05-a - fibre optics-theory

1 Copyright © Antigone Consulting 2016 2 April 2016

AANNTTIIGGOONNEE CCOONNSSUULLTTIINNGG

MOBILE PHONES OFF PLEASE



FIBRE OPTICS Optical Fibre Theory

  Why Fibre Optics   Actual and Future Business Development   What is Fibre Optics   Construction of Optical Fibre   Fibre Transmission Factors   Types of Optical Fibre   Standards



Who am I?

Roberto Fornasiero Academic education 1998 : Italian Certified Electrical Engineer 2007 : Executive MBA – SDA Bocconi School of Management Work Experience 1990 – 2007 : experience in data communication business as sales manager for PANDUIT, ANIXTER and ADC KRONE 2008 – today   Independent business consultant   ETK KABLO sales manager for Italy,

Spain and Algeria



What happens in an Internet Minute?



Long Ago, People Danced@Concert Now They Video/Click/Share/Tweet

1990s 2010s



Media + Data Uploading + Sharing from Mobiles = Ramping Fast & Still Early Stage



Top 5 Bandwidth-Hungry Apps High-Definition Telepresence 24 Mbps and about a 50 millisecond latency to recreate the feeling of sitting in a room speaking with people. Telemedicine and Remote Surgery 10 Mbps and about a 1 millisecond latency to connect doctors with remote physician and, next step, surgery done by robot Video Instant Messaging and Video Presence 10 Mbps on mobile network, needs of LTE (4G) and fibre backhaul

High-Definition Television 5-8 Mbps to deliver crisp video

Real-Time Data Backup 2 Mbps and 10 millisecond latency to allow enterprises storing and keeping data secure and without interruptions



Dal 1° Luglio 2015   tutti gli edifici di nuova costruzione   tutti gli edifici da ristrutturare con permesso a costruire

DEVONO ESSERE EQUIPAGGIATI con 1.  un’infrastruttura fisica multiservizio passiva interna

all’edificio, costituita da adeguati spazi installativi e da impianti di comunicazione ad alta velocità in fibra ottica fino ai punti terminali di rete.

2.  un punto di accesso Gli edifici conformi al presente articolo possono beneficiare, ai fini della cessione, dell’affitto o della vendita dell’immobile, dell’etichetta volontaria e non vincolante di

“EDIFICIO PREDISPOSTO ALLA BANDA LARGA”

G.U 11 Novembre 2014 – Art. 135-bis Norme per l’infrastrutturazione digitale degli edifici



1. Infrastruttura fisica multiservizio   grande innovazione impiantistica: cambia il modo di pensare,

progettare e realizzare impianti di telecomunicazioni digitali e domotici

  Impiantistica attuale = infrastruttura per ciascun impianto. Videocitofono + TV + Allarme + Domotica + LAN

  Impiantistica futura = un cablaggio unico per tutti gli impianti Indipendenza dal portante fisico (cavo)

  L’unicità della infrastruttura consentirà di rendere “interoperabili” i vari sistemi in modo che la somma delle funzionalità possibili sia molto più ampia e potente delle funzionalità di tutti gli impianti presi singolarmente.

2. Passiva   i componenti (cavi, derivazioni, derivatori, prese) si limitano a

realizzare una “rete” intermodale di trasporto ad elevato livello qualitativo e trasparente alle vari tipologie di applicazione

Significato



Multiservizio   i vari servizi devono utilizzare questo unico portante   2 categorie di servizi

Servizi esterni all’edificio: Providers fissi (Telecom, Fastweb, Netflix, Google…) Providers wireless (Tim, Vodafone, Linkem, Tooway…) Broadcasting (Rai, Mediaset, Sky, La7, TVSat…)

Servizi interni all’edificio: Sorveglianza e sicurezza Domotica di edificio e appartamento Videocitofonia Reti LAN e WI-FI

Punto di accesso   Punto fisico interno o esterno all’edificio, accessibile alle imprese

autorizzate a fornire reti pubbliche di comunicazione

Il legislatore dice che tutto ciò deve essere predisposto per servizi di accesso in fibra ottica a banda larga.

Infrastruttura fisica multiservizio passiva. Cosa significa?



