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WDM-EPON DBA

WDM-EPON DBA. Liu Zhe 11. Outline. Background WDM Extensions to MPCP Classification of DBA Simulation Results of online and offline DBA ref: Michael P. McGarry etc. “ WDM ETHERNET PASSIVE OPTICAL NETWORKS ” IEEE Optical Communications • February 2006

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WDM-EPON DBA

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  1. WDM-EPON DBA Liu Zhe 11.

  2. Outline • Background • WDM Extensions to MPCP • Classification of DBA • Simulation Results of online and offline DBA ref: Michael P. McGarry etc. “WDM ETHERNET PASSIVE OPTICAL NETWORKS” IEEE Optical Communications • February 2006 • Problem definition of online DBA • Results ref: KonstantinosKanonakis etc. “Improving the Efficiency of Online Upstream Scheduling and Wavelength Assignment in Hybrid WDM/TDMA EPON Networks” IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 28, NO. 6, AUGUST 2010

  3. Background Bandwidth update: 1) Increase the line rate of TDM EPONs all nodes need to be upgraded, result costly 2) WDM EPON provide a cautious upgrade path that is pay-as-you-grow manner

  4. WDM Extensions to MPCP • Discovery and Registration 1) Tx_type and Rx_type 2) Tx_tuning_time and Rx_tuning_time 3) Wavelength_id_type 4) Tx_waveband and Rx_waveband 5) Tx_surported_wavelength and Rx_surported_wavelength

  5. Classification of DBA • Online Scheduling ONU is scheduled as soon as the OLT receives the RPT PDU from this ONU • Offline Scheduling ONUs are scheduled once the OLT has received the RPT PDU from all ONUs • Just-in-Time Scheduling ONUs are scheduled once the OLT has received the RPT PDU from part of all ONUs

  6. Online Scheduling • NASC(next available supported channel) policy: schedule the upstream transmission for an ONU on the wavelength channel available earliest among the channels supported by the ONU

  7. Offline Scheduling ISCG(inter-sheduling cycle gap)=the computation time + transmission time for Grant PDU + RTT to the first ONU in the next round least flexible job (LFJ) first policy:schedules transmissions by the ONUsthat support the fewest wavelength channels

  8. Simulation Results • Requirement 1) 10 ONUs(5 lightly loaded non-WDM ONUs & 5 heavily loaded WDM ONUs) 2) WDM ONUs support all wavelengths using a tunable Tx with negligible tuning time 3) Each wavelength supports 1Gb/s link speed 4) scheduler grants each ONU the full bandwidth request

  9. Problem definition of online DBA • Spread of round-trip values among the various ONUs results the scheduling voids which can not be utilized in online DBA

  10. i波长中最新的调度结束时间 第K个ONU支持的波长集合 请求多少就授权多少 W波长上的第n个授权起始时间满足的条件 授权窗口不出现重合

  11. Solutions for online USWA • EFT(Earliest Finish Time)、LFT(Latest Finish Time) • EFT-VF，LFT-VF (VF: Void Filling) • DBG(Distance-Based Grouping)

  12. The EFT Algorithm • 波长选择为最近调度中最早完成的那个波长 • 该波长中最近完成的调度序号j

  13. The LFT Algorithm

  14. The EFT-VF Algorithm

  15. The DBG Concept

  16. Simulation Requirement 1) GENERIC topology 2) N = 32, L = 0.1~0.9 , w = 4 3) guard band of 5us between different ONUs for laser tuning delays 4) inter-packet gap(IPG) is 96ns 5) the network load is be provided in Erlangs per wavelength 6) Ethernet frames were generated at each ONU 7) all ONUs support all W upstream wavelengths Performance metrics were the average end-to-end delay

  17. Simulation Result 1 1. 不同波长数的EFT算法下端到端延时

  18. Simulation Result 2 2. 不同算法下的波长利用率

  19. Simulation Result 3 3. 不同算法下端到端延时

  20. Simulation Result 4 4. 不同Dk下EFT-VF算法相对于EFT算法端到端延时的减少量

  21. Conclusion • Online USWA does better than offline in end-to-end delay • LFT , EFT-VF, LFT-VF ,DBG scheme reduce the delay ,comparing to the EFT

  22. Thank you

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