GPON Fundamentals

PTCL Training & Development

GPON/FTTH

PTCL Training & Development 2

Content Development Team

• Muhammad Usman Senior Instructor, PTC Lahore

• Muhammad Pervaz Ahmad Senior Instructor, PTC Faisalabad

• Muhammad Zeeshan Senior Instructor, PTCL Staff College, Haripur

• Nasir Mahmood, Lecturer, PTCL Academy, Islamabad

• Muhammad Pervez, Lecturer, PTCL Staff College, Haripur

• Jamil Ahmed, Lecturer, PTC Peshawar

• Jamil-ud-din, Instructor, PTC Multan

• Muhammad Zaheer, Instructor, PTC Quetta

• Muhammad Umer Farooq, Junior Instructor, PTC Karachi

• Ahmad Ali Shah, Junior Instructor, PTC Peshawar

• Ghulam Mustafa, Junior Instructor, PTC Sukkur


Objectives

After completion of this course, the participants will be able to:– List the limitations of traditional copper based

access network and explain how GPON addresses these limitations

– Describe the Architecture of an optical access network

– Identify the components and operation of GPON

– Describe Key GPON technology.


Contents

1. Overview of Optical Access Network

2. Basic Concepts of PON

3. GPON Standards

4. GPON Reference Model

5. GPON Key Technologies

6. GPON Management and Service Provisioning

7. Basic Services over GPON Network


Overview of Access Network


Definition (AN)

It is access of customer to the telecommunication services or vice versa.

Traditionally it was called OSP (Outside Plant) or LN (Local Network) or Local Loop.

Access Network is a network that connects a user to the telecommunication services.


Access Network

LEEND USER

EX

EX

AN is called “the last mile of Telecom Network”

Access Network


Role of AN in the Operator’s Business

• Final tool for service delivery to the end users

Quality & flexibility of AN determine the speed and quality of service to the end users • Major cost factor for the operator

Accounts for about 40~50% of total telecom network investment • Very important in a competitive environment End user oriented, generates revenue for operators

Services

Services Access Network

node

End user

Motive: revenue

Good AN, Better Services, More Revenue ! 138


Types of Access Networks

• Wired Access Networks– Copper wired Access Networks

• 2 W-Loop for POTS, ISDN,XDSL

• Fiber optic based access Networks– FTTB

– FTTC– FTTH

• For POTS, ISDN,XDSL, VOIP, TV, MSAN.

• Hybrid Fiber-Coaxial Cable Systems– Access network for the cable TV networks, Internet, VOIP.

• Wireless Access System (WLL)– CDMA– Wi-MAx


Copper Cables Based

• Point to point/star architecture• Tailored to voice/low speed data • passive

Characteristics of Traditional Access Mode

Distribution layer Feeder layer Drop layer

500m~1 km

10~300 m 3~5 km

LE Connection Distribution USER Cabinet Box Central office

C C D.P


Copper Cables Based • Small coverage • Limited bandwidth• Maintenance complexity• Reliability cut down• Enormous investment

Limitation of Traditional Access Mode

Distribution layer Feeder layer Drop layer

500m~1 km

10~300 m 3~5 km

LE Connection Distribution USER Cabinet Box Central office

Traditional access mode has become the “bottleneck” of modern telecom network!

C C D.P


How to Overcome the “bottleneck”

Optical Integrated Services ! Access Network

Advantages:

Wide Coverage Broad Bandwidth Easy Maintenance High Reliability Low Investment 140


Access Network Status

During the current period of transition, global telecom carriers need to:

1. Enhance service competitiveness and provide more services.

2. Increase ARPU (Average Revenue Per User) value and reduce the maintenance cost by binding multiple services.3. Improve customers’ satisfaction on the network and reduce the customer churn rate.

To make a success in the transition, To make a success in the transition, increasing the bandwidth is the prerequisite.increasing the bandwidth is the prerequisite.


Introduction-Broadband Services

• Voice services revenue is getting flat• On a world wide basis, the market is calling

out for broadband which allows for the wide range of applications and products e.g.,• High speed internet access• Sophisticated telephony services• High definition TV• Video on demand• Network based gaming• Music and moving down load• Education and business based video conferencing• Telemedicine.


Narrowband and Broadband Services

Internet connection speed

Time to down load a typical web page

Time to down load a typical 5 min song

Streaming video quality

56K dial-up modem 14 sec 12 min 30 sec -

256K broadband 3 sec 3 min Low Quality

512K broadband 1.6 sec 1 min 30 sec

1Mb broadband 0.8 sec 41 sec

2Mb broadband 0.4 sec 20 sec Medium Quality

4Mb broadband 0.1 sec 5 sec

6Mb broadband Instantaneous Instantaneous

8Mb broadband Instantaneous Instantaneous TV Quality


How to provide Broadband services through Access Network

• Digital Subscriber Line• Cable Modem• Fiber in The Loop• Wireless• Satellite• Broadband over Power Lines


Service

Access

Core

X.25

ADSL

Ethernet

PSTN

IP

ATM

FR

GSM/GPRS CDMA

Cable

PDHSDH

Wire

less V

oice

Wire

less D

ata

Hig

h S

peed

Inte

rnet

Voice

Stre

am

ing

Dia

l-up

VoIP

Messa

ge

FTTH

GPON

DS

L

Wireless

Eth/IP/MPLS

Aggregation Network

Loca

tion &

Pre

sen

ce

Messa

ge

On

line G

am

ing

Voice

Data

Vid

eo

Sto

rag

e

Dire

ctory

Development Trend of the Access Network - All over IP


What is FTTH? Copper

Fiber

2 MbpsOld networks, optimized for voice

CO/HE

1 Gbps +Optical networks, optimized for voice, video and data

CO/HE//

CO/HE//

//

Note: network may be aerial or underground


What is FTTH?

• “An OAN in which the ONU is on or within the customer’s premise. Although the first installed capacity of a FTTH network varies, the upgrade capacity of a FTTH network exceeds all other transmission media.”

– OAN: Optical Access Network– ONU: Optical Network Unit

– OLT: Optical Line Termination

//

ONUOLT

CO/HE

OAN


High Transmission Capacity Low Attenuation Long Repeater SpacingNo Cross talk and Signal LeakageSmall size and Light weightSecurity of service

FEATURES OF OPTICAL FIBER


Small bending causes radiation lossOptical Fiber connections need to align the fiber

core with fine precisionA very small flaw (hole) at the fiber surface

weaken the strength of fiberOptical Fiber is very Fragile

DISADVANTAGES OF OPTICAL FIBER


Why FTTH? - fiber versus copper

• A single copper pair is capableof carrying 6 phone calls

• A single fiber pair is capable ofcarrying over 2.5 million simultaneous phone calls 64 channels at 2.5 Gb/s)

• A fiber optic cable with the sameinformation-carrying capacity (bandwidth) as a comparable copper cable is less than 1% of both the size and weight

• A single copper pair is capableof carrying 6 phone calls

• A single fiber pair is capable ofcarrying over 2.5 million simultaneous phone calls 64 channels at 2.5 Gb/s)

• A fiber optic cable with the sameinformation-carrying capacity (bandwidth) as a comparable copper cable is less than 1% of both the size and weight


Why FTTH? - fiber versus copper

Glass• Uses light• Transparent• Dielectric material-

nonconductive– EMI immune

• Low thermal expansion• Brittle, rigid material• Chemically stable

Copper• Uses electricity

• Opaque• Electrically conductive material

– Susceptible to EMI• High thermal expansion• Ductile material

• Subject to corrosion and galvanic reactions

• Fortunately, its recyclable


What is a Fiber Optic Cable?

• An optical fiber (or fiber) is a glass or plastic fiber designed to guide light along its length

http://en.wikipedia.org/wiki/Light


History of Optical Communication

Hand signals, Flags and Smoke Signals

Light Transmission through bent water jet

1000 Nature of light was defined and laws of reflection given

1880 Photo Phone by A.G. Bell

1962 Laser diode

1966 Idea of optical fiber for communication by Kao & Hock ham

1970 Chemical vapor deposition(VCD) < 20 db/ Km by Corning

1973 MCVD <1 db/Km by Bell Systems


INTRODUCTIONINTRODUCTIONToTo

LIGHTLIGHT


Law of Reflection

This law states that “ when a ray of light is reflected from a surface, the angle of reflection is equal to the angle of incidence”.


i2 r2i1 r1

Normal Normal

i2= r2

Law of Reflection

i1= r1


Refraction

It is the bending of light rays due to changes in the speed of propagation when light enters from one medium to another.

