[Olsr-dev] Seeking comments: OLSR+ETX v/s DSR+ETX

[Henning Rogge]

On Dec 19, 2007 3:58 PM, elektra <(spam-protected)> wrote:
> Before we decided to choose ETX as metric for olsrd we were experimenting with
> measuring round trip times. Axel Neumann tried to implement this while we
> were still using mobilemesh, but the measurement results seemed to be quite
> arbitrary. But I assume this was a problem of our implementation, because any
> implementation of ping does a much better job than what we had achieved.
>
> And btw. I don't see any irrational 'voodoo' in LQ/NLQ/ETX - at night I can do
> downloads in our mesh via 18 hops with approx. 12 kByte/sec... Some people
> claimed that a mesh only works up to three hops. So the 'voodoo' seems to
> help a lot ;-)

This might be interesting for anyone interested in ETX...
[ETX metric 2003] Couto, Douglas S. J. D. ; Aguayo, Daniel ; Bicket, John ;
  Morris, Robert: A High-Throughput Path Metric for Multi-Hop Wireless Routing.
  URL http://pdos.csail.mit.edu/papers/grid:mobicom03/paper.pdf, September 2003

> So I still think it would be a valuable idea to measure RTT for different
> packet sizes. And the payload of these packages should transport something
> useful... For example the results of the last RTT-measurement could be
> included.
How do you want to do this for unicast packages ? I can see it working
for broadcast
(no retransmission on Layer 2), but broadcast and unicast timing are
not the same.

Henning Rogge

-- 
"Wo kämen wir hin, wenn alle sagten, wo kämem wir hin, und niemand
ginge, um einmal zu schauen, wohin man käme, wenn man ginge." (Kurt
Marti)