Wireless
HDTV
by
Ken
Freed.
.
IBM
and MediaTek join forces for Wireless HDTV
chipset
as diverse standards initiatives move
forward.
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Advocates
of wireless HDTV continue moving toward their goal of
in-home microwave networks capable of transmitting DTV
video and audio at high speeds.
As a step in that
direction, IBM and MediaTek have launched a joint
research and development initiative to create ultra-fast
chipsets that can wirelessly transmit full-length movies
and other HD content to and from a home computer,
hand-held device, retail kiosk, or television
set.
In tandem with this
initiative, several wireless standard-setting projects
are moving ahead. Will these diverse wireless standards
be compatible? Also, questions remain about the health
risks of wireless technologies.
Leading the chipset
development drive for IBM are experts at the T.J. Watson
Research Center. Established in 1961, the Watson Research
Center is based in Westchester County, New York, and
Cambridge, Massachusetts, with almost 1,800 people
staffing four facilities.
"We are developing
bipolar 60 GHz silicon-germanium chipsets that combine
with regular CMOS transistor technology to transmit and
receive HD wireless signals," said Mehmet Soyuer, group
manager of the wireless and wireline communications
technology department at the Watson labs.
Silicon-germanium
(SiGe) chips can be integrated with CMOS logic to form
heterojunction bipolar transistors. A bipolar junction
transistor usually has three semiconductor terminals used
to amplify or switch signals. The transistors are called
"bipolar" because they use both electrons and "holes,"
that is, is the absence of an electron from the otherwise
full valence band, affecting the speed of the carrier
signal. Heterojunction bipolar transistors offer higher
forward gain and lower reverse gain than homojunction
bipolar transistors, which yields better low current and
high frequency performance, making SiGe a viable choice
for the mixed-signal circuits needed in HDTV.
Soyuer added that
the SiGe transmit and receive chips in the chipset each
will be about 1.5 x 2 mm in size. Each will drive a
semiconductor antenna of close to the same dimensions. A
downversion mixer in the chipset will lock the signal
loop. "Since the 60 MHz wavelength is very short, we'll
be able to implement two low-gain 60 MHz antennas into
the chipsets with a range of five to ten meters. This is
why chipset applications may include uncompressed HD
video."
The Watson Research
Center will develop all elements of the chipset except
the baseband chips, "Which we don't do," said Soyuer. The
baseband chips will come from MediaTek, headquartered in
Taiwan with subsidiaries in Mainland China, India, Korea,
Singapore, and Silicon Valley, California.
Development will
not be overnight, however. Soyuer said he expects the
chipset to be ready for consumer electronic devices by
2010 or 2011.
This timing means
the chipset will enter the market after most of the
wireless standards setting projects have offered their
specifications for ratification.
Soyuer said the IBM
chipset is meant to comply with the specification slated
for release in 2008 by the IEEE 802.16.cc Working Group,
"which is targeting 60 GHz applications, including HD
video transfer at both1080i and 1080p. It's going to take
awhile for these types of products to ramp up to high
volume, so I don't think there's going to be any wireless
HD products in the marketplace by 2010, but if there are,
the manufacturers still could upgrade to our
chipset."
A specification for
wireless HDTV is just one of the 50 projects now in
development by the IEEE 802 LAN MAN Standards Committees,
said Paul Nikolich, chair of the iEEE 802 LMSC, which
coordinates the efforts of more than 1300
people.
Or example, the 802
.11 wireless local area network (LAN) working group
includes a study of video streaming throughput at rates
up to 1 GB/s, Nikolich said. The 802.15 wireless working
group is concentrating on the 60 GHz physical layer with
data rates up to 1 GB/s. Another group is tasked with
audio-video bridging and related architecture.
Yet IEEE is not the
only one playing in the wireless sandbox.
The Israeli company
Amimon is leading a drive to promote WHDI (Wireless High
Definition Interface), which seeks to establish a 60 GHz
wireless standard capable of delivering uncompressed HD
video and audio across an effective range of 100 to 150
feet from source like a PC or DVD player to any display,
such as a flat panel screen.
"We demonstrated
WHDI solutions at CES as well as at shows in Japan and
Germany, said Noam Geri, Amimon co-founder and vice
president of marketing and business development. "The key
is that WHDI uses a video modem approach as opposed to
the data modem approach at the center of the IEEE effort.
As a result, we've already shipped chipsets to some
leading CE manufacturers for products that will be on the
shelves by early 2008."
Geri declined to
list the CE manufacturers incorporating WHDI into their
products, but did not deny that Motorola may use WHDI in
their cable set-tip boxes.
"We're not really
competing with any other wireless standards," said Geri.
"We see our efforts as complementary."
Among those Amimon
supposedly complements is the 60 GHz standard now being
developed by the WirelessHD consortium, which consists of
LG, Samsung, Sony, Toshiba, and Matsushita (Panasonic and
SiBEAM).
WirelessHD chair
John Marshall said using the unlicensed 60GHz frequency
band means no interference with other household devices
that typically operate in the 2-6GHz range. The
WirelessHD specification, expected to be released by the
end of 2007, will enable HD video streaming over
distances of up to 32 feet without the need for
line-of-sight connection, as with IR remotes.
Marshall said he's
not concerned about consumer protection activists who
claim that wireless technology poses a health hazard in
the home. "The FCC wanted to conduct a study of how 60
GHz ineracted with the human body. They found that for
the most part, 60 GHZ signals reflect off water, and
since the human body is mostly water, the signals will
not penetrate tissue. There's a white paper at the SiBEAM
website to support all this."
The main thing,
Marshall said, "is that the industry is now looking at a
major technology breakthrough with chips smaller than my
fingernail that will deliver HDTV without a tangle of
cables in the home. That's historic."
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