3. Multiservizio   tutti i servizi devono utilizzare un unico portante: la FIBRA OTTICA   2 categorie di servizi

Servizi esterni all’edificio Providers fissi (Telecom, Fastweb, Netflix, Google…) Providers wireless (Tim, Vodafone, Linkem, Tooway…) Broadcasting (Rai, Mediaset, Sky, La7, TVSat…)

Servizi interni all’edificio Sorveglianza e sicurezza Domotica di edificio e appartamento Videocitofonia Reti LAN e WI-FI

4. Punto di accesso   punto fisico interno o esterno all’edificio, accessibile alle imprese

autorizzate a fornire reti pubbliche di comunicazione Il legislatore dice che tutto ciò deve essere predisposto per

servizi di accesso in FIBRA OTTICA a banda larga

Significato



What is "Fibre Optics"?

  A technology that uses glass (or plastic) threads (fibres) to transmit data

  A fibre optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves

  Not a "new" technology   Concept over a century old   Used commercially for 35 years



Fibre Advantages

  Less susceptible than metal cables to interference   Immunity to static interferences

  Lightenings   Electric motors   Fluorescent light

  Higher environment immunity: weather, temperature, etc.   Thinner and lighter than metal wires   Longer Lasting   Security: tapping is difficult

Remember: Fibre is non-conductive Hence, change of magnetic field has NO IMPACT!



Fibre Advantages   Greater bandwidth than metal cables (10GHz vs. 16kHz)   Data can be transmitted digitally rather than analogically   Ex. copper cable of about 1000 pairs vs. 2 cores fibre cable

  each pair can only carry about 24 telephone conversations a distance of less than 4 kilometres

  fibre cable carries more than 32.000 conversations hundreds or even thousands of kilometres without regeneration

à  each fibre can simultaneously carry over 150 times more à  cost of transmitting a single phone conversation over fibre

optics is only about 1% the cost of transmitting it over copper wire! That’s why fibre is the exclusive medium for long distance communications.

  Economics:   Low transmission loss (dB/km)   Fewer repeaters   Less cable



  Myth #1: Fibre is too expensive Today, fibre is cheaper than kite string or fishing line

  Myth #2: Fibre is extremely hard to work with Grind-and-polish connectors era is finished!

  Myth #3: Fibre needs expensive and complicated installation and test equipment

  Myth #4: Fibre is fragile Fibre optic cable can withstand a higher pulling tension than copper, is rated for larger temperature ranges, and is immune to EMI/RFI Military prefers fibre for its ruggedness and survivability!

Myths of Fiber Optics



Ø  Optical fibre ends are extremely sharp, don’t let them penetrate the skin.

Ø  Dispose of any fibre off-cuts in a suitable container. Don’t leave them sticking in the carpet!

Ø  Don’t look into the end of a fibre if it is connected (or even if you suspect it may possibly be connected) to a transmitting system. Not all lights from fibre harm eyes. LEDs used with multimode fibre are generally too low in power. Some lasers can cause issues. BUT NEVER LOOK INTO THE END OF THE FIBER ANYWAY BETTER BE SAFE THAN SORRY

Safety First



Fibre Optic Construction

Core Glass with a higher index of refraction than cladding It carries signal Cladding Glass with a lower index of refraction than the core Buffer Protects the fiber from damage and moisture



Fibre Construction

There are 3 main components:

COATING

CLADDING

CORE



Fibre Optic Types

  Light is "guided" down the centre of the fiber called the "core”

  The core is surrounded by a optical material called the "cladding"

  The fiber is coated with a protective plastic covering called the "primary buffer coating"



In 1870 John Tyndall demonstrated how to guide a light beam through a falling stream of water. “Total Internal Reflection”: a special optical condition in which optical rays cannot escape the material in which they are traveling

Fibre Optics

Total Internal Reflection




  Optical fibers work on the principle of total internal reflection   With light, the refractive index is listed   The angle of refraction at the interface between two media is

governed by Snell’s law:

n1 sinθ1 = n2 sinθ2


AANNTTIIGGOONNEE CCOONNSSUULLTTIINNGG Numerical Aperture

  The numerical aperture of the fiber is closely related to the critical angle and is often used in the specification for optical fiber and the components that work with it

  The numerical aperture is given by the formula:

  The angle of acceptance is twice that given by the numerical aperture

22

21.. nnAN −=



Fibre Optics

  Total Internal Reflection

  Rays of light referred to as modes

Transmitter Receiver



Fiber Optic Data Links

  Fiber optic transmission consists of a transmitter on one end of a fiber and a receiver on the other end

  The transmitter takes an electrical input and converts it to an optical output from a laser diode or LED

  The receiver converts the light back into an electrical signal at the other end



Fiber Optic Data Links



Fibre GBIC Modules

Switch and module slots combinations GBIC Modules Typically LC (small form factor)



Fiber Wavelength

  Wavelength is colour of light   The range of light is called the spectrum   Humans see from 400-770nm : Visible Light   Fibre optics utilize 850-1675 nm: Infrared Light   Frequency (cycles per second) is mesured in Hertz (Hz) while

light in fibre optics is more commonly measured in billionths of a meter (nm)



Light propagation is a function of Attenuation, Dispersion and non-linearities.

Attenuation Dispersion

0 2

1

2

2 2

2

2 == ++ ∂∂

-- ++ ∂∂

∂∂ A A

dT

A A i

z A i γγ ββ αα



Pure Glass=Si O2

Si

Si O O O

Si

Si O

Si

Cu O

Imperfections

Losses in optic fibres Absorption: light is absorbed due to chemical properties or natural impurities in the glass. The worst culprits are hydroxyl ions and traces of metals. Accounts for about 5% of total loss.

scattering

Scattering is the loss of light due to small localized changes in the refractive index or by impurities. Accounts for about 95% of total less and depends on the size of the discontinuity compared with the wavelength of the light so the shortest wavelength, or highest frequency, suffers most scattering.

Light scattered

Impurities



Fiber Attenuation Attenuation is total loss of light signal

= Absorption + Scattering



Bending Losses

Microbending Microbending losses are due to microscopic fiber deformations in the core-cladding interface caused by induced pressure on the glass. These are generally a manufacturing problem.

Attenuation due to macrobending increases with wavelength (e.g. greater at 1550nm than at 1310nm)

Macrobending Macrobending losses are due to physical bends in the fiber that are large in relation to fiber diameter. The problem of macrobend loss is largely in the hands of installers



Bending Losses for SM fibre



Bending Losses for MM fibre



Elements of Loss

Pout (Received

Power)

Power variation

Fiber Attenuation   Caused by scattering & absorption of light as it travels through the

fiber   Measured as function of wavelength (dB/km)

OTDR Trace of a fiber link

Pin (Emitted Power)


AANNTTIIGGOONNEE CCOONNSSUULLTTIINNGG Typical Attenuation Values

  0.22 dB/km for singlemode fiber at 1550 nm   0.35 dB/km for singlemode fiber at 1310 nm   1 dB/km for multimode fiber at 1300 nm   3 dB/km for multimode fiber at 850 nm   0.05 dB for a fusion splice   0.3 dB for a mechanical splice   0.5 dB for a connector pair



Signal Distortion in fibres Optical signal weakens from attenuation mechanisms and broadens due to distortion effects.

Eventually these two factors will cause neighboring pulses to overlap.

After a certain amount of overlap occurs, the receiver can no longer distinguish the individual adjacent pulses and error arise when interpreting the received signal.

Pulse broadening and attenuation



Step Index Multi-mode

Graded Index Multi-mode

Intermodal Dispersion

Solution to problem is to change the refractive index progressively from the centre of the core to the outside. If the core centre has the highest refractive index and the outer edge has the least, the ray will increase in speed as it moves away from the centre.



Pulse Spreading

Chromatic Dispersion Chromatic Dispersion is the effect that different wavelengths (colours or spectral components of light) travel at different speed in a media. The more variation in the velocity, the more the individual pulses spread which leads to overlapping: longer wavelengths travel faster

Pulse stream without chromatic dispersion

Pulse stream with chromatic dispersion



Fibre Optic Types

Multi Mode

Single Mode



OPTICAL FIBRE THEORY

Fibre Optic Types

OM1OM2 OM3 OM4

OS1 OS2



  Multi mode has light travelling in many rays... called modes   Three main categories

62.5/125-µm à OM1 50/125-µm à OM2 Laser-Optimized 50/125-µm à OM3 and OM4

  Low cost sources LED (Light Emitting Diode) and VCSEL (Vertical Cavity Surface Emitting Laser) @ 850 nm Laser @ 1300nm

  Low cost connectors + lower installation costs = lower system cost

  Higher fibre cost   Higher loss, lower bandwidth   Distance up to 2000 m   Best for LAN, SAN, Data Centre

Multimode fibres



Standardized Multimode Fibre Specifications

Multimode fibres



  Light travels in only one ray or better in only one mode   High cost sources

1310+ nm lasers 1 ÷ 10 Gb/s 1 ÷ 25 Gb/s with DWDM High precision packaging

  Higher cost connectors + Higher installation costs = Higher system cost

  Lower fiber cost   Lower loss, higher bandwith   Distance to 60km +   Best for WAN, MAN, Access, Campus

Singlemode fibres



Standards Singlemode fibres

  Two primary sources of specification of singlemode optical fibre: ITU-T G.65x series IEC 60793-2-50 (and the equivalent to EN 60793-2-50)

  19 different singlemode optical fibre defined by the ITU-T: ITU-T G.652a, b, c and d (low water peak) ITU-T G.653a and b; ITU-T G.654a, b and c; ITU-T G.655a, b, c, d and e; (nonzero dispersion-shifted) ITU-T G.656; ITU-T G.657 Categories A1, A2, B1 and B2.

