Objective

Create a wireless mesh network using OLSR or any other routing protocol at layer 3, which is able to do not reuse the channel channel at each hop.

Problem

In most mesh networks such as Freifunk, packets are routed through the network by reusing the same frequency. Since WiFi cards are half-duplex, each card cannot receive and transmit at the same time, thus dividing the bandwidth by a factor of 2 at each hop.

Solution

Use at least 2 channels to obtain full duplex links, and higher throughput.

Testbed

For this tested, I used 10 foneras flashed with OpenWRT Kamikaze, and I have installed olsrd 0.5.3.

I used 2 foneras per node, one on channel 1 with the BSSID fixed on ca:fe:ca:fe:ca:fe and ESSID bombolong1:

root@zoomesh08$ cat /etc/config/wireless
config wifi-device wifi0
option type atheros
option channel 1
option agmode 11g
option diversity 0
option txantenna 1
option rxantenna 1

config wifi-iface
option device wifi0
option network wlan
option mode adhoc
option ssid bombolong1
option hidden 0
option txpower 16
option encryption none
option bssid ca:fe:ca:fe:ca:fe

And the other one on channel 11 with the BSSID fixed on 00:11:00:11:00:11 and ESSID bombolong11:

root@zoomesh07$ cat /etc/config/wireless
config wifi-device wifi0
option type atheros
option channel 11
option agmode 11g
option diversity 0
option txantenna 1
option rxantenna 1

config wifi-iface
option device wifi0
option network wlan
option mode adhoc
option ssid bombolong11
option hidden 0
option txpower 16
option encryption none
option bssid 00:11:00:11:00:11

The 2 foneras are linked with an ethernet cable.

The first fonera has an olsrd.conf config file with a default weight of 0.10:

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While the second fonera has an olsrd.conf config file with a default weight of 0.20:

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Here are the routes:

Simulator

Test with some 20 openvz instances and ebtables in order to simulate the behaviour of the network. Also try with Uml-wifi, as explained here.

Improvements

Negative weights with Bellman-Ford instead of Dijkstra?