1. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 1 July 2009 W. Y. Lee et. al Contention-based Directional MAC Protocols: A Survey Date: 2009-07-14 Authors:

2. doc.: IEEE 802.11-09/0796r0 Submission Taxonomy of Contention-based Directional MAC Protocols Slide 2 July 2009 W. Y. Lee et. al CSMA/CA based protocols Data/ACKs are transmitted directionally

3. doc.: IEEE 802.11-09/0796r0 Submission Non-Circular Directional MAC Protocols Slide 3W. Y. Lee et. al July 2009

4. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 4 July 2009 W. Y. Lee et. al Omni-directional RTS/ Omni-directional CTS

5. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 5 July 2009 W. Y. Lee et. al A MAC protocol for mobile ad-hoc networks using directional antennas Mulitple Non-circular Directional antennas Assumed RTS is transmitted omni- directionally via all antennas (ORTS) A.Nasipuri, S.Ye,J.You,R.E.Hiromoto, "A MAC protocol for mobile ad-hoc networks using directional antennas", In Proceedings of IEEE Wireless Communications and Networking Conference(WCNC), Chicago, IL, 2000

6. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 6 July 2009 W. Y. Lee et. al A MAC protocol for mobile ad-hoc networks using directional antennas If not intended receiver for the RTS, it blocks its antenna(s). Nodes overhearing RTS blocks its antennas => bad spatial reuse A.Nasipuri, S.Ye,J.You,R.E.Hiromoto, "A MAC protocol for mobile ad-hoc networks using directional antennas", In Proceedings of IEEE Wireless Communications and Networking Conference(WCNC), Chicago, IL, 2000

7. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 7 July 2009 W. Y. Lee et. al A MAC protocol for mobile ad-hoc networks using directional antennas If intended receiver for the RTS, it transmits CTS omni-directionally via all antennas (OCTS) If not intended receiver for the CTS, it blocks its antenna(s). Nodes overhearing CTS blocks its antennas => bad spatial reuse A.Nasipuri, S.Ye,J.You,R.E.Hiromoto, "A MAC protocol for mobile ad-hoc networks using directional antennas", In Proceedings of IEEE Wireless Communications and Networking Conference(WCNC), Chicago, IL, 2000

8. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 8 July 2009 W. Y. Lee et. al A MAC protocol for mobile ad-hoc networks using directional antennas The originators of RTS and CTS block all antennas except the one that is used for DATA/ACK. A.Nasipuri, S.Ye,J.You,R.E.Hiromoto, "A MAC protocol for mobile ad-hoc networks using directional antennas", In Proceedings of IEEE Wireless Communications and Networking Conference(WCNC), Chicago, IL, 2000

9. doc.: IEEE 802.11-09/0796r0 Submission A MAC protocol for mobile ad-hoc networks using directional antennas Slide 9 July 2009 W. Y. Lee et. al Event-driven simulator (M=# of antennas)

10. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 10 July 2009 W. Y. Lee et. al A MAC protocol for mobile ad-hoc networks using directional antennas Tx/Rx RTS (Tx)Omni (via M antennas) RTS (Rx)Omni CTS (Tx)Omni (via M antennas) CTS (Rx)Omni Info in RTS/CTS frameSource Address/Destination Address Additional Control FrameNone Additional Info stored in a deviceNone Deafness problemIntermediate since ORTS/OCTS can inform neighboring nodes projected communication Hidden node problemBad since directional DATA can interfere other ongoing communications (Asymmetry in gain) Spatial Reuse FeatureSince nodes overhearing RTS or CTS blocks their antennas, the spatial reuse is bad.

11. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 11 July 2009 W. Y. Lee et. al Directional RTS/ Omni-directional CTS

12. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 12 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks DMAC: Directional MAC (the first DMAC, but its name has been shared by several descendants.) Assumptions –Location information is determined by GPS (not in practice). –A node shares the location information with its neighbors. YB Ko, V Shankarkumar, and NH Vaidya, Medium access control protocols using directional antennas in ad hoc networks, INFOCOM 2000, Tel Aviv, Israel, 2000, pp. 13 – 21. N38 º W 27º N39 º W 28º

13. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 13 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks Since a source knows the destinations location, it transmits RTS to the destination directionally (DRTS). –If nodes overhear the DRTS, they block their antenna. –Nodes in other direction of the DRTS can exploit spatial reuse. YB Ko, V Shankarkumar, and NH Vaidya, Medium access control protocols using directional antennas in ad hoc networks, INFOCOM 2000, Tel Aviv, Israel, 2000, pp. 13 – 21. Destination Source DRTS

14. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 14 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks If the intended receiver receives the DRTS successfully, it responds with CTS omni-directionally (OCTS). Nodes overhearing OCTS block their antennas. YB Ko, V Shankarkumar, and NH Vaidya, Medium access control protocols using directional antennas in ad hoc networks, INFOCOM 2000, Tel Aviv, Israel, 2000, pp. 13 – 21. Source Destination OCTS OCTS

15. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 15 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks Spatial Reuse Improvement by using DRTS A BC D E DRTS (B,C) OCTS (C,B) DATA ACK OCTS (E,D) DRTS(D,E) DATA ACK Node D cannot transmit anything toward node C due to OCTS(C,B). Since Node Ds RTS is directional to E, node D can initiate DRTS to node E. Spatial reuse is improved by DRTS.

16. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 16 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks Problems –Since B transmits DRTS directionally to C, node A does not aware of it. (deafness) –This creates significant collisions from A. FABC D DRTS (B) DATA ACK OCTS(B,C) DRTS (A) OCTS(B,C)

17. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 17 July 2009 W. Y. Lee et. al Simulation (1/3) NS-2 based simulation Mesh topology No mobility Bulk TCP traffic based on several scenarios 2 Mbps links Two adjacent rows and two adjacent columns being separated by 200 meters Traffic model: FTP with infinite backlog at each source node TCP packet size: 1460 bytes Maximum advertised window is 8 packets 510152025 49141924 38131823 16111621 27121722

18. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 18 July 2009 W. Y. Lee et. al Simulation (2/3) Scenario 1 510152025 49141924 38131823 16111621 27121722 12 In 802.11, communication of connections 1 and 2 cannot occur at the same time unlike in DMAC Fairness in 802.11 is not good unlike in DMAC ConnectionsIEEE802.11DMAC No.11130.42771.27 No.2214.571040.21 Total throughput1344.991811.48

19. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 19 July 2009 W. Y. Lee et. al Simulation (3/3) Scenario 2 510152025 49141924 38131823 16111621 27121722 3 4 ConnectionsIEEE802.11DMAC No.3653.641250.14 No.4634.581251.64 Total throughput1288.222501.78 Better throughput at the DMAC since it exploits spatial reuse.

20. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 20 July 2009 W. Y. Lee et. al Medium access control protocols using directional antennas in ad hoc networks Tx/RxDMAC RTS (Tx)Directional RTS (Rx)Omni CTS (Tx)Omni CTS (Rx)Omni Info in RTS/CTS frameSource Address/Destination Address Additional Control FrameControl Frame for sharing location of neighboring nodes Additional Info stored in a deviceDevices location information by GPS Deafness problemDirectional RTS can cause the Deafness problem behind the RTS originator. Hidden node problemDirectional RTS can cause the Hidden node problem behind the RTS originator. Spatial Reuse FeatureIntermediate since originator of RTS has its direction of communication

21. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 21 July 2009 W. Y. Lee et. al Directional RTS/ Directional CTS

22. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 22 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks DMAC/DA protocol –Each device maintains a neighbor table by communication history. –Devices neighbor table maps each neighboring nodes ID with that devices beam number. –Deafness duration: the time of Deafness (initiated by WTS), e.g., C notifies that C will be busy for T c. –Link Activity: Latest transmission time from backlogged nodes (e.g., D and E). => WTS is necessary M Takata, M Bandai and T Watanabe, "MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks," Proc. IEEE Goblecom 2007, pp.620-625, 2007 E A B C D (1) (2) (3) (4) (5) (6)

23. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 23 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks –(1) DRTS –(2) DCTS –WTS is transmitted circularly to avoid deafness and hidden node problem (3) WTS (Wait-to-Send) A->E and B->G (4) WTS A->D –(5) DATA –(6) ACK M Takata, M Bandai and T Watanabe, "MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks," Proc. IEEE Goblecom 2007, pp.620-625, 2007

24. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 24 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks –WTS (Wait To Send) message

25. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 25 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks Simulation –Event Driven –Node: 100 (randomly distributed) –1500x1500m –Transmission range Omni: 250m Directional: 500m –Data rate:11Mbps

26. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 26 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks Simulation Result NPN: Next Packet Notification (to increase throughput) PCS: Physical Carrier Sensing MDA: MAC protocol for Directional Antenna [12]

27. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 27 July 2009 W. Y. Lee et. al MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks Tx/RxDMCA/DA with NPN RTS (Tx)Directional RTS (Rx)Omni CTS (Tx)Directional CTS (Rx)Omni Info in RTS/CTS frame Source Address/Destination Address, # of WTSs (which will synchronizes the transmission time of DATA) Additional Control FrameWTS Additional Info stored in a deviceNeighbor Table (Beam index, Deafness duration, and Link Activity) Deafness problem Intermediate since WTS can effectively avoid deafness problem (But not enough since WTS is selectively transmitted to subset of beams) Hidden node problem Intermediate since WTS can effectively avoid hidden node problem (But not enough since WTS is selectively transmitted to subset of beams) Spatial Reuse FeatureGood since neighbor table is maintained

28. doc.: IEEE 802.11-09/0796r0 Submission Circular Directional MAC Protocols Slide 28W. Y. Lee et. al July 2009

29. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 29 July 2009 W. Y. Lee et. al Circular Directional RTS/ Directional CTS

30. doc.: IEEE 802.11-09/0796r0 Submission MeNeighborMy beam Neighbors beam AB42 A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks CRTS protocol maintains location table –Through Circular RTS, each node records location table. July 2009 W. Y. Lee et. alSlide 30 Tx beam 2 A B Rx beam 4 T. Korakis, G. Jakllari, and L. Tassiulas, "A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks," Proc. ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc), pp.98–107, June 2003. Circular RTS (B with Tx beam 2)

31. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 31 July 2009 W. Y. Lee et. al CRTS protocol –Source node transmits RTS c ircularly. –Destination node transmits CTS directionally toward RTS originator. –Nodes behind the destination does not aware of it. –Node receiving either RTS or CTS blocks its corresponding antenna. A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks T. Korakis, G. Jakllari, and L. Tassiulas, "A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks," Proc. ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc), pp.98–107, June 2003. Circular DRTS DCTS

32. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 32 July 2009 W. Y. Lee et. al Problem of CRTS protocol –Since DCTS does not inform nodes behind the destination node, collision may occur (hidden node problem) A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks T. Korakis, G. Jakllari, and L. Tassiulas, "A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks," Proc. ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc), pp.98–107, June 2003. Collision Circular DRTS DCTS

33. doc.: IEEE 802.11-09/0796r0 Submission A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks Simulation –Event driven simulation –Physical channel is error free –Propagation delay is zero –Packet length is constant and equal to 1024 bytes –The packet arrival at each station is a Poisson process with the same mean –Each simulation runs for 200 seconds with a warm up period of 50 seconds. July 2009 W. Y. Lee et. alSlide 33

34. doc.: IEEE 802.11-09/0796r0 Submission A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks Simulation –Scenario 1 July 2009 W. Y. Lee et. alSlide 34 Throughput (%) In high load DMAC (DRTS/OCTS) CRTS Node A33.3440.21 Node C15.5739.89 Total throughput48.9180.1 (2) Now, C is trying to send RTS to B DMAC: Since either DRTS from A or OCTS from B does not reach to C, C can continuously transmit RTS to B (Hidden node problem) CRTS: Since As CRTS inform C of communication with B, C suppress its RTS. (1)A and B are communicating

35. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 35 July 2009 W. Y. Lee et. al A MAC protocol for full exploitation of directional antennas in ad-hoc wireless networks Tx/RxCRTS RTS (Tx)Circular (one round and waits until CTS) RTS (Rx)Omni CTS (Tx)Directional to the RTS beam CTS (Rx)Omni Info in RTS/CTS frameSource Address/Destination Address, Source Beam Index/ Destination Beam Index Additional Control FrameNone Additional Info stored in a deviceLocation Table Deafness problemBad since CTS is transmitted directionally Hidden node problemBad since CTS is transmitted directionally Spatial Reuse FeatureGood since location table is maintained

36. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 36 July 2009 W. Y. Lee et. al Circular Directional RTS/ Circular Directional CTS

37. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 37 July 2009 W. Y. Lee et. al Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks CRCM (Circular RTS and CTS MAC) protocol –Source transmits RTS circularly –Destination sends CTS circularly –Circular CTS is partially transmitted to non-overlapping region of CRTS to reduce overhead. –Node receiving either RTS or CTS blocks its corresponding antenna. –Circular RTS/CTS reduces Deafness and hidden node problems. Circular RTS Circular CTS G Jakllari, J Broustis, T Korakis,S V. Krishnamurthy, and L Tassiulas, "Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks," Proc. IEEE 16th International Symposium on PIMRC, pp.1284-1288, 2005 Location of RTS originator is determined by location table

38. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 38 July 2009 W. Y. Lee et. al Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks Location tracking and maintenance –Using location table, relative location of nodes can be figured out. –Under the following scenario, node C needs to block beams 2 and 4. 4 4

39. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 39 July 2009 W. Y. Lee et. al Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks Simulation –Opnet ver. 10.0 –4 nodes in the line 2134 RTS Scenario: Node 2 initiates communication to node 3. Now, node 4 tries to send RTS to node 3 in CRTS protocol. Throughput of CRCM is better than CRTS.

40. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 40 July 2009 W. Y. Lee et. al Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks Tx/RxCRCM RTS (Tx)Circular (one round and waits until CTS) RTS (Rx)Omni CTS (Tx)Circular CTS (Rx)Omni Info in RTS/CTS frameSource Address/Destination Address, Source Beam Index/ Destination Beam Index Additional Control FrameNone Additional Info stored in a deviceLocation Table Deafness problemIntermediate since circular RTS and circular CTS Hidden node problemIntermediate since circular RTS and circular CTS Spatial Reuse FeatureGood since location table is maintained

41. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 41 July 2009 W. Y. Lee et. al Comparison of Directional MAC Protocols Non-Circular DMACCircular DMAC ORTS/OCTSDRTS/OCTSDRTS/DCTSCRTS/DCTSCRTS/CCTS DMACNasipuri et alCW-MACDMACToneDMACMMACDMAC/DAUDAANCRTSDMAC-PDXCRCM [Infocom00][WCNC00][COMSWARE07][Infocom00][Tech report][Mobicom02,[Globecom07][JSAC05][Mobihoc03,[Globecom07][PIMRC05] (Scheme 2) (Scheme 1),TMC06] TMC08] RTS Tx/Omni/ Directional/ Circular/ RTS RxOmni Directional/ Omni, Directional CTS Tx/Omni/ Directional/ Circular/ CTS RxOmni Directional Omni DirectionalOmni DATA Tx/Directional/ DATA RxDirectional ACK Tx/Directional/ ACK RxDirectional Additional Control Frame None Tone Multihop RTS WTS None Test frameNone (out-of-band)Wait to Send DeafnessIntermediate GoodBadIntermediateBadIntermediateBad Intermediate Hidden IntermediateBadGoodBadIntermediateBadIntermediateBad Intermediate Node Spatial Bad Intermediate BadIntermediateGood IntermediateGood Reuse

42. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 42 July 2009 W. Y. Lee et. al References [1] A.Nasipuri, S.Ye,J.You, R.E.Hiromoto, "A MAC protocol for mobile ad-hoc networks using directional antennas", In Proceedings of IEEE Wireless Communications and Networking Conference(WCNC), Chicago, I L, 2000 [2] YB Ko, V Shankarkumar, and NH Vaidya, Medium access control protocols using directional antennas in ad hoc networks, INFOCOM 2000, Tel Aviv, Israel, 2000, pp. 13 – 21. [3] R. R. Choudhury and NH Vaidya, Deafness: a mac problem in ad hoc networks when using directional antennas, ICNP 2004, pp. 283 – 292. [4] R. R. Choudhury, X. Yang, R. Ramanathan and NH Vaidya, On designing MAC protocols for wireless networks using directional antennas, IEEE Trans. Mobile Computing, Volume 5, Issue 5, May 2006, pp.477 – 491 [5] R.R. Choudhury, X. Yang, N.H. Vaidya, and R. Ramanathan, Using Directional Antennas for Medium Access Control in Ad Hoc Networks, Proc. ACM MobiCom, June 2002 [6] M. Takata, M. Bandai and T. Watanabe, "MAC Protocol with Directional Antennas for Deafness Avoidance in Ad Hoc Networks," Proc. IEEE GLOBECOM, pp.620- 625, 2007 [7] R. Ramanathan, "Ad Hoc Networking With Directional Antennas: A Complete System Solution," IEEE JSAC 2005, vol.23, no.3, pp.496-506, Mar 2005 [8] G. Jakllari, J. Broustis, T. Korakis,S V. Krishnamurthy, and L. Tassiulas, "Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks," Proc. IEEE 16th International Symposium on PIMRC, pp.1284-1288

43. doc.: IEEE 802.11-09/0796r0 SubmissionSlide 43 July 2009 W. Y. Lee et. al [9] F. Yildirim and H. Liu, "Directional MAC for 60 GHz using Polarization Diversity Extension (DMAC-PDX)," Proc. IEEE GLOBECOM, pp.4697-4701, 2007 [10] G. Li, L.L. Yang, "On Utilizing Directional Antenna in 802.11 Networks: Deafness Study," Proc. IEEE COMSWARE 2007, pp. 1-6, Jan 2007 [11] A P Subramanian and S R. Das, "Addressing Deafness and Hidden Terminal Problem in Directional Antenna based Wireless Multi-Hop Networks," Proc. IEEE COMSWARE,pp. 1-6, Jan. 2007 [12] H. Gossain, C. Cordeiro and D. P. Agrawal, MDA: An Efficient Directional MAC scheme for Wireless Ad Hoc Networks, Proc. IEEE GLOBECOM, Nov. 2005. [13] T. Korakis, G. Jakllari, and L. Tassiulas, "A A MAC protocol for full exploitation of Directional Antennas in Ad-hoc Wireless Networks", Proc. ACM MobiHoc 2003, 2003 [14] T. Korakis, G. Jakllari, and L. Tassiulas, "CDR-MAC: A Protocol for Full Exploitation of Directional Antennas in Ad Hoc Wireless Networks," IEEE Transactions on Mobile Computing, Vol.7, No.2, Feb 2008. [15] M. Taksata, M. Bandai, and T. Watanabe, "A Directional MAC Protocol with Deafness Avoidance in Ad Hoc Networks," IEICE Trans. Commun, Vol.E90-B, No.4, APR 2007 [16] M. Takata, M. Bandai, and T. Watanabe, Performance analysis of a directional MAC protocol for location information staleness in MANETs, IPSJ J., vol.46, no.11, pp.2623–2632, Nov. 2005. [17] J. Wang, Y. Fang, and D. Wu, SYN-DMAC: A directional MAC protocol for ad hoc networks with synchronization, Proc. IEEE Military Communications Conference (MILCOM), pp.2258–2263, Oct. 2005. [18] M. Takata, K. Nagashima, and T. Watanabe, A dual access mode MAC protocol for ad hoc networks using smart antennas, Proc. IEEE International Conference on Communications (ICC), pp.4182–4186, June 2004.