A WDM Passive Optical Network Architecture for Multicasting Services

Student： Tse-Hsien Lin

Teacher： Ho-Ting WuDate： 2005.05.31

Outline

Background Motivations A WDM Passive Optical Network

Architecture The Proposed Multicast Algorithm Simulation Future work Conclusions Reference

Background

PON TDM PON WDM PON

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

The TDM PON

In a TDM PON, end users share the bandwidth in time domain

In the CO, an optical line terminal (OLT) transmits the downstream traffic to the end users and manages the upstream traffic flows from the end users

The TDM PON

The WDM PON

What’s is WDM At the same time, The fiber can carry Independe

nt data streams on different wavelengths WDM PONs create point-to-point links betw

een the CO and end user, no sharing wavelength

Advantage Scalable High Capacity

Motivations

Network Environments WDM Passive Optical Network Wavelength Spatial Reused

Downstream Multicast Transmission Unicast Transmission

To Design a Multicast Scheduling Algorithm Simple Efficient Scalable

Arrayed Waveguide Grating

The AWG is a wavelength-routing device Every second wavelength is routed to the same output port This period of the wavelength response is called free

spectral range (FSR)

1 2 3 4` λ

1 2 3 4` λ

1 2 3 4

λ

λ

1 2 3 4

2 x 2

AWG

SUCCESS-DWA PON Architecture -Previous Works

TL = Tunable laser CH X = Thin-film WDM filter

Functional diagrams of the OLT and ONU Previous Works

A WDM Passive Optical Network Architecture

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.

A WDM Passive Optical Network Architecture

TL 1

TL 2

TL 3

TL 4

AWG

Splitter

Splitter

Splitter

Splitter

ONU 1

ONU 16ONU 17

ONU 32

ONU 33

ONU 48

ONU 49

ONU 64

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 four fields, destination address, guard time of each destination, wavelength, and offset time

TL Timing Structure

Wc Wc Wc Wc WcW4 W3 W3 W4 W1

DataControlt

Guard Time

Wc Wc Wc WcW3 W2 W3 W2 W3

Wc WcW2 W1 W2 W2 W2

Wc Wc Wc WcW1 W2 W4 W3 W4TL1

TL2

TL3

TL4

TL Timing Structure

TL 1

AWG

Splitter

4s

1s

ONU 1

ONU 16

2s ONU 4

DataControlt

Guard Time

TL1

ONU16

ONU4

ONU1

Function Diagrams of the OLT and ONU

Dispatcher

TL

TL

TL

TL

AWGScheduler

Queue

Downstream

TR

OLT

FT

ONU

Function Diagrams of the OLT and ONU

Dispatch packet Sequence Random Short Queue First

The Scheduler Multicast Algorithm was satisfied Partition or without Partition Receiver Collision

The Proposed Multicast Algorithm

An All-out Packet Is Defined to Be a Queued Packet with All of Its Intended Recipients Free and at the same AWG output port in the Scheduling Time

Select a HOL Packet at Queue

Check the destinations of HOL packet in the same AWG output

port?

Is the HOL packet a All-Out Packet?

Check the TLs available?

No

Yes

The scheduler has finished TLs assignment

No

Partition the idle destinations.

Partition the idle and the max number of destinations of HOL packet at the

same AWG output port

Update new intended destination for the HOL packet

Check the destinations of HOL packet are idle?

Partition the max number of destinations of HOL packet at the

same AWG output port

Assign TL to the HOL packet

Yes

Yes

Yes

No

No

Check Next Queue

Restart at next time Slot

Select a HOL Packet at Queue

Check the destinations of HOL packet in the same AWG output

port?

Is the HOL packet a All-Out Packet?

Check the TLs available?

No

Yes

The scheduler has finished TLs assignment

No

Partition the idle destinations.

Partition the idle and the max number of destinations of HOL packet at the

same AWG output port

Update new intended destination for the HOL packet

Check the destinations of HOL packet are idle?

