Field Testing of fiber optic infrastructure for 10, 40 and 100Gbits/s readiness Christian Schillab Product Manager Media Test Fluke Networks Europe Member BritishStandards Institute Working Group TCT 7/ /1 /1 & CENELEC TC215 WG1 PTH und PTT christian.schillab@flukenetworks.com
Topics Intelligent test regimes which optimize performance margins with little increase in testing time The evaluation & documentation of the performance and condition of the test tset up Choosing the optimal test method for complex hybrid channels Testing of complex and demanding MPO cassettes based channels with a later migration to 40GBASE R4, 100GBSE SR10 in mind
With 40GBASE R4, 100GBSE SR10 a trend continues which provides significantly higher bandwidth at the expense of distance and insertion loss budget?
From The Archive. BICSI 2002
IEEE 802.3ba 40/100GB/s Justification for Field Testing / Inspection 1. Field ermination 2. Patched multi segment channels Multi vendor Add Changes and Moves performed by operator 3. Dusteffects performance 4. Demanding limits
IEEE 802.3ba Field Testing? Wie wichtig ist die Abnahmemessung? Structured Cabling Connector Less Channel Permanent Link / Channel
40/100 GbE Fiber Applications 40GBASE SR4 40GBASE LR4 40GBASE FR Mulitmode Single Mode Source 4 x 10Gb VCSEL 4 x 10Gb Laser 1 x 40Gb 100GBASE SR10 100GBASE LR4 Laser 100GBASE ER4 Optics Parallel Mulitmode Simplex Single Mode Connnector Source MPO 10 x 10Gb VCSEL LC 4 x (or 10Gb similar) Laser 1 x 40Gb Laser Wavelenght Optics 850 nmparallel 1271 1331 nm Simplex 1550 (4λ @ 25Gb) Fiber Connnector OM3 OM4 MPO OS2 LC (or OS2similar) MaxDistance Wavelenght 100 m 150 850 m nm 10,000 000 1300 nm 2,000m 1550 nm Loss Budget 1,9 db 1,53 db 6.7 db (DWDM) 4.0 db (DWDM) Fiber OM3 OM4 OS2 OS2 Max Distance 100 m 150 m 10,000 m 40,000m Loss Budget 1,9 db 1,53 db 8.3 db 18 db
40/100GBase SR/LR/ER: Which ISO Channel supports it?
Fiber Optic Test Methodes Standard Methods TIA 568 C Tier 1 Tier 2 ISO 11801 AMD.1 / ISO/IEC 1476 3 BASICTest Regime LSPM:Light Source & Power Meter EXTENDED Test Regime OTDR: Optical Time Domain Reflectometer The two methods are complimentary! OTDR based method does not replace the LSPM based solution Both methods have advantages and limitations
OTDR s Have Multiple Points of View - 0.23 db + 0.41 db 0.33 db 0.32 db + 0.44 db - 0.20 db
Causes for Directivity Potential causes for different results depending on the direction i 1. Two fibers are different Diameter Back Scatter Index NA. Numerical Aperture Major difference in IR Index of Refraction 2. Damaged fiber end faces Glassis chipped off
Bi Directional Averaging The averaging can be performed manually or by advanced results management software
Can We Quantify Directivity No standard defines how to calculate it but it is simple ISO/IEC 14763 3 defines no maximum allowed directivity
How to Quantify Directivity Delta of measured loss from End 1 and End 2 divided by two @ 0m: Δ ( 0.23 023and 0.41) / 2 = 06/ 0.6 2 = 03dB 0.3dB @50m: Δ (0.44 and 0.20) / 2 = 0.6 / 2 = 0.3dB Inthisexample: Priorto averaging the result willbe over stated by 0.30dB in one and understated by 0.3dB in the other directions NOTE: The overall loss is not suffering from directivity Only if launch and receive fiber exhibit no directivity if tested without a link
No Bi Directional Averaging Consequences A directivity of 0.2 0.4 can often be seen with out mixing 50 and 60µm and new and OM1/2 fiber Even fiber from the same supplier will show up to 0.15dB of directivity For this example we assume a 100m patch panel to patch panel link with connectors win an IL ranging from 0.15 to 0.25dB. The fibers loss is 3dB/km The assumed directivity is 0.2dB for launch/tail fiber link and ~ 0dB between launch & tail Meas. Meas. Avg. Actual Limit f. End 1 Meas. f. End 2 Meas. Meas. Avg. Actual Limit f. End 1 f. End 2 Meas. 0 m 0.15 db 0.75 db 0.05 0.35 0.15 0 m 0.15 db 0.30 db 0.05 0.35 0.15 100m 0.25 db 0.75 db 0.45 0.05 0.25 100m 0.25 db 0.30 db 0.45 0.05 0.25 Atten.Koeff. 3dB/km 3.5dB/km 3.00 3.00 3.00 Atten.Koeff. 3dB/km 3.5dB/km 3.00 3.00 3.00 Overall Loss 0.70 db 1.85 db 0.70 0.70 0.70 Overall Loss 0.70 db 0.95 db 0.70 0.70 0.70 Take Away: PASS/FAIL / info for a is available right away for over all Panel to Panel loss for individual elements in the link only after computing the average
MPO Cassettes / Panel Panel Loss Budgets what you need 10GBASES SR requirement is 2.6 db @ 850 nm 40/100GBASE SR requirement is 1.5dB @ 850 nm 300 m 150 m LC MPO Trunk MPO LC Total TIA 0.75 0.75 1.05 0.75 0.75 4.05 ISO (2002) 0.75 0.75 1.05 0.75 0.75 4.05 ISO (2006) 0.30 0.75 1.05 0.75 0.30 3.15 0.30 0.30 1.05 0.30 0.30 2.25 MPO treated as a splice 0.50 0.50 0.50 1.50 2 nd Gen. Cassettes State of the art 0.30 0.40 0.30 1.00 Cherry Picked Components
