Download Comparisons and Validation of Statistical Clustering techniques for

Traffic Grooming in
Optical WDM Networks
Presented by :
Md. Shamsul Wazed
University of Windsor
November 18, 2005
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Abstract
November 18, 2005
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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 :
 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
 Choice
of optical fiber :
High bandwidth, low error rate, reliability
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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

November 18, 2005
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

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A six-node network
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Mathematical (ILP) Formulation
 ILP

formulation :
Maximize the total successfully-routed lowy,t
y*S
sd
speed traffic, i.e. 
y,s,d,t

Allowed low-speed stream, y Î {1,3,12,48}
y ,t
sd =

S

t Î {1, …,Ty,s,d}

1 if success, 0 otherwise
sd ,t
y
*

 ij , y  Vij * C
, Lightpaths cannot exceed
wavelength capacity
y ,t s , d

November 18, 2005
A six-node network
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Mathematical (ILP) Formulation
 Numerical
Result 1:
Multi-hop
Throughput
Lightpath #
T=3, W=3
74.7% (OC-78)
18
T=4, W=3
93.8% (OC-927)
24
T=5, W=3
97.9% (OC-967)
28
T=7, W=3
97.9% (OC-967)
28
T=3, W=4
74.7% (OC-738)
18
T=4, W=4
94.4% (OC-933)
24
T=5, W=4
100% (OC-988)
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where, T is number of Transceivers and W is number of wavelength
 A six-node
November 18, 2005
network
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Mathematical (ILP) Formulation
 Numerical
Result 2:
Virtual Topology and Lightpath Utilization (T=5, 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

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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) Conference’04,
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
November 18, 2005
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
November 18, 2005
Slide outline
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Transmission Speed
Optical 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
November 18, 2005

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
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
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
November 18, 2005
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