Joint Channel Assignment and Routing in Real Time Wireless Mesh Network

1. Joint Channel Assignment and Routing in Real Time Wireless Mesh Network Xiaoguang Li†, ChangqiaoXu‡ †College of Software Engineering, Southeast University, Nanjing, China ‡Institute of Software, Chinese Academy of Sciences, Beijing, China † ‡ Athlone Institute of Technology, Athlone, Ireland IEEE WCNC 2009

2. Outline • Introduction • Interference Based Channel Assignment • Performance Evaluation • Conclusion

3. Introduction • The performance of the IEEE 802.11 a/b/g-based WMNs can be increased via the use of multiple channels.

4. Introduction • The channel allocation and interface assignment schemes • Static algorithms • Assign channels and interfaces permanently • Dynamic algorithms • Allow the wireless mesh network to adapt to the changing traffic patterns • Short term basis

5. Introduction • We define the requirements of a multi-channel, multi-interface solution as follows: • Improve network capacity • Utilizing all the available channels and channel-switch, even if the number of interfaces is smaller than the number of available channels.

6. Introduction • We define the requirements of a multi-channel, multi-interface solution as follows: • The interference should be considered from the start. • At that time, there is no traffic in the network. The adaptive channel switch can improve the network performance. • Two nodes that communicate with each other directly should share at least one common channel.

7. Enhanced AODV Route in WMNs CH12 CH4 CH8 CH8 CH4 CH7 CH11 CH7 CH11 CH11 CH9 CH3 CH6 CH3 CH6 CH11 CH1 CH1

8. Interference Based Channel Assignment C B A E F D

9. Interference Based Channel Assignment Level=0 Level=1 Level=2 7 8 9 Level=3 Level=1 Level=2 12 13 14 Level=2 Level=3 Level=4 17 18 19

10. Interference Based Channel Assignment The current maximum number of neighbor 7 8 9 8 7 17 7 3 2 2 2 12 13 14 7 17 8 7 List 2 2 3 2 17 18 19

11. Interference Based Channel Assignment The current maximum number of neighbor 7 8 9 12 13 14 13 12 8 18 7 14 List 3 3 3 3 2 4 9 17 18 19 …

12. Interference Based Channel Assignment The current maximum number of neighbor 7 8 9 12 13 14 13 12 8 18 7 14 List 3 3 3 3 2 4 9 17 18 19 …

13. Interference Based Channel Assignment pair(7,19) pair(8,18) pair(19,17) 7 8 9 12 13 14 17 18 19

14. Interference Based Channel Assignment pair(7,19) pair(8,18) pair(19,17) transmitting receiving 7 8 9 transmitting receiving 12 13 14 17 18 19

15. Performance Evaluation • ns-2 • 12 channels • sense range : 22 meters • hear range : 44 meters • This means every node is sense range can be the neighbors of each other

16. Performance Evaluation

17. Performance Evaluation

18. Performance Evaluation

19. Performance Evaluation

20. Conclusion • We proposed a static channel assignment algorithm KN-CA is used to avoid the interference before the traffic going. • We have implemented all the system in ns-2 simulator. And the simulation results show how the performance is improved after channel switched.