The angle at which the light bends is a function of the medium’s “ index of refraction”.


Angle of Refraction

Angle of Reflection

Angle of Incidence=

D

The critical angle of incidence.

GlassAir

B

GlassAir

Angle of IncidenceA

GlassAir

Critical Angle

900CGlass

Air


Refraction of a light ray passing through an optically denser medium .

n 1

n 2

β

α

n 1n 2 >

Refraction


Index of Refraction

It is the ratio of the speed of light through a medium to the speed of light through vacuum.

gIndex of refraction = n = cV

V


Index of Refraction

It is equal to the sine of the angle of incidence divided by the sine of the angle of refraction.

Index of refraction = n = sin θ isin θ r


Refractive Indices

MATERIAL

VACCUM

AIR

MERCURY VAPOUR

WATER

GLASS

DIAMOND

INDEX OF REFRACTION

1.0000

1.0003

1.0009

1.3

1.6

2.4

Selected indices of refraction


Optical Fiber

Propagation Principlesin


Different wavelengths of light are directed through the fiber core by refraction & reflection.

Different wavelengths relate to different colors.

Optical fiber is basically a glass waveguide.

Fiber Optic Principles


1310 nm and 1550 nm / Single-mode LED

Invisible = Infrared (high band)

Visible = 400 - 750 nm

Invisible = Ultra-violet (low-band)

850 nm and 1300 nm / Multi-mode LED

Wavelength


Propagation of light in an optical fiber requires that the light be totally confined within the fiber.

The above object can be obtained in two different ways Total Internal Reflection

Light Propagation in Optical Fiber

Continuous Refraction


Most widely used method for the propagation of light through optical fiber is the total internal reflection.

Total Internal Reflection

The amount and direction of deflection is determined by the amount of difference in refractive indices as well as the angle at which the rays strike the boundary.


For incidence angles equal to or greater than the critical angle, the glass air boundary will act as a mirror and no light escape from the glass.

Example:

Sin 90Sin Ø c

=n2 (Glass)

n1 (Air)=

11.5

Sin Øc = 0.6667 Ø c = 41.80

Total Internal Reflection(Continued)


For incidence angles equal to or greater than the critical angle, the glass air boundary will act as a mirror and no light escape from the glass.

Example:

Sin 90Sin Ø c

=n2 (Glass)

n1 (Air)=

11.5

Sin Øc = 0.6667 Ø c = 41.80



Incoming Ray

Out Going Ray

Light propagation within a flexible glass fiber.



Very complex core structure

High refractive index (n1) at the center decreases gradually to a lower refractive index (n2) at the circumference.

Continuous Refraction(Continued)


In step index fiber, the index profile for a constant index fiber displays a sharp step at the fiber’s perimeter.

The variable index fiber shows an index profile that has its highest value in the center and slops away gradually. This is referred to as a graded-index fiber.



A comparison of index profiles for step-index and graded-index fibers.

n1

n2

A B

STEP INDEX FIBER GRADED INDEX FIBER



n1

n2

n3

n4

n1

n2

n3

n4

How light rays react to a gradually changing index ?

Hypothetical Multilayer Fiber

Continuous Refraction (Continued)


Light propagation with in a hypothetical multi layer fiber.

n 2

n 2

3n

3n

n 4

n 4

1

2

3

4

5

6

7

1n



Fiber Radius (microns)

Core Profile

Cladding Cladding62.5 micron core

60 40 20 0 4020 60

Ref

ract

i ve

Inde

x D

iffe

renc

e

1.490

1.485

1.480

1.475

1.470

1.465

(Continued)


The effects of increasing the number of refractive layers while maintaining the same n



OUTSIDE

CENTER

FOUR LAYERS

n



OUTSIDE

CENTER

EIGHT LAYERS

n



INFINITE LAYERS

OUTSIDE

CENTER

n



Graded-index fiber becoming very popular for specialized applications.

It is relatively expensive to manufacture, due to its complex core structure.

It is also more difficult to workwith.

Graded index Fiber


Two Methods of Optical Confinement

A

B

Continuous Refraction (Graded Index Fiber)

Total Internal Refraction (Step Index Fiber)


Areas of Application

Classification of Optical Fiberon the basis of


Direct Burial Cable

FIBER OPTIC CABLES

Internal External

Simplex Cord

Duplex Cord

Breakout Cable

Distribution Cable

Underground Cables

Underwater Cable

Duct Cable

Aerial CablesLong Span Cable

OPGW Cable

Short Span Cable


Classification on ApplicationClassification on Application

Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable



Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable


Breakout Cable

Simplex Cord

Duplex figure – 8 / Zip Cord


Breakout Cable

PVC sheath

Centre member

Buffered Optical Fiber

PVC jacket

Aramid yarn

Continued


Distribution Cable

Optical FiberTight buffer

Aramid yarn

Flame retardant PVC & zero halogen sheath



Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable


Direct Burried CableDirect Burried Cable

PE outer sheath

PE inner sheath

Corrugated coated steel tape armour

Central strength member

Jelly filled loose tube

Moisture barrier sheath



Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable


DUCT CABLE

Polyethylene outer sheathPolyester tapes

Small Loose tubestrength memberJelly

Optical fiber



Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable


Several variations of Aerial cables are available for fiber optic, depending on the placement, application and environment.

Aerial Fiber Optic Cable


AERIAL CABLE – Tight Buffer

PE sheath

Supporting strength member


Tight buffer


AERIAL CABLE – Loose Tube

High density PE sheath

Jelly filed Loose tube

Supporting strength member


Optical fiber


AERIAL CABLE - Short Span

High density PE sheath

PE sheath

Aramid yarn


Loose tube

Moister resistant jelly


PE outer sheath

PE Inner sheath

Rods Reinforcing

Optical Fiber

Jelly Filled Slotted core

AERIAL CABLE – Long Span



Indoor cable

Duct cable

Aerial cable

Direct buried cable

Underwater cable


Under Water Cable

Optical fibers in loose tube

PE outer sheath

Armoring wires

Bitumen layer

PE inner sheath

Moisture barrier sheath

Heat sealable tape



Connector Insertion loss Repeatability Fiber type Application

0.06-1.00 dB 0.20dB SM,MM Telecommunication

0.20-0.50dB 0.20dB SM,MM Telecommunication

0.20-0.70dB 0.20dB MM Fiber Optic Networks

0.50-1.00dB 0.20dB SM,MM Datacom,Telecommunicat

ion

0.20-0.70dB 0.20dB SM,MM Fiber Optic Networks


Connector Insertion loss Repeatability Fiber type Application

0.30-1.00dB 0.25dB SM,MM High–density

Interconnects

0.20-0.45dB 0.10dB SM,MM Telecommunication

0.2-0.45dB 0.10dB SM,MM Datacom

0.40-0.80dB 0.30dB MM Military

Typ.0.40dB (SM)Typ.0.50dB (MM)

Typ.0.40dB (SM)Typ.0.20dB (MM)

SM,MM Inner-/intra-building Security, Navy


ADAPTERS

ST Adapter SMA Adapter


ADAPTERS

D4 Adapter DIN Adapter

Continued


ADAPTERS

Biconic Adapter FC Adapter

Continued


ADAPTERS

SC Adapter Mini- BNC Adapter

Continued


Optical Fiber Structure• Core

Thin glass centre of the fiber where the light travels

• Cladding Outer optical material surrounding the core that reflects the light back into the core

• Coating Plastic coating that protects the fiber from damage and moisture

• Glass Glass core – glass cladding Lowest attenuation

• Plastic Plastic core – plastic cladding Highest attenuation

• Plastic-clad silica Glass core – plastic cladding Intermediate attenuation


In single-mode fibre only one ray, or mode, of light

propagates down the core at a time. It is used

primarily for telephony and cable television

applications, and is used increasingly for campus

backbones.

2. MULTI-MODE

TYPES OF FIBRES

SINGLE-MODE

1. SINGLE-MODE


Multi-mode fibre was the first type of fibre to be

commercialized and is commonly used for data

communications. In multi-mode fibre many rays, or

modes, of light propagate down the core

simultaneously. Multi-mode fibre typically is used in

private premises networks, where signals are

transmitted less than two kilometers.

