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FTTH Testing solutions
2004 All Rights Reserved 2
Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
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2004 All Rights Reserved 3
Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
2004 All Rights Reserved 4
EXFO’s FTTH leadership
Our objective:Maintain our dominant leadership in FTTHtesting• We started very early in the FTTH history (during UNE-P
discussions, spring 2003)• We worked closely with US Tier 1 telcos to develop test
solutions• We invested massively into R&D to get the most complete
FTTH testing product portfolio• With above 80% of the market and our test instrument
deployed in most of the FTTH project, we have gained adominant position worldwide
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EXFO’s FTTH
We Launched Many FTTx products• World first PON Power meter: The PPM-350B
• Passthrough and built-in filtering allowing simulatenouslymeasurement of all 3 PON signals
• Allows burst signal mesurement (ONT)• Pass-warning-fail
• FTB-7000D OTDR• Best dead zones of the industry allowing measurment of close
optical events• Test through splitters• PON wavelengths
• FOT-930/FTB-3930 Automated OLTS• New FTTx features• PON wavelengths
• 300 & 600 series OLTS• PON wavelengths
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EXFO’s FTTH
FTTH Council member• Active member
Litterature• Articles in many magazines• PON FTTH testing pocket Guide
~ 2nd edition~ For field technicians
• FTTx Survival guide• FTTH testing book by Andre Girard• Training Video
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Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
2004 All Rights Reserved 8
FTTH technical review : Standards
Full Service Access Network (FSAN)• APON (ATM-PON) - ITU-T G.983.1.
~ Mid-1990s~ ATM based 155 Mbps~ Not deployed
• BPON (Broadband PON) - ITU-T G.983.3~ Addition of Video~ 155 Mbps upstream / 622 Mbps downstream~ Current solution in North America
• GPON (Gigabit PON) -ITU G.984~ 2001~ 2.5 Gps Upstream/Downstream~ Future solution in North America
Ethernet in the First Mile Alliance (EFMA)• EPON (Ethernet Based PON)
~ 2001~ IEEE (group 802.3ah)~ 1.25 Gb/s symmetrical system~ Most popular solution in Asia
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FTTH technical review : Topologies
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FTTH technical review : Outside Plant
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FTTH technical review : Passive equipment
PON = Passive Optical NetworkNo active equipment between the C.O. and the subscriber
Passive components:• Optical fiber• WWDM Coupler• Splitter• Drop Terminal• Drop Cables• Connectors• Enclosures• Splices
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FTTH technical review : Passive equipment
•In Controlled Environment•Wide WDM•0.7 to 1.0 dB IL•Bidirectional•High Input Power at 1550 nm
WDM coupler:
1490nm1310nm
DataData
Video
Central Office (CO)
WWDMCoupler
Video
1490nm1550nm
1550nm
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FTTH technical review : Passive equipment
PON Splitters:Various PON deployment scenarios are available dependingon
• Housing development topology• Cost/benefit analysis and deployment environment
Typical: 32 branches maximum• 1x32 (one stage)• Other combinations (multiple stages)
Splitting Ratio IL (dB)Uniformity
(dB)1x2 3.6 0.5 - 0.91x4 7.7 0.5 - 0.91x8 10.8 0.8 - 1.2
1x16 14.5 1 - 1.71x32 18 1.3 - 2
Installed inside the Fiber Distribution Hub (FDH) or enclosuresfor small splitters
•Some installers willuse splices instead ofconectors•UPC connectors canbe used where video isdigital or absent
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FTTH technical review : Passive equipment
FDH Enclosures:
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FTTH technical review : Passive equipment
Drop Terminal or Drop Enclosure:•Connection point between the « Drop Cable » and the cable fromthe splitter•Multpile drop terminals are be linked to one splitter depending onthe subscriber density at the drop location
Mutliple Drop Terminal Scenario
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Drop technical Terminal in Hand hole
