Traffic%20Grooming%20in%20Optical%20WDM%20Networks

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Traffic Grooming in Optical WDM Networks
Presented by Md.
Shamsul Wazed University of Windsor
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• Abstract

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Abstract

• Requested bandwidth of a traffic stream can be
  lower than the wavelength capacity
• Grooming the low-speed traffic streams onto high
  capacity optical channels
• Objective

• Improve network throughput
• Minimizing network cost

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Abstract

• Most previous work on traffic grooming in the
  ring network topology
• Traffic grooming is an important problem for
  Wavelength Division Multiplexing (WDM) network
• Recent research works with a mathematical
  formulation will be discussed here

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Outline

• Introduction
• Multiplexing Techniques
• Minimizing Network Resources
• Grooming Switch Architecture
• Grooming with Protection
• Mathematical (ILP) Formulation
• Conclusion

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• Introduction

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Introduction

• 3 generation of networks
• Choice of optical fiber
• High bandwidth, low error rate, reliability

• 1st generation network copper wire based
• 2nd generation network mix of copper wire and
  optical fiber (SONET, WDM, SDH etc)
• 3rd generation network all-optical based

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Introduction

• Objective of Traffic Grooming
• To combine low-speed traffic streams onto
  high-capacity wavelengths
• Improve bandwidth utilization
• Optimize network throughput
• Minimize the network cost
• (transmitter, receiver, fiber link, OXC, ADM,
  amplifier, wavelength converter etc)

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• Multiplexing Techniques

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Multiplexing Techniques

• Different multiplexing techniques used in traffic
  grooming

• Space-division multiplexing (SDM) - bundling a
  set of fibers into a single cable, or using
  several cables within a network link
• Frequency-division multiplexing (FDM) a given
  fiber to carry traffic on many distinct
  wavelengths.
• Time-division multiplexing (TDM) multiple
  signals can share a given wavelength if they are
  non-overlapping in time.

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Multiplexing Techniques

• 6 node network
• Wavelength Capacity OC-48
• 3 connection requests
• OC-12 at (0,2)
• OC-12 at (2,4)
• OC-3 at (0,4)
• 2 lightpaths1 carrying Connection 3

1 logical communication route between two nodes
established if wavelength is available
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• Minimizing Network Resources

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Minimizing Network Resources

• Network resources must be used efficiently
• Electronic ADMs can be saved and network cost
  will be reduced
• WDM add/drop multiplexers (WADMs) is capable to
  drop or add wavelength
• Depends upon designing of Network topology

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Minimizing Network Resources
SONET/WDM ring (Ungroomed)
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Minimizing Network Resources
SONET/WDM ring (Groomed)
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• Grooming Switch Architecture

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Grooming Switch Architecture

• Static traffic grooming can be measured by fixed
  traffic matrices
• WADM allows wavelength to either be dropped and
  electronically processed at the node or optically
  bypass
• Node architecture for a WDM mesh network has the
  static traffic grooming capability

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Grooming Switch Architecture
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• Grooming with Protection

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Grooming with Protection

• Connection also requires protection from network
  failure
• A single failure may affect a large volume of
  traffic
• Working path carrying traffic at normal operation
• Backup path re-routed the traffic after path
  failure

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Grooming with Protection
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• Mathematical (ILP) Formulation

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Mathematical (ILP) Formulation

• In our example, we consider

• A six-node multi-hop network
• Capacity (C) of each wavelength OC-48
• 3 types of connection request (OC-1, OC-3, and
  OC-12)
• 3 Traffic matrices generated randomly
• Total traffic demand OC-988

• A six-node network

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Mathematical (ILP) Formulation

• Assumptions

• At most one fiber link between each node pair.
• Nodes do not have wavelength conversion
  capability (i.e. no wavelength converter).
• The transceivers in a network node are tunable to
  any wavelength on the fiber.
• Each node has unlimited multiplexing /
  demultiplexing capability

• A six-node network

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Mathematical (ILP) Formulation

• ILP formulation

• Maximize the total successfully-routed low-speed
  traffic, i.e.