MULTI-MODE


SINGLE-MODE

1. Diameter of core is less

2. Only one mode is propagated

3. Used for Short Haul & Long Haul Transmission

MULTI-MODE

1. Diameter of core is more

2. More than one mode are propagated

3. Used for Short Haul transmission

WHAT IS THE DIFFERENCE


Fiber Optic ITU Standards• G.651 MMF

Large core: 50-62.5 microns in diameterTransmit infrared light (wavelength=850 to 1300

nm)Light Emitting Diode

• G.652 SMFSmall core: 8-10 microns in diameterTransmit laser light (wavelength= 1200 to 1600

nm)Laser Diode


OPTICAL FIBRE CABLE

Polly-ethylene sheet

Steel Armoring

Middle Polly-ethylene

sheet

Corrugatedsteeltape

Inner Polly-ethylene

sheet

Slotted Core

Fibres

Strengtheningmember


Fiber Optic Cable Construction


Why Total Internal Reflection• Concept

Light travels through the core constantly

bouncing from the cladding

• DistanceA light wave can travel great distances because

the cladding does not absorb light from the core

• Signal degradation

Mostly due to impurities in the glass


Atomic Defects in Glass composition Impurities of metal ions Electronic absorption bands in the ultra-violet

region Atomic vibration bands in the near infrared

region Intrinsic absorption

REASON OF ABSORPTION LOSSES IN FIBER


Attenuation Vs. Wavelength


O-band E-band S-band C-band L-band U-band


Optical Fiber Transmission System• Optical Transmitter:

• Produces and encodes the light signal.

• Optical Amplifier:

• May be necessary to boost the light signal (for long distance)

• Optical Receiver:

• Receives and decodes the light signal

• Optical Fiber:

• Conducts the light signal over a distance

Tx Amp Rx


Optical Transmitter•Function:

–Electrical to optical converter•Types:

–Light Emitting Diode (LED)–Laser Diode (LD)

•Comparison:Item LED LD

Data rate Low High

Mode Multimode Multimode/Single mode

Distance short long

Temp sensitivity minor substantial

cost low expensive


Optical Amplifier• Definition:• An optical fiber with a doped coating• How it works:

Most atoms in excited state rather then in ground stateWhen perturbed by a photon, matter loses energy resulting in

the creation of another photonSecond photon is created with the same phase, frequency,

polarization and direction of travel as the original.The perturbing photon is not destroying in the process

• Elements:Erbium-rare, so expensiveErbium Doped Fiber Amplifier (EDFA)

amplifier


Optical Receiver• Function:

– Optical to electrical conversion.

• Types – photo detector:APD - (avalanche Photo Diode)PIN – (Positive Intrinsic Negative Photo Diode)

• How it works:– Gives an electrical pulse when struck by light

• Error:Thermal noise is an issue.To make pulse powerful enough, the error rate can

be made arbitrarily small

Rx


Optical Transceiver

• Definition:– A transmitter and a receiver in a single

housing• Practical Implementation:

Transceivers typically comes as SFPSmall-form-factor pluggable unit

TX

Rx


Joining Fibers - connectors• Properties:

Good alignment/correct orientation.Presentation at the termination point of the fiberAlways introduce some loss

• Connector types:Amount of mating cyclesLC, FC, SC,…

• Color codeAPC – greenPC - blue


Optical Power Splitter

• Optical Splitter:Typically divide an optical signal from a single

input into multiple (e.g two) output signalGenerally provide a small optical loss to the signal passed through it


Optical Power Splitter

• Power of 2 split

• 3.5 dBm loss every split

• 1x8 has on average 3.5x3=10.5 dBm of loss

• 1x32 has on average 3.5x5=17.5 dBm of loss

• Optical budget 28 dBm = 20 km


Fiber Cable – loose tube• Ideal for long distance

• Easy drop-off• Standard buffer tubes for excess fiber length• Anti-bucking central strength member• Termination and splicing requires cleaning

• Gel may weaken fiber

• Inflexible – stress buildup, cracks, water penetration


Loose Tube Cable in FTTH• Advantages:

Proven technology

Lower cost for fibers below 144 fibers

Ease of access to individual fibers

• Disadvantages:

Available in size only up to 432 fibers

Cable becomes very large for size over 288 fibers

Restoration can take longer for large count cable

Need to pay attention to buffer tube storage in cold

weather


Tight Buffer• Usually indoor

• Single fiber for patch-cords, pig-tails, jumpers, linking devices.

• Multi fiber in riser application


Ribbon Cable in FTTH• Advantages:

Proven technologyLower cost for 144 fibers and largeEase of access to individual fiberLarge count cables will fit in a smaller duct than the

same sized loose tubeHigher fiber count in a splice tray

• Disadvantages:More difficult to store pass-through fiber in a ped or

splice caseRibbon is less tolerant to physical damage than loose

tube


HOW FIBRE WORKS


Types of Windows used• Wavelengths used for Single Mode Fiber (long distances) communications

– 1310 nm• Usually lowest cost lasers• Used for shorter broadcast runs and short to moderate data runs

– 1550 nm• Can be amplified with relatively low-cost erbium doped fiber amplifiers

(EDFAs)• Lasers are fabricated on a number of different wavelengths (about

1535 – 1600 nm) for wave division multiplexing (WDM) applications• Slightly lower fiber loss at 1550 nm

– 1490 nm• Increasingly popular for downstream data in 3l systems.

– Cannot be amplified as easily– Somewhat higher device cost


Single and Dual Fiber Systems

• Single Fiber– Downstream broadcast* on 1550 nm– Upstream data on 1310 nm– Downstream data on either 1310 or 1490 nm* depending on

system– Advantages

• Less fiber deployed• Fewer optical passives (taps or splitters)• Fewer labor-intensive connections

* Downstream data can be carried at 1550 nm if not used for broadcast


Single and Dual Fiber Systems• Dual Fiber

– Various plans, usually one fiber will be used for downstream and one for upstream, or one will be used for broadcast and one for data. Sometimes one will be used for specialized services, such as returning RF-modulated data from set top terminals

• Advantages

– Simplifies terminal passive components

– Somewhat lower signal loss


SAFETY MEASURES REGARDING OPTICAL FIBRE CABLE HANDLING


Safety issues relevant to operation and maintenance staff involved in optical fiber systems fall into one of three categories:

- Laser light Sources- Handling of bare optical fiber ends- Hazardous Chemicals

Optical Fiber and LASER Light Safety


LASER LIGHT SOURCES

This includes both optical line transmission equipment and Optical test equipment.A laser can cause damage to human tissue either on the surfaceof the skin or in and around the eyes.

- The Eyes- Laser Safety Requirements- Laser safety Procedures- Some General Rules on Laser Safety


The eyes, being a very sensitive part of the human body, canBe very susceptible to the hazards of laser light.

Laser Safety RequirementsOnly staff who have attended an optical fiber training course And had their eyes tested may install, test and optical fiber cables.

The Eyes

Laser Safety Procedure-Ensure that the power is turned off at both ends of the section while the optical fiber cable is being worked on.-Under no circumstances should an optical fiber or connector


Vision Hazard


Continued

LASER

WARNING

Vision Hazard


Don’t add fiber to your food !

Fiber

Ingestion


Bare fiber

Continued

Fiber


OPTICAL FIBRE CABLE

That is connected to an optical source, be viewed directly with the eye or be directed at the skin.

- In some circumstances it may be necessary to test fusion slices in conjunction with jointing operations. Under no circumstanceMust a light signal from an OTDR) be transmitted through a fiberUntil jointing staff have completed splicing operations on the fiberAnd have notified the testing Officer that it is safe to do so.


Some General Rules on Laser Safety

• Never look into the beam of a transmitting laser, either via the output port of equipment or the end of a connected fiber

– Initially assume that all fiber and equipment is active in transmitting light.

• Optical connectors should always be held at least 300mm from the eye, etc.


HANDLING OF THE BARE FIBERS

• Bare fibers should be treated with more care than handling a piece of broken glass in the home

• If optical fiber glass accidentally penetrates the skin, it probably remain there and eventually infect the area around it

• However in extreme cases it could potentially end up in the blood stream, which would be extremely dangerous.


• Always dispose of broken fibers or fiber.• Off cuts in receptacle designated for this

purpose i.e. fiber bin.• Do not throw bare fiber in a waste disposal bin

or on the floor.• Always wash hands thoroughly after handling

optical fiber, especially when eating food.• Never touch the end of a bare fiber

HANDLING OF THE BARE FIBERS


FITL -Fiber in the loop

FTTB Fiber to the Building/Basement

FTTC Fiber to the Curb/Cabinet

FTTH Fiber to the Home


CO

Curb

CustomerPremise

BA

FTTC

FTTB

OLT

OLT

Architecture of Optical Access Network

DSLAM

250-700m

Urban Coverage

3.5-5kmRemote BusinessxDSL 2~20Mbps

OLTFTTH

ODN

MDU

ONT

ONU

Optical Line Termination Optical Networks Termination

Optical Networks Unit

Multi-Dwelling Unit

2.5Gbps Down /1.25Gbps Up




From the architecture diagram, the optical access network comprises the following scenarios:

1. FTTB scenarioSBU : Single business unit ; providing a comparatively small number of ports such as

POTS, 10/100/1000BASE-T and DS1/T1/E1 ports

MTU :Business Multi-tenant unit ; providing a comparatively larger number of ports, including POTS, 10/100/1000BASE-T and DS1/T1/E1 ports.

