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Basic Principal ofBasic Principal ofFO INSTALLATIONFO INSTALLATION

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Fiber Connector Types

EpoxyEpoxy-less

Pre-polished

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Splicing

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CONNECTING IT ALL TOGETHERCONNECTING IT ALL TOGETHER

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Mechanical Splices

Flat plate

V-groovedsubstrateButt jointed fiber

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Fusion Splices

Movable blockElectrodes

Fixed block

Fiber alignment groove

Fiber

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MT-RJ

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AMP SC Duplex Style Connector

Dust CoverDust Cover

Connector BodyConnector Body

Ferrule AssemblyFerrule Assembly

Crimp SleeveCrimp Sleeve

Cable BootCable Boot

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SC Connector (Epoxy)

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SC Connector (Epoxyless)

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ST Connector (Epoxyless)

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Fiber CleavingMethod A (Using Scribe Tool) Method B (Using Cleave Tool)

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Fiber Connector PolishingStep 1 : Air polishing Step 2 : Polishing on polishing plate

Procedure :Install the connector into the polishing bush and polish the connector tip using the 5 µm polishing film. With a thin layer of epoxy on the connector tip, replace the 5 µm with a 1 µm polishing film and continue polishing until the epoxy is totally removed.Finally, using 0.3 µm polishing film, polish until a smooth clear finishing on the fiber tip is achieved.

Procedure:Air polish the connector tip by gently rubbing the tip of the connector in small circles (or figure 8) until the cleaved fiber no longer makes scratches on the film.

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Inspecting The Fiber Termination

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Optical Fiber Cabling Systems

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Optical Fiber Parameters

• Optical Fiber Type• Cable Performance• Cabling Distance• Connector Performance• Splice Performance• System Performance• Performance Testing

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Optical Fiber Cable Types

• Horizontal Cabling− 50/125µm multimode − 62.5/125µm multimode

• Backbone Cabling− 50/125µm multimode − 62.5/125µm multimode− Singlemode

• Optical fiber types must be manufactured to meet attenuation specifications measured at both wavelengths specified for each type

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Optical Fiber Transmission Performance

Optical FiberCable Type

Wavelength(nm)

MaximumAttenuation

(dB/km)

Minimum Info.Transmission

Capacity(MHz•km)

50/125µm

62.5/125µm

SinglemodeInside Plant

SinglemodeOutside Plant

850

1300

850

1300

1310

1550

1310

1550

3.5

1.5

3.5

1.5

1.0

1.0

0.5

0.5

500

500

160

500

N/A

N/A

N/A

N/A

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Horizontal Cabling Distance

6 m 90 m 3 m

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Backbone Cabling Distance

HC/FD 1500m2500m

HC/FD 2000m3000m

IC/BD

500m

500m Multi-modeSinglemode

MC/CD EP

Cross-connect jumpers/patch cables = 20m

Telecommunications equipment cables = 30m

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Centralized Optical Fiber Cabling

300 meters90 meters

90 meters

WA

WA

CentralizedCross-

Connect

Pull-through

TC

Splice/Interconnect

TC

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TIA-568B.1 Maximum Fiber Distances50/125

(850MHz/1300MHz)62.5/125

(850MHz/1300MHz)10BASE-FL4 & 16 Mbps Token RingIEEE 802.12: Demand Priority

ATM @ 155 MbpsATM @ 622 Mbps

Fiber Channel (FC-PH) @ 266 Mbps

Fiber Channel (FC-PH) @ 531 MbpsFiber Channel (FC-PH) @ 1062 Mbps1000BASE-SX/LXFDDI LCF-PMD (low-cost)FDDI PMD100BASE-FX

Fiber Channel (FC-PH) @ 133 Mbps

2000m/---2000m/---

500m/2000m

1000m/2000m300m/500m

2000m/1500m1000m/---500m/---

550m/550m---/500m

---/2000m---/2000m

2000m/---2000m/---

500m/2000m

1000m/2000m300m/500m---/1500m

700m/1500m350m/---300m/---

220m/550m---/500m

---/2000m---/2000m

Network Platforms

ATM @ 52Mbps ---/3000m ---/3000m

---/1500m

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Connector Performance

• Attenuation Specifications- 0.75 dB max/mated pair- 1.5 dB max through a cross-connect

(based on 2 panels)

• Typical Attenuation- SC - .3 dB- ST - .3 dB

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Splice Performance

• Attenuation Specifications- 0.3 dB max- Fusion or Mechanical

• Typical Attenuation- Fusion - 0.1 dB- Mechanical - 0.2 dB

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Power Budgets - Definition

“The difference in optical power between what the transmitter delivers into a fiber and what

the receiver requires from the fiber to operate properly”

-19dBm

15dB

-36dBm

TX RX

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System Power Budget

TxTx RxRxInput powerLaunch Power (dBm)

Output Power = Power launched into a specific type fiber (i.e. 62./125)

Sensitivity = Minimum input power to obtain specified bit error rate

Example = Power -14 dBm to -19 dBm

Sensitivity = -14 dBm to -36 dBm

Power Budget : -19-(-36) =17dB

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Power Budgets - Units of Measure

• dB- A Measurement of Loss/Gain- In This Case a Positive Number

• dBm, dBu- A Measurement of Power as Compared

to One Milliwatt or One Microwatt- Normally a Negative Number

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Power Budgets - Elements for Calculation

• TX Power Out

• RX Sensitivity

• Margin (Average = @3 dB)

−Aging−Safety Aging- Safety

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Power Budgets - Calculation Example

TX Power: -19dBm

RX Sensitivity: -36dBm

Margin: 3dB

-19-(-36)-3Formula:

14dBPower Budget =

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Link Loss Budget

Elements for Calculation−Fiber Attenuation−Connector Loss−Splice Loss−Passive Component Loss

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Link Loss Budget

- _______ (Fiber Attenuation)

- _______ (Connector Loss)

- _______ (Splice Loss)

- _______ (Passive Component Loss)

=

Link Loss Budgets - Calculation Example

RX

1Km(62.5/125µm)

Splice

Connectors

TX

3.5 dB1.5 dB0.3 dB0.0 dB5.3 dB

System loss measurement should always be less than the link loss budget

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Link Margin - Calculation Example

RX

1Km(62.5/125µm)

Splice

Connectors

TX

System Power Budget = 17 dB

Link Loss = 5.3 dB

Link Margin = 11.7

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Inspection & Test Equipment∗ Microscope : 100 - 200x

Visual Inspection of Connector End Faces

∗ Power Meters : Measure power (mW) and relative power (dB)

∗ OTDR : Measures length of fiber Attenuation Connector and SpliceReturn Loss

Look for :Multiple wavelengths - 850 -1300 -1550Short dead zoneAccuracy & resolution

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Testing Requirements

• Link Attenuation− Required

• Polarization− Recommended

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Horizontal Link Attenuation

Horizontal Link Measurement• Measured at only one Wavelength

− Either 850 nm or 1300 nm− Only one direction required

• ANSI/EIA/TIA-526-14A, Method B− One Reference Jumper

• Attenuation results less than 2.0 dB− Based on the loss of two connector pairs plus 90 meters of optical

fiber cable

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Centralized Link AttenuationCentralized Link Measurement• Measured at only one Wavelength

− Either 850 nm and 1300 nm− Only one direction required

• ANSI/EIA/TIA-526-14A, Method B− One Reference Jumper

• Attenuation results less than 2.9 dB − Based on the loss of two connector pairs plus 300m meters of optical

fiber cable and 1 splice in the TC

• Attenuation results less than 3.3 dB− Based on the loss of two connector pairs plus 300m meters of optical

fiber cable and an interconnection

A

B

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Centralized Link Attenuation Example300 meters(1.05 dB)

.75 dB(mated pair)

.75 dB(mated pair)

.3 dB(splice)

A

.75 dB(Interconnection)

.75 dB(mated pair)

.75 dB

B

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Backbone Link Attenuation Measurement

Backbone Link Measurement• Measured at both operating Wavelengths

− Multi-mode at 850 nm and 1300 nm− Singlemode at 1310 nm and 1550 nm− Only one direction required

• ANSI/EIA/TIA-526-14A, Method B− Multi-mode - one Reference Jumper

• ANSI/TIA/EIA-526-7, Method A.1− Singlemode - one Reference Jumper

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Backbone Link Attenuation SpecificationsBackbone Link Attn. = Cable Attn. + Connector Attn. + Splice Attn.

Connector Attenuation (mated pair) = 0.75 dB

Optical FiberCable Type

Wavelength(nm)

MaximumAttenuation

(dB/km)

50/125µm

62.5/125µm

SinglemodeInside Plant

SinglemodeOutside Plant

850

1300

850

1300

1310

1550

1310

1550

3.5

1.5

3.5

1.5

1.0

1.0

0.5

0.5

Splice Attenuation = 0.3 dB

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Backbone Link Attenuation Example

300 meters(1.05 dB)

.75 dB(mated pair)

.75 dB(mated pair)

.3 dB(splice)

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Optical Fiber Link Certification

EIA/TIA-526-14A EIA/TIA-526-7• Measures Optical Loss of Cable

Plant• Specifies Power Meters and OTDR• Indicates if Cable Plant Meets

Power Budget• For Singlemode Fiber Only• Includes Two Methods• Includes Three Methods for Power

Meters and One for OTDR

• Measures Optical Loss of Cable Plant

• Specifies Power Meters• Indicates if Cable Plant Meets

Power Budget• For Multimode Fiber Only• Includes Two Methods

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EIA-TIA-526-14A(B)/TIA/EIA-526-7(A.1)

Source Detectors

Reference

1P

Test Jumper 1

TestTest Jumper 1

2P

Cable PlantTest Jumper 2

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Troubleshooting

FlashlightMicroscope

OTDR

VFL Power Meters

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Common Failures/Faults• Polarity

− Patch/drop cables reversed

• Attenuation− Cable Breaks

− May be caused by exceeding tensile load or bend radius

− Core Mismatch/Misalignment− Caused by mixing different fiber types in the same channel− Caused by connecting hardware imperfections/installation/assembly

− Poor Splice− Poor cleave, fusion arc, mechanical assembly

− Poor Finish on Connector− Dust, chipped/cracked/pistoned fiber

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Loss Mechanisms in Connections

Loss from End SeparationLoss from Angular

MisalignmentLoss from Lateral Displacement

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OTDR Troubleshooting

Cable Plant

Dead Zone Fiber

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Backscatter plot from a fiber under test with an OTDR

Fiber end

Distancefromlaunch

Fiber

Faulty region ofhigh attenuation

Splice

Light pulselaunched into fiber

undertest

Reflectedpower Backscatter

Reflectionfrom joint

Fault loss

Fresnel end reflection

Time

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WHAT IS BACK REFLECTION ?WHAT IS BACK REFLECTION ?

Refractive Barriers Caused by Polishing

Air

Reflected Signals Travel Backward Toward Light Source

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ANGLED PC FERRULESANGLED PC FERRULES

Back Reflection is Directed Away from the Core and Cladding

8 ° Angle, PC PolishAngle PC (APC)

60dB

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Summary• Identified performance characteristics and industry

standard specifications of optical fiber types and connecting hardware

• Defined power budgets• Determined how to calculate unused margins• Identified attenuation specifications for both

horizontal and backbone optical fiber cabling links• Identified the industry standards methods for the

certification of an optical fiber cabling system• Determined how to recognize common faults in an

optical fiber cabling system