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Drop technical Terminal
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FTTH technical review : Passive equipment
Drop Cables:•Can be pre-connectorized for fast deployment (requiresconnectoirized drop terminals)•Makes the link between the Drop Terminal and the subscriber•Can be spliced in the Drop Terminal
Drop cables
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FTTH technical review : Active Equipment
OLT
ONT
2004 All Rights Reserved 20
Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
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Construction Testing
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Construction Testing
• Optical loss measurement• Optical return loss (ORL) measurement• At three PON wavelengths• End to end or per segment
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Construction Testing
Optical Return Loss (ORL)•Defined by the standards. The ITU organization will specify themaximum ORL in order to get an “error free” transmission•If the ORL specification is not respected, the effects could be:
~ Multipath interference (MPI) ghost images (analog video)~ Fluctuations in the laser output power~ Limited speed~ Increased BER in digital systems
Connector type Typical Reflection(dB)
UPC -50 to -55APC -65 to -70
ITU Rec.Max. ORL (dB)
(for the link)
G.983.1 32G.984.2 32
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FOT-930/FTB-3930: FTTH features
Point to Multi-Point testing
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FTTx result in FOT-930
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FTTx result in FTB-3930
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Testing FTTH
Construction & installation tests• Link characterization using an OTDR
~ End to end~ Per Segment
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OTDR Testing Through a Splitter
Required OTDR characteristics for testing PONs
• High dynamic range:• Must exceed the PON loss budget by a reasonable margin
in order to perform end-to-end link characterization.• Minimum requirement of 30 dB
• Short dead zones:• Required to characterize closely spaced events
• Triple-wavelength testing:• Required to test the PON at 1310, 1490 and 1550 nm
• Recovery• Must be able to see after the splitter (high loss)
• distinguish between the splitter loss and an end of fiber
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Testing Through a 1x32 Splitter
Blind after the splitter
PON-Optimized OTDR:
Standard OTDR:
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Potential Problems
High loss due to• Macro-bendings (many manipulations)• Damaged connectors• Dirty connectors
Will result in• Increased BER• No ONT « detection »
Transmission problems dues to• High ORL• High reflectance
Will result in• MPI• Ghost images
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High reflections in an Analog CATV System
Signal type:• Amplitude Modulation Vestigial Side Band (AM-VSB) transmission
Cause:• Important localized reflections (e.g. -55 dB)
~ Before or after the splitter~ Even though total ORL can be as low as 32 dB
Problem:• Multipath interference (MPI) ghost images
Standards specify reflections less than –55 dB (ORL above 55 dB)• Bellcore GR-326-CORE• TIA/EIA-568-B.3
Testing method:• The only way to verify that each connection in the network meets this
standard is to use an OTDR• APC connectors are required
ConnectorType
TypicalORL (dB)
UPC 50-55
APC 65-70
2004 All Rights Reserved 32
Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
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Service Activation Testing
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Service activation testing
Subscriber Activation Scenario1. ONT is installed2. Drop fiber is installed (can be pre-connectorized)3. ONT is powered up4. Optical signals are measured (must meet power-level
criteria)
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Service activation testing
New challenge:Will be performed by access technicians
• Often called I&R or I&M• Experienced with Copper only• Newly trained on fiber
They need and want a low cost meter providingpass/fail information.