FTTb ~ Fiber to the Building , is the deployment of fiber (optical) cable to a specific location within a building, then connected to the buildings existing copper, cable facilities.

• This deployment is also referred to as FTTB (Fiber to the Basement) & FTTB (Fiber to the Business).

• This deployment will be the typical for MDU’s & MTU’s also known as ** FTT mdu ~ Fiber to the MDU **

What is Optical Access Network?


2. FTTC & FTTCab scenario

. FTTC & FTTCab scenarioMDU : Multi-dwelling unit ;providing a comparatively larger number of ports, including 10/100/1000BASE-T, VDSL2, and so on.

• FTTc ~ Fiber to the Curb , is the deployment of fiber close to the customer but not fully to the customers residence.

• In this deployment the existing copper plant is still used to deliver service to the actual customer.

• FTTN (Fiber to the Neighborhood) & FTTC (Fiber to the Cabinet) generally fall under the FTTC category. Both services are in deployment and in use, a perfect example is a DLC/NGDLC (Digital Loop Carrier) which some of us get our phone service from.

• A direct fiber from the CO (Central Office) is terminated at the DLC/NGDLC and then service is delivered to the customers residence via the copper plant.


3. FTTH scenario

• FTTH scenarioSFU : Single family unit , providing a comparatively small number of ports, including following types: POTS, 10/100/1000BASE-T, and RF.

• FTTh ~ Fiber to the Home , is the complete deployment of fiber to the customers home, with replacement of there existing NID (Network Interface Device).This replacement device is called an ONT (Optical Network Terminator).


Strategic Drivers for FTTH

• Multi Service Network - Service Convergence

• Each – Long distance (20 Km)

• Only active components ate OLT and ONT splitter Passive

• Remote service provisioning

• Future proof (almost infinite bandwidth)

• Reduce operational costs

• Fiber cost decreasing compared to copper


Basic Concepts of PON


PON concept

• PON is short for Passive Optical Network ;

• GPON architecture: Passive optical network featuring one-to-multiple-point;

– Optical Line Terminal (OLT)

– Optical Network Unit (ONU)

– Optical Distribution Network (ODN).

Passive Optical Splitter

Optical Network Unit

Passive Optical Network

Optical Line Terminal

OpticalNetwork Termination

..

...

.

..

...

.PSTNPSTN

InternetInternet

IPTVIPTV


Why GPON?

• GPON supports :

– Triple-play service

• HDTV: 16-20M/program;

• Data: 10M;

• Video Conference: 4.5M • GPON is the choice of large carriers in the international market.

<1Mbps 3M 8M 25M 2.5G

ADSL/ADSL2+

Copper Based

VDSL / ADSL2+

Copper Based

PON

Fiber Based

2002 2003 2006 2010Time

InternetVideo conferenceRemote control

AccessTechnology

Servicerequirement

s

VoDHDTVGame

Live TVVoDHDTV

<3km <2km <1km ~20kmCoveragediameter

High-bandwidth up to 1.25Gbps/2.5Gbps Long-reach up to 20km


Why PON?

• Enormous information carrying capacity• Easily upgradeable• Ease of installation• Reduced O&M costs• Long distance reach• Secure• Immune to electromagnetic noise• Best suited for triple play services


GPON Services

• Business Services– E1/PRI– BRI– 2G/3G– SIP/POTS etc– VPN & Ethernet Leased Lines/Internet Leased line

• Residential Services– HSI (High Speed Internet) (Al Shamil)– IPTV– POTS


Philosophy• Two types of FTTH networks exist today

– Retail• Vast majority of FTTH builds today• Network owner sells services directly to subscribers• Follows traditional telecommunications and cable television

models– Wholesale

• Market created by a few state laws• Network owner sells capacity to multiple providers who in turn

sells services to subscribers• Only examples in US today are some municipal FTTH

networks


Technical considerations• Data

– How much per home?– How well can you share the channel?– Security – how do you protect the subscriber’s data?– What kind of QoS parameters do you specify?– Compatible business services?

• SLAs• T1

• Support for voice?• Support for video?

– Broadcast– IPTV


Technical considerations• Data

– How much per home?

– How well can you share the channel?

– Security – how do you protect the subscriber’s data?

– What kind of QoS parameters do you specify?


Technical considerations - Speed

• Data requirements– Competition: ADSL, cable modem ~0.5 to ~1.5 Mb/s

shared, asymmetrical– FTTH ~10 to 30 Mb/s non-shared or several 100 Mb/s

shared, symmetrical

– SDTV video takes 2-4 Mb/s today at IP level

– HDTV takes maybe 5 times STDV requirement

– Pictures can run 1 MB compressed– 5.1 channel streaming audio would run ~380 kb/s


Technical considerations - Speed

Service

Required Data Rate

VoIP

Streaming audio

Picture in 15 seconds SDTV

HDTV

FTTH

DSL or cable modem


Technology Minutes Hours Days

Modem 56 kb/s

2

ISDN 128 kb/s

20

12

DSL 1 Mb/s 2.5

Cable 2.5 Mb/s

1

45

FTTH 0.4

Estimated minimum time to acquire BraveheartAugust 17, 2001:MGM, Paramount Pictures, Sony Pictures, Warner Brothers, and Universal Studios unveiled plans for a joint venture that would allow computer users to download rental copies of feature films over the Internet.

December 9, 2002:“Hollywood's Latest Flop”

Fortune Magazine“The files are huge. At 952 Megabytes, Braveheart took just less than five hours to download using our DSL Line at home… in the same time we could have made 20 round trips to our neighborhood Blockbuster”

Technical considerations – Speed (IPTV Reference)


Standards


STANDARDS• ITU-T G.983

– APON (ATM Passive Optical Network). This was the first Passive optical network standard. It was used primarily for business applications, and was based on ATM (Asynchronous Transfer Mode) 53-byte cell to transfer data.

– Initial offering 155.52 Mbps Downstream, 155.52 Mbps upstream.

– BPON (Broadband PON) is a standard based on APON architecture. It adds support for WDM, dynamic and higher upstream bandwidth allocation, and survivability. It also created a standard management interface, called OMCI, between the OLT and ONU/ONT, enabling mixed-vendor networks.


BPON - PON FSAN / ITU-T G.983

• * BPON standard of APON (Asynchronous Transfer Mode) –

• Fiber Cable Span no more than 20Km (12Miles) of Single-mode fiber

• Asymmetrical 622 (STM-4) / 155 (STM-I) Mbs bandwidth per OLT path of 32 ONT's.

• OLT - WDM (Wave Division Multiplexing) • 1550nm downstream bandwidth for (Analog / Digital / HDTV) • 1490nm downstream data rate of 622Mbps for Voice / Data • 1310nm upstream data rate of 155Mbps for Voice / Data • TDM (Time Division Multiplexing) of ATM packets • 1:32 Passive Splitter OSP Topology


STANDARDS (contd)

• IEEE 802.3ah EPON or GEPON (Ethernet PON) is an IEEE/EFM standard for using Ethernet for packet data. 802.3ah is now part of the IEEE 802.3 standard.

-There are currently over 15 million installed EPON ports. -With China's 2008 EPON deployments total installed base is

expected to reach nearly 20 million subscribers by year end 2008.

-EPON uses IP-based protocol to transfer data.- 100 Mbps Symmetrical.- 1.25 Gbps Symmetrical.


STANDARDS (contd)

• ITU-T G.984 GPON (Gigabit PON) is an evolution of the BPON standard. It supports higher rates, enhanced security, and choice of Layer 2 protocol (ATM, GEM, Ethernet). In early 2008, Verizon began installing GPON equipment, having installed over 800 thousand lines by mid year. British Telecom, and AT&T are in advanced trials. GPON uses IP-based protocols to transfer data.


