[amsat-bb] WI-FI already migrating on 5ghz
Luc Leblanc VE2DWE
lucleblanc6 at videotron.ca
Thu Sep 7 19:55:30 PDT 2006
What they are telling us about 2.4 and 5GHZ wi-fi system in a few minutes searching. It is not
rigorously mathematics and statiscally not rigorous but ALL the actual and past commenting forecast
a move towards 5 ghz. Wireless phone at 2.4 are at less that 25$ et some manucturers does not
produce them anymore!
Excerpt from the internet.
When vendors began work on 802.11a, they did not want to stay in the 2.4-GHz range used with
802.11b products. The spectrum at 2.4 GHz is a shared frequency, so devices like cordless
telephones and microwave ovens can create interference problems. Also, the vendors are able to
squeeze out only about five channels -- or simultaneous user connections -- in this range, which
relies on direct-sequence spread-spectrum technology, a signaling technique that places a premium
on security and reliability while sacrificing efficient use of available bandwidth.
Keeping to Themselves
In the late 1990s, the Federal Communications Commission Latest News about Federal Communications
Commission opened up a new frequency range -- the 5-GHz range -- that is only available for
wireless LANs, so there is no outside interference. Also, it uses orthogonal frequency division
multiplexing for modulation, which increases bandwidth efficiency so an access point can support
about 10 simultaneous connections.
By Paul Korzeniowski
01/28/04 5:00 AM PT
With multiple formats available, Grewe said it's difficult to predict which technologies customers
will demand. Multiband components are complicated, requiring two complete radio systems to send
data over either frequency, but the result is a chip that works in any wireless system.
Grewe expects faster wireless networking systems to take off in late 2003. One scenario calls for a
broadband connection to a home media hub, which could distribute TV signals, digital audio, gaming
and other entertainment wirelessly throughout the house.
With high-definition TV signals requiring nearly 20 Mbps of bandwidth, 802.11b's 11 Mbps won't be
"We think home multimedia will be a big application (for faster wireless networking systems), but
we don't expect to see that really happen until 2004 or 2005," Grewe said.
One reason: Need for a 54-Mbps wireless connection hardly exists when today's DSL and cable modem
connections rarely pull data at speeds faster than 11 Mbps.
"People tend to forget that faster home networking is going to require faster broadband pipes to
deliver content to the home," said Kim.
But 802.11a offers at least one advantage right now: more radio channels.
"Using more channels is like having more lanes on the freeway," said Robert Fan, a representative
for Resonext Communications. "It means 802.11a gives you the capacity to support more users at the
same time," important on networks in schools, large businesses and public places.
By Will Wade| Also by this reporter
02:00 AM Nov, 21, 2002
Bellanet Sandbox 2004
Higher frequency 5GHz band seems to be a more promising platform for deploying higher speed 54Mbps
and up WiFi infrastructure. WiFi equipment in this band incorporates two additional features into
the IEEE 802.11a standard (WiFi standard), namely, dynamic channel selection and transmit power
control. Dynamic channel selection improves the ability to coexist with other user of the 5GHz
bands as devices may select channels based on real-time feedback. Transmit power control is used in
selecting lower-powered channel for short-range applications or higher-powered channel for long-
Although, 5GHz band deployment has not been reviewed in this book. The deployment method is fairly
similar to the 2.4GHz band. Quite a bit of 5GHz implementation has been done in the developing
countries. Some use it as the long-haul backbone infrastructure. In dense area, some use 5GHz WiFi
infrastructure for last mile access infrastructure.
by Lisa Phifer, VP, Core Competence
20 Feb 2003
Although 802.11a is by no means immune to interference, it's likely to encounter less interference
simply because of the 5 GHz frequencies on which it broadcasts. The reason? The 5 GHz band is
shared by far fewer devices than the 2.4 GHz band used by 802.11b/g.
Why AMSAT should be always 180 degres off phase with the real world...They are not only want us
believe they scarp S mode only for technical reasons. If they work in a so close relation with
AMSAT-DL folks why they don't convince them to scrap their S band in a way to avoid them costly and
The medium is the message...The content is the audience...;)
Luc Leblanc VE2DWE
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