Hello,
I have a 3 node mesh network with layout as follows:
node #1 node #2 node #3 192.168.2.1 192.168.2.5 192.168.2.9
Each node has only one radio and #1 talks to #3 via #2 and vice versa. If I want to improve the throughput between #1 and #3, logically I would add another radio to #2 so it can communicate to both #1 and #3 simultaneously w/o having the single radio switching back and forth between #1 and #3.
However, I ran IPERF between #1 and #3 before and after adding the second radio to node #2 and the bandwidth didn't really improve. In my node #2 configuration, I did not bridge the two wifi interfaces so I have ath0 and ath1 with their own IP addresses. All three nodes are configured with the same channel. My batmand command line for node #2 is: batmand ath0 ath1.
Can anyone advise me on what I did wrong?
Thanks, Shane
Hi Shane -
if all radios are operating on the same channel you can't expect any improvement. So operate one link on channel 1 and the other on channel 11, 13 or 14 according to the regulations in your country. Channels in the 5 GHz range are even better ;-)
Note also that many embedded devices have not enough CPU power to saturate the capacity of a single radio link operating at full speed. At 54 Mbit a single link can have approx. 3 MByte/sec throughput, but we have experienced that a 200 MHz MIPS CPU doesn't provide enough power for more than 1.2 to 1.6 MByte/sec with a single interface depending on the chipset/type of your wifi card.
cu elektra
Hello,
I have a 3 node mesh network with layout as follows:
node #1 node #2 node #3 192.168.2.1 192.168.2.5 192.168.2.9
Each node has only one radio and #1 talks to #3 via #2 and vice versa. If I want to improve the throughput between #1 and #3, logically I would add another radio to #2 so it can communicate to both #1 and #3 simultaneously w/o having the single radio switching back and forth between #1 and #3.
However, I ran IPERF between #1 and #3 before and after adding the second radio to node #2 and the bandwidth didn't really improve. In my node #2 configuration, I did not bridge the two wifi interfaces so I have ath0 and ath1 with their own IP addresses. All three nodes are configured with the same channel. My batmand command line for node #2 is: batmand ath0 ath1.
Can anyone advise me on what I did wrong?
Thanks, Shane _______________________________________________ B.A.T.M.A.N mailing list B.A.T.M.A.N@open-mesh.net https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n
Are both of your radios using 2.4 GHz channels? How close are they and are you using external antennas?
This paper [1] p13 and this paper [2] p6 both talk about an inter radio interference issue when using multiple radios on one node.
Dave
[1] http://citeseer.ist.psu.edu/raniwala04centralized.html [2] http://research.microsoft.com/research/pubs/view.aspx?tr_id=667
Quoting elektra onelektra@gmx.net:
Hi Shane -
if all radios are operating on the same channel you can't expect any improvement. So operate one link on channel 1 and the other on channel 11, 13 or 14 according to the regulations in your country. Channels in the 5 GHz range are even better ;-)
Note also that many embedded devices have not enough CPU power to saturate the capacity of a single radio link operating at full speed. At 54 Mbit a single link can have approx. 3 MByte/sec throughput, but we have experienced that a 200 MHz MIPS CPU doesn't provide enough power for more than 1.2 to 1.6 MByte/sec with a single interface depending on the chipset/type of your wifi card.
cu elektra
Hello,
I have a 3 node mesh network with layout as follows:
node #1 node #2 node #3 192.168.2.1 192.168.2.5 192.168.2.9
Each node has only one radio and #1 talks to #3 via #2 and vice versa. If I want to improve the throughput between #1 and #3, logically I would add another radio to #2 so it can communicate to both #1 and #3 simultaneously w/o having the single radio switching back and forth between #1 and #3.
However, I ran IPERF between #1 and #3 before and after adding the second radio to node #2 and the bandwidth didn't really improve. In my node #2 configuration, I did not bridge the two wifi interfaces so I have ath0 and ath1 with their own IP addresses. All three nodes are configured with the same channel. My batmand command line for node #2 is: batmand ath0 ath1.
Can anyone advise me on what I did wrong?
Thanks, Shane _______________________________________________ B.A.T.M.A.N mailing list B.A.T.M.A.N@open-mesh.net https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n
B.A.T.M.A.N mailing list B.A.T.M.A.N@open-mesh.net https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n
b.a.t.m.a.n@lists.open-mesh.org
-
David Murray -
elektra -
Shane Chao