Gwenn AMICESenior Applications engineer

Fiber Optical Deployment and Troubleshooting With Great Power Comes Great Responsibility

Fiber links characterisation , certification and troubleshooting using Fiber certifier and multi-pulse iOLM

• With the needs for speed beyond the Gigabit Ethernet, optical fiber is replacing Cat 5/6/7 everywhere.

• In this session, we will give you 5 tricks that will help you to avoid 95% of the troubles in your fiber optic networks.

• The subjects covered in this technology session are the following: Cleaning and inspection of optical connectors, stress and macro-bends detection, link certification, accurate references, troubleshooting using intelligent optical link mapper tools or an OTDR.

Cloud Traffic analysis

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Multimode or Singlemode fiber?

Source: Open Optics MSA Design Guide: http://www.openopticsmsa.org/pdf/Open_Optics_Design_Guide.pdf

Will Wide Band MM Fiber WBMMF (OM5?) enable coherent CFPs inside DC (4 colors @ 840-950 nm) or singlemode fiber will dominate?

10G line rate for 100G links, OM4 distance limit: 300 meters25G line rate for 100G links, OM4 distance limit: 100 meters100G line rate for 100G links, OM4 distance limit: 50 meters

STANDARDS REVIEW

Interfaces for Multimode

Multi-fiber connections• Due to Modal dispersion the maximum

achievable transmission rate in Multimode fiber is limited by the distance

Multimode fiber

Difference between OM3 fiber and OM4 fiber

Optimum launch conditions

Installation best practices• Where are the troubles coming from?

• Connector cleaningness and macrobending

95%

FIRST-TIME-RIGHT SYSTEM ACCEPTANCE STEPS

1 Connector inspection & cleaning

2 Cable certification, Tier-1 testing (OLTS @ new build)

3 Performance assessment, Tier-2 testing (OTDR/ iOLM) -

4 Documentation & reporting

Loss measurement in MM: Encircled flux, the new standard

› Encircled flux is a new method to define the launch conditions of a light source› EF measurement is based on the power distribution measurement on the

connector end face of the light source, reference jumper or conditioner

MM IL measurement is highly sensitive to the source launch conditionsExample: IL of a link varies greatly depending on whether a VCSEL or LED is used to perform the measurement

TIP#1: Make sure your unit is EF compliant

Why should anyone change?When upgrading from 1GigE to 10GigE and 100GigE loss budgets are much tighter

~ 3.5 dB @ 1GbE

~ 2.6 dB @ 10 GbE

~ 1.5dB @ 40/100GbE

• A 1dB uncertainty is lethal!

• Connector cleaning/ inspection is key!

Multi-fiber connectors

A whooping 7776 fibers!!!

PERFORMANCE EXPECTATION FROM MTP CONNECTION

MTP performance is primarily driven by three factors:

1. Selecting quality connector components: US Conec’s SM Elite and MM Elite grade of MTP connectors (optimized for 10G, 40G, 100G applications) have tighter tolerances on several key attributes, including guide pin & fiber hole diameter and location.

2. Achieving physical contact: Physical contact is heavily dependent on how well the MT ferrule is terminated and polished (i.e. the endface geometry). Physical contact is also dependent on using the proper spring force inside the MTP.

3. Ensuring endface cleanliness: Defects or debris on a physical contact connector can significantly degrade performance.

MM MT Elite®

Multimode MT FerruleSM MT Elite®

Single-mode MT Ferrule

Insertion loss (IL)

0.1dB Typical0.35dB Maximum2,3,5

0.10dB Typical0.35dB Maximum1,4,5

Return loss (RL)

> 20dB 5 > 60dB (8° Angle Polish) 5

1 As tested per ANSI/EIA-455-171 Method D32 As tested per ANSI/EIA-455-171 Method D13 As tested with proposed encircled flux launch condition on 50um fiber and 850nm per IEC 61280-4-14 Compliant with proposed IEC 61755-3-31/GRADE B5 For 32-fiber MM MTs, or 24-fiber SM MTs, performance assumes physical contact on all fibers. For these higher fiber counts, physical contact may be difficult to achieve.

New MTP-16TM Multi-fiber Optical Connector Supports Next Generation 400G Applications

MPO Connector endfaceMultiple fibers connector

• 3 levels of magnifications to cover a larger surface• MTP/MPO SM connectors are usually APC,MM are flat polished

100X 200X 400X

Low mag view:Allows to see what fiber is being inspected in High magnification

Blue Arrow indicates the fiber active in high mag view

“MF” mode

MPO Analysis as per IEC or Custom

Connectors!!!!! Again

TIPs #2To avoid 85% of the issues in the field:• Never assume that connectors are clean• Always inspect connectors• Always clean• Never use wet cleaning without drying the connector after• Never clean an MTP connector is it doesn’t need to be cleaned

Link Characterisationwhat does the standard say?

• ISO/IEC-14763.3• All optical fibre links must be tested for:

– Continuity and maintenance of polarity; – Length; – Propagation delay; – Optical attenuation of link, 2 x wavelengths, 2

x direction. • Using LSPM (OLTS) equipment. Where

LSPM results exceed the Power Loss Budget, the link shall be investigated with an OTDR to determine the location of the faulty component.

