dynamic traffic grooming in elastic optical network made from a reserch paper

Presented to: Dr. Rashid Hussain

Dynamic Traffic Grooming in Elastic

Optical Networks

Project members: Anees Ahmed Awan BETL/H/F10/0102Abdur Rehman BSTN/H/F10/0101Imtiaz Ali BSTN/H/F10/0102

Contents

Hamdard Institute of information & technology

Abstract Introduction Dynamic Traffic Grooming

AuxialiaryGraph,Algorithim,Policies

Illustrative Numerical Examples

Spectrum Reservation(SR) Scheme

Abstract


when provisioning new connection in an elastic optical network, control plane has to solve two problems.

The electrical layer routing The optical layer routing and spectrum

assignment

Here in this presentation ,we propose a multi layer auxiliary graph to solve both these routing problems.

We also propose a spectrum reservation

scheme to tackle the bandwidth problem.

Abstract

Introduction


Wh

at is

Dyn

amic

Tra

ffic

G

roo

min

g?WDM divides the optical spectrum of a fiber into

separate channels with a spacing of 50 or 100 GHz. Optical transponders support fixed rate of typically

10,40,or 100 Gbps. This leads to inefficient utilization of resources.

To handle this situation we use traffic grooming i.e. effectively increasing the efficiency of traffic utilization.

Archetecture of elastic optical network:-

It uses different technologies like..

Bandwidth-variable transponders

ROADMs (reconfigurable optical add-drop multiplexers)

WSSs (bandwidth-variable wavelength selective switches)

Dynamic Traffic Grooming


In Dynamic Traffic Grooming ,a connection request arrive one at a time & hold for certain timeA connection request is represented by r(s,d,b)s= sourced= destinationb=requested bandwidth

Dynamic Traffic Grooming

Auxiliary Graph, Algorithim, Policies


Auxiliary graph is constructed each time a connection request arrive

The node in the auxiliary graph represent a node in the physical topology

There is one electrical layer and three optical layers as in example in the fig.

There are three kinds of edges in the auxiliary graph: lightpath, spectrum & transponder edges.

Auxiliary Graph

1. When a connection request r(s,d,b) arrives:2. Construct the auxiliary graph3. Run Djikstra’s shortest path algorithim4. If no path is found5. block the connection request6. If path contains transponder edges &

spectrum edges then7. Establish the new lightpath8. end if9. If path contains lightpath edges10. route request along exiting lightpaths11. end if12. update network13. End if14. When connection termionates15. Tear down all lightpaths16. Update network state

General Dynamic Traffic-Grooming Algorithim

Spectrum Reservation (SR) Scheme


Due to large transmission capacity, a light path carrying small traffic is under utilized.

Like in the example in the fig. two paths carrying different spectrum width through the same wire.

We can also reserve spectrum for high-capacity transponders

Spectrum Reservation Scheme

Spectrum Usage Of The Two Lightpaths

Illustrative Numerical Examples


Technology

dynamic traffic grooming in elastic optical network made from a reserch paper