Interference-Aware Channel Assignment in Multi Radio Wireless Mesh Networks

The paper is yet another in Multi Channel category. Here r the salient points:
1. have a common default channel between all nodes – eliminates problems like
(i) partitioning
(ii) disruption of flows ongoing at times of channel assignment change (by link-redirection)
(iii) sub-optimal routing
2. can assign channel based on interference on each channel, thus minimizing overall intra- and inter- mesh interference
(i) Minimize interference between routers in the mesh: Tree Shaped traffic pattern -> high priority to link starting from the gateway
(ii) Minimize interference between the mesh network and wireless networks co-located with the mesh: CAS periodically determines the amount of interference
3. External Interefernce Estimation process-
(i) Number of interfering radios on each channel supported by each router
(ii) One NIC -> packet capture mode for each channel, each physical layer type for 3 sec
(iii) # of interfering radio = # of unique MACs external to the mesh
(iv) rank each channel according to interference estimated on it
4. Multi Radio Conflict graph used for Internal Interference Estimation
5. BFS-CA for channel assignment-breadth first search to assign channels to the mesh radios, satisying the goal for internal interference
(i) CAS obtains the interference estimates from the mesh routers
(ii) Choose the channel for the default radios
(iii) CAS create the MCG for the non-default radios
(iv) uses the BFS-CA algorithm to select channels for the non-default radios
(v) CAS instructs the routers to configure their radios
6. Link Redirection before reconfiguring channel-
(i) The node broadcast “INTERFACE-INACTIVE” message
(ii) Any neighbors received message modify routing-table
(iii) Redirect existing flow using default channel interface