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PPM-350B PON Power Meter
LCD showing all 3 power valuessimultaneously
LEDs provide pass/failinformation for all three signals
Green = PassYellow = WarningRed = Fail
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PPM-350B: PON Power Meter measuring capability
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PON Power Meter—Testing Procedure
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Service Activation Scenarios
Two major types of installation schemes can bedone:
OLT
CO FDH DT ONT
OLT
CO FDH DT ONT
1. Connectorized
2. All spliced
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Service Activation Testing- Testing points
Connectorized networks allows multiple test points:
Test point 1: At the splitter output~ Output power for Video downstream at 1550nm~ Output power for Data downstream at 1490nm~ Each splitter port can be tested individually
OLT
CO DT ONTFDH
Parki
ng
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Service Activation Testing- Testing points
Connectorized networks allows multiple test points:
Test point 2: At the Drop Terminal~ Output power for Video downstream at 1550nm~ Output power for Data downstream at 1490nm~ Signal from the CO through the splitter~ Each drop port can be tested individually
OLT
CO DT ONTFDH
Parki
ng
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Service Activation Testing- Testing points
Connectorized networks allows multiple test points:
Test point 3: At the ONT (pass through unit required)~ Output power for Video and Data downstream~ Output power for Data upstream~ Signal through each component of the PON network~ The EXFO PPM-350B features a « Pas Through » feature for
PON activation
OLT
CO DT ONTFDH
Parki
ng
1310nm
1490
nm15
50nm
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Service Activation Testing- Testing points
All spliced networks allow only two test points:1. At the CO2. At the ONT
OLT
CO FDH DT ONT
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Service Activation Testing- Pass/Fail testing
The EXFO PPM-350B features programmable thresholds:• A set of thresholds for each wavelength:
~ 1310, 1490, 1550nm
• A set of thresholds for different test points:~ Drop, ONT, FDH, etc
Example at ONT location:
Fail (blink)
Pass
Warning
Fail
6 dBm(pass)2 dBm(warning)1 dBm(fail)
1310 nmONT
Fail (blink)
Pass
Warning
Fail
-4 dBm(pass)-22 dBm(warning)-25 dBm(fail)
1490 nmOLT
Fail (blink)
Pass
Warning
Fail
6.9 dBm(pass)-10.6 dBm(warning)-13.6 dBm(fail)
1550 nmVIDEO
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Service Activation Testing- Expected signal levels
Typical thresholds levels (dBm) according to ITU 983ONT
Data Up (1310 nm)OLT
Data Down (1490 nm)VIDEO
Cable TV (1550 nm)
No Name FAIL WRNG Pass FAIL WRNG Pass FAIL WRNG Pass
1 ONT -5.5 -4.5 2 -26.5 -23.5 -6 -7.7 -4.7 12.8
2 Split Out -7 -6 1 -25.5 -22.5 -4.5 -6.7 -3.7 14.3
3 Split In -24 -23 -14 -10.5 -7.5 4 8.3 11.3 23
4 OLT -31.5 -28.5 -8 -0.5 0.5 4 18.3 19.3 23
5 ONT G (pour GPON) -1 0 4 -25 -22 -4 -13.6 -10.6 6.9
6 Split Out G -2.5 -1.5 3 -24 -21 -2.5 -12.6 -9.6 8.4
7 Split In G -19.5 -18.5 -12 -9 -6 6 2.4 5.4 16.9
8 OLT G -27 -24 -6 1 2 6 12.4 13.4 16.9
9 ONT EPON 1 2 5.5 -25 -22 -4 -13.6 -10.6 6.9
10 OLT EPON -25 -22 -4.0 0.5 1.5 6.0 12.4 13.4 16.9
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Outline
FTTH introduction• EXFO’s FTTH• FTTH technical review
FTTH testing solutions• Construction• Service Activation• Trouble Shooting
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Troubleshooting steps for specific problems
No communication between OLT and ONT• PPM-350B to verify optical signals• OTDR to localise break
Increased BER• If a signal level is outside the transmission window (above or under) BER
may increase• The PPM-350B is the best tool to monitor each signal level• OTDR can be used to localise fault
Macrobendings• A VFL can be used to find and correct macrobends in splice trays• OTDR can be used to detect and localise problem
Bad connectors• A Fiber Probe can be used to find and clean dirty connectors
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Main ONT types and alarms
• When the communication is disturbed between the OLT and ONT,alarms will be generated.
• The alarm codes will vary depending on the system vendor• Alarms are sent to the OSS and redirected to technicians for field
service
OSS(Operation Support System)
OLT
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Main ONT types and alarms
Alarm examples:
Alarm code Description
TFTransmitter Failure:The OLT transmitter is declared in failure when there is nonominal backfacet photocurrent or when the drive currents gobeyond the maximum specification.
SDiSignal Degraded of ONUi:When the upstream BER of ONUi becomes ≥10-5 , this state isentered.
