Traffic Grooming in Optical WDM Networks Presented by

Traffic Grooming in Optical WDM Networks Presented by : Shamsul Wazed Md. University of Windsor November 18, 2005 1

Abstract November 18, 2005 2

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 : Ø Improve network throughput Ø Minimizing network cost November 18, 2005 3

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 November 18, 2005 4

Outline Ø Introduction Ø Multiplexing Techniques Ø Minimizing Network Resources Ø Grooming Switch Architecture Ø Grooming with Protection Ø Mathematical (ILP) Formulation Ø Conclusion November 18, 2005 5

Introduction November 18, 2005 6

Introduction ¥ 3 generation of networks : Ø 1 st generation network – copper wire based Ø 2 nd generation network – mix of copper wire and optical fiber (SONET, WDM, SDH etc) Ø 3 rd generation network – all-optical based ¥ Choice of optical fiber : High bandwidth, low error rate, reliability November 18, 2005 7

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) November 18, 2005 8

Multiplexing Techniques November 18, 2005 9

Multiplexing Techniques ¥ Different multiplexing techniques used in traffic grooming : Ø Space-division multiplexing (SDM) - bundling a set of fibers into a single cable, or using several cables within a network link Ø Frequency-division multiplexing (FDM) – a given fiber to carry traffic on many distinct wavelengths. Ø Time-division multiplexing (TDM) – multiple signals can share a given wavelength if they are non-overlapping in time. November 18, 2005 10

Multiplexing Techniques § § 1 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 lightpaths 1 carrying Connection 3 logical communication route between two nodes established if wavelength is available November 18, 2005 11

Minimizing Network Resources November 18, 2005 12

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 November 18, 2005 13

Minimizing Network Resources SONET/WDM ring (Ungroomed) November 18, 2005 14

Minimizing Network Resources SONET/WDM ring (Groomed) November 18, 2005 15

Grooming Switch Architecture November 18, 2005 16

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 November 18, 2005 17

Grooming Switch Architecture November 18, 2005 18

Grooming with Protection November 18, 2005 19

Grooming with Protection Ø Connection also requires protection from network failure Ø A single failure may affect a large volume of traffic Ø Working path carrying traffic at normal operation Ø Backup path re-routed the traffic after path failure November 18, 2005 20

Grooming with Protection November 18, 2005 21

Mathematical (ILP) Formulation November 18, 2005 22

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 Ø November 18, 2005 A six-node network 23

Mathematical (ILP) Formulation ¥ Assumptions : At most one fiber link between each node pair. Ø Nodes do not have wavelength conversion capability (i. e. no wavelength converter). Ø The transceivers in a network node are tunable to any wavelength on the fiber. Ø Each node has unlimited multiplexing / demultiplexing capability Ø Ø November 18, 2005 A six-node network 24

Mathematical (ILP) Formulation ¥ ILP formulation : § Maximize the total successfully-routed lowspeed 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 Ø November 18, 2005 A six-node network 25

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, 74. 7% (OC 18 W=4 738) where, T is number of Transceivers and W is number of wavelength T=4, 94. 4% (OC 24 Ø A six-node network W=4 933) November 18, 2005 T=5, 100% (OC- 29 26

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%) 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%) 0 0 1 (100%) Node 4 1 (100%) 0 0 0 1 (91%) Node 5 0 (100%) 0 2 (98%) 1 (100%) 0 Ø November 18, 2005 A six-node network 27

Conclusion November 18, 2005 28

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 November 18, 2005 29

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 30

Ø November 18, 2005 Slide outline 31

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] Ø Back to Introduction November 18, 2005 Ø Back to ILP Formulation 32