1. Multimedia and Mobile Communication Laboratory

2. Outline Multimedia and Mobile Communication Laboratory

3. Outline Multimedia and Mobile Communication Laboratory

4. 1. Introduction to CRN Cognitive Radio Network Dynamic spectrum access Opportunistically utilize spectrum resources Active monitoring, tuning, working Cognitive Radio Network Dynamic spectrum access Opportunistically utilize spectrum resources Active monitoring, tuning, working Multimedia and Mobile Communication Laboratory

5. Primary Users (PU), Secondary Users (SU) PU can start transmission anytime SU has to use bands occupied by no PU Primary Users (PU), Secondary Users (SU) PU can start transmission anytime SU has to use bands occupied by no PU Multimedia and Mobile Communication Laboratory Art of SUs life in CRN : Jump and fill in the blanks!

6. Outline Multimedia and Mobile Communication Laboratory

7. 2. Multi-radio Multi-path Multimedia and Mobile Communication Laboratory A B C DE

9. Multiple Cognitive Radios 1 for control signaling, M for data traffic Share mode Switch mode 1 + N bands, N M Multiple Paths Split transmission manner Duplicated transmission manner Multiple Cognitive Radios 1 for control signaling, M for data traffic Share mode Switch mode 1 + N bands, N M Multiple Paths Split transmission manner Duplicated transmission manner Multimedia and Mobile Communication Laboratory

10. Multi-path in Multi-radio Multi-hop CRN Multimedia and Mobile Communication Laboratory

11. Spectrum Pool All parameters of licensed/unlicensed bands Radio and Band Usage Table (RBT) B: Several available bands I: Number of flows that are using this band in this SU N: Number of flows that are using this band within 1-hop neighbors R: Which radio is using this band in this SU X will be used to indicate PU occupation Periodical exchange of hello message Spectrum Pool All parameters of licensed/unlicensed bands Radio and Band Usage Table (RBT) B: Several available bands I: Number of flows that are using this band in this SU N: Number of flows that are using this band within 1-hop neighbors R: Which radio is using this band in this SU X will be used to indicate PU occupation Periodical exchange of hello message Multimedia and Mobile Communication Laboratory

12. A Multi-radio Multi-hop CRN Example Existing SU flows: Current PU traffics: P1 : b1 P2 : b4 P3 : b5 A Multi-radio Multi-hop CRN Example Existing SU flows: Current PU traffics: P1 : b1 P2 : b4 P3 : b5 Multimedia and Mobile Communication Laboratory

13. Route Discovery (DSR-like) Attach its own RBT into the RREQ New RREQ_ID or old RREQ_ID but with hop count previous one rebroadcast (multipath) Route Discovery (DSR-like) Attach its own RBT into the RREQ New RREQ_ID or old RREQ_ID but with hop count previous one rebroadcast (multipath) RREQ with RBT S S A B D F E RREQ with RBT S, E RREQ with RBT S, A RREQ with RBT S, E, F RREQ with RBT S, A, B Multimedia and Mobile Communication Laboratory

14. RREQs arrives at D First RREQ Primary Path (PP) Later RREQs Candidate Path (CP) Radio & band selection Preference: Idle radio > Share > Switch RBTs should be updated after every comparison! RREQs arrives at D First RREQ Primary Path (PP) Later RREQs Candidate Path (CP) Radio & band selection Preference: Idle radio > Share > Switch RBTs should be updated after every comparison! Multimedia and Mobile Communication Laboratory

15. RBT S & RBT A RBT S & RBT A RBT A & RBT B RBT A & RBT B RBT B & RBT D RBT B & RBT D … … RBT S & RBT A RBT S & RBT A RBT A & RBT B RBT A & RBT B RBT B & RBT D RBT B & RBT D … … Multimedia and Mobile Communication Laboratory

16. Path Evaluation Metrics: Hop Count: N PP : Hop count of PP N CP : Hop count of CP Band Overlapping Factor: F CP α: weight factor balancing how we emphasize the jointness of paths Path Evaluation Metrics: Hop Count: N PP : Hop count of PP N CP : Hop count of CP Band Overlapping Factor: F CP α: weight factor balancing how we emphasize the jointness of paths Multimedia and Mobile Communication Laboratory

17. Finally, two paths are established: Primary Path: Secondary Path: ( selected from CPs) Data Striping: Packets will be splitted and transmitted throughput different paths simultaneously Dual path: odd / even Finally, two paths are established: Primary Path: Secondary Path: ( selected from CPs) Data Striping: Packets will be splitted and transmitted throughput different paths simultaneously Dual path: odd / even Multimedia and Mobile Communication Laboratory

18. Recovery: Multimedia and Mobile Communication Laboratory b1 S F P4 E b4 D b3 b1 1 2 1 3 1 2 X Stop transmitting to me, go other path! Who is involved in this PU insertion? New radio&band is assigned, lets keep going E 3 ---- 3 F 2 b2 3

19. Outline Multimedia and Mobile Communication Laboratory

20. 3. Evaluation MPMR vs. MPSR(SMR) vs. SPMR NS2 802.11a, 6Mbps, UDP 7 orthogonal channels from 11a: 36, 44, 52, 60, 149, 157, 165 3 radios 2 paths MPMR vs. MPSR(SMR) vs. SPMR NS2 802.11a, 6Mbps, UDP 7 orthogonal channels from 11a: 36, 44, 52, 60, 149, 157, 165 3 radios 2 paths Multimedia and Mobile Communication Laboratory

21. Maximum End-to-end Throughput: MPMR achieves much high end-to-end throughput MPSR uses single radio, low throughput SPMR uses one path, limited high throughput Maximum End-to-end Throughput: MPMR achieves much high end-to-end throughput MPSR uses single radio, low throughput SPMR uses one path, limited high throughput MPSR( ) Multimedia and Mobile Communication Laboratory

22. Recovery Evaluation P4 begins at 3 sec. E detects the insertion is interrupted E and F re-select b2 ~120 ms Recovery Evaluation P4 begins at 3 sec. E detects the insertion is interrupted E and F re-select b2 ~120 ms Multimedia and Mobile Communication Laboratory E 3 ---- 3 F 2

23. There is a degradation of throughput, for all MPSR achieves low throughput ( lets ignore it…) SPMR transmission is terminated MPMR keeps high speed transmission There is a degradation of throughput, for all MPSR achieves low throughput ( lets ignore it…) SPMR transmission is terminated MPMR keeps high speed transmission MPMR SPMR MPSR(SMR) Multimedia and Mobile Communication Laboratory

24. Outline Multimedia and Mobile Communication Laboratory

25. 4. Conclusion Multi-path Routing in Multi-radio Multi-hop Cognitive Radio Networks Route Discovery Radio/Band Selection Route Recovery Finally Higher route connectivity Higher end-to-end throughput Multi-path Routing in Multi-radio Multi-hop Cognitive Radio Networks Route Discovery Radio/Band Selection Route Recovery Finally Higher route connectivity Higher end-to-end throughput Multimedia and Mobile Communication Laboratory

26. Currently Massive simulations Detailed evaluation Future Work More efficient radio & band selection algorithm More evaluation metrics of paths Faster route recovery of SSs traffic Try to cancel the extra radio for control signal This is the most practical problem! Currently Massive simulations Detailed evaluation Future Work More efficient radio & band selection algorithm More evaluation metrics of paths Faster route recovery of SSs traffic Try to cancel the extra radio for control signal This is the most practical problem! Multimedia and Mobile Communication Laboratory