LOSiLoss of signal of ONUi:No valid optical signal at the O/E receiver received for ONUi whenexpected during eight upstream sequential cells.
Reference: ITU G.983.1
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Troubleshooting Steps- No communication between OLT and ONT
Trouble example: Loss of signal from ONT• Testing with the PPM-350B can be done from to ONT towards the
OLT to identify the defective section
OLT
CO FDH DT ONT
1234
• The PPM-350B allows to measure the power in dBm for eachwavelength simultaneously
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Troubleshooting Steps- No communication between OLT and ONT
Trouble example: Loss of signal from ONT (suite)• If a section of fiber is defective, an OTDR can be used to locate the break• Fiber must be disconnected at the FDH or CO to ensure no signal is
present (only dark fibers can be tested with regular OTDRs !)
• The OTDR can be connected at the FDH or ONT location
OLT
CO FDH DT ONT
This OTDR test locationallows to test the link from the
Splitter OUT to the ONTThis OTDR test location
allows to test the link from theONT to the FDH or COdepending if the PON isactive before the splitter
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2nd line testing - OTDR
Trouble example: Weak signal at ONT
Requires Out of band OTDR
•Filtered 1650nm
•Allows in service testing
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FTTH Testing – what’s the future
Construction testing• Large deployments imply
~ Efficient link qualification tools• Testing all the fibers and complete link• Usable by non experts• Easy data export• Fast
~ Reliable solutions• Complate end to end testing• Transposed (wrong ports) fibers
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FTTH Testing – what’s the future
Service Activation & Troubleshooting• Same reliability and availability as standard
POTS must be offered. This implies~ More simple, compact, user friendly & affordable
tools to complement the PPM-350B• Provide more information on problem source/cause• Easy to interpret by non experts
~ Complete OAM strategies• The protocol layer and network elements are currently
addressed• The physical layer must also be included
• Fault isolation• Fault location
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PPM-350B PON Power meterFOT-930 MaxTester
loss/ORL/distance/connector probe
AXS-100/AXS-110 Access OTDR,including connector probe,
VFL and PMStandard OTDR test mode
Live OTDR test mode
FTB-200 Compact Platform,including connector probe
FTB-7300E OTDR moduleFTB-3930 OLTS module
Fiber inspection probe:optional on FOT-930, FTB-200, AXS-100/AXS-110,
also as a stand-alone instrument
Isporučeni instrumenti T-HT za FTTH
OPREMA SE POKAZALA KORISNA IUBRZALA RAD I GRUPAMA ZA
ODRŽAVANJE I IZGRADNJU“BACKBONE” MREŽA
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PODRŠKA TVRTKE m.TEHODRŽANI TEČAJEVI KORIŠTENJA OPREME PREMA
UGOVORUODRŽAVANJE CERTIFICRANIH TEČAJEVA EXFO “Be-
an-Expert” NA HRVATSKOM JEZIKUPODJELJENE KNJIGE EXFO FTTHPODJELJENA TRI FILMA:1. EXFO FTTH TESTING2. EXFO FTB-200 TRAINING3. EXFO FOT-930 TRAININGPODRŠKA PRILIKOM MJERENJA – TELEFONSKI I NA
TERENUPODRŠKA U IZRADI IZVJEŠTAJA – USKLAĐIVANJE
PREMA ZAHTJEVIMA PLANIRANJA
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IZVJEŠTAJI – BAZAPODATAKA
Ogromne količine mjerenja – što brže mjerenje te izradai spremanje izvještaja
LITE REPORTER – besplatni softver za izradu OTDRizvještaja
FAST REPORTER – sva mjerenja (OTDR FTB-200,OLTS FOT-930, PON Mjerač snage PPM-350B)integrirana u jedan softver – baza podataka FTTHmreže
DOBRO POZNAVANJE MREŽE- SMANJENJE OPEX-a PRILIKOM EKSPLOATACIJE, TE BRŽERJEŠAVANJE PROBLEMA POJEDINIH KORISNIKA
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