In message <200008260010.e7Q0Auc10818@flash.vaultron.com>, Andrew Gillham write
s:
>John Hawkinson writes:
>> 
>> Module Name:	syssrc
>> Committed By:	jhawk
>> Date:		Sat Aug 26 00:05:56 UTC 2000
>> 
>> Modified Files:
>> 	syssrc/sys/dev/pcmcia: if_wivar.h
>> 
>> Log Message:
>> oops, missed this file earlier (Doh!):
>> Add support for "microwave oven robustness" with wiconfig -M.
>
>Ok is it just me, or does a commit message about microwave ovens just
>scream, "more details please!?"

That's opaque text about a feature implemented in the card firmware.
It's just a boolean. ;-)

>If my WaveLAN can get wiped out by a microwave, can I zap popcorn
>if I set it next to my laptop? :-)

Yeah, yeah. See the Lucent driver documentation for information
on what it does. Basically you should only turn it on if you're
have a problem with such interference.

But quoting from the Lucent driver...

--jhawk

Interference Robustness

This option should only be used in exceptional cases upon advice of a
ORiNOCO expert.  For example when you suspect that reported slow
performance of the ORiNOCO network could be related to in-band
interference from Microwave ovens.  To determine whether this is the
case in your situation, you can perform diagnostic measurements using
the ORiNOCO Client Manager tool.  Microwave oven interference will
usually show a poor Signal to Noise Ratio (SNR) that is based on:

' Good Signal Quality, AND

' High Noise level (interference), where the noise is typically
perceived as "random bursts of interference".

See also:

' Interference Robustness - How it works

' Auto Transmit Rate Select Mechanism

Copyright (c) 2000 IBM Corp., All Rights Reserved

Interference Robustness - Details

In most network environments, the Auto Transmit Rate Select Mechanism
will prove most efficient, as the ORiNOCO PC Card will try to send its
data at the maximum speed whenever possible.

In special circumstances however, you may encounter that your
unexpected throughput behavior of your ORiNOCO PC Card even though the
Signal level is Excellent.  In such situations, your ORiNOCO system
might suffer from recurrent 'bursts' of in-band interference, that
affect your network response times.



This behavior is often also typically perceived on specific stations,
where

' the "trouble" station or access point is close to a microwave oven,
or

' a microwave oven is located in the signal path between the "trouble"
stations and the access point.



In network environments where microwave ovens are operational, such
recurrent 'bursts' of in-band interference, might cause loss of
wireless data messages.

' Normally your ORiNOCO PC Card will always try to retransmit these
'lost messages'.

' When a retransmission fails again, the ORiNOCO radio in Auto
Transmit Rate Select mode will attempt to retransmit the message again
at a lower data speed.  However as data transmissions at lower speeds
may take longer, such retransmission make the communication even more
vulnerable to new bursts of interference.

In a situation where recurring 'bursts' of interference keep forcing
your ORiNOCO devices to switch to lower Transmit Rates this might
cause congestion on your wireless network, that will be experienced as
'long network response times'.

The option Interference Robustness will enable fragmentation of data
frames when the automatic transmit rate selection switches to a lower
transmit rate.

The level of fragmentation differs for the various supported transmit
rates, and is designed to apply an identical frame length at each
transmit rate. This fragmentation will avoid increased vulnerability
due to longer frame lengths of transmissions at lower data speeds.

Copyright (c) 2000 IBM Corp., All Rights Reserved