🚀 go-pugleaf

On Mon, 29 Apr 2002 16:16:13 GMT, "Gary Funck" <gary@intrepid.com>
wrote:

>SMC7004AWBR - 4 port router/firewall, 802.11b WAP, with printer server

Garbage.  Limited features and configuration options.

>USR2410 - US Robotics 802.11b PCMCIA (client) card

No experience.

>I looked at 802.11a stuff, but was unwilling to pay $400-$500 more for the
>privilege of trying out the latest technology.

5.6GHz has more speed at less range.  If you have range problems,
5.6GHz is not the answer.  If you want more bandwidth for your Video
On Demand installation, then 802.11a is the only answer.

>They didn't have the Lucent/Orinoco 802.11b PC card.

You should have bought the Lucent/Orinoco/Agere/Wavelan/Whatever card.
It's a good card, well supported, and with exellent performance.  I
did a side by side comparison of an Orinoco Silver card, with a
Netgear PCMCIA card.  The Orinoco card got much better range and held
the connection more reliably.

>(...)
>driver comes in two flavors: "ad hoc" and "infrastructure", which has
>something to do with whether it roams or not, I think, but very little
>explanation is given.

Ad hoc means that the flow is not controlled by a central access
point.  Infrastructure means that everything is controlled by the
central access point.  You probably want infrastructure (unless you're
doing something strange).

>- now the bad news: with the laptop about 6 feet from the transmitter, I'm
>seeing signal strength of about 80%, and "link quality" oscilating between
>90-100%, and dropping to 80%.

That's normal.  Link quality is actually something like data error
rate.  The assumption is that the bit error rate will get worse as the
signal strength drops.  It is NOT a direct measure of signal strength.
If you get errors from any source, the link quality will drop.  If
you're too close, you could be dealing with reflections and overload,
which probably causes the 80% reading.  If you move back a bit, it
will probably go to 100% and stay there.  Move back furthur, and it
will start to drop.

>Okay, not so bad - but if I take the computer
>upstairs (40 feet, max.) the signal strength drops to 30-40%, and unless the
>card is oriented just right, the signal strength and link quality drop to
>zero(!).

Think in terms of walls.  Microwaves do not like to go through walls.
They sneak through holes and slots, but to not penetrate anything
truely solid.  If you're going through one wall, no problem.  Two
walls is problematical.  Three walls is hopeless.  Going between
floors is the worst case situtation because your in the worst part of
the antenna pattern (up/down), and you're probably going through more
than one wall.

>So much for the advertised 300 feet max.

You should be able to get 300 ft line of sight, horizontally if you
can see the access point.  It will also depend on the laptop
orientation.  If you block the line of sight with the laptop itself,
my guess is 50 ft max.

>I tried moving the
>transmitter away from the DSL router and computer, but this didn't change
>things.

Interference is possible, but unlikely.  Look for sources of 2.4Ghz
interference.  There are plenty.  Microwave ovens are the biggies.
Other users of 802.11b are also a problem.  Bluetooth will trash
802.11b.  Cordless phones and wireless TV extensions don't seem to
bother it much.

>What next?

External antenna(s) on the access point.

>Right now, anything more than 15-20 feet (line of sight) away
>looks marginal.

Something is broken.  You should be able to do much better than that.
However, that's about right for trying to go through a wall.  Location
is everything.  You could cheat and run an upstairs external antenna
to one of the TNC-R connectors.  However, the coax cable loss will
probably be fatal.  Methinks you should determine what can be expected
from your site by borrowing some known working radios, and to test
your purchases in a known working (and clean) RF environment.

Try asking the same question in the BAWUG mailing list.
   http://www.bawug.org


-- 
Jeff Liebermann  150 Felker St #D  Santa Cruz CA 95060
(831)421-6491 pgr (831)426-1240 fax (831)336-2558 home
http://www.LearnByDestroying.com   WB6SSY
jeffl@comix.santa-cruz.ca.us   jeffl@cruzio.com