> And what do these "experts" think is different about an
> "enterprise" WAP versus an off-the-shelf one?  802.11x
> is a standard, and it has limitations, and those don't
> extend to sending 6MB to 120 users at once!  Ya canna'
> change the laws o' physics, captain!

My point, exactly.  We really have two insurmountable
obstacles here:  physics and the US Federal Government.
If the Federales increased the band we are allowed to use
for 802.11, we could add more WAPs.  If physics allowed
us to transmit multiple signals in the same band, we could
add more WAPs.  I leave it to reader to decide which is
more likely.

>  If they are on a single channel, only one WAP or user
> can be transmitting at any one moment in time, and
> if more than one tries, all will fail and will go into a
> wait-and-retry loop, so reducing the theoretical
> throughput dramatically.

AIUI, some WAPs can be setup to negotiate their wait/
retry through the wired network, to reduce the hit from
broadcast collisions.  I don't know how much good that
does- after all, the two WAPs still can't broadcast at the
same time.

> Any of these "experts" should
> have known that would happen

Hence the quotation marks.  I'm not sure how expert their
knowledge really is.

> > The bottom line, what I can't get people to understand, is
> > that only so many WAPs can be in one place without
> > interfering with one another
>
> Yes, in the USA it's three, since that is the number of
> non-overlapping channels (In Europe & Japan it's more
> like 4 - I have no idea why the US chopped off the top
> few channels).  So the best case you could hope for is
> 3 x 40 users, so in an ideal situation each user would
> get 1/40th of 54Mb/s, which a rough calculation shows
> would mean a bit over a minute and a half to get 6MB to
> everyone.  But of course the collisions problem makes
> this far from ideal, and I think you could reckon on at least
> 5 minutes in a real situation - maybe much
> longer.

That assumes that users don't inadvertently begin second
or third file transfers by double clicking again, and again,
and again, when the file doesn't instantly open.  It took
about 15 minutes before we got everyone going.

Mike H.

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