GPON - PON FSAN / ITU-T G.984

• Fiber Cable Span no more than 20Km (12Miles) of Single-mode fiber

• Asymmetrical 1.244 Gbps or 2.444 Gbps / 155 or 622 Mbs bandwidth per OLT path of 32 ONT's

• OLT - WDM (Wave Division Multiplexing) • 1550nm downstream bandwidth for (Analog / Digital / HDTV) • 1490nm downstream data rate of 2.4 Gbps for Voice / Data • 1310nm upstream data rate of 1.2 Gbps for Voice / Data • TDM (Time Division Multiplexing) of ATM packets • 1:32 Passive Splitter OSP Topology


ITU-T G.984.3• Specifications of TC layer in the GPON system

• GTC multiplexing architecture and protocol

stack

• GTC frame

• ONU registration and activation

• DBA specifications

• Alarms and performance

ITU-T G-984.1/2/3/4

Simple development processPowerful compatibility

ITU-T G.984.1• Parameter description of GPON network

• Requirements of protection switch-over

networking

GPON StandardsGPON Standards

ITU-T G.984.4• OMCI message format

• OMCI device management frame

• OMCI working principle

ITU-T G.984.2• Specifications of ODN parameters

• Specifications of 2.488Gbps downstream optical port

• Specifications of 1.244Gbps upstream optical port

• Overhead allocation at physical layer


xPON Protocols


Basic Performance Parameters of GPONGPON identifies 7 transmission speed combination as follows:

Upstream Rate(Gbps)

Downstream Rate(Gbps)

0.15552 1.24416

0.62208 1.24416

1.24416 1.24416

0.15552 2.48832

0.62208 2.48832

1.24416 2.48832

2.48832 2.48832

1.24416 Gbit/s up, 2.48832 Gbit/s down is the mainstream speed combination supported at current time.


Basic Performance Parameters of GPON

Maximum logical reach

60 km

Maximum physical reach

20 km

Maximum differential fibre distance

20 km

Split ratio 1 ： 64/up to1 ：128 The distance

between nearest and farthest ONTs


ITU Full Service Access Network-FSAN Standards.

• The following standards apply for APON and GPON.- Fiber loop length limited to 20 Km between OLT and ONT.- System will support from 2 to 64 splits within the 20 Km in any increments or combinations (1:2, 1:4, 1:8, 1:16, 1:32, 1:64). Most designs are based on a 32-way split.

• Total optical budget is 30 db. Note. ITU G.984.2 Amendment 1 limits this to 28 db.

• Maximum difference in optical budget between the first ONT and the last ONT is 20 db, although many manufacturers can now support a higher optical budget difference.- Video is an analog overlay to the digital voice and data.- Voice and Data downstream transmission is 1480 to 1500nm.- Voice and Data upstream is 1260 to 1360nm. - Analog Video overlay on a single fiber system for downstream is 1550nm.


PON Architecture Choices


Selecting the Best of Multiple Choices• Active– Sometimes called Point-to-Point or P2P– Dedicated fiber and optics for each subscriber• PON– Uses passive optical splitters to serve many subscribers from one optical unit– Comes in several formats:• GPON• BPON• EPON

Architectural Choices


Active Architecture

Central Switch

Drops

Connectors

(NID)


Active Architecture

• Benefits

– Dedicated bandwidth per subscriber

– Simple, point-to-point topology

• Challenges

– Cost: each subscriber requires a separate pair of optical transmitters/receivers

– Limited deployment options


PON Architecture

Central Switch

Drops

Passive Optical Splitter

Feeder

Connectors

(NID)


PON Architecture

• Benefits

– Low-cost for high total bandwidth: matches video broadcast traffic patterns

– Flexibility in outside plant topology

• Challenges

– More complex outside plant topology

– Choices: APON, BPON, GPON, EPON?


• A recent study found:– Top 5% of users consume 56% of total bandwidth– Top 20% of users consume 97% of total bandwidth

• The study also reported bandwidth by application:– Peer-to-peer - 66%– Web surfing - 27%– E-Mail - 7%

• Potential Conclusion:– Most users aren’t so bandwidth hungry or application-sophisticated as pundits think

Source: Ellocoya Networks study, as reported by telephony.com

Considerations


The Answer is

The best choice for now and the future is:

GPON


Types Of Splitting


Types of Splitting

• Centralized Splitting

• Partially Distributed Splitting

• Fully Distributed Splitting


Centralized Splitting

Architectural Models

Feeder

Distribution

Drops

Splitters are here

Central Switch

Local Convergence Point NAP(Splice)

(Splice)

Connectors

(NID)


Centralized Splitting

• Target Applications:

– High customer churn

– Requirement for highly flexible connectivity

• Homerun Consolidates all Splitting to the CO

• Most Flexible Due to Central Splitting

– Highest headend flexibility/scalability

• Requires the Most Amount of Fiber

• Most Expensive, Most Flexible



• Partially Distributed Splitting

Central Switch

Local Convergence Point(Splitter)

Splitters are here

(Splice)

NAP

Feeder

Distribution

Drops

Connectors

(NID)


Partially Distributed Splitting

• Target Application:

– Overbuild with anticipated customer churn, slower build out, or lower-to-mid-level take rates

• Consolidates Local Subscribers to Central

Splitter Cabinet for Adds & Drops

• Reduces Feeder Fiber Needs

• Heavy Fiber Usage in Distribution

• Second Most Expensive Design



Fully Distributed Splitting

Central Switch

Local Convergence Point

Splitters are here

Feeder Distribution Drops

(1xn Split)

NAP(1xn Split)

(100% Take Rate)

Connectors

(NID)


Fully Distributed Splitting

• Target Application:– Higher Take Rates– Low Anticipated Customer Churn

• Fiber Lean Distribution and Feeder• Least Expensive Up Front Cost• Headend Does Not Scale as Well as Previous

Architectures– Requires higher take rates to offset investment


PON Architecture Summary

Architecture Type Cost Flexibility Application

Fully DistributedSplitting

$ Least Higher Take RatesLow Customer Turnover

Partially DistributedSplitting

$ Mid Low to Mid Take Rates/Slow BuildHigh Customer Turnover

Centralized Splitting $ Most High Customer TurnoverNeed for High FlexibilityCash to Burn


The Optimum Optical/Copper Solution

The Ideal Platform Supports

GPON and Copper• Provides triple-play service delivery over both

• Allows for a managed migration

• This combined GPON and copper platform would:

– Offer all the choices of different split architectures

– Also add “Really” Fully Distributed option of putting the OLT in the remote loop carrier



“Really” Fully Distributed Splitting

Many OLTs share common feeder transport fibers

Copper

Drops

Fiber

Drops

Splitters are here

Copper and Fiber loop carrier

(1xn Split)

Feeder Distribution

Central Switch

(1xn Split)

NAPs

Connectors

(NID)


Operational Considerations.

Advantages of a Copper and Fiber Platform• Common Administration

– Reduced Training Cost– Reduced Cost for Flow-through Provisioning– Reduced Sparing

• Common Customer Service Experience– Triple play regardless of serving infrastructure

• Orderly Network Migration– Paced by your depreciation schedules and recovery issues, not service offerings


PON Topologies

(a) Tree topology (using 1:N splitter)

OLT

ONU1

ONU2

ONU3

ONU4

ONU5

(b) Bus topology (using 1:2 tap couplers)

OLT

ONU1 ONU2

ONU3 ONU4ONU5

(c) Ring topology (using 2x2 tap couplers)

OLT

ONU1

ONU2

ONU3

ONU4

ONU5

(d) Tree with redundant trunk (using 2:N splitter)

ONU1

OLTONU3

ONU5

ONU2

ONU4


System Architecture


GPON ARCHITECTURE

• OLT (Optical line Terminal)

• Access Media

• Optical Splitter

• ONU (Optical Network Unit) / Residential Gateway

• ODN (Optical Distribution Network)


Components of PON


COMPONENTS

• A PON consists of an Optical Line Terminal (OLT) at the service provider's central office and a number of Optical Network Units (ONUs) near end users.

• A PON configuration reduces the amount of fiber and central office equipment required compared with point to point architectures.


OLT

The OLT provides the interface between the PON and the service providers network services. These typically include:

• Internet Protocol (IP) traffic over Gigabit, 10G, or 100 Mbit/s Ethernet

• Standard time division multiplexed (TDM) interfaces such as SONET or SDH

• ATM UNI at 155-622 Mbit/s


OLT ~ Optical Line Terminal

• OLT is the networks control card. This card resides in the local CO (Central Office) cross connected to the video and data networks that will be delivered to your home, it consists of a special DFB (Distributed Feedback) calibrated laser that is always on.