• Allowed low-speed stream, y 1,3,12,48

• 1 if success, 0 otherwise

• t 1, ,Ty,s,d

• , Lightpaths cannot
  exceed wavelength capacity

• A six-node network

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Mathematical (ILP) Formulation

• Numerical Result 1

Multi-hop Multi-hop
Throughput Lightpath
T3, W3 74.7 (OC-78) 18
T4, W3 93.8 (OC-927) 24
T5, W3 97.9 (OC-967) 28
T7, W3 97.9 (OC-967) 28
T3, W4 74.7 (OC-738) 18
T4, W4 94.4 (OC-933) 24
T5, W4 100 (OC-988) 29
where, T is number of Transceivers and W is
number of wavelength

• A six-node network

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Mathematical (ILP) Formulation

• Numerical Result 2

Virtual Topology and Lightpath Utilization (T5,
W 3)
Node 0 Node 1 Node 2 Node 3 Node 4 Node 5
Node 0 0 2 (70) 0 (100) 1 (89) 1 (100) 1 (100)
Node 1 1 (100) 0 1 (100) 2 (100) 1 (100) 0
Node 2 1 (100) 1 (95) 0 1 (100) 2 (100) 1 (70)
Node 3 2 (100) 1 (100) 1 (100) 0 0 1 (100)
Node 4 1 (100) 1 (100) 0 0 0 1 (91)
Node 5 0 (100) 0 2 (98) 1 (100) 1 (100) 0

• A six-node network

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• Conclusion

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Conclusion

• Recent research and development in traffic
  grooming in WDM network reviewed
• Objective multiplexing low-speed traffic
  streams on to high-capacity optical channels
• Optimum utilization of bandwidth, lower the
  network resource cost
• Node architecture, Path/Link Protection
• Illustrated an example by using ILP formulation
• Many significant results of practical importance
  are forthcoming

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References

• 1 R. S. Barr, M. S. Kingsley and R. A.
  Patterson, Grooming Telecommunication Networks
  Optimization Models and Methods, Technical
  Report 05-EMIS-03, June 2005.
• 2 K. Zhu and B. Mukherjee, Traffic Grooming in
  an Optical WDM Mesh Networks, IEEE Journal
  Selected Areas in Communications, Vol. 20, No. 1,
  January 2002.
• 3 K. Zhu and B. Mukherjee, A Review of Traffic
  Grooming in WDM Optical Networks Architectures
  and Challenges, Optical Networks Magazine, Vol.
  4, No. 2, March/April 2003, pp 55-64.
• 4 E. Modiano and P. Lin, Traffic Grooming in
  WDM Networks, IEEE Communication Magazine, Vol.
  39, No. 6, July 2001, pp 124-129.
• 5 B. Mukherjee, C (Sam) Ou, H. Zhu, K. Zhu, N.
  Singhal and S. Yao, Traffic Grooming in Mesh
  Optical Networks, IEEE Optical Fiber
  Communication (OFC) Conference04, March 2004.
• 6 W. Yao and B. Ramamurthy, Survivable Traffic
  Grooming With Path Protection at the Connection
  Level in WDM Mesh Networks, Journal of Lightwave
  Technology, October 2005, Vol. 23, No. 10, pp.
  2846-2853

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Thanks...
Questions ?

• Slide outline

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Transmission SpeedOptical level Bit
rate OC-1 52 Mbps OC-3 156 Mbps OC-12 622
Mbps OC-48 2,488 Mbps OC-192 9,953 Mbps
OC-768 39,813 Mbps
(in near future) OC-n n 51.84 Mbps

• Back to Introduction

• Back to ILP Formulation

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Optical Cross-Connect (OXC)

• Back to Introduction

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Optical Add-Drop Multiplexer (ADM)

• Back to Introduction

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Sample Traffic Matrix of OC-3 Connection Request

• Back to Switch Architecture

• Back to ILP Formulation

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Wavelength Converter (WC)

• Back to ILP Formulation

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Physical Topology of a Six-Node Network

• Back to ILP Formulation