiver for ATSC *and* DVB-T,
not to mention NTSC, PAL, SECAM, ISDB, n-QAM and DOCSIS, and
DVB-C, and all for $9.95, according to EE Times. (I didn't
find the Xceive article in EE Times in electronic form yet.)
--------------------------------------------------------
Europe seizes lead in on-the-go TV
By Junko Yoshida , EE Times
May 24, 2004 (2:55 PM EDT)
URL: http://www.eet.com/article/showArticle.jhtml?articleId=3D20900259
PARIS - The futuristic notion of watching TV on a cell phone or iPod,
or in cars or high-speed trains, is no longer so farfetched. Europe's
homegrown specification for mobile digital video broadcast, DVB-H
(for "handheld"), is already in field trials, and commercial services
are scheduled to go live in 2005.
Most carriers and industry analysts in the United States remain
dubious about mobile TV, and openly wonder if anyone would watch.
Allen Nogee, principal analyst for wireless technology at In-Stat/MDR,
questioned not only consumer interest but also whether "carriers even
want this, especially [using] a form that transmits over the air"
instead of via their own cellular networks.
Europeans think otherwise. Rather than add only an existing analog or
digital TV tuner to mobile handsets, they are creating a converged
platform built on a 2.5G/3G cellular network and a digital
terrestrial TV broadcast infrastructure. Europe, which led the world
mobile-communication revolution with the GSM standard, believes it
has now devised a winning formula for the next stage by marrying
DVB-H with Internet Protocol (IP) datacasting.
DVB-H promises to deliver multimedia content"encapsulated in IP packets
"by means of terrestrial digital TV to large audiences at low cost,
without clogging a cellular network. Proponents say the spec creates
opportunities for mobile operators, through their billing mechanisms,
to carry and charge for the new broadcast services.
"Sixty thousand people in a soccer stadium, for example, will be able
to see an instant playback of a goal scored, broadcast by DVB-H, on
their mobile phones," without shorting out an entire cellular network,
said Ulrich Reimers, professor at the Technical University of
Braunschweig, Germany. The network platform is designed to decide
intelligently between a terrestrial DTV network and a mobile net to
deliver the soccer highlight to each DVB-H terminal.
Many chip vendors and consumer systems houses hungry for the next big
thing are already putting their money on DVB-H. Philips Semiconductors,
for example, makes no secret of its efforts to develop a low-power
silicon tuner, low-power channel decoder and low-power baseband decoder
optimized for handheld TV applications.
"TV has been migrating into a number of consumer products," said Steve
Turner, business development manager responsible for Europe at Philips
Semiconductors. "TV will become a significant feature in a major mass
consumer device"which obviously is a mobile phone."
STMicroelectronics, meanwhile, is transferring Nomadik processor cores,
originally developed by its mobile-phone group, to portable set-top-box
applications. For ST, TV-on-mobile extends to in-car applications and
to gadgets such as iPod-style MP3 players, said Chris Carter, marketing
manager of the satellite and terrestrial business at ST's set-top
division.
Xceive Corp., a Silicon Valley startup developing RF-to-baseband
receiver ICs, this week will announce a complete silicon tuner for
ultrasmall analog and digital terrestrial and cable receivers. "Within
the next five years, TV will become a commonly accepted feature on
mobile handsets," said Jordan Du Val, vice president of sales and
marketing at Xceive, just as a camera is now integral to many
handsets.
Cell phone giant Nokia, meanwhile, has developed a device called the
Nokia Streamer, billing it as the first mobile IP datacast receiver.
It will attach, like a battery pack, to the Nokia 7700 media phone.
That combination will get a trial for video broadcast to mobile
devices in Berlin and in Helsinki, Finland.
Not all U.S. cellular operators dismiss the idea out of hand. Sprint
Corp. has launched a subscription-based service, MobiTV, beaming a
live television program in a continuous stream, although only at a
few frames per second, using a CDMA 1X network.
MobiTV "is a fantastic idea, but they are using the wrong
technology," said Jukka Henriksson, research fellow at Nokia Research
Center. Henriksson is chairman of the ad hoc technical module
responsible for developing the DVB-H specifications at the DVB Project,
an industry-led consortium designing global standards for digital
television and data services.
Instead of resorting to cellular networks, DVB-H applies an improved
version of the radio spec in the DVB-T (terrestrial) standard to deliver
TV programs as IP data packets to low-power handhelds. The DVB-H spec
is specifically aimed at lower-power TV reception with a high-speed
mobility feature.
"With DVB-H, telecom operators, for the first time, can offer something
consumers already know about; they know what it is and how to use it,"
said Ari Beilinson, director of business development at Nokia Ventures.