• This control card acts as a traffic signal to the remote ONT's for complete data / video throughput upstream and downstream.


ONU

• ONT is an ITU-T term, whereas ONU is an IEEE term. In Multiple Tenant Units, the ONT may be bridged to a customer premise device within the individual dwelling unit using legacy technologies such as Ethernet over twisted pair, Ethernet over Coax, or DSL.

• An ONT is a device that terminates the PON and presents customer service interfaces to the user.

Some ONUs implement a separate subscriber unit to provide services such as telephony, Ethernet data, or video.


ONU ~ Optical Network Unit

• ONU ~ Optical Network Unit , this is similar to the SFU-ONT but for a MDU / MTU, or small business.

• It contains 12 - 24 POTS Lines, multiple "Ethernet" or "VDSL" connections, and one / two high-powered RG video outputs.

• These ONT's come in two forms, a wall mountable or rack-mountable unit, they are typically installed in a stairwell area, or basement next to the existing SAI for that floor


ONT• The ONT terminates the PON and presents the

native service interfaces to the user. • These services can include voice plain old

telephone service (POTS) or voice over IP (VoIP)), data (typically Ethernet), video.


ONT


Functions of ONT


Functions of ONTOften, the ONT functions are separated into two

parts:• The ONU, which terminates the PON and presents a converged interface –

such as xDSL, coax, or multiservice Ethernet – toward the user.• Network termination equipment (NTE), which provides the separate, native

service interfaces directly to the user. • Note: This is the CPE (Customer Premise Equipment) endpoint of

the ODN. The ONT is an Optical to Electrical to Optical device , that delivers your triple play services. It will replace your existing copper NID (Network Interface Device) , and coax connections. The existing POTS / Coax inside wiring will be cross connected to the ONT. Since we understand that a PON is completely passive the endpoint must contain an AC voltage connection to perform the Optical to Electrical conversions for your services.


Fusion Splitter

1 x 4 Fusion Splitter

1310 nm

1490 nm

1550 nm

Fiber


Fusion Splitter

Fiber

1310 nm

1490 nm

1550 nm

2 x 4 Fusion Splitter


Planar Splitter

1 x 8 Planar Splitter


Planar Splitter


BEAM SPLITTER

• A beam splitter is an optical device that splits a beam of light in two.

Schematic representation of a beam splitter cube


BEAM SPLITTER - Design 1

• In its most common form, a cube, it is made from two triangular glass prisms which are glued together at their base using Canada balsam.

• The thickness of the resin layer is adjusted such that (for a certain wavelength) half of the light incident through one "port" (i.e. face of the cube) is reflected and the other half is transmitted.



• Another design is the use of a half-silvered mirror. This is a plate of glass with a thin coating of aluminum (usually deposited from aluminum vapor) with the thickness of the aluminum coating such that, of light incident at a 45 degree angle, one half is transmitted and one half is reflected. Instead of a metallic coating, a dielectric optical coating may be used. Such mirrors are commonly used as output couplers in laser construction. Similarly, a very thin pellicle film may also be used as a beam splitter.



• A third version of the beam splitter is a dichroic mirrored prism assembly which uses dichroic optical coatings to split the incoming light into three beams, one each of red, green, and blue. Such a device was used in multi-tube color television cameras and also in the three-film Technicolor movie cameras. It is also used in the 3 LCD projectors to separate colors and in ellipsoidal reflector spotlights to eliminate heat radiation.


FDH ~ Fiber Distribution Hub

• FDH ~ Fiber Distribution Hub , is the cross connection splice-point for the Central Office Fiber and Distribution Fiber to the FDT's servicing the customers community.

• This hub can come in various configurations (Aerial Pole mount / Ground Pedestal), the providers configuration will typically be the 144 / 216 user count, designed to be a plug and play system for the FDT / Drop Cable connections.



(ADC) FDH Rear Panel


FDH Splitter CabinetCore Component: Splitter Cabinet for 432 subscribers (13 Splitters), available also for 144 and 288

subscribers (pre-stubbed and pre-connectorized)

OptiTect Cabinet CouplerModules | Photo CCO108


Splitter Module


1xN FTTH Splitters

1x16 slot 1x8 slot 1x2 slot


FDH


Corning OptiTect FDH Gen III - 432 & 288 Field Installation


PON Splitter Cabinet Sizing

• Sizes available: 32 Fiber (1 Splitter) to 864 Fiber (Home Run and Centralized Local Distribution Cabinet)

• Sizing will be dependent on rural or urban applications.

• Specific cabinet sizing is trade off between size of the distribution area and number of cabinets.

• Rural areas: Serving areas tend to get too large well before the ideal cabinet size is reached.

• Urban areas: Due to the density, the number of fibers can exceed the available cabinet sizes before the serving areas become unmanageable.


Outdoor Fiber Distribution Hub (FDH).

• The outdoor (FDH) provides for connections between fiber optic cables and passive optical splitters in the OSP environment.

• The outdoor (FDH) utilize standard SC/APC to interconnect feeder and distribution cables via 1:32 optical splitters and connectors.


Indoor Fiber Distribution Hub (FDH)

• The indoor FDH is designed to organize and administer fiber optic cables and passive optical splitters in an indoor environment typically suitable for high rise buildings and is placed in the telecom room.

• These FDH are used to interconnect main cable (Feeder) and drop cable (2F) via optical splitters in a FTTH network application.

• No splices are allowed between the Telecom Room and Flats.

• Where the building has less than 32 customers, a wall mounted splitter FDH (indoor type) is more suitable. The unit will serves as a Mini ODF with splitter assembly and facility to terminate drop cables.


Distribution Cables & Drop Cables

• From Outdoor FDH Cabinet location, distribution cable (loose tube) sizes 24F, 16F and 8F combinations may be considered, depending upon the grouping of villas/homes, number and locations.

• The drop closures to be installed inside joint boxes, close to group of villas/homes or as per site requirements. These have single entry on one side and 24+ outlets for drop cables.

• The drop cables are 2F construction, it is recommended that both the 2F are spliced through in the drop closure, so that the fibers are through to the splitter location.

• In the FDH Cabinet, only one fiber of 2F drop cable is required to be terminated.

• In the case of single villas, company shall extend and terminate the drop cable in the micro ODF (Low Homes Areas).


DROP CABLE

• DROP CABLE ~ This cable is the final connection to the customers ONT. This cable can be spliced from an aerial / underground FDT. Most providers have moved to a pre-terminated drop cable system, this saves cost and installation time.

• Drop Cable ~ This cable will enter the customers apartment from the FDT that's usually located in a closet, or stairwell in a high-rise building. In a small garden-style MDU deployment your drop cable may come from an FDT located on the outside of your building, and routed through the roof breezeway into your apartments designated closet.

http://www.broadbandsoho.com/FTTx/ADC_MST_Drop%20Example.jpg

http://www.broadbandsoho.com/BBS_VZ_FTTH-13.jpg


SFH (Single Family Home) - Corning OptiFit Drop Cable.

Corning OptiFit Drop Cable


Corning SST-Drop Cable


Corning OptiSheath Multi-Port Terminal – FDT


Pre-terminated drop cable system


FDT ~ Fiber Distribution Terminal

• FDT ~ Fiber Distribution Terminal , is the cross connection splice-point between the community serving FDH Distributing Cable, and the Drop Cable to the customers ONT.


SFU (Single Family Unit)• The SFU ONT is primarily used in single

dwelling homes.• This ONT will replace your existing demarc that

currently delivers your home service.• This same unit (The 611i is the preferred

model for this deployment) can also be used in MDU Garden Style installations.

• In these MDU installations the SFU is preferred so that the ONT can be placed directly in the unit, with the responsibility and electric cost passed to the customer.


Tellabs 612 SFU ONT


Motorola 1000v SFU ONT (Scroll over pic)


GPON Principle----Data Multiplexing

• GPON adopts Wavelength Division Multiplexing (WDM) technology, facilitating bi-direction communication over a single fiber.

1490nm

1310nm


Data Multiplexing

• To separate upstream/downstream signals of multiple users over a single fiber, GPON adopts two multiplexing mechanisms:

– In downstream direction, data packets are

transmitted in a broadcast manner;– In upstream direction, data packets are

transmitted in a TDMA manner.


GPON Principle----Downstream Data

• Broadcast mode

11 22 33 11 22 33

1122

33

1122

33

11

22

33

Data for specified ONU

Data for specified ONU


GPON Principle----Downstream Data

• Line rate.• Downstream : 2.488 Gb/s.• Upstream : 1.244 Gb/s.

