1. Exploiting Spectral Reuse in Resource Allocation, Scheduling,and Routing for IEEE 802.16 Mesh Networks Lien-Wu Chen, Yu-Chee Tseng Department of Computer Science, National Chiao-Tung University Da-Wei Wang, and Jan-Jan Wu Institute of Information Science, Academia Sinica IEEE VTC 2007

2. Outline  Introduction  Related work  Resource Allocation and Scheduling Schemes  Routing Tree Construction  Simulation  Conclusion

3. Introduction  The IEEE 802.16d specifies a centralized scheduling scheme for mesh networks  The SSs notify the BS Data transfer requirements The quality of their links to their neighbors  The BS uses the topology information along with the requirements of each SS to decide the routing and the scheduling

4. Background_ maintain routing tree BS broadcast MSH-CSCF (Mesh Centralized Scheduling Configuration) message to all SSs

5. Background_ uplink and downlink (1) BS collects MSH-CSCH: request (Mesh Centralized Scheduling) message from all SSs (2) BS broadcasts MSH-CSCH:grant to all SSs Request grant

6.  Title: Interference-Aware IEEE 802.16 WiMax Mesh Networks  Authors: H.-Y. Wei, S. Ganguly, R. Izmailov, and Z. Haas.  From: IEEE VTC’05 Related Work

8.  the algorithm does not fully exploit spectral reuse and it is not load- aware Related Work

9.  Title: Spatial Reuse in IEEE 802.16 Based Wireless Mesh Networks  Authors: L. Fu, Z. Cao, and P. Fan.  From: IEEE ISCIT’05 Related Work

10. link 1,4,7 and link 2,5,8 are simultaneous, respectively L8 SS 8 SS 7 SS 6 SS 5 SS 4 SS 3 SS 2 SS 1 L7 L6L5L4L3L2L1

11. Related Work new

12.  the algorithm does not fully exploit spectral reuse and it is not load- aware  Although how to attach a new SS to a mesh tree is discussed, but scheduling is not addressed in that work Related Work

13. Resource Allocation and Scheduling Schemes_ goal  First, dynamically adapt the bandwidths between uplink and downlink subchannels  Second, proportionally allocate frame timeslots among SSs  Finally, obtain higher gateway throughput based on the above two manners.

14. Resource Allocation and Scheduling Schemes_ System Model

15. Resource Allocation and Scheduling Schemes is uplink rate of SS i is uplink traffic demands of SS i is the demand of transmission time of SS i is the total uplink transmission time of the network is the total uplink transmission time of extended neighborhood of SS i

16. Resource Allocation and Scheduling Schemes time SS 1 addition The maximal transmission time for SS i = for non-real-time or best effort traffic

17. Resource Allocation and Scheduling Schemes, the bottleneck SS will see 100% busy carriers time

18. Resource Allocation and Scheduling Schemes  Channel-Level Scheduling  Link-Level Scheduling downlink time uplink Channel-Level Scheduling :

19. Resource Allocation and Scheduling Schemes_ link level scheduling 3 1 2 4 5 6 7 + Phase 1Phase 2

20. Resource Allocation and Scheduling Schemes

21. Routing Tree Construction

22. 1

23. 3 1 2 4 5 6 7 A={3,4,5,6,7} B={ } A={3,4,5,7} B={6 } Initial : is the highest data rate among links of SS j to its neighbors with less or equal hop count is uplink traffic demands of SS i,

24. Simulation System parameter :  A single channel OFDM PHY  A single BS ( node 0 )  84 SSs ( node 1 ~ 84 )  Channel bandwidth is set to 50Mb/s  Data rate of all links are the same  The extended neighborhood of each SS includes one-hop and two-hop neighbors

25. Simulation_ Physical Layer Parameter

26. Simulation_ Burst Profile

27. Conclusion  An integrated spectral reuse framework for centralized scheduling scheme and routing tree construction is developed  This method is most complete in exploiting spectral reuse

28. Thank You~