According to Nokia, most of those who watch up to 2.5 hours of TV daily
also use mobile phones about 10 minutes a day. "We just want to give
the possibility for them to spend 10 minutes of their TV-viewing time
on a mobile handset," said Beilinson. If the average tube-watching
phone owner tunes in for 10 minutes of handset TV every day, it would
instantly double mobile-phone usage time, he added. "This is a goal
easily achievable."
It's unclear if DVB-H will remain strictly a European phenomenon.
"Certainly some regions of the world potentially have a better chance
at this [mobile TV] than others," In-Stat/MDR's Nogee said. "In areas
where public-transportation commutes are long, it's a possibility."
He argued, however, that "LCD portable TVs have been around for years,
and I have never seen a large use of these products."
Nonetheless, "Nothing stops U.S. operators from embracing DVB-H,"
said ST's Carter, noting the absence of a mobile TV spec that can
compete with DVB-H in the United States. DVB-H, in fact, is coming to
the U.S. market this year in a trial led by Crown Castle, a company
that delivers turnkey infrastructure and network services to
broadcasters and wireless operators. Crown Castle is quietly launching
the three-site Single Frequency Network in Pittsburgh using DVB-H
technology.
Because of the flexible network infrastructure designs DVB-H allows,
it's possible to multiplex DVB-H services in an existing terrestrial
digital TV network based on DVB-T. It's possible, too, to launch DVB-H
services on a newly dedicated DVB-H network, independent of a
terrestrial DTV network. In a DVB-H rollout, U.S. carriers would not
have to use ATSC, the U.S. terrestrial digital TV standard, whose
vestigial-sideband (VSB) modulation scheme is considered unfit for
mobile-TV transmission.
European industry leaders have long toyed with the idea of offering
mobile applications via DVB-T, claiming the orthogonal
frequency-division multiplexing it uses is more inherently resistant
to multipath and fading problems than ATSC's 8-VSB and thus is ideal
for mobile use. The DVB Project, however, has concluded that DVB-T
"does not do the job" for mobile, according to Nokia's Henriksson.
Power consumption was the main problem.
To develop DVB-H, the DVB Project introduced features, modifications
and options to DVB-T's technical specifications, seeking lower power,
more robust mobility and better quality-of-service in portable-TV
reception. Among the key optimizations are time slicing and
multiprotocol-encapsulation forward error correction (MPE-FEC).
Time slicing, which is required in DVB-H, transmits information to a
portable device by organizing data in 1- to 2-Mbit bursts, making it
possible to "switch off the radio for a majority of the time" between
slices, said Philips' Turner. The DVB group claims that time slicing
can achieve a power savings of up to 90 percent in video streaming.
The target is to enable the DVB-H delivery chain"including tuner,
channel decoder and back-end processing"at less than 100 milliamps,
Turner said. In comparison, today's DVB-T requires 500 to 800 mA, he
added.
The DVB-H spec also offers additional error correction, MPE-FEC, for
improving mobile performance and tolerance to impulse noises. "You
need to add another layer of extra error correction for much more
robust signals for portable reception," said Turner. A rooftop
antenna designed for DVB-T-based TV sets, for example, can easily
pick up primary TV signals without interference from signals coming
in over the next channel or from reflecting signals, Turner said.
On the other hand, a mobile TV receiver zooming down the autobahn or
on a train whizzing by at 300 to 400 km/hour must pick up signals
from multiple sources while staying connected.
Another optional feature in DVB-H's physical layer is the so-called
4k mode and 4k symbol interleaver for air interface enhancement.
(Strictly speaking, "4k" means a 4,000-point fast Fourier transform,
but in TV jargon it stands for the modulation scheme.) Nokia's
Henriksson said DVB-H's flexible network architecture "offers a lot
of options including 2k, 4k and 8k mode." In the 4k mode, mobility
doubles over the 8k, he said. Use of 4k also allows a doubling in
the maximum single-frequency network size over what's possible with
2k. If more robust demodulation is needed, operators can use
quadrature phase shift keying. An option for 16QAM or 64QAM
modulation is also available, Henriksson said.
The spec's new Transmission Parameter Signaling bits, meanwhile, can
tell mobile devices that an incoming signal is DVB-H and if it's
using MPE-FEC. This ensures faster signal acquisition and better
support for handover, the developers say.
In designing DVB-H handsets, phone manufacturers might share a
"display, battery, battery charger, user interface and audio/video
decoder" with other designs, said Bill Krenik, wireless-advanced-
architecture manager at Texas Instruments Inc. "But the commonality
stops there. One needs to integrate a DVB-H tuner and a channel
decoder." Two radios are mandatory so that TV broadcasts can be
interrupted for incoming phone calls.
Krenik predicted a higher demand for a signal-processing chain in
DVB-H-based mobiles than with other handset types. He also pointed
out that DVB-H will be the first mobile technology in which
performance differences on handsets "will be very apparent to
users." Two users could easily compare TV picture quality on their
handsets by standing side by side.
Copyright =A9 2003 CMP Media
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