DWL-900AP+ External Mounting

Akash Heimlich akash at zeroplus.de
Mon Mar 24 21:10:39 EST 2003

Hello All,

I'm *very* new to wireless but have done lots of research on the net and
got myself 3 DWL-900AP+ (firmware 2.5) units.  Since it get rather hot
in India, I decided to house the units in a large PVC pipe.  I opened
the unit, and fixed the external antenna connector to the top of the PVC
Pipe to mount an omni on top.  I then 'tied' the unit to an aluminium
plate (which acts as a heat sink) inside the PVC tube. I then wrapped
the entire tube in silver foil to protect it from the heat.  Oh, and
since the unit is running of a solar panel/batter, I have an LM317
converter to provide 5V DC, this is in a separate unit, and it's set to
give exactly 5V at the end of 4 m cable the goes into the unit.

Now, the idea was to have one act as access point and one as repeater.
They are about 500 m apart with 5dBi omnis, and line-of-sight.  At 11
mbit they drop packets when sending but they function ok at about 2
MBit.  Now I have 3 problems:

First, in the configuration as ap-repeater-client, I could access the
repeater from about 500m away using my 3rd DWL-900AP+ as a client.
Downloading went well, but I could not UPLOAD through the repeater,
although pings worked fine!   So, I had to change the configuration to
client-ap-client, and then I could upload/download successfully.

Second, sometimes the speed would drop to 1 MBit due to something or
other.  At 1 MB, it shows me that I have an excellent connection, but
the unit does NOT transfer data and pings timeout. (I tried this using a
netgear PCMCIA card).  And the worst of it is that it if ever drops to 1
MBit it never recovers, which means I have to reset the unit.  I am
wondering if this could have anything to do with the aluminium plate the
ap is tied to?  I have it configured with full strength on the external
aerial, so I doubt it's that, but...?

And third and wierdest, every day between 10 am and 1:05 pm, the unit
connected to the solar panel/battery resets randomly every 30 seconds or
1 minute.  At 1:05 (I saw this 3 days in a row) it just started to work
fine.  Now, I could imagine a heat problem, but at 1 its still the
hottest time of day, so that’s not logical.  And the power supply cannot
be that unstable either, since the problem would occur more frequently
then.  Of course yesterday at 1:05 it just hung (kept sending packets
but was not responsive).  Any ideas?

Thanks in advance,


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