which wireless router?

Larry Hartman larryhartman50 at vzavenue.net
Tue Feb 26 01:55:59 UTC 2008

On Monday 25 February 2008 01:14:16 pm Derek Broughton wrote:
> Nils Kassube wrote:
> > Derek Broughton wrote:
> >> Nils Kassube wrote:
> >> > Derek Broughton wrote:
> >> >> How can it tell one has a better signal unless it's constantly
> >> >> testing it?
> >> >
> >> > Yes, that's how diversity works, constant testing. You have 2
> >> > receivers and monitor the signal with both antennas simultaneously.
> >>
> >> Yeah, but you have two _transmitters_ too.  Or does it simply assume
> >> that the one with the best reception must be the one which will be best
> >> for transmitting?
> >
> > I don't think there are 2 transmitters too. They would have to transmit
> > simultaneously and that would mean interference on the receiver side.
> Well, two transmitters, or one transmitting via both antennas at the same
> time would be the same problem...
> > So
> > the transmitter is switched to the antenna which had the better signal
> > during the last reception period. That is the best choice because usually
> > the signal quality for one antenna doesn't change very fast.
> Thanks.  I used to hang out on alt.internet.wireless, but it was too
> technical for me :-)
> --
> derek

Interesting discussion.....I've dealt with some basic radio transmission 
theory on and off the last few years.  It has been pointed out to me along 
the way that if two antennas are operating at the same frequency at the same 
time, that when they are a given distance apart, the signal strength 
perpendicular to the axis of the two antennas greatly increases, while the 
signal strength along that axis reduces. 

This theory is why truck drivers employ two antennas for their CB's.  In their 
example the typical width of a tractor cab is about the right width necessary 
for signal strengthening in front of and behind the truck.  As was explained 
to me, the improvement can sometimes be measured in terms of miles.

Depending on the electronic environment, the employment of two antennas may 
not always generate interference, but may be complimentary.  Dunno about 
Linksys or any other vendor, but it is a consideration.


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