MAC Layer Algorithms for PON and Hybrid PON Access Networks PhD Comprehensive Exam: March 5 th, 2014 Anu Mercian Committee Members: Martin Reisslein (Chair) Michael McGarry Cihan Tepedelenlioglu Yanchao Zhang

Agenda Introduction Passive Optical Networks Dynamic Bandwidth Allocation (DBA) Extension-DBA: Multi-thread Polling Remote Message Scheduling Roadmap to Dissertation PON-DSL PON-Wireless or FiWi (Fiber-Wireless) Conclusion

Introduction Basic PON structure: –EPON IEEE 802.3ah (1Gbps), IEEE 802.3av (10Gbps) –GPON ITU-T G.984, ITU-T G.987 OLT ONU splitter ONU 0-15Km 0-5Km

PON Analysis Importance of PON MAC Layer Analysis: Upstream Traffic Modeling What changes can we bring in and where: Central Office for effective DBA. Other functions can be Routing, Load Balancing, Controllability PON Cycle: REPORT and GRANT

DBAs and their importance Grant Scheduling Framework: Offline and Online. Grant Sizing Framework: Gated, Limited, Excess Grant scheduling Policy: SPD Offline Scheduling Online Scheduling

Long-Reach PON Long range PON, advantageous - Multi- thread polling[1]. The original technique was based on “Offline” and we introduced a complementary DBA for LRPON, called Online MTP with much lower delay. OLT ONU splitter ONU Km [1] Huan Song; Byoung-Whi Kim; Mukherjee, B., "Multi-thread polling: a dynamic bandwidth distribution scheme in long-reach PON," Selected Areas in Communications, IEEE Journal on, vol.27, no.2, pp.134,142, February 2009

Motivation Questions Can scheduling policies be useful for techniques based on offline grant scheduling framework? SPD only, based on [2] Can fairness be achieved in MTP Online using online excess bandwidth distribution (OEBD) Implemented MTP Online a new technique and can be explored further. will it be promising for GPON as well? Similar performance as EPON Can multiple polling techniques be of use to LRPON Yes What if distances between ONU and OLT are random, how will the techniques perform? SPD will be of very useful How can delay performance for MTP online be improved for SRPON. MTP techniques are complex are used for Long-reach mostly.

Extensive Analysis of MTP * * Anu Mercian, Michael P. McGarry, and M. Reisslein. Offline and Online Multi-Thread Polling in Long-Reach PONs: A Critical Evaluation, IEEE/OSA Journal of Lightwave Technology, 31(12): , June Offline and Online Multi-Thread Polling in Long-Reach PONs: A Critical EvaluationIEEE/OSA Journal of Lightwave Technology, 31(12)

MTP Offline & Online

Quantitative Analysis Difference of MTP On and MTP Off Online Excess Bandwidth

Thread Tuning: To balance the threads from one thread monopolizing the cycle bandwidth Idle time Evaluation

Simulation Set-up IEEE 802.3ah, REPORT and GRANT – 64 Bytes, tg = 1us ITU-T G.984, DBRu and BW Maps – 4 Bytes every 125us, tg = 30ns Capacity (C) = 1Gbps Self-similar packet generation, Long-tail distribution with Hurst parameter 0.75 Quad Mode packet distribution – 60% 64 bytes, 4% 300 bytes, 11% 580 bytes, 25% 1518 bytes, CSIM based C Simulator for EPONSIM

Online Excess Algorithm Bounded excess pool Online Excess: Pool size

Simulation Results Average Delay for Z=2msAverage Delay for Z=4ms Average Delay for Z=8ms MTP Offline and MTP online MTP offl. and STP off. exc STP off. Exc and MTP off STP on lim and MTP off.

Observation Parameters for Z=4ms 1.Average Cycle Time (Z) 2.Average Grant Duration (G) 3.Average Idle Time (I) Grant size of MTP off > Grant size of MTP on Idle time for MTP off & on are same Avg cycle time of STP off. Exc Gated are slightly higher.

GPON Results Delay slightly higher only for Z=2ms, but the delay performance is very similar to EPON. Higher delay is because of static periodic signaling of bandwidth requests and upstream transmission window in GPON frame. Average Delay for Z=2ms

MTP Online Conclusions MTP online reduces channel idle time compared to MTP offline Offline MTP gives lower delay than offline STP but not online STP for LRPON. MTP online, STP online excess and DPP excess gives somewhat similar and lowest delay performance. For Z = 8ms, DPP and STP online excess will be sufficient so that the extra overhead and complexity of MTP Online can be avoided.

PON Control Messages For EPON (IEEE 802.3ah, IEEE 802.3av) – Standard has 64 bytes Control messages are GRANT and REPORT. (IEEE) No specific scheduling of Control Messages. –GRANT (OLT  ONU) –REPORT (ONU  OLT) For XGPON (ITU-T G.984 and ITU-T G.987) – Control message sent every 125us of (4 Bytes) Control Messages are sent at the beginning of Upstream TX. –T-CONT (Transmission Container) (OLT  ONU) –DBRu (Dynamic Bandwidth Rate Upstream) (ONU  OLT) Literature considers REPORT sent only at the end of upstream transmission mostly.

Report Message Scheduling # RMS can be done in three different ways: 1. Sent at the beginning of payload transmission – scheduling decision can be taken and grant sent before the packet upstream transmission 2. Sent at the end of payload transmission – can report newly arrived packets in-between packet upstream transmission 3. Dynamic Optimization of RMS: (Offline Scheduling Framework) – Report sent at the end for O-1 ONUs and sent at the beginning for the Oth ONU. # Anu Mercian, Michael P. McGarry, Martin Reisslein. Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPON, Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPON Optical Switching and Networking, 12:1-13Optical Switching and Networking, 12:1-13, April 2014.

