Fiber Optics For Broadcast Video Applications

Eric FankhauserV.P. Advanced Product Development

Fiber Optics

Need for Fiber Optics technology is constantly increasing Driven by increasing data rates Declining implementation cost

Many advantages Extremely High Data Carrying Capacity Low signal attenuation Free From Electromagnetic Interference Lightweight

Presentation Overview

Technologies / Building blocks available Lasers Receivