OC7 Multi-Domain Optical Modelling Tool aka MOMoT Anna Manolova - - PowerPoint PPT Presentation

OC7 Multi-Domain Optical Modelling Tool aka MOMoT

Anna Manolova Fagertun, DTU Fotonik Nicola Sambo, SSSUP/CNIT Martin Nordal Petersen, DTU Fotonik JRA1 Network Architecture Workshop November 12th 2014

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Outlook

The MOMoT in a nutshell The consortium The project structure NREN survey The model and initial field-trial calculations The End

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MOMoT in a nutshell

MOMoT: Multi-Domain Optical Modeling Tool (18 months duration) The part-goals: Investigate the need, interest and requirements for providing an Alien Wavelength (AW) service in the GÉANT community. Develop a modeling tool that will enable users to evaluate the feasibility of a potential AW path through one or more NRENs. The approach 3 phase project

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Gathering needs, and requirements, designing specifications (Based on surveys )

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Designing the tool (model, input/output parameters, etc.)

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Implementation, validation and tests

The vision of this project is to develop a modeling tool for the GÉANT community, which can estimate and predict AW performance and assess implications on existing traffic in the network path

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The consortium

DTU Fotonik Project coordinator Requirements specification Modeling tool design

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Martin Nordal Petersen – mnpe@fotonik.dtu.dk

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Anna Manolova Fagertun – anva@fotonik.dtu.dk Competences

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Multi-domain networking, experience with AW deployment and modeling, know-how in using diverse modeling tools (networking and physical layer) CNIT / SSSUP (Scuola Superiore Sant'Anna) Modeling tool implementation Validation and verification

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Nicola Sambo – n.sambo@sssup.it Competences

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Experience with the design and development of optical network modelling of transparent optical.

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Alien Wavelengths and MOMoT

What is an AW ? This is an optical signal, emitted by a third-party transponder, carried within the WDM line system together with “native” wavelength channels. Advantages:

• Mix and match components and sharing – can reduce cost
• All-optical services (where transparrency is requirred)

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What the tool will NOT provide

Guaranteed performance metrics The tool will provide indications and guidance, not guarantees. Live-network parameter extraction The input will be as much as possible unified to one structure. Mapping every single deployed vendor’s equipment is at this point unrealistic This above can eventually be extensions if MOMoT becomes successful. The tool and its building blocks can be used for further developments.

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The MOMoT tool – High-level view

The demand structure (e.g., source and destination nodes, physical parameters) will be fed to the tool to compute a path from source to destination along with the performance (Quality of Transmission ‘QoT’)

• f the lightpath and the performance impact on existing traffic.

The path computation module utilizes a QoT estimator to compute the path and estimated signal quality. Demand structure (input) MOMoT Core Module Computed path(s) and QoT indicators Network Topology (nodes, links, physical parameters, existing lightpahts)

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The Demand structure

The input parameters to the MOMoT core module are considered as the “Demand structure” input. It may include: Source and Destination node in the network AW frequency, bit-rate, input power, and other physical parameters Possibly other parameters obtained through discussion and interviews with NRENs/vendors

Demand structure (input) MOMoT Core Module Computed path(s) and QoT indicators Network Topology (nodes, links, physical parameters, existing lightpahts)

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The MOMoT core module

The MOMoT core engine includes the following building key blocks: Path computation: Using the information from existing lightpaths in the network, the network topology (nodes and links) the Path Computation module finds a path from source node to destination and its esimated QoT. QoT evaluation is responsible to compute the QoT of the computed path and its potential impact on the existing lightpaths. This block utilizes:

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the analytical solutions to a set of equations,

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analytical models for physical impairments : Amplifier Spontaneous Emission (ASE) noise, Chromatic dispersion (DC), and Cross Phase Modulation (XPM)

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Option for lookup tables (offline computational tools) The models is implemented using Fortran and C++ A GUI / interface will be also designed for the tool

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MOMoT output

MOMoT core module will compute the path(s) and the corresponding QoT indicator(s) The impact of the computed lightpath on the existing lightpaths can be also evaluated and reported as the output. The computed paths would be the shortest path or k-shortest path or in case of 1+1 protection a node/link disjoint path The QoT indicator gives a guidance on the impact of the AW path on the overall network performance (RED – YELLOW - GREEN)

Demand structure (input) MOMoT Core Module Computed path(s) and QoT indicators Network Topology (nodes, links, physical parameters, existing lightpahts)

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Survey sent to NRENs

Do you know what an “Alien Wavelength” is? Where have you heard about Alien Wavelengths? Have you discussed Alien Wavelengths within your organization? Have you or your org participated in an Alien Wavelength trial or setup? If you have participated in or are planning to deploy an Alien Wavelength, would you find it useful to have a tool to help evaluate the feasibility of the deployment (e.g. signal quality, wavelength path, selection of wavelength). Have you received requests from clients in your network to establish an Alien Wavelength connection? Does your organization plan to deploy Alien Wavelength within your own network? Does your organization plan to deploy Alien Wavelengths to interconnect with neighboring domains via cross-border- fiber? Describe a potential application scenario of Alien Wavelength in your network, possibly based on customer request or your own needs. What do you think about the potential benefits of Alien Wavelength in your network?

• 11 question survey sent out aimed at CTOs
• Sent to 47 of which 30 replied (64%)

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Survey results I

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Q9 - Does your organization plan to deploy an Alien Wavelength to interconnect with neighboring domains via cross-border-fiber? Q8 - Does your organization plan to deploy Alien Wavelength within your own network? Q7 - Have you received requests from clients in your network to establish an Alien Wavelength connection? Q6 - If you have participated in or are planning to deploy an Alien Wavelength, would you find it useful to have a tool to help evaluate the feasibility of the deployment (e.g. signal quality, wavelength path, selection of wavelength)? Q5 - Have you or your organization participated in an Alien Wavelength trial or setup? Q4 - Have you discussed Alien Wavelengths within your organization? Q2 - Do you agree with this definition of what an Alien Wavelength is? Q1 - Do you know what an "Alien Wavelength" is?

Yes No Don't know/Other

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Survey results II

“What do you think about the potential benefits of Alien Wavelength in your network?”

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Survey conclusion

86%, of the NREN management has heard of alien wavelength (AW) More than 60% have also discussed AWs within their origination 30% have already participated in alien wavelength trials 30% are planning to deploy alien wavelengths 30% have already received actual requests from clients

Full details and analysis can be found in MOMoT milestone report M2.1

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The MOMoT model

First evaluation of Amsterdam-Hamburg link Nicola Sambo CNIT / SSSUP, Pisa, Italy

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Link and estimation: BER?

• Amsterdam-Hamburg
• Spans:
• fiber length and attenuation from SurfNet table
• Amplifier at each span: Nf=5
• Modulation format: PM-QPSK
• Coherent detection
• R: rate
• P: launch power
• Ch Spacing: 100GHz
• BER estimation accounting for ASE and SPM
• assumptions:
• CD and PMD are compensated by DSP
• 100GHz ch spacing enough to neglect XPM or consider it as worst-case

margins

• Margins M to account for filtering effects, aging and fluctuations, other non-

linear effects (e.g., XPM). M has been set to 3dB (considered as an OSNR penalty)

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The model

where:

• Ik(x): ordered-k modified Bessel’s function of the first kind
• σ2

NL: the variance of the non-linear phase noise

• ρ|dB=OSNR|dB +10log10(B/Rb) +3

where: – OSNR|dB: the OSNR of the 100Gb/s signal considering both polarizations – B=12.5 GHz – Rb=bit-rate split in two polarizations

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Model input parameters

INPUTS

• Launch power
• Fibers:
• Length, attenuation, dispersion parameter, PMD parameter, effective area
• Amplifiers:
• Noise figure, gain (fixed gain)
• Node:
• Node losses

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Amsterdam-Hamburg BER: a first estimation

R [Gb/s] P [dBm] BER 50

• 4.5

3.88·10-5 100

• 4.5

3.62·10-3 100

• 1.5

4.43·10-5

• Doubling R ➞ SNR decreases by 3dB ➞ BER increases
• Doubling R & Power increase of 3dB ➞ BER almost unchanged

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Clarifications, improvements…

• Availability of model for non-coherent transmission:
• OOK with direct detection (e.g., at 10Gb/s),

DQPSK with differential detection (e.g., at 40Gb/s)

• Possibility to include XPM (from 10Gb/s to 100Gb/s)
• Accounts for XPM as worst-case margins (e.g., OSNR penalty)
• r through Guard Band
• Provide model with user-friendly interface

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Thank you!