Quantitative Analysis

Time instant of end of arrival of upstream transmission: Now, we can say that scheduling instant (γ) for beginning is always less or equal to end:

Idle time evaluation:

Dynamic RMS Scheduling Effect of Number of ONUs – Lesser number of ONUs, more effect of “Report in the beginning” vs “Report in the end” Dynamic RMS and Report in the beginning give very similar performance.

Simulation Results Similar simulation set-up as earlier. Average Delay for Z=2ms Z=4ms Z=8ms S off. lim and S off. exc S Off gat STP on. Lim and exc MTP on. DPP

Average Idle Time (I) Z=2ms Z=4ms Z=8ms

Average Delay for Z = 4ms for xGPONAverage Idle Time for Z = 4ms for xGPON

Average Delay for C=10Gbps Channel Z=2ms Z=4ms Z=8ms

Average Idle Time for C=10Gbps Channel Z=2ms Z=4ms Z=8ms

Average Delay for C=10Gbps Z = 4ms for xGPON Average Channel Idle Time for C=10Gbps Z = 4ms for xGPON

Conclusions to RMS Report in the beginning lower delay for Offline framework 10Gbps performance analysis Analysis for xGPON Online STP and MTP and DPP – The RMS is not a problem.

Publications Anu Mercian, Michael P. McGarry, Martin Reisslein. Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPON, Optical Switching and Networking, 12:1-13, April 2014.Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPONOptical Switching and Networking, 12:1-13 –Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPON (Extended Version) A Mercian, MP McGarry, M Reisslein - arXiv preprint arXiv: , 2013Impact of Report Message Scheduling (RMS) in 1G/10G EPON and GPON (Extended Version) Anu Mercian, Michael P. McGarry, and M. Reisslein. Offline and Online Multi-Thread Polling in Long-Reach PONs: A Critical Evaluation, IEEE/OSA Journal of Lightwave Technology, 31(12): , June 2013.Offline and Online Multi-Thread Polling in Long-Reach PONs: A Critical EvaluationIEEE/OSA Journal of Lightwave Technology, 31(12) –Offline and Online Multi-Thread Polling in Long-Reach Pons: A Critical Evaluation (Extended Version) A Mercian, M McGarry, M Reisslein - Arizona State University, Tech. Rep., Feb, 2013Offline and Online Multi-Thread Polling in Long-Reach Pons: A Critical Evaluation (Extended Version)

Roadmap to Dissertation Hybrid PON Access Networks Compatibility with transmission medium such as Copper Cables and Wireless. Therefore, extended research of PON in tandem with DSL and Wireless

PON DSL PON back-haul networks with existent DSL cables would reduce additional installation costs FTTdp – Fiber to the drop point Drop point – ONU-DSL Unit that bridges copper and fiber transmissions. OLT ONU Drop point splitter ONU Drop Point ONU Drop Point Short Range or Long Range 0-5Km

Flow Control to PON-DSL Current Ethernet standard for Flow Control – PAUSE frame [3] M.P. McGarry, Y. Luo, and E. Gurrola "On the Reduction of ONU Upstream Buffering for PON/xDSL Hybrid Access Networks",IEEE Global Communications Conference, Atlanta, Georgia, December 9-13, 2013

DBA based Flow Control A recent flow control technique introduced: GATED Flow Control [3] The OLT decides the polling of the DSL-CPE Advantages: –Reduced packet loss, –Lowers ONU Buffering thus reduced costs, –stable delay performance, –reduced delay performance for LRPON Future directions: DSL Overhead is higher than PON, thus there is Grant sizing problems and differential grant sizing

PON-Wireless or FiWi OLT ONU splitter ONU 0-10Km GW WLAN 200 m 0-5Km

Configuration ONUs [1-4] Wireless Traffic ONUs [5-8] Wired Traffic

PON DBA with FiWi Motivation: Net Utility of ONU connected to WLAN < Maximum Utility of WLAN (IEEE g) – 54Mbps Thus, (ONU-WiFi) Є Underloaded ONUs Unused bandwidth of ONU-WiFi can be used for Overloaded ONUs with wired Traffic. Therefore, DBAs like Excess Bandwidth Division will be very useful for FiWi Architecture.

Concluding notes MTP online, excess – on average the best performing DBA Remote Message Scheduling – Our optimum scheme (Report in the end for O-1 ONUs and report in the beginning for Oth ONU for Offline techniques) PON-DSL Flow Control and grant sizing issues PON-Wireless – DBA for better BW utilization

Publications & References [1] Huan Song; Byoung-Whi Kim; Mukherjee, B., "Multi-thread polling: a dynamic bandwidth distribution scheme in long-reach PON," Selected Areas in Communications, IEEE Journal on, vol.27, no.2, pp.134,142, February 2009 [2] Michael P. McGarry and Martin Reisslein. Investigation of the DBA Algorithm Design Space for EPONs, IEEE/OSA Journal of Lightwave Technology 30(14): , July 2012.Investigation of the DBA Algorithm Design Space for EPONsIEEE/OSA Journal of Lightwave Technology 30(14) [3] M.P. McGarry, Y. Luo, and E. Gurrola "On the Reduction of ONU Upstream Buffering for PON/xDSL Hybrid Access Networks",IEEE Global Communications Conference, Atlanta, Georgia, December 9-13, 2013

THANK YOU Prof. Martin Reisslein Dr. Michael McGarry Dr. Cihan Tepedelenlioglu Dr. Yanchao Zhang My sister, Anju Lab mates: Yousef, Revak, Xing, Po, Ziyad Friends: Chris, Rushil and Suhas Thank you for taking time to attend my Comprehensive