A WDM Passive Optical Network Architecture for Multicasting Services

1. 能支援群播服務之分波多工被動式光纖網路的架構能支援群播服務之分波多工被動式光纖網路的架構 A WDM Passive Optical Network Architecture for Multicasting Services 研 究 生：林澤賢 指導教授：吳和庭 博士

2. Outline • Motivations • Backgrounds • A novel WDM Passive Optical Network Architecture • The Proposed Multicast Algorithm • Simulation results • Scalability problem • Conclusions • Future works

3. Motivations • Network Environments • Combined PSC and AWG • WDM Passive Optical Network • Downstream • Multicast Transmission • Unicast Transmission • To Design a Multicast Scheduling Algorithm • Simple • Efficient

4. Backgrounds • Optical Devices • PSC • AWG • Passive Optical Networks • TDM PON • WDM PON • SUCCESS-DWA PON

5. Optical Device-PSC • The Passive Star Couple is a passive multiport device • Wavelengths launched onto any input port are broadcast to every output port

6. Optical Device-PSC • The PSC is the preferred device to single-hop WDM networks • broadcast-and-select single-hop WDM network • TDM PON • Advantages • Broadcast signal • Low cost • Disadvantages • Power loss • Do not wavelength spatial reused

7. Optical Device-AWG • The AWG is passive wavelength routing device • The same wavelength into any input port are routed to different output port • This period of the wavelength response is called free spectral range (FSR)

8. The application of AWG device

9. Optical Device-AWG • Advantages • Static wavelength routing • Wavelength spatial reused • No power loss • Disadvantages • No broadcast channel

10. Passive Optical Network • In a PON, all components between the end users and the central office (CO) are passive, such as optical fibers and couplers • TDM PON • WDM PON • SUCCESS-DWA PON

11. The TDM PON • In a Time-Division-Multiplexing PON, end users share the bandwidth in time domain • In the CO, an optical line terminal (OLT) transmits the downstream traffic to optical network unit (ONU) and manages the upstream traffic flows from the ONUs

12. The TDM PON

13. The WDM PON • What’s is Wavelength-Division-Multiplexing • At the same time, a single fiber can carry Independent data streams on different wavelengths • WDM PONs create point-to-point links between the CO and end user, no shared wavelength • Advantages • High Capacity • Scalable

14. SUCCESS-DWA PON Architecture

15. Functional diagrams of the OLT and ONU

16. Proposed WDM Passive Optical Network Architecture • Downstream – Splitter • Upstream – Combiner

17. Downstream mode • OLT use four tunable lasers to transmit control message on control channel or data packet on any wavelength • Each ONU consists of a tunable receiver which allow them to receive control message on a control channel (or data on any wavelength) • The multicast packet is received by the ONUs attached to the corresponding splitter • Each splitter equally distributes all incoming wavelengths to all attached receivers.

18. Downstream mode

19. TL Timing Structure • Each TL transmits control message which corresponded to the ONUs of the same AWG output port in the control time • Each TL transmits data packet to reach all ONUs attached to the same AWG output port in the data time • A control packet consists of three fields, destination address, wavelength, and offset time

20. TL Timing Structure

21. Functional Diagrams of the OLT and ONU - Downstream mode

22. Functional Diagrams of the OLT and ONU - Downstream mode • Dispatch Mechanism • Sequential • Random • Short Queue First • The Criteria for whether to Partition Multicast Packets depend on • Multiple AWG Outputs ? • Receiver Collision ?

23. The Proposed Multicast Algorithm • An All-Out Packet Is Defined to Be a Queued HOL Packet with All of Its Intended Recipients Free and at the same AWG output port in the Scheduling Time

24. The scenario of multicast algorithm • The HOL packet of Queue 1 is all-out packet

25. Simulation Parameters (Unicast) • The parameters are N = 64 ONUs • The Tunable laser TLs = 4 • Packet generation follows the Poisson arrival process • Mean arrival rate = 0.48~4.32 packets/slot • Bandwidth = 1Gbps • Packet Size = 1518 bytes • Time slot = 12 us • The Simulation during 1000000 slot time • TDM  Four-TDM-PON • DWA  SUCCESS-DWA PON

26. Unicast – Average Packet Delay • Average packet delay defined as the average time from the generation of a packet until the completion of the multicast transmission

27. Simulation Parameters (Multicast) • Packet generation follows the Poisson arrival process • Mean arrival rate = 0.12~2.28 packets/slot • Bandwidth = 1Gbps • The time slot = 12us • Packet size = 1518 bytes • The destination nodes of a multicast packet are randomly selected among all ONU • Mean multicast throughput is defined to be the mean number of All-Out packets in the average time slot

28. Simulation Parameters

29. Simulation Results (Multicast) • Comparison with different PON

30. Simulation Results (Multicast) • Comparison with different Mean multicast size E[S]

31. Scalability Problem • Expanding ONUs • Expanding TLs of the OLT • Comparisons with different AWG ports • 4 x 4 AWG port • 8 x 8 AWG port

32. Expanding ONU

33. Expand TL of the OLT (1/2)

34. Expand TL of the OLT (2/2)

35. Simulation results

36. Conclusions • Proposed The Multicast Scheduling Mechanism for WDM Passive Optical Network • Compare our proposed WDM PON with SUCCESS-DWA PON • Scalability problem Study • ONU • FSR

37. Future works • Keep solving the scalability problem • The upstream issue • Compare with the AWG based Single-Hop WDM network and our proposed WDM network architecture

38. THE END