  IEC 60793-2-50:2008 (EN 60793-2-50) specifies 7 different single mode optical fibres (equivalent to 16 of the ITU-T specifications)

Type B1.1: equivalent to ITU-T G.652a and b; Type B1.2: equivalent to ITU-T 654 b and c Type B1.3: equivalent to ITU-T G.652c and d; Type B2: equivalent to ITU-T G.653a and b; Type B4: equivalent to ITU-T G.655c, d and e Type B5: equivalent to ITU-T G.656; Type B6: equivalent to ITU-T G.657.



ITUT-T G692/694 Transmisssion Bands Singlemode fibres

“Band” terminology used in FTTx/PON: ITU-T G983/984 Basic band (1480 to 1500 nm) Enhancement band (1550 to 1560 nm)

Wavelength Band Purpose Fibre Type 1260 to 1360 nm O-band Standard single mode operation G.652 SM

1360 to 1460 nm E-band For future use including CWDM G.652.D SM

1460 to 1530 nm S-band Downstream FTTx operation G.652, G.655 SM

1530 to 1565 nm C-band Long haul, DWDM, CATV G.655 SM

1565 to 1625 nm L-band Future testing and maintenance monitoring G.655 SM

1625 to 1675 nm U-band Future testing and maintenance monitoring G.655 SM



Standards Singlemode fibres

Mode Field Diameter (MFD) specifications of singlemode optical fibre



OPTICAL FIBER THEORY

Fibre Optic Categories




Fibre Optic Categories

SM (OS1)

MM (OM4)

MM (OM3)

MM (OM2)

MM (OM1)

Core Diameter (µm) 8,3 / 9 50 50 50 62,5

Mode field diameter 9,3 ±0,5 N/A N/A N/A N/A

Cladding diameter (µm) 125 125 125 125 125

Numerical Aperture 0,13 0,20 0,20 0,20 0,275

Attenuation (dB/km)

850 nm 1300 nm 1550 nm

N/A 0,4 0,3

2,3 0,6 N/A

2,3 0,6 N/A

2,5 0,8 0,6

3,5 1,5 0,3

Bandwidth (MHz x km)

850 nm 1300 nm

N/A N/A

4.700 500

2.000 500

600 1.000

160 500

Dispersion (ps/nm x km)

1310 nm 1550 nm

3,2 1,7

N/A N/A

N/A N/A

N/A N/A

N/A N/A

SM

MM

SM



Size Does Matter !

CAUTION: You cannot mix and match fibers!




Categories OS1 and OS2

GUIDANCE

  OS1 and OS2 are cabled Single Mode optical fibre specifications   Category OS1 is appropriate to Indoor and Universal tight buffered

cable constructions   Category OS2 is appropriate to Outdoor and Universal loose tube

cables (where the cabling process applies no stress to the optical fibres)   Cables with either OS1 or OS2 performance are constructed from B1.3

optical fibres (also known as ITU specification G.652D) or B6_a fibres (a less bend sensitive singlemode optical fibre which is similar to, and compatible with, B1.3. Also known as ITU specification G.657)

  OS1 or OS2 performance is not related to Single Mode optical fibres according to ITU specification G.655 (Non Zero Dispersion Shifted fibre)



Categories OS1 and OS2

EUROPEAN STANDARDS and ISO/IEC

  The European Standard EN 50173-1:2007 states that both OS1 and OS2 cabled optical fibres can only be constructed from B1.3 (or ITU G.652D) and B6.a (or ITU G.657) optical fibre according to EN 60793-2-50

  Unfortunately, ISO/IEC have not made this logical leap - even in the latest proposed amendment of ISO/IEC 11801 (which now features both OS1 and OS2).



