[MLB-WIRELESS] The Age Technology article

Steven Haigh netwiz at optusnet.com.au
Sat Nov 16 14:55:01 EST 2002


Is there any difference in bandwidth (ie channel width) of the 802.11b+
equipment? or is the speed increase only due to the PBCC modulation?

Also, something else you might be able to clear up for me... the upcoming
802.11g, is it true that there will only be 1 channel available due to the
extremely wide bandwidth of this standard? If so, I can see it possibly
causing issues in the future with b/b+ clients.....

Signed,
Steven Haigh
http://wireless.org.au
(Visit https://wireless.org.au to install our Root Certificate.)


----- Original Message -----
From: <Michael_Florence at dlink.com.au>
Cc: "melbourne wireless" <melbwireless at wireless.org.au>;
<syd-wireless at lists.sydneywireless.com>
Sent: Saturday, November 16, 2002 4:31 PM
Subject: Re: [MLB-WIRELESS] The Age Technology article


>
>
> Hi Matt.
>
> Hope my email clears it up.
>
> The original 802.11 standard used 2.4Ghz and Direct Sequence Spread
Spectrum
> Modulation (DSSS) or Frequency Hopping Spread Spectrum Modulation (FHSS).
Both
> of which have been used as modulation schemes by military for decades.
Speed was
> 1 or 2Mbps and even included infra red!
>
> The amended 802.11 standard, 802.11b, uses 2.4Ghz and standardised on the
Direct
> Sequence Spread Spectrum Modulation (DSSS). Link speed is 11Mbps
>
> 802.11a uses 5Ghz and Orthogonal Frequency Division Multiplexing
Modulation
> (OFDM) Link speed is 54Mbps. OFDM is a more complex and newer modulation
scheme
> than DSSS or FHSS, thus the speed.
>
> 802.11g is designed to use 2.4Ghz standard OFDM modulation to run at
54Mbps.
> 2.4Ghz is chosen so that there is an ability to be backwards compatible
with
> 802.11b due to it's wide installation. For example D-Link worldwide has
sold
> over 25 million wireless products with thw majority of those being
802.11b.
>
> Texas Instruments developed PBCC Modulation so that they could run at 22MB
on an
> 802.11b network. D-Link uses their chipset in their AirPlus range. Thus
the
> commonly referred "802.11b+" product. Obviously these devices can only
"talk" to
> others running the same modulation scheme, so therefore can only run in
802.11b
> mode with DSSS modulation (standard 802.11b) or "802.11b+" mode in PBCC
> modulation (enhanced 802.11b). Oh and guess what? PBCC is an option for
802.11g
> standard so can you see what Texas Instruments are trying to do here?
>
> The AirPlus product is popular because it offers twice the speed of
standard
> 11MB (and twice the WEP encryption), while maintaining the range advantage
of
> 2.4Ghz 802.11b. at over 15 metres AirPlus is around the same speed as
802.11a,
> due to the high propagation loss inherent in higher frequencies such as
5Ghz
> 802.11a.
>
> Hope this helps,
>
> Michael Florence
> michael at dlink.com.au
>
>
>
>
>
>
>
>
> "Dave Keller" <david at bay.net.au> on 16/11/2002 08:56:08 AM
>
>
>
>
>
>
>
>
>  To:      "melbourne wireless" <melbwireless at wireless.org.au>
>
>  cc:      (bcc: Michael Florence/Sales/DLINK-AUST)
>
>
>
>  Subject: Re: [MLB-WIRELESS] The Age Technology article
>
>
>
>
>
>
>
>
> Similar to the 56k modem standards, their was the same battle between two
> different methods to get the higher speed connections. While the IEEE were
> off having their little infighting trying to decide which standard to
use..
> Texas Instruments had their standard, based on PBCC, which is sometimes
> called 802.11b+ which is sort of backward compatible with 802.11b. If they
> cant talk at "802.11b+" they just start talking 802.11b.
>
>
http://geelong.wireless.org.au/modules.php?name=News&file=article&sid=4&mode
> =&order=0&thold=0
>
> Ciao,
> Dave.
>
> ----- Original Message -----
> From: "Matt Pearce" <mattpearce at optusnet.com.au>
> To: "melbourne wireless" <melbwireless at wireless.org.au>
> Sent: Friday, November 15, 2002 7:43 PM
> Subject: [MLB-WIRELESS] The Age Technology article
>
>
> > Hey all,
> >
> > Just read this interesting little article in the age, it claims that
> 802.11g
> > is a 20mb connection and is compatible with 802.11b, correct me if I am
> > wrong but I though that the 20mb connection was used by people such as
> > D-Link and was not actually a ratified standard.  I also thought that it
> is
> > only compatible when it drops back to 11mb speeds.  And I also thought
> that
> > 802.11g is 54mb connection on 2.4G ??
> >
> > Anyone care to correct me or is this reporter correct ??  See the link
> below
> > for the full article.
> >
> > http://www.theage.com.au/articles/2002/11/09/1036308526730.html
> >
> > Matt.
> >
> >
> >
> > To unsubscribe: send mail to majordomo at wireless.org.au
> > with "unsubscribe melbwireless" in the body of the message
> >
>
>
> To unsubscribe: send mail to majordomo at wireless.org.au
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>
>
>
>
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>


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