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Old February 17th 06, 04:05 PM posted to rec.radio.amateur.digital.misc
Bob Bob
 
Posts: n/a
Default Can't run TCP/IP through AX.25 using Linux

Hi Braath

The kind of stats I am talking about is more the bit error rate one. ie
what percentage of the radio packects are mangled or not getting
through. It is common in a radio system to have some percentage of
failure. I use to administer two non licensed links, one on 2.4Ghz and
the other on 5.7. Towards the end of its useful life the 2.4GHz link had
about 90% retries mainly from interferring sources. In that case we got
much better reliability limiting it to the 1MB speed (as against 11).
The newer less populated 5.7GHz link ran about 20% retries.

The fullduplex radio pair configuration I suggested would use separate
frequencies and maybe even antenna polarisation/space separation to
reduce interference. ie two antennas at each end. Using a diplexor to
allow two boxes on the one antenna is probably a bit cost wasteful. The
idea is that at one end you force one box into transmit mode and the
other to receive. You also have to specify a fixed channel instead of
allowing automatic operation. The node names would also have to be
paired. Connection to the computer is as you stated but some
configuration of the handshaking lines (RTS, CTS, DTR etc) would also be
needed. I expect that Connexlink would have already done this with their
equipment so there may even be an application note on it available. It
would of course be smart to run all lines back to the PC and do the
patching there, in case you want to send commands to the unit itself and
need both TX/RX lines available.

Cheers Bob


Braath Waate wrote:
--

I'm sorry I don't understand the radio pair suggestion; wouldn't the
pair of radios just interfere with each other? Is the idea to hook the
tx lead of the serial port to one radio and the rx lead to the other?
How would they hook to the antenna?