Multi Channel MBSS

Implementation

HOWTO

Code

To test the multi channel MBSS operation, you will need a custom iw and linux kernel:

iw

repo: [email protected]:cozybit/iw.git branch: ft-mbss-sharing

linux

repo: [email protected]:cozybit/open80211s.git branch: ft-multi-if

Here we assume the reader is familiar with the build and installation process for the above.

Operation

To enable MBSS sharing across multiple mesh interfaces, simply add the new mesh setup parameter share {on,off} while joining the same mesh ID:

$ iw wlan0 mesh join meshtest share on
$ iw wlan1 mesh join meshtest share on

Path selection information sharing and frame forwarding will now take place between wlan0 and wlan1.

Example

You will need 3 mesh nodes, where at least one of them has 2 physical radios. We'll call these node_1, node_2, and node_3.

As an example, let's simulate the following linear topology using multi-channel MBSS:

node_1(0) <-----> [node_2(0), node_2(1)] <-----> node_3(0)

The radio pairs (node_1(0), node_2(0)) and (node_2(1), node_3(0)) are on orthogonal channels as a means of enforcing a certain link topology.

link setup

node_1

$ iw wlan0 set type mp
$ iw wlan0 set channel 1
$ ip link set wlan0 up
$ iw wlan0 mesh join meshtest
$ ip addr add 10.10.10.1/24 dev wlan0

node_2

$ iw wlan0 set type mp
$ wi wlan1 set type mp
$ iw wlan0 set channel 1
$ iw wlan1 set channel 149
$ ip link set wlan0 up
$ ip link set wlan1 up
$ iw wlan0 mesh join meshtest share on
$ iw wlan1 mesh join meshtest share on

node_3

$ iw wlan0 set type mp
$ iw wlan0 set channel 149
$ ip link set wlan0 up
$ iw wlan0 mesh join meshtest
$ ip addr add 10.10.10.2/24 dev wlan0

Now you can ping node_3 from node_1 through node_2!

Known Issues