• Broadcast mode. . continous mode operation.

. traffic in the downstream is sent to/received by every ONU. • Issue. Data confidentiality . AES-Advanced Encryption Standard used for link layer encryption.


GPON Principle----Upstream Data

• TDMA (Time Division Multiplex Access) mode

11 22 33 22

11

33

11

22

33

Data from specified ONU

Data from specified user


GPON Principle----Upstream Data

• TDMA- Time Division Multiple Access.• burst mode operation.• the OLT controls which ONU gets access to the

upstream at a particular moment in time.

• Issues: potential collision.

. access granting. . distance ranging.


Upstream Bandwidth Allocation

• The OLT is responsible for allocating upstream bandwidth to the ONTs. Because the optical distribution network (ODN) is shared, ONT upstream transmissions could collide if they were transmitted at random times.

• ONTs can lie at varying distances from the OLT, meaning that the transmission delay from each ONT is unique.

• The OLT measures delay and sets a register in each ONT via PLOAM (physical layer operations and maintenance) messages to equalize its delay with respect to all of the other ONTs on the PON.



• Once the delay of all ONTs has been set, the OLT transmits so-called grants to the individual ONTs.

• A grant is permission to use a defined interval of time for upstream transmission.

• The grant map is dynamically re-calculated every few milliseconds.

• The map allocates bandwidth to all ONTs, such that each ONT receives timely bandwidth for its service needs.



• Some services – POTS, for example

– require essentially constant upstream bandwidth, and the OLT may provide a fixed bandwidth allocation to each such service that has been provisioned.


AES Encryption in GPONEnd UserEnd User

11

End UserEnd User33

ONTEnd UserEnd User

22

33 33

1133

33

2211

1111 11

22

ONT

ONT

1133

33

2211

11

11 33 3322 11 11OLT

Encryption

Decryption

Decryption

Decryption

11

11 33 3322 11 11

OLT applies Advanced Encryption Standard (AES) 128 encryption.

GPON supports encrypted transmission in downstream direction, such as AES128 encryption.

In the case of GEM fragments, only the payload will be encrypted.

GPON system initiates AES key exchange and switch-over periodically, improving the reliability of the line.

AES: Advanced Encrypt Standard

A globally-used encryption algorithm


GPON reference Model


GPON Network Model ReferenceGPON Network Model Reference

WDM

ONU/ONT

NE

WDM

OLT

NE

Service node

Optical splitter

T reference pointV reference point

R/S S/RODNUNI SNI

IFpon IFpon

ONU Optical Network Unit

ONT Optical Network Terminal

ODN Optical Distribution Network

OLT Optical Line Terminal

WDM Wavelength Division Multiplex Module

NE Network Element

SNI Service Node Interface

UNI User Network Interface


GPON Multiplexing ArchitectureGPON Multiplexing Architecture

IFpon

O

N

U

O

N

U

O

N

U

T-CONT Port

T-CONTPort

Port

T-CONT

T-CONT

Port

Port

Port

Port

Port

ONU-ID identifies

ONUs

Alloc-IDs identifies T-CONTs

Port-ID identifies GEM

ports

GEM Port: the minimum unit for carrying services.

T-CONT: Transmission Containers is a kind of buffer that carries services. It is mainly used to transmit upstream data units. T-CONT is introduced to realize the dynamic bandwidth assignment of the upstream bandwidth, so as to enhance the utilization of the line.

IF pon: GPON interface. Based on the mapping scheme, service traffic

is carried to different GEM ports and then to different T-CONTs. The mapping between the GEM port and the T-CONT is flexible. A GEM port can correspond to a T-CONT; or multiple GEM Ports can correspond to the same T-CONT.

A GPON interface of an ONU contains one or multiple T-CONTs.


GPON Multiplexing ArchitectureOLT ONT

T-CONT

T-CONT

GEM Port GEM Port

Cl assi -f i cati on

UNI

IF-PON

ONUOLT

Cl assi -f i cati on

I F-PON

QoS/Forward

SNI

Opti cal Fi ber

f l owVi rtual

UNI

T- CONTGEM portGEM port


Physical Control Block Downstream (PCBd)

Payload

AllocID Start End AllocID Start End

1 100 200 2 300 500

T-CONT0(ONT 1)

T-CONT 0(ONT 2)

Slot

100

Slot

200

Slot

300

Slot

500

PLOu PLOAMu PLSu DBRu XPayload x DBRu Y Payload y

Upstream Bandwidth Map

125usDownstream Framing

Upstream Framing

GPON Frame StructureGPON Frame Structure

OLT

ONT 0

ONT 63


PLOu PLOAMu PLSu DBRu x Payload x DBRu y Payload y PLOu DBRu z Payload z

PreambleA bytes

DelimiterB bytes

BIP1 bytes

ONU-ID1 bytes

Ind1 bytes

ONU IDMsg ID1 bytes

Message10 bytes

CRC1 bytes

DBA 1,2,4bytes

CRC1byte

DBA ReportPad if needed

GEMheader

Framefragment

GEMheader

Full frame

GEMheader

Framefragment

PLI Port ID PTI HEC

ONT A ONT B

Upstream Framing

GPON Upstream Frame StructureGPON Upstream Frame Structure


PCBdn

Payloadn

PCBdn + 1

Payloadn

Psync4 bytes

Ident4 bytes

PLOAMd13 bytes

BIP1 bytes

Plend4 bytes

Plend4 bytes

US BW MapN*8 bytes

FEC Ind1 bit

Reserved1 bit

Super-frame Counter 30 bits

Blen BW MapLength 12 bits

Alen ATM PartitionLength 12 bits

CRC8 bits

Access 18 bytes

Access 28 bytes

…..Access n8 bytes

Alloc ID12 bits

Flags12 bits

SStart2 bytes

SStop2 bytes

CRC1 byte

Send PLS1 bit

Send PLOAMn1 bit

Use FEC1 bit

Send DBRu2 bits

Reserved7 bits

125us

Coverage of this BIP Coverage of next BIP

Downstream Framing

GPON Downstream Frame Structure

GPON Downstream Frame Structure


TDMTDM data Payload

TDM fragment

HEC

PTI

Port ID

PLI

GEM Frame

Ingress buffer

TDM Buffer

Mapping of TDM Service in GPONMapping of TDM Service in GPON

TDM frames are buffered and queued as they arrive, then TDM data is multiplexed in to fixed-length GEM frames for transmission.

This scheme does not vary TDM services but transmit TDM services transparently.

Featuring fixed length, GEM frames benefits the transmission of TDM services .


GEM

Payload

CRC

PTI

Port ID

PLI

GEM FrameEthernet Packet

DA

SFD

Preamble

Inter packet gap

SA

Length\Type

MAC client data

FEC

EOF

5 bytes

Mapping of Ethernet Service in GPONMapping of Ethernet Service in GPON

GPON system resolves Ethernet frames and then directly maps the data of frames into the GEM Payload.

GEM frames automatically encapsulate header information.

Mapping format is clear and it is easy for devices to support this mapping. It also boasts good compatibility.


GPON Key Technologies-

• Ranging

• DBA

• T-CONT

• AES

• Attenuation


Ranging• OLT obtains the Round Trip Delay (RTD) through ranging process, then specifies

suitable Equalization Delay (EqD) so as to avoid occurrence of collision on optical

splitters.

• To acquire the serial number and ranging, OLT needs open a window, that is, Quiet

Zone, and pauses upstream transmitting channels on other ONUs.

ONU3

ONU2

ONU1

OLT


DBA• What is DBA?

– DBA, Dynamic Bandwidth Assignment

• Why DBA?

– It enhances the uplink bandwidth utilization of PON ports.

– More users can be added on a PON port.

– Users can enjoy higher-bandwidth services, especially those requiring comparatively greater change in terms of the bandwidth.

• DBA operation modes

– SR-DBA: status report-DBA

– NSR-DBA: non status report-DBA


SR-DBA Operation

DBA block in the OLT constantly collects information from DBA reports, and sends the algorithm result in the form of BW Map to ONUs .

Based on the BW Map, each ONU sends upstream burst data on time slots specified to themselves and utilizes the upstream bandwidth.

DBA algorithm logic

DBA report

BW Map

Time slot

T-CONT

T-CONT

T-CONTScheduler

ONUOLT

Control platform

Data platform


SR-DBA Operation

PayloadUS BW

Map

Data Report

PCBd

D/S Direction

U/S Direction

OLT ONT

①

②

③

④

Based on the algorithm result of

last time, OLT delivers BW Maps in the header of

downstream frames.

