MIMO

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Has anybody any experience with MIMO products? Do they, in fact, increase
speed and range as claimed? Is it also the case in a mixed network with both
802.11g and MIMO products?
Thanks!
Knud



Re: MIMO



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Absolutely no difference whatsoever.  It's a SALES term used to make people
think it will be better.  People replacing badly configured or
malfunctioning equipment will say it is better, but they would say that no
matter what they plugged in to correct the problems!
In a test side by side there was NO difference, people that sell often lie
and take out huge campaigns in the hope that people will fall for
advertising.
Nothing will increase speed beyone the limitations of the wireless
specification.  The only thing that increases range is more power, high
gain/directional aerial or different arrangemet of aerials to increase the
signal in one or two directions.
A bit of software can't do anything to RF power or radiation patterns,
unless it was to have a number of aerials and transmit in the direction of
best reception, which would slow the router down severely.



Re: MIMO


:
: > Has anybody any experience with MIMO products? Do they, in fact, increase
: > speed and range as claimed? Is it also the case in a mixed network with
: > both 802.11g and MIMO products?
: > Thanks!
: > Knud
: >
: >
: Absolutely no difference whatsoever.  It's a SALES term used to make people
: think it will be better.  People replacing badly configured or
: malfunctioning equipment will say it is better, but they would say that no
: matter what they plugged in to correct the problems!
: In a test side by side there was NO difference, people that sell often lie
: and take out huge campaigns in the hope that people will fall for
: advertising.
: Nothing will increase speed beyone the limitations of the wireless
: specification.  The only thing that increases range is more power, high
: gain/directional aerial or different arrangemet of aerials to increase the
: signal in one or two directions.
: A bit of software can't do anything to RF power or radiation patterns,
: unless it was to have a number of aerials and transmit in the direction of
: best reception, which would slow the router down severely.

That answer is bullshit and should be ignored. MIMO software doesn't claim to
"do anything to RF power or radiation patterns"; it simply exploits the way
the radiation patterns behave in response to the conditions that prevail in a
given transmission path. It has been shown to have some positive effect by
people more knowledgeable in such things than any of us probably are.

That said, there are certainly factors that limit the effectiveness of MIMO.
The most obvious is that the access point and the computer's wireless
interface are designed to work together, so you have to buy a particular
manufacturer's wireless card to get the benefit. And MIMO technology is in its
infancy and therefore poorly understood. A particular design may work well
under some conditions and provide no benefit whatever under others.

I've bought a few MIMO routers, but only because they support channel hopping,
while competing non-MIMO routers in the same price range don't (or didn't at
the time).

Re: MIMO



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Review of various MIMO products:
  http://www.pcmag.com/article2/0,1895,1822495,00.asp
  http://www.tomsnetworking.com/2005/11/28/mimo_face /

Comparison of MIMO versus beam forming technology with test results:
  http://www.antennasonline.com/ast_newsletter_11-05.htm#why

Also:

http://groups.google.com/group/alt.internet.wireless/msg/11a8efd2638d674b?fwc=1

802.11n (MIMO) draft standard tests:
  http://www.tomsnetworking.com/2006/06/01/draft_11n_revealed_part1 /

--
Jeff Liebermann     jeffl@comix.santa-cruz.ca.us
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Re: MIMO


og54 wrote:
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Yea, Ian is a dolt.

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