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Re: Newbie Wireless Question [7:95793] posted 01/06/2005
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""Matthew Saskin""  wrote in message 
news:200501061653.j06GrjoC005478@xxxxxxxxxxxxxxxxx
> Russ,
>
> Could you expand on this a bit?  I recall from a while back (the last time 
> I
> used wireless in anything but a home application) that as long as you 
> spaced
> out the AP's on channels 1, 6, and 11 you'd be OK with getting full
> bandwidth to each one as there isn't too much frequency overlap between 
> the
> channels.

Please be very careful with your terminology. "Full bandwidth" means many 
things to many people. There is nothing more furstrating than dealing with 
an RFP that calls for "full bandwidth for all user in the coverage area"

We are talking radio here. Just like that thing in the car that plays music 
between annoying commercials. Channels are frequencies, and only one station 
may use a frequency at any one time. That one station may be the AP or the 
client station. Otherwise, just as with your broadcast radio, when more than 
one transmitter uses the same frequency you get noise.

802.11 has build into it a number of overhead items, including chipping, 
backoffs, interframe gaps, etc.

Plus, only one side can broadcast at any one time, unless you like noise. ;)

>
> Any more to add?  More technical info is always good in my book ;)
>
> ~matt
>
> -----Original Message-----
> From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of 
> Russ
> Uhte
> Sent: Thursday, January 06, 2005 8:37 AM
> To: cisco@xxxxxxxxxxxxxx
> Subject: Re: Newbie Wireless Question [7:95793]
>
> Marko Milivojevic wrote:
>>>So, on a 54 Mbps system, that number truly is the maximum raw data
>>>rate for all combined traffic on that access point. Is that a correct
>>>statement?
>>
>>
>>     If I understand how those things work, it's not only on that AP, but
>> within range of any other transmitting device, be it on that AP, or the
> one
>> next to it. I might be very very wrong about this, though...
>
> This all depends on how your channels are spaced.  If your channels are
> properly spaced, the traffic on 1 AP will not affect the traffic on
> another AP.  For example, if you have 1 AP on channel 1, and the next
> one on channel 6, they can both operate at their full bandwidth.
> However, if you have an AP on channel 1, and then one right next to it
> on channel 2, there will be interference across the frequencies, and you
> will definitely notice a slow down on both devices.
>
> -Russ
> ---
> [This E-mail scanned for viruses by Declude Virus]




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