• TIA-568-C.3 • Source and power meter methodology should

be used to test end to end loss, link length and polarity check (Tier one )

• OTDR should be used to verify the loss and reflectance of localized event (Tier two) with a visual picture of the installed fiber optic network

OLTS vs. OTDR vs. iOLMOLTS OTDR iOLM

Number of technician required 2 1 1

Need to reference tester Yes No NoTechnical expertise needed to

perform testLow Medium to high Low

Number of acquisition/test per fiber 1An average of 3 to fully characterize all the

elements. For each acquisition, we can estimate an average of 30 sec/wavelength

1 (average of 45 sec, include all wavelengths)

Average test time per fiber* 3s dual λ bidir Typically 2 to 5 minutes depending on the link complexity and technician 's skills 45 seconds to 1 minute

Graphical representation of the link Link view, simplified Traditional graphical representation Link view detailed

Provide Insertion Loss Yes bidirectional Yes YesProvide Length of the fiber Yes Yes Yes

Automatic-Diagnostics Macrobend detection and pass/fail status Macrobend detection and pass/fail status Yes, global and individual pass/fail status plus diagnosis information for each failure

Allow locating faults No Yes YesLive testing No Yes Yes

Offer easy transpose fiber detection Yes No Yes with receive box

Loop back mode No No Yes

LS&PM uncertainty• The measurement uncertainty of LS&PM is mainly

induced by the reference process, the source stability and the uncertainty of the power meter

Typical Uncertainty with one patch cord reference: +/- 0.2dBTypical Uncertainty with two patch cord reference: +/- 0.35dB

Optical loss test set: Fastest

DUPLEX Testing›Two fibers›FasTesT to power meter port›DataCenter approved method

SIMPLEX Testing›One fiber›FasTesT to FasTesT port›TelCo approved method

Methods

Optical loss test set: Automated• Reference methodology

Optical loss test set: AutomatedReference methodology

http://www.thefoa.org/tech/ref/testing/5ways/fiveways.html

• Patent pending method• Allows to exclude the coupler loss from the reference values• GREATLY improves on IL accuracy• Extremely useful for short fiber test

Optical loss test set: Single fiber reference

TIP#3: Make sure your reference is valid

Single fiber reference.• The problem with Single fiber reference is that you need a second patchcord to

connect the remote patch panel .

OLTS report• With link view

CertificationSelecting certification standards

• The comities and standards you can choose from are grouped by categories.• You can select more than one standard and you can select standards from different

categories at the same time: the most restrictive values of the selected standards are then used to determine if the test results is a pass or a fail status.

Installation best practices:

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• IOLM: Multipulses analysis• OTDR: Single pulse

End to end loss using the IOLM›In order to fully characterize a link end to end a launch fiber and a receive fiber need to be used.›The launch fiber will help the IOLM measuring the first connection.

›The receive fiber will help the IOLM measuring the last connection.›Launch and receive fiber needs to be from the same fiber type in order to reduce the uncertainty due to MFD mismatch.

End to end loss using the IOLM

TIP#4: Even if the loss is within the budget, distributed loss must be performed to

FTTH PtP Link: Loss measurements

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FUT150m

Jumper5m

SC/PC

Launch150m

Receive500m

Jumper5m

SC/PC

iOLM

FTTH characterization (PON 1x32)

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OTDR/IOLMLaunch150m

Fusion0.7dB

25mSC/APC

1:32

50m

SC/APC

Macrobend3dB 280m 800m

12mA1

A2

End to end loss using the IOLMIOLM Specification (dB)

Typical Notes

Link IL uncertainty 0.08 Link loss for 3m<L<500m.Single connector IL uncertainty 0.08 15m≤ L <500m

Reflectance uncertainty 0.75 From -45 to -65 dB

Short link ORL uncertainty 1(L<15 m). Includes two connectors and fibre loss

uncertainties. Events may be merged.

Certification using iOLM

Preset test configs Complete report with selected standard

Certified configurations

Thresholds values on report – Jan15

Intelligent Optical link mapper

New challenges for the OTDR

Short links requirements:• High resolution• Fast acquisition time• Length measurement accuracy• Loss accuracy• Close events• Macro bend detection

Long links requirements:• High Dynamic range• High sensitivity• First 10Km high res• Macro bend detection• Loss accuracy• ORL accuracy

Data centers, FTTH, C-RAN, FTTA, FTTB, Backhaul, Front haul

DWDM, RAMAN, ROPA, 100G, 200G BackbonesR

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utio

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icOTDR short pulses OTDR long pulses

Intelligent optical link mapper: IOLM

OTDR medium pulses… …

OP

TIM

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Higher resolution with true 3ns pulse

Loopback testing

iOLM Loopback Uni-dir or Bi-Dir

Original measurement

Pass/Fail, display, SOR/iOLM files, and PDF report for Fiber 2

Pass/Fail, display, SOR/iOLM files, and PDF report for Fiber 1

Split

iLoopAutomatically separates the two fibers for individual results

iLOOP testing for FTTx or DC

© 2016 EXFO Inc. All rights reserved. | 41

• SAVE 50% ON YOUR TESTING TIME BY TESTING 2 FIBERS AT ONCE

• SPLIT MEASUREMENTS AND PASS/FAIL WITH NO POST-PROCESSING

• GET INDIVIDUAL FILES, REPORTS, SOR TRACES

• TEST FROM THE FDP OR PT

Macrobend detection in OLTS

TIP#5: In Single mode 1310 loss should be higher than 1550nm, if not you have a macro bend in your link

Questions