Re: [iPAQ] 802.11b cards

On Tuesday 22 January 2002 08:26 am, Walter Johnson wrote:
> Russ Nelson wrote:
> > Devin Butterfield writes:
> > > I think you will find that the two cards will interfere with each
> > > other. It's the classic "near-far" problem. If radio 1 is transmitting
> > > while radio 2 is receiving, the transmitter of radio 1 will cause the
> > > receiver of the other radio to go deaf (and not hear the "far"
> > > station, due to the interference from the "near" station).
> >
> > Even on different channels?
>
> Why not operate the 802.11b on two of the three non-overlapping bands. In
> the US it is 1, 6, 11. You should have minimal interference unless you need
> to operate on the same channel.

They will still interfere with each other...the question is how much. The
basic problem is that because these are direct sequence spread spectrum
radios, they have VERY wide receiver front ends (it's something like 22 MHz
!!) and as such they are very susceptable to strong nearby radio
emissions--even if there is several MHz of separation and the interfereing
signal is out of the receiver's pass band. And in this case, the transmitting
antenna is practically coupled (electromagnetically) to the receiving antenna
because they are so close.

However, with that said, he might be able to make it work if the two chunks
of spectrum are separated far enough. Hopefully he will report back to the
list and let us know if he managed to get any usable performance out of them.

--
Regards, Devin.