[olsr-dev] Fwd: Frottle and Meshes
Fri Mar 3 12:15:01 CET 2006
Hi Tim and Jim,
We in Melbourne Wireless have been playing with Frottle in an attempt to
create a version more usable in Mesh situations.
A Frottle patch and OpenWRT IPKs here:
It doesn't completely do away with Master and Client just yet but it
introduces "control domains". We are testing a multi-master, multi-client
version for use on nodes with more than one wireless interface. I was
recently testing the code but various events have put the testing on hold
for now. Please feel free to test the code and report bugs! :)
I've been reading papers on Token circulation - I read the Wireless token
ring protocol paper from berkeley
However I think this protocol is limited because it specifies a maximum size
for a ring - if the ring reaches it's maximum size no new nodes are
admitted. The paper suggests that those nodes change to a different channel
which doesn't seem a workable solution.
Another good paper on Token circulation can be found here:
It looks more at the logic behind efficient token-passing.
Using the knowledge obtained from these two papers I've come up with some
flowcharts that suggest possible code for a self-configuring,
distributed-token version of Frottle:
It's been a little while since I put these flowcharts together, but they are
commented so if you follow them through it should make sense.
View my blog:
> -----Original Message-----
> From: (spam-protected)
> [mailto:(spam-protected)] On Behalf Of Tim Schmidt
> Sent: Friday, 3 March 2006 3:08 PM
> To: OLSR development
> Subject: Re: [olsr-dev] Fwd: Frottle and Meshes
> > just because you can't hear a node doesn't mean it can't hear you.
> Of course. I think I noted in my message that hearing the
> 'permission slip' being passed to a node not in your ETX
> table would allow you a one-time-use transmit window. That's
> a gamble. I'm essentially relying on the fact that it's a
> one-time-use only and that the MAC and IP stack on the node
> with the legitimate permission can deal with any interference
> so long as it only happens once. Of course, transmission
> window length would be pretty easy to play around with to
> balance this out depending on the topology of your network,
> or just in general.
> For instance, the permission-window could be 3x the
> one-time-use window.
> > Also, I'm curious to know if you've thought about recovery,
> should the
> > node thats holding the 'permission slip' become unreachable.
> Yup... hence the timeout in the original mail.
> > so write the perl and I'll see about convering it to 'C'.
> I'll see what I can do. Would you mind if I mailed you a
> month or two from now upon completion?
> > One of the *fundamental* problems with current 'mesh networks',
> > however, is the 802.11 MAC.
> Agreed. However, it does perform some useful functions, and
> even the most problematic machines, if at least reliably
> problematic, can be exploited to do legitimate work.
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