Hi Joseph,
On Thursday 07 May 2015 13:00:52 Joseph Zimmer wrote:
Hello,
I am working with BATMAN-ADV and have successfully setup a mesh. In my implementation of the mesh, the network requires BATMAN to operate in a linear topology and ideally have node 1 hop to node 2 then through node 3 and finally node 4.
Node1 .Node2 ..Node3 Node4In this network hops are preferred rather than distant links with low RSSI values(-70). The problem that Im seeing is that the protocol chooses routes that have the least hops but have RSSI values at about -78 to -90 rather than routing through the closest node with RSSI values in the -50 range.
We adjusted the hop penalty to a low value (we used 1 and 0) and we did see improvement with the hop selection but the throughput is very low due to an RSSI of -64 or less.
Questions:
Is there a way to adjust BATMAN using batctl to select routes basedon the RSSI value? a. That is, choose to hop through a node with an RSSI of -50 and never select a node that has a lower RSSI
Nope, BATMAN only uses packet loss as a metric. It could be possibly adjusted to do so or low signal links could be filtered otherwise, but we would consider that a bad hack.
There is another suggestion: You could increase the multicast rate to a high value, e.g. 36 MBit/s or even higher. Higher rates only work with good signals, and since batman-adv uses broadcasts (which is multicast for WiFi), this will have a direct effect on your network.
Does the algorithm for route selection use RSSI in the calculationand if so can we modify the algorithm to increase the importance of RSSI in the selection?
It currently doesn't use RSSI
How do we gain access to the code to make these modifications?
Batman-adv is open source, and so is mac80211 and hopefully the WiFi driver you use. However, it'd really suggest to start with tuning the multicast rate. :)
Cheers, Simon