FTTH Testing solutions - Mostar, Bosna i Herecegovina · High reflections in an Analog CATV System Signal type: • Amplitude Modulation Vestigial Side Band (A M-VSB) transmission

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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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Outline




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


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 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


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



•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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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



FDH Enclosures:

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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


Drop technical Terminal in Hand hole

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Drop technical Terminal



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


Outline



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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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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


FOT-930/FTB-3930: FTTH features

Point to Multi-Point testing

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FTTx result in FOT-930


FTTx result in FTB-3930

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Testing FTTH

Construction & installation tests• Link characterization using an OTDR

~ End to end~ Per Segment


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:


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


Outline



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Service Activation Testing


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.


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


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


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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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




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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All spliced networks allow only two test points:1. At the CO2. At the ONT

OLT

CO FDH DT ONT


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


Outline



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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


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


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


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


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


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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Documents

FTTH Testing solutions - Mostar, Bosna i Herecegovina · High reflections in an Analog CATV System Signal type: • Amplitude Modulation Vestigial Side Band (A M-VSB) transmission