Graduate EngineerLunch & LearnEdmonton, 2011

The Evolution of FTTH Technology

Jonathan Hnit, P.Eng

August 25th, 2011

2

Outline

Fibre Optics

Why FTTH?

GPON Overview

FTTH Evolution NG-PON1 (10G) NG-PON2 (40G & beyond)

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Fibre Optics

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Optical Data Transmission

Optical: relating to light

Laser can be used to transmit a beam of light.

Optical receiver can detect a beam of light.

By pointing a laser at an optical receiver, I can transmit a signal to it.

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ReceiverTransmitter

Optical Transceivers

Transceiver

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Digital Signaling

Two states: Laser OFF = “0” Laser ON = “1”

Each “1” or “0” in a transmission is called a bit

Bits are the building blocks for larger pieces of information Letter ‘A’ = “1000001” Letter ‘B’ = “1000010”

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Data Rates

Bandwidth: the amount of data we can transmit in a given time period.

BW is measured in bps (bits per second)

Low Bandwidth

High Bandwidth

vs

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Sample Data Rates

Data Signal Data Rate Bits Per Second Time required to count that high

Voice (phone) 64 Kbps 64,000 18 hours

Music (CD Quality) 320 Kbps 320,000 89 hours

SD TV 2.2 Mbps 2,200,000 25 days

HD TV 5.6 Mbps 5,600,000 65 days

Internet Connection 15.0 Mbps 15,000,000 174 days

GPON port 2.5 Gbps 2,500,000,000 79 years

Fibre uplink 10.0 Gbps 10,000,000,000 317 years

Note: K = Kilo = Thousand = 1000x bps M = Mega = Million = 1,000,000x bps G = Giga = Billion = 1,000,000,000x bps

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Fibre Optic Cable

Glass tube capable of bending light

Can direct a laser beam through a fibre optic cable to a receiver

Fibre has a max bending radius, if you bend it too far, the light escapes out the sides

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Fibre Optic Transmission System

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Why FTTH?

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Access Network

Network to deliver services (TV, phone, internet) from a Central Office to our customers

Central Office

customer

customer

DSL modem

DSL modemDSLAM

101010

101010

Copper

Copper

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Limits of Copper

Bandwidth Limitations ADSL2+ 15Mbps VDSL2 40 Mbps VDSL2 with bonding

70Mbps VDSL2 with bonding & vectoring

100Mbps

Distance Limitations ADSL2+ 1400m from CO VDSL2 600m from CO

Maintenance Copper cable lasts ~20 years Requires replacement

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Ongoing Bandwidth Drivers

10Kb

100Kb

1Mb

10Mb

100Mb

1990 1995 2000 2005 2010 2015

Bandwidth Usage Projections1Gb

Historical BW growth is ~1.4x per year

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FTTH – Fibre to the Home

Uses fibre instead of copper to deliver services to the home

Higher Bandwidths 2.5Gbps shared by 32 customers (72+

Mbps)

Longer Reach 20km between CO and customer’s home

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GPON – Gigabit Passive Optical Network

Breakdown of key-words in GPON:

Gigabit – Dealing with high Bandwidths (2.5Gbps per PON port) Passive – No power required between Central Office and the

customer’s home Optical – Data transmitted using light Network – Access network between the Central Office and the

customer’s home

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GPON – Gigabit Passive Optical Network

Central Office

customer

customer

DSL modem

DSL modemDSLAM

Drop Copper

Drop Copper

Feeder Copper

Feeder Copper

OLT

ONT

ONT

Splitter(1:32)

Feeder Fibre

Drop Fibre

Drop Fibre

Current: Electrical signals over copper

GPON: Optical signals over fibre

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GPON Overview

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Bi-Directional Transmission

Splitter(1:32)

ONT customer

ONT customer

OLT

Central Office

2.5Gbps @1490nm

1.25Gbps @1310nm

OLT transmits downstream on a single feeder fibre 2.5Gbps @ 1490nm

ONT transmits upstream on the same fibre 1.25Gbps @ 1310nm

Drop Fibre

Drop Fibre

Feeder Fibre

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OLT – Optical Line Terminal

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Splitter

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Optical Network Terminal

• Optical to Electrical conversion

• Integrated ATA for voice service

• 8 hour battery backup via UPS

4x GE ports

2x POTS ports

UPS Power

1x PON port

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Downstream Transmission - Broadcast

Signal is split 32 ways at the splitter

Each ONT receives the exact same frames

ONT discards the frames that are not addressed to it

OLT uses continuous mode optics

ONT Customer A

ONT Customer B

OLT

Central Office

B A BA

BA

B

AB

ASplitter(1:32)

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Upstream Transmission - TDMA

If both ONTs transmit at the same time, their signals interfere with each other when they reach the splitter…

Splitter(1:32)

ONT Customer A

ONT Customer B

OLT

Central Office

B

AA

B

A

B

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Upstream Transmission - TDMA

ONT Customer A

ONT Customer B

OLT

Central Office

B

AA

B

A

B

ONTs use TDMA to take turns transmitting upstream

OLT broadcasts a BWmap to all ONTs

BWmap assigns each ONT a different timeslot in which to transmit

ONT use burst mode optics

Splitter(1:32)

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PON Evolution

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PON Standards Roadmap

2005 2010 2015

GPON

EPON

2.5 Gbps

1.0 Gbps

10 Gbps

40+ Gbps

XG-PON

10G-EPON

NG-PON

Co-existenceCo-existence

NG-PON2• WDM PON ?• 40G TDM

PON ?

Component R&D

Disruptiv

e

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XG-PON

Approved by ITU-T in early 2010

10Gbps downstream @ 1577nm

2.5Gbps upstream @ 1270nm

Co-existence with GPON

Split ratio of up to 1:256

Successful field trials of XG-PON completed in 2010

XG-PON demo systems available today

XG-PON commercial systems expected early 2012

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XG-PON Addition

OLT

ONUcustomer

ONU customer

Feeder Fibre

Drop Fibre

Drop Fibre

2.5Gbps @1490nm

1.25Gbps @1310nm

Splitter(1:32)WDM1r

XG-PON

10.0Gbps @1577nm2.5Gbps @1270nm

XG-ONU

customer

Drop Fibre

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NG-PON2 – TWDM-PON Selected

OLT

Central Office

Feeder Fibre

ONU - Blue

ONU - RedAWG

TR-Blue

TR-Red

AWG

ONU - Blue

ONU - Red

Splitter

Splitter

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ONU Evolution

Simple Complex

Mini ONUs Integrated RG/ONUs

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Questions?