Partition the max number of destinations of HOL packet at the

same AWG output port

Assign TL to the HOL packet

Yes

Yes

Yes

No

No

Check Next Queue

Restart at next time Slot

The scenario of multicast algorithm

The HOL packet of Queue 1 is all-out packet

1,10,2

Scheduler

Queue

10,25,26

13,12,2

19,9,3

Simulation (Unicast)

The parameters are N = 64 ONUs The Tunable laser TLs = 4 Packet generation follows the Poisson arr

ival process with parameter λ = 0.04~0.36

The time slot = 12us The Simulation during 1000000 slot time TDM Four-TDM-PON DWA SUCCESS-DWA PON

Simulation (Unicast Packet Delay)

0.01

0.1

1

10

100

1000

10000

100000

0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32 0.36

Mean Arrival Rate

Average Packet Delay(us) DWA TDM WDM(Sequence) WDM(Random) WDM(Short)

Simulation (Unicast Queue Depth)

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

1.00E+02

1.00E+03

0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32 0.36Mean Arrival Rate

Average Queue Size(slots)DWA TDM WDM(Sequence) WDM(Random) WDM(Short)

Simulation (Multicast)

The parameters are N = 64 ONUs The Tunable laser TLs = 4 Packet generation follows the Poisson arrival pr

ocess with parameter λ = 0.02~0.18 The time slot = 12us The destination nodes of a multicast packet are

randomly selected among all ONU The ONUs in the multicast size S are randomly

chosen from the uniform distribution [1,5] The Simulation during 250000 slot time

Simulation (S = 5 Packet Delay)

1

10

100

1000

10000

100000

1000000

10000000

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18Mean Arrival Rate

Average Packet Delay (us)

DWA WDM(Sequence) WDM(Random) WDM(Short)

Simulation (S = 5 Queue Depth)

0.001

0.01

0.1

1

10

100

1000

10000

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

Mean Arrival Rate

Average Queue Size(slots)DWA WDM(Sequence) WDM(Random) WDM(Short)

Proposed Multicast Scheduling Algorithms – LookBack Mechanism

Search for an All-out Packet in the Input Queue up to the Lookback Length L

2,44,33

Scheduler

20,25,50

13,12,2

23,45,46

2,4,6

2,49,4517,33,40

10,25,261,10,214,40,50

17,23,3031,25,261,10,2

63,2,752,45,5931,42,401,10,2

39,44,4715,18,24

Queue

Length L = 5

Simulation (Multicast Length)

The parameters are N = 64 ONUs The Tunable laser TLs = 4 Packet generation follows the Poisson arrival process wi

th parameter λ = 0.02~0.18 The time slot = 12us The destination nodes of a multicast packet are randoml

y selected among all ONU The ONUs in the multicast size S are randomly chosen f

rom the uniform distribution [1,5] The LookBack Length L = 1,2,3,4,5,10,15,20,100,1000,1

0000,∞ The Simulation during 250000 slot time

Multicast Length L =1~5 Packet Delay

1

10

100

1000

10000

100000

1000000

10000000

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

Mean Arrival Rate

Average Packet Delay(us)

DWA WDM(Sequence) WDM(Lookback_1) WDM(Lookback_2)

WDM(Lookback_3) WDM(Lookback_4) WDM(Lookback_5)

Length L =10,15,20,100,1000,10000,Infinite Packet Delay

1

10

100

1000

10000

100000

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

Mean Arrival rate

Average packet delay(us)

WDM(Lookback_10) WDM(Lookback_15) WDM(Lookback_20) WDM(Lookback_100)

WDM(Lookback_1000) WDM(Lookback_10000) WDM(Lookback_Infinite)

Future work

Performance Key Packet delay Receiver throughput

Conclusion

Proposed The Multicast Scheduling Mechanism for WDM Passive Optical Network

Reference

Ho-Ting Wu, Po-Hsin Hong, and Kai-Wei Ke, “On the Multicast Scheduling Mechanisms for Interconnected WDM Optical Network”, IEEE GLOBECOM 2003

Martin Maiser, Michael Scheutzow, and Martin Reisslein, “The Arrayed-Waveguide Grating-Based Single-Hop WDM Network: An Architecture for Efficient Multicasting”, Select Areas in Communications, IEEE Journal , November 2003

Yu-Li Hsueh, Matthew S. Rogge, Wei-Tao Shaw, and Leonid G. Kazovsky, “SUCCESS-DWA: A Highly Scalable and Cost-Effective Optical Access Network”, IEEE Optical Communication August 2004

Glen Kramer and Gerry Pesavento, “Ethernet Passive Optical Access Network (EPON): Building a Next-Generation Optical Access Network”, IEEE Communications Magazine February 2002