The Design of power saving mechanisms in Ethernet Passive Optical Networks

1. The Design of power saving mechanisms in Ethernet Passive Optical Networks Yun-Ting Chiang Advisor: Prof Dr. Ho-Ting Wu 2014.01.09

2. Outline • Introduction • Motivation and Research Objective • Research Background • Passive Optical Network (PON) • EPON (Ethernet PON) • Multi-Point Control Protocol (MPCP) • Interleaved Polling with Adaptive Cycle Time (IPACT) • Power Saving Mode on ONU

3. Outline • The Design of Power Saving mechanisms in EPON • ONU power saving mode • Power saving and MPCP • The design of ONU three mode transform mechanism (Sleep to Doze) • Transform mechanism and Timer • Scheduling for transform mechanism • Downstream scheduling • Simulation result and Discussion • Conclusion and Future work • Reference

4. Introduction : Motivation and Research Objective • Motivation • Greenhouse Effect • End users require much bandwidth • Research Objective • Consider both performance and power saving

5. Passive Optical Network (PON) • Optical line terminal (OLT) • Optical network units (ONUs) or Optical network terminals (ONTs) • Use broadcast on Downstream • Use TDMA on Upstream

6. Multi-Point Control Protocol (MPCP) • REPORT and GATE message • REPORT • ONU to report its bandwidth requirements • OLT passes REPORT to the DBA algorithm • GATE • After executing DBA algorithm, OLT transmits GATE downstream to issue up to four transmission grants to ONU • Transmission start time • Transmission length • Timestamp (used by ONU for synchronization)

7. Interleaved Polling with Adaptive Cycle Time (IPACT) • OLT maintain a Table with Byte and RTT • First grant, G(1), is set to some arbitrary value • In polling cycle n, ONU measures its backlog in bytes at end of current upstream data transmission & piggybacks the reported queue size, Q(n), at end of G(n) • Q(n) used by OLT to determine next grant G(n+1) => adaptive cycle time & dynamic bandwidth allocation • If Q(n)=0, OLT issues zero-byte grant to let ONU report its backlog for next grant

8. Figure source: “IPACT: A Dynamic Protocol for an Ethernet PON”

9. Power Saving Mode on ONU : L. Shi’s research[1] Two energy-modes in ONU • In L. Shi, B. Mukherjee, and S. S. Lee, "Efficient PON with Sleep-Mode ONU: Progress, Challenges, and Solutions," refer two energy-modes including active and sleep modes. They separatehigh/low priority packet.

10. Power Saving ModeonONU : L. Shi’s research[1] Two energy-modes in ONU • Time overhead and Power overhead • When ONU switch mode will have overhead. • Sleep to Active : Time overhead (2.125ms) • Active to Sleep : Power overhead • Early wake up

11. Early wake up Because of Toverhead, ONU have wait 2.125ms to receive GATE msg. from OLT

12. ONU power saving mode • Active mode • Tx : on, Rx: off • Doze mode • Tx : off , Rx : on, support early wake up • Sleep mode • Tx: off , Rx : off, support early wake up • p.s. Tx use to transmit REPORT • Rx use to receive GATE

13. Power saving mode and MPCP • In MPCP, OLT and ONU have to handshake every 50ms. In order to decrease power consumption, we have to extend the rule.

14. Improve three energy-modes in ONU • Increase doze mode’s utilization • Decrease three energy-modes switching

15. The design of ONU three mode transform mechanism (Sleep to Doze) A -> S [1] No upstream and downstream data when OLT get ONUx’s REPORT. A -> D [2] No upstream data but has downstream data when OLT get ONUx’s REPORT S -> A [3] Upstream high priority data coming // Early wake up S -> D [4] Stay at sleep mode for consecutive Y clock // variable Y protects downstream high priority data，Yis maximum of downstream high priority datadelay.

16. The design of ONU three mode transform mechanism (Sleep to Doze) D -> A [5] Stay at doze mode for consecutive Z clock || upstream high priority data coming // Timer avoids upstream long low priority data delay //variableY、Zprotects upstream low priority data ， Y+Zismaximum upstream low priority data delay p.s. Active mode trigger: If reportmsg. request bandwidth = 0, means no upstream data.

17. Transform mechanism and Timer • Because we can’t use REPORT msg. in doze mode and sleep mode, we have to use timer to synchronize. Then OLT will know the state of ONUs.

18. Downstream scheduling • Although downstream slot and upstream slot are difference but there have some relationship. // Downstream Data&& GATE • Different from general EPON, because ONU[x] in sleep mode, OLT can’t send downstream data, downstream scheduling have to be considered. • ONUs’ doze mode maybe overlap so OLT need to select one of ONUs to send downstream data.

19. How to select an ONU to service • We have 32 queue for downstream data to ONUs. • Check downstream queues have data or not. • Ignore no data queues • Separate Active table, Doze table and Sleep table • Ignore sleep table • If (Doze table is empty) { If ( Active table is empty ) return false; // means no ONU have to service else // return an ONU which select by round-robin from Active table ; } // end if else // return an ONU which select by round-robin from Doze table ;

20. Upstream scheduling • Using Limited service. • Limited service : OLT grants requested number of bytes, but no more than MTW • OLT polling table record ONU state.

