Info on an 800m link with 2 x DLink AP-900+

[Tim Smith]

Hi
I have just completed a 802.11 link for a customer of mine, it is over a
distance of 6.4 kms, it has line of site, I used 18db yagi's from RFI and 2
linksys WAP11's. I initally locked the rate down to 2mbit but have since
allowed it to auto rollback from 11mbit. The reason for the link was to
extend a ADSL service to a unserviced area, I have checked the available
bandwidth at the ADSL box and at the end of the link and there is no
apparent diference. I have to say that i was quite chuffed at the
performance and the painless setup of the link over that distance!
To cut a long story short from my experiance here i would think that you
should be able to let the ap900's run at full speed, the only catch may be
as someone else suggested, the other 2.4Ghz stuff operating nearby efectivly
reducing the signal to noise ratio and therfore the available
bandwidth/speed
Crank it up and see what happens?????

regards
Tim



----- Original Message -----
From: "Haydn Lowe" <mrlowe at users.sourceforge.net>
To: <wireless at lists.samba.org>
Sent: Monday, May 26, 2003 8:17 AM
Subject: Info on an 800m link with 2 x DLink AP-900+


> Hi there,
>
> I originally planned to write to ask for help - but have since figured it
out,
> and thought I would present my experiences...
>
> I've finally managed to get an 800 m link up and running at 5.5 Mbps using
two
> DLink AP900+ units.
> I have used two stand alone bi-quad antennas as described by Trevor
Marshall,
> and other associated web sites. Sealed in good old Woolworths tupperware
> specials (complete with rubber seals!)
>
> Initially, all I could get was a 500Kbs link, which dropped out
frequently.
> The error rate was nearly 25%, and I had Line of sight, but simply
couldn't
> figure out why. I've had many different iterations all with about the same
> results. On the weekend I finally figuring it out!
>
> It turns out that the AP900 units have a built in second antenna, which I
guess
> isn't all that surprising, but wasn't well documented AND that there is a
> hidden configuration page http://<ap900-URL>/weca.htm which allows you to
> control the antenna configuration, as well as a few other things...
>
> I disabled the internal antenna - and set it to use only the right antenna
> (this is the external one). And this has fixed my problems!
>
> I don't know if it is simply diversity, or a combination problem with the
fact
> I am running the far unit in repeater mode, but I do know that tweaking
with
> the antenna settings has fixed my problems. So I thought I'd share the
info...
>
> Does anyone know what sort of link speeds I should be able to get to work
over
> an 800 m  stretch? Is 5.5 about right, or should I be trying to get it
faster?
>
> Any thoughts on all this are welcome!
>
> Cheers
> Haydn
>