fiber to the home technology - os3 · ftth technology 17 fiber networks ! transport networks layers...

slide

Winitu Consulting

Klipperaak 2D

2411 ND Bodegraven

The Netherlands

Fiber to the Home technology Erik Radius OS3 Fiber Day

May 24, 2012

Agenda 2

Agenda

1

2

3

Introduction

Fiber to the Home – Technology

Access Network Architectures

4 Test Cases all along!

Introduction of the speaker

!   Erik Radius

Introduction

slide

FTTH technology

Why do we use light signals in networking??

4

let’s explain this with some

physics of conductors

slide

FTTH technology

Electrons versus photons

!   Electrons in metal wire

!   Spin ½, obeys Fermi-Dirac statistics (Fermion)

!   Collisions: resistance, restricted flow

!   Suitable for lightbulbs & toasters

!   Photons in glass

!   Spin 1, obeys Bose-Einstein statistics (Boson)

!   No collisions: zero resistance, no flow limit

!   ‘Superconductors’ for data transport

5

A closer look at an optical fiber

FTTH technology

!   Optical fiber is a compact, low-loss carrier for broadband signals

!   Optical fiber consists of 3 main parts !   1: glass core

!   2: glass cladding

!   3: plastic buffer coating

Optical fiber inner workings

!   Optical signal is contained within the fiber

!   Higher index of refraction in core than in cladding

!   Total internal reflection at the core/cladding boundary

FTTH technology

Multimode versus Singlemode (1)

!   Multimode

!   ‘Bigger’ core: 50 / 62,5µm !   Multiple optical modes

supported/transmitted

!   Bandwidth*distance

product is limited !   Only suitable for shorter

distances (<1km)

FTTH technology

Multimode versus Singlemode (2)

!   Singlemode

!   Small core: 9µm

!   1 optical mode is supported/transmitted

!   Signal may be carried over very large distance

!   More information online, e.g.

!   http://www.rp-photonics.com/fibers.html

FTTH technology

Transmitter & receiver

!   Optical fiber is only a passive waveguide

!   Active components at the end points: !   Signal source: laser diode or LED

!   Receiver: photo diode

!   (Amplitude)modulation of the data stream !   Light signal is the ‘carrier’ wave

!   Both digital and analog transmission possible

FTTH technology

11 slide 11

Signal loss in optical fiber is wavelength dependent

12 slide 12

Power budget

12

source: http://www.thefoa.org/

slide

power budget

Optical power budget

!   Fiber link design: what is involved

!   Fiber type (single mode? multi mode?)

!   Fiber length (km)

!   Licht source: output power (dBm)

!   Detector: receiver sensitivity (dBm)

!   Elements in the link that cause additional signal loss

!   Fiber link budget or optical power budget

!   The amount of light available to make a fiber optic connection

!   Provides the maximum distance with the available optics

!   Take a minimum of 3dB safety margin into account

13

slide

power budget 14

Optical power budget: case #1

!   Laser power: -7 dBm

!   Fiber attenuation: 0,4 dB per kilometer

!   Fiber length: 20 km

!   Receiver sensitivity: -29 dBm

!   Splice loss: 0,1 dB (max.)

!   Connector loss: 0,5 dB (max.)

!   # of connectors: 2

!   # of splices: 4

Calculate Link Budget: laser power – receiver sensitivity

Calculate Margin: laser power – receiver sensitivity

– [link losses]

Transmitter Receiver fiber

slide

power budget 15

Optical power budget: case #2

!   Laser power: +1 dBm

!   Fiber attenuation: 0,25 dB per kilometer

!   Fiber length: 40 km


!   Splice loss: 0,1 dB (max.)




Calculate Link Budget: laser power – receiver sensitivity

Calculate Margin: laser power – receiver sensitivity

– [link losses]

Transmitter Receiver fiber

Pros and cons of optical fiber

!   Question for you all... Give me

!   3 advantages of optical fiber over metallic wiring

... and ...

!   3 disadvantages

FTTH technology

slide

FTTH technology 17

Fiber networks

!   Transport networks layers

!   Core (+ international) network

!   Metro(politan) network

!   Access network

!   Access network for telecom/cableTV partial fiber

!   Telecom

!   Optical fiber up to central office

!   Copper connection into the home

!   Cable TV

!   Optical fiber up to street cabinet

!   coax connection into the home

18 slide 18

International networks (submarine cable systems)

19 slide 19

National networks

source: GIGAport website

20 slide 20

City networks (metro rings)

source GIGAport website

Fiber penetration in the access network

!   Fiber….

!   to the Node

!   Central office, >300m

!   to the Curb/Cabinet

!   Street cabinet, <300m

!   to the Building/Basement

!   Multi-storey buildings

!   to the Home

!   Into the utility closet

(meterkast)

http://upload.wikimedia.org/wikipedia/commons/3/32/FTTX.png

FTTH technology

FTTH cabling concept

!   Access network branches off multiple times between

central office and the home

!   Installed: underground or above ground (!)

FTTH technology

slide

FTTH in Romenia (Bucharest)

FTTH technology

Fiber installation above ground: example

23

slide

FTTH technology

Underground installation

!   Several underground deployment methods available

!   1: modular tubes; insert fiber as needed (blown fiber)

!   2: fiber inside rugged cable (buried fiber)

24

Miniduct system for access network

!   1, 7, 12, 24 thin tubes in a rugged outdoor cable

!   Branching off one or

multiple tubes is

relatively simple

FTTH technology

Fiber in mini duct

!   Install thin cable into duct using airflow

FTTH technology

slide

FTTH technology

Fiber connection in the home

!   Example optical fiber

network terminal

!   Services for end user:

!   Internet

!   (Analogue) television

!   Phone

!   Most often installed in the

utility cabinet (‘meterkast’)

27

Bidirectional data transmission popular in FTTH

!   Single fiber bidirectional for data

!   Different signal wavelengths for uplink vs downlink

!   1500nm downlink

!   1310nm uplink

!   Reason?

!   Less fiber needed in the field

!   fiber management is expensive

!   Space in the Central Office is scarce

FTTH technology

slide

FTTH technology

Bidirectional fiber optic modules (tranceivers)

29

POP fiber management

FTTH technology

Fiber architectures (1): Point-to-point

!   point-to-point

!   1 on 1 fiber connection between Central office and Home

Central Office

FTTH technology

Fiber architectures (2): PON

!   point-to-multipoint (PON: passive optical network)

!   optical splitter in the link, to send same signal to

multiple end points

Central Office

FTTH technology

33 slide 33

Passive splitter/coupler

34 slide 34

PON: shared medium

system reach

slide

!   Laser power: +2 dBm


!   Fiber attenuation: 0,4 dB per km @ 1310nm

!   0,25 dB per km @ 1550nm !   Splice loss: 0,1 dB (max.)




!   Splitter loss (1:16) 14,0 dB



!   Calculate max. reach (in km) with 1:16 split or 1:64 split

PON reach calculation

FTTH technology 35

PON versus Point-to-Point: who uses which?

!   PON popular with telcos

!   USA

!   Japan

!   Australia

!   ‘closed business/network model’

!   Point-to-point mostly popular in Europe

!   Scandinavia

!   Netherlands, France, etc

!   ‘open network model’

FTTH technology

slide

That’s all for now!

Questions?

37

fiber to the home technology - os3 · ftth technology 17 fiber networks ! transport networks layers...

Documents