Based on the bandwidth allocation information, ONU sends the status report of data currently waiting in T-CONTs in the specified time slots.

OLT receives the status report from the ONU, updates BW Map through DBA algorithm and then delivers the new BW Map in the next frame.

ONU receives the BW Map from the OLT and sends data in the specified time slots.


NSR-DBA Operation• NSR-DBA

– NSR is an algorithm scheme that realizes DBA. It helps to predict the

bandwidth allocated to each ONU based on the traffic from ONUs.

• Procedure:

– Step1: Monitor the number of data packets received by OLT within the

specified interval.

– Step2: Use the result of real time monitoring in step 1 to calculate the

utilization rate.

– Step3: Recognize the congestion status by comparing the utilization

rate with the specified limits.


DBA Working Principle

Based on service priorities, the system sets SLA for each ONU, restricting service bandwidth.

The maximum bandwidth and the minimum bandwidth pose limits to the bandwidth of each ONU, ensuring various bandwidth for services of different priorities. In general, voice service enjoys the highest, then video service and data service the lowest in terms of service priority.

OLT grants bandwidth based on services, SLA and the actual condition of the ONU. Services of higher priority enjoy higher bandwidth.


T-CONT Bandwidth Terms• Transmission Containers (T-CONTs): it dynamically receives grants delivered by

OLT. T-CONTs are used for the management of upstream bandwidth allocation in

the PON section of the Transmission Convergence layer. T-CONTs are primarily

used to improve the upstream bandwidth use on the PON.

• T-CONT BW type falls into FB, AB, NAB, and BE.

• Five T-CONT types: Type1, Type2, Type3, Type4, and Type5.


T-CONT Type and Bandwidth Type

Type1 T-CONT is of the fixed bandwidth type and mainly used for services sensitive to delay and services of higher priorities, such as voice services.

Type2 and type3 T-CONT is of the guaranteed bandwidth type and mainly used for video services and data services of higher priorities.

Type4 is of the best-effort type and mainly used for data services (such as Internet and email), and services of lower priorities. These services do not require high bandwidth.

Type5 is of the mixed T-CONT type, involving all bandwidth types and bearing all services.


QoS Mechanism of ONU in GPON

DATA

GPON

VOIP

VOD

TDM

Traffic-flow

Scheduling

And buffer

control

Service

differentia

based on

802.1p

GPON

VOIP

VOD

TDM

Traffic-flow

Scheduling

And buffer

control

Service

differentia

based on

802.1p

OLT

Splitter

Service traffic based on

GEM Port-id

Traffic classification of services based on LAN/802.1p.

Service scheduling based on the combination of strict priority (SP) and Weighted Round Robin (WRR) algorithms.

Service transmission based on service mapping with different T-CONTs, enhancing line utilization and reliability.


QoS Mechanism of OLT in GPON

VOIP

BTV

DATA

TDM

GPON

GPON

GE/10GE

Upstream service traffic based on different VLANs

Ethernet

bridging

Non-

blocking

switching

802.1p

COS

Queuing &

scheduling

DBA

TDM GatewayPSTN

BSR

OLT

Traffic classification based on VLAN/802.1p.

Service scheduling based on combination of strict priority (SP) and Weighted Round Robin (WRR) algorithms.

DBA algorithm, enhancing uplink bandwidth utilization.

Access control list (ACL)-based access control on layers above layer-2.


(ADC) - FTTP Infrastructure


(ADC) - FTTx Architecture


(ADC) - FTTx MDU Architecture


Corning PON Overview


Tellabs PON Overview


Ring Protection


Verizon MDU - Garden Style Installation






Property Buried Distribution - FDH feed to FDT InstallationPic1- Each property will have a main buried drop splice-point from the main FDH

servicing the property.


Pic 2 - Each individual building will have a buried fiber pig-tail spliced into the main fiber

back to the FDH.


Pic 3 - This fiber pig-tail is already pre-terminated to that new FDT, which will

usually be located next to existing OSP facilities.


FDT - Exterior Molding Apartment Pathway


Each building FDT is capable of providing service to 24 apartments. As

service is activated each jumper is then connected to that unit.


Aerial Feed / Distribution Splice Enclosures


Aerial Premise Drop Enclosure / Aerial to Buried Distribution Pedestal

Enclosure


Pic 1 - Open view of Aerial FDH 216 Pic 2 - Scroll over the enlarged pic ~

Pole Mount ADC FDH 216 w/ Aerial Feed & Distribution enclosure above.


FTTH Planning-Outgoing FO Cable from CO.

• The OSP fiber counts from the Central Office should be of suitable size, to ensure meeting the future capacity requirements.

• The number of fibers in the OSP cable would more likely end up being closer to 1 Fiber per 16 tenants.

• Requirements of direct fibers for business establishment should also to be considered, while sizing the main cables.

• Where the diversity is required for an important office, Airport, Police, Hospital etc the fiber can be routed in two different routes.

• Fibers already laid for local network & CATV Network can be considered while developing the GPON Network.


The Number of Splitters per (FDH) Cabinet & Sizing of (Feeder) Cable.

• Every splitter requires a single fiber from OLT.• The total number of splitter requirement per cabinet

shall be based on 5th year tenants forecasted.• 25% spare fibers should be considered in the FO cable

size, for future requirements, maintenance, etc.• Number of Splitter per Cabinet=No of Tenants / Split

Ratio (1:32).• The provision of the number of fibers may equal to at

least 20 year tenants forecasted.• Feeder cable to be loose tube 8F/16F/24F.


•Calculating optical splitter attenuation :

•Insertion loss of the optical splitter (<1dB):

•∑(Power_input) - ∑(Power_output of all branches)

Input Output1:2 optical splitter

2:N optical splitter

∵ 10 log(0.5) = - 3.01∴Attenuation of a 1:2 optical splitter: 3.01 dB Attenuation of a 1:16 optical splitter: 12.04 dB Attenuation of a 1:64 optical splitter: 18.06 dB

Optical Power Attenuation


Fibre Attenuation and Power Budget

Fibre attenuation relates to the fibre length

The attenuation of fibre splicing point is

generally less than 0.2dB

Other factors may cause attenuation, such

as fibre bending

About 0.35 dB per kmfor 1310,1490nm

Table G.984.2 – Classes for optical path loss

Class A Class B Class B ＋ Class C

Minimum loss 5 dB 10 dB 13 dB 15 dB

Maximum loss 20 dB 25 dB 28 dB 30 dB

NOTE – The requirements of a particular class may be more stringent for one system type than for another, e.g. the class C attenuation range is inherently more stringent for TCM systems due to the use of a 1:2 splitter/combiner at each side of the ODN, each having a loss of about 3 dB.

Huawei’s OLT and ONU28 dB (Class B+)


Items Unit Single fibre

OLT: OLTMean launched power MIN dBm +1.5

Mean launched power MAX dBm +5

Minimum sensitivity dBm -28

Minimum overload dBm -8

ONU: ONU

Mean launched power MIN dBm 0.5

Mean launched power MAX dBm +5

Minimum sensitivity dBm -27

Minimum overload dBm -8

Parameters of GPON (Class B+)


GPON Management and Service Provisioning


GPON Service ProvisioningCarriers’ nightmare

Application scenario

Service Provisioning

NMS 2000

Access Network

Billing

1 Subscribe for services

2 Configure service network

3

Order Management

Start up ONT and make registration with serial numberONTONT

ONTONT

CRM

User

Send terminals to users

1

2

Finish the auto-configuration of OLT

Initial configurations (such as service system information configuration, data configuration) are required on terminals and then they can be put into use. To finish these configurations, it is not cost-effective to carriers.

GPON supports zero configuration on terminals and plug-and-play of terminals, which is cost-effective.

Flexible Configuration plan of GPON

STB

3

Use OMCI to finishing data configuration on ONT


Basic Services over GPON Network


BRASAAA Server

IP Core

ASP/ISP CPE

Firewall

Ethernet

OLT

Softswitch

Internet

VoD ServerMiddle

wareNMS

TL1/CORBA/API

BB service platform

Carrier’s OSS

Notification

Triple Play Solution in GPON

IPTV

Phone

PC

SFU

Phone

PCSBU

CPEMDU

VDSL

NSP

IP

Voice

CBU

E1

FE

ODN

Splitter

Base station


Summary

• In this presentation, we introduced GPON basic concept , architecture , and principle.

• We also discussed about GPON service provisioning and application.


THANK YOU

Documents

GPON Fundamentals