[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 
fast enough.

"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-
range applications.

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 
fatal errors?


The medium is the message...The content is the audience...;)

Luc Leblanc VE2DWE
Skype VE2DWE

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