21. SimulationResult • ONU = 16 • ONU queue size 100MByte • EPON Frame size = 64Bytes ~ 1518 Bytes • Channel capacity = 1Gbps • Max rate = 100 * 1000 * 1000 = 100Mbps • Guard time = 5 * 10-6 • Y = 20ms, Timer, use to change mode from sleep to doze • Z = 50ms, Timer, use to change mode from doze to active • Simulation time 11s (1s warm-up)

22. Dynamic downstream loading

23. Dynamic downstream loading

24. Dynamic downstream loading

25. Dynamic downstream loading:upstream high priority ratio 100%

26. Dynamic downstream loading:upstream high priority ratio 100%

27. Dynamic downstream loading:no upstream

28. Dynamic downstream loading:no upstream

29. Dynamic upstream loading

30. Dynamic upstream loading

31. Dynamic upstream loading

32. Conclusion • In this study, power saving mechanisms focus on reduce high priority downstream data delay in power saving EPON. • In order to raise up doze mode utilization, we design Sleep to Doze transform mechanism to increase it. • All results discuss between power saving and performance, it’s trade off. Maybe we can improve traffic scheduling or switching mechanism for future.

33. Future work • System parameter test • Improve scheduling algorithm • Doze to sleep transform mechanism • Bidirectional transform mechanism

34. System parameter test • Timer : Y • Timer : Z • Different Timer set will change power consumptionand performance

35. Improve scheduling algorithm • We also can improve scheduling algorithm to reduce much power and increase performance

36. Doze to sleep transform mechanism

37. Bidirectional transform mechanism

38. Reference [1] L. Shi et al., "Efficient PON with Sleep-Mode ONU: Progress, Challenges, and Solutions," IEEE Network Magazine, vol. 26, no. 2, pp. 36-41, march-april 2012. [2] J. Mandin, "EPON Powersaving via Sleep Mode," IEEE 802.3av Meeting, 2008. [3] L. Zhang et al., "Dual DEB-GPS Scheduler for Delay-Constraint Applications in Ethernet Passive Optical Networks," IECE Trans. Commun., Vols. E86-B, no. 5, pp. 1575-1584, 2003. [4] Intel, "Intel and Ethernet," [Online]. Available: http://www.intel.com/content/www/us/en/standards/ethernet-innovation-case-study.html.

39. [5] COMMSCOPE, "White Paper GPON - EPON Comparison," 2012. [Online]. Available:http://www.commscope.com/. [Accessed 7 11 2013]. [6] J. Kani, S. Shimazu, N. Yoshimoto, and H. Hadama, "Energy efficient optical access networks - Issues and technologies," IEEE Commun. Mag., vol. 51, no. 2, pp. S22-S26, Feb. 2013. [7] ITU-T, “G.Sup 45 : GPON power conservation,” 2009. [8] D. Hood, Gigabit-capable Passive Optical Networks, Hoboken : John Wiley & Sons, 2012. [9] ITU-T, Recommendation G.987.3, 2010-10.

40. [10] M. Ma, Y. Zhu, and T. Cheng, "A Bandwidth Guaranteed Polling MAC Protocol for Ethernet Passive Optical Network," Proc. IEEE INFOCOM, vol. 1, pp. 22-31, August 2003. [11] S.-I. Choi, J-D Huh, "Dynamic Bandwidth Allocation Algorithm for Mutimedia Services over Ethernet PONs," ETRI Journal, vol. 24, no. 6, pp. 465-468, Dec. 2002. [12] C. Assi et al., "Dynamic Bandwidth Allocation for Quality-of-Service Over Ethernet PONs," IEEE JSAC, vol. 21, no. 9, pp. 1467-77, Nov. 2003. [13] G. Kramer, B. Mukherjee, and G. Pesavento, "IPACT: A Dynamic Protocol for an Ethernet PON (EPON)," IEEE Commun. Mag., vol. 40, no. 2, pp. 66-73, Feb. 2002. [14] G. Kramer et al., "Supporting differentiated classes of service in Ethernet passive optical network," OSA J. Opt. Net., vol. 1, no. 8, pp. 280-298, Aug. 2002.

41. [15] R. Kubo, J. Kani, Y. Fujimoto, N. Yoshimoto, and K. Kumozaki, "Adaptive Power Saving Mechanism for 10 Gigabit Class PON Systems," IEICE Trans. Commun., Vols. E93-B, no. 2, pp. 280-288, Feb. 2010. [16] X. Guo, G. Shou, Q. Xiao, Y. Hu, Z. Guo, “Toward green PON with adaptive sleep mode,” IC-NIDC, pp. 184-188, Sept. 2012. [17] Y. Yan, S.-W. Wong, L. Valcarenghi, S.-H. Yen, D. Campelo, S. Yamashita, L. Kazovsky, and L. Dittmann, "Energy Management Mechanism For Ethernet Passive Optical Networks (EPONs)," May 2010.

42. Thanks for your listening