Fiber Optic Link Power Budget

Cable plant Loss Calculation Total Loss = (0.5 dB X # connectors) + (0.05 dB x # splices) + loss length of cable (dB/Km)



Loss Formula Fibre Attenuation x km + Splice Attenuation x # + Connectors Attenuation x # + Safety margin = Total Loss

Wavelength/Mode Core diam. Att./km Splice Connector 850 nm Multimode 50 µm 3 dB 0.2 dB 0.5 dB 850 nm Multimode 62.5 µm 3 dB 0.2 dB 0.5 dB 1300 nm Multimode 50 µm 0.75 dB 0.2 dB 0.5 dB

1300 nm Multimode 62.5 µm 0.75 dB 0.2 dB 0.5 dB

1310 nm Singlemode 9 µm 0.35 dB 0.05 dB 0.5 dB 1550 nm Singlemode 9 µm 0.22 dB 0.05 dB 0.5 dB

Fiber Optic Link Power Budget

Ex: 10 km of 1310 SM fibre 0.35 dB x 10 = 3.50 dB + 0.05 dB x 1 = 0.05 dB + 0.50 dB x 5 = 2.50 dB + 3 dB Safety = 3.00 dB

Total Loss = 9.05 dB



Applicable Standards and Loss Budgets

Year Application Data Rate Standard Loss Budget (dB)

1982 Ethernet 10 Mbps IEEE 802.3 12,5

1991 Fast Ethernet 100 Mbps IEEE 802.3 11

1998 Short Wavelength Fast Ethernet

10/100 Mbps TIA/EIA-7885 4

2000 1G Ethernet 1.000 Mbps IEEE 802.3z 3,56

2004 10G Ethernet 10.000 Mbps IEEE 802.3ae 2,6

2010 40G Ethernet 40.000 Mbps IEEE 802.3ba 1,9

2010 100G Ethernet 100.000 Mbps IEEE 803.3ba 1,9



Indicative Link Lengths

Multimode Fiber Type

62.5/125 µm 50/125 µm 850 nm laser-optimized

50/125 µm 850 nm laser-optimized

50/125 µm TIA 492AAAA

(OM1) TIA 492AAAB

(OM2) TIA 492AAAC

(OM3) TIA 492AAAD

(OM4)

Application Distance 850 nm

1300 nm

850 nm

1300 nm

850 nm

1300 nm

850 nm

1300 nm

10Base-FL m 2000 - 2000 - 2000 - 2000 -

100Base-FX m - 2000 - 2000 - 2000 - 2000

100Base-SX* m 300 - 300 - 300 - 300 -

1000Base-SX m 220 - 550 - 800 - 880 -

10GBASE-S m 33 - 82 - 300 - 550 -

(*)100Base-SX (short wavelength multi-mode) is not formally adopted standards, but are commonly understood and used in fiber optic networking



8.45 – Ricevimento / Apertura Lavori 9.00 – Basi teoriche

  Perché la fibra ottica   Mezzo trasmissivo e principi di funzionamento   Fattori di trasmissione   Metodi di trasmissione   Normative: IEC 11801 2°ED, ANSI/TIA 568

10.15 – Cavi in fibra ottica   Tipi di cavo   Installazioni interne ed esterne   Come scegliere un cavo

11.15 – Coffee Break 11.30 – Installazione di cavi in fibra ottica

  Procedure e linee guida generali   Raggi di curvatura e trazioni   Metodi di posa   Preparazione di un cavo

13.00 – Pranzo

Programma Corso



14.00 – Terminazione della fibra ottica   Connessione e giunzione   Caratteristiche e tipologie di connettori e giunzioni   Procedure operative per la giunzione   Preparazione di un cassetto ottico   Preparazione di una muffola

15.00 – Test e collaudo   Normative   Strumentazione   Certificazione di Base   Test con Sorgente/Power Meter   Certificazione Estesa   Test con OTDR   Risoluzione dei problemi

16.00 – Coffee Break

Programma Corso



16.15 - Dimostrazioni pratiche   Giunzione con giuntatrice a fusione   Giunzioni con connettori pre-lappati   Cavi pre-terminati   Collaudo con Power Meter   Analisi di un OTDR

17.45 – Chiusura lavori   Tavola rotonda

Programma Corso

Gruppi – non meno di 10 e non più di 15 persone Costo – 275 Euro + IVA per partecipante

sconti per più partecipanti di medesima azienda

A tutti i partecipanti verrà fornito   attestato di partecipazione   dispensa del docente sugli argomenti trattati



AANNTTIIGGOONNEE

CCOONNSSUULLTTIINNGG Roberto Fornasiero [email protected]

05-a - fibre optics-theory

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