[Server-devel] [OLPC Networking] RSSI value questions

[Ryan Crawford Comeaux]

I realized after chatting with Ben that my assessments were wrong about this
being a feasible project for the summer.  The main issue is still that the
radios dynamically adjust their gain to increase RSSI between nodes that are
farther apart.  I do have ideas that may be possible to overcome this, but
some experimentation would be needed.  Depending on how often the gain is
adjusted and in what ways, inferring the gain may be possible.
According to the link below, the setbcnavg command can be used to "set the
weighting factor for calculating RSSI," but I'm not sure how this affects
connectivity between nodes.  If setting the value as high as possible or as
low as possible causes nodes to disappear from a radio's "view," then
direction is easy to discover by having all XOs step through the values and
recording which nodes come back within view and when.  I think this would
provide direction, unless the command doesn't affect connectivity.

I'll post the rest of my thoughts later, as I need to finish some other
work.  Unfortunately, I don't have the equipment necessary to test out any
other theories, nor do I feel I have the technical knowledge to see this
project through, so I'm afraid this is where I get off the bus.  Thanks for
all of your input.

http://wiki.laptop.org/go/Wireless_Driver_README

- Crawford
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