Low Loss MPO The Drivers Zoned Data Centers Distributor in accordance with ISO/IEC 11801 Network access cabling system Main distribution cabling system Zone distribution cabling system Equipm. cabling Courtesy: TE Connectivity
Testing Zoned Data Centers After the installation only the links can be testet The Patched Channel is configured by the network user Link Test #1 Link Test #2 Link Test #3 Channel Courtesy: TE Connectivity A common mistake is to test a links to channel limits Correct is to certify compliance with the link limit and/or compliance with component limits
Testing a Complex Channel Assumptions: Complex cannel consisting iti of 4 segments One connection is very poor (1.00dB) All other connections 0.25dB and fiber 3.0dB/km Conn. #1 Fiber #1 Conn. #2 Fiber #2 Conn. #3 Fiber #3 Conn. #4 Fiber #4 Conn. #5 Total L (m) 30 30 30 30 120 0.30 0.105 0.75 0.105 0.75 0.105 0.75 0.105 0.30 2.40 Value 0.25 0.09 0.25 0.09 0.25 0.09 1.00 0.09 0.25 2.32 Take Away: Tier1/BASIC LSPM Testing: The good connections may cover up for one very poor one Only an OTDR can find the unnecessary bottle neck
Testing a Complex Channel Assumptions: Complex cannel consisting iti of 4 segments One connection is very poor (1.00dB) All other connections 0.25dB and fiber 3.0dB/km Conn. #1 Fiber #1 Conn. #4 Total L (m) 30 30 0.30 0.105 0.30 0.70 1) Value 0.25 0.09 1.00 1.34 Take Away: PASS/FAIL based on the length depended link budget will flag bad connectors. The OTDR will allow to identify the poor end and which cassette to swap/connector inspect and clean Conn. #1 Fiber #1 Conn. #4 Total L (m) 30 30 0.75 0.105 0.75 1.605 Value 0.25 0.09 1.00 1.34 Take Away: OTDR PASS/FAIL testing should be based on component limits. More generous component limits make the information valuable even before computing the accurate average
Can OTDRs PASS/FAIL a link based on a length dependent limits? This function is common in LSPMs (Light Source and power meters) Directivity and tight ISO or even tighter project specific limits i makes this function also desirable for an OTDR The time saving is significant > 50% Such a function in an OTDR will not obsolete LSPMs because they will always provide the most accurate loss measurement They are less expensive and often considered to be easier to use
OTDR PASS/FAIL Based on a Length Dependent Link Limit - 0.23 db 0.33 db + 0.44 db Automatic Limit Calculation for OTDR PASS/FAIL testing: First Connector 0.30 db Fiber 50.49*3.5/1000 = 0.18 db Last Connector 0.30 db Total 0.78 db
Bi Directional OTDR Tests Without a Tail Fiber - 0.23 db 0.33 db 0.32 db + 0.44 db - 0.20 db
Testing Of Parallel Optics Based Cabling Infrastructure MPO / MPT
Fiber Inspection Equipment exists for inspecting MPO connectors
Polarity MPO/MTP System Type A 26
Polarity MPO/MTP System Type A 27
Polarity MPO/MTP System Type B Tech Forum "Verkabelung Netze Infrastruktur" 28
Polarity MPO/MTP System Type B 29
Polarity MPO/MTP System Type C Tech Forum "Verkabelung Netze Infrastruktur" 30
Polarity MPO/MTP System Type C 31
Field Test Method Available Today Multiplesteps arerequiredrequired because 1. Lack of a non critical MPO connection on the meter 2. Lack of a switchable source 3. Keys prevent a modified 2 jumper method with fan out (Hydra) only 4. Tight limit require a initial verification of the auxiliary SC / LC cords 5. Tight limits require a normalization of the auxiliary SC/LC cords
MPO Field Tester Wish List 1. Testing of all fibers in the link in one go 2. Non critical MPO connector on the meter to support the most accurate one jumper method 3. Switchable MPO source to verify polarity System A, B, C,. Field terminated connectors 4. MPO Test Reference Cords with reference grade connectors A definition for reference grade MPO connectors!
Conclusio Standards d based dlimits it can not be used to test tan installation ti Test needs to be based on limits agreed by the supplier, customer/consultant and the installer Procedures for testing and setting the reference need to be agreed on by Test cords (Fan Out) will be specific for the project Attention needs to be paid to cleaning and inspection Complex channels constructions can only be supported with components exceeding the normative requirements
Thank You! for Your Attention I would be happy to answer an further question christian.schillab@flukenetworks.com