[opendtv] The next big thing in wireless
- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
- To: "OpenDTV (E-mail)" <opendtv@xxxxxxxxxxxxx>
- Date: Tue, 7 Dec 2004 18:20:58 -0500
Here are two short articles with interesting contrast.
BTW, in the current issue of the IEEE Communications
Magazine is a series of articles on MIMO wireless
systems (multiple in, multiple out, otherwise known
as space time codes). IEEE 802.16a (WiMAX) includes
MIMO and COFDM in its wireless interface, which
stretches its spectral efficiency right up close to
the Shannon limit. WiMAX uses multiple channel
bandwidths, from 1.5 MHz to 20 MHz, but possibly more
depending what the frequency band allows. The receiver
sensitivity spec is interestingly not very remarkable.
For a familiar combination, 64-QAM, 3/4 FEC, 6 MHz
channel, the required sensitivity is -70 dBm.
Nothing spectacular. ATSC I think uses -85 dBm as
a planning factor, at the same spectral efficiency.
WiMAX uses the basic convolutional and Reed-Solomon
concatenated FEC, same as DTT systems, but
optionally allows turbo block codes vs. RS.
In one example cited in one of the IEEE magazine
articles, it seems to exceed the Shannon limit,
but this must be only because they are accepting a
significant error rate in that example.
Also BTW, MIMO can consist of multiple transmitting
antennas and multiple receive antennas, all sending
and receiving the same information bit stream
(perhaps arranged in different order from each
antenna). However, its full potential is achieved
when the multiple transmit antennas send different
parallel bit streams, over the same RF channel, and
the receiver with equal number of receive antennas
recombines these into one high speed bit stream.
Fancy stuff.
Bert
-----------------------------------
WiMAX to be 'clear winner' in broadband wireless
John Walko
Dec 07, 2004 (7:19 AM)
URL: http://www.commsdesign.com/showArticle.jhtml?articleID=3D55300022
LONDON - WiMAX and other emerging high-speed wireless
technologies will capture more than 40 percent of the
wireless broadband business over the next few years,
leaving 3G with less than 60 percent of the market in
2009, according to a just published report from
TelecomView.
The report suggests the new technologies provide
significant opportunities for both incumbent and
competitive carriers.
"Our forecasts show that WiMAX will be the clear
winner amongst the new high-speed wireless
technologies," said Ian Cox, principal analyst at
TelecomView and co-author of the report. "WiMAX will
pick up 70 percent of this new market segment by 2009
due to its higher performance and flexibility
compared to the alternatives. 3G will be important for
its mobility, but WiMAX will directly compete with
DSL." The report, which covers deployments, regulatory
issues and analyses of the business case for both
urban and rural areas, suggests that the return on
investment (ROI) for these new wireless broadband
technologies is significantly better than for 3G.
According to Bob Larribeau, the other author of the
study and also a principal analyst at TelecomView,
said: "In fact, the business case for WiMAX, in
particular, is close to that for wireline DSL, which
makes it an excellent broadband technology
alternative."
Copyright 2003 CMP Media
---------------------------------------
Sprint spends $3 billion to upgrade mobile network
John Walko
Dec 07, 2004 (11:13 AM)
URL: http://www.commsdesign.com/showArticle.jhtml?articleID=3D55300094
LONDON - Sprint Corp. is extending its supply
agreements with Lucent Technologies, Nortel and
Motorola in an upgrade of its cellular network
valued at $3 billion over the next three years, the
operator said Tuesday (December 7th).
Lucent said its deals for base station gear for third
generation network based on CDMA2000 1xEV-DO
technology and IP Multimedia Subsystems should be
worth over $1.5 billion over the three years.
Nortel puts the value of its contracts for CDMA 1X
basestations, controllers and switching platforms at
$1 billion, while Motorola suggests its share of the
extension to the PCS network extension is worth $450
million.
Sprint said in June it would add EV-DO capabilities
to its network in major metropolitan areas in 2005.
The company said this portion of the upgrade would
cost $1 billion, with the majority being spent in
2005.
The $3 billion also includes options for 1xEV-DV
Release D broadband speed upgrades, with all three
manufacturers saying they are in the running to
supply gear for this extension.
Copyright 2003 CMP Media
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