[Soekris] problem using multiple wireless cards

[Chris Babcock]

RB wrote:
> On Fri, Jul 25, 2008 at 12:07 PM, Chris Babcock <cbabcock at utiliware.com> wrote:
>> So then to the users here organize their networks to avoid radio contention?
> 
Yeah, there was a typo there...  It should have read:

So then how do the users here organize their networks to avoid radio 
contention?

> Not sure what you're asking here (you seem to be due to the ?), but
> yes - radio contention is a real and normal problem.  You can take the
> Cisco approach and "channelize", or organize your APs in
> minimally-overlapping, non-adjacent (both frequency and arrangement)
> cells much like cellphone coverage.  The alternative is Jim Thompson's
> approach and use a single channel with minimal physical overlap (I
> think?) - he's provided some rather convincing and informative posts
> on the subject.
> 
>> My immediate thought would be to use limit units to 1 radio each and
>> connect a pair of units through a small switch, but that sounds like an
>> expensive messy hack.
> 
> Much less messy, but just connect the devices via a crossover.  Even
> so, most multi-radio configurations are in two different bands, using
> one (i.e. 802.11b/g) for client connectivity and the other (802.11a)
> as backhaul.  My imagination is limited, but I can't imagine much use
> for two radios in such physical proximity on the same band.  Maybe
> with directional/high-gain antennas for expanded coverage, but that
> has pretty limited utility for typical client device powers.
> 
Agreed, 2 radios on the same band in the same box is probably not a good 
idea.  Most radio devices don't just perfectly emit on a single band 
with no other EM output.  When building a unit with 2 radios in one box 
there's nothing shielding the radio's from each other's interference.

How much of an issue is this with modern radio cards?

> IMHO, the 4801 in this case is maxed out and we're not talking about
> interference anyway.
> 
Which also brings up the question, how much processing power should be 
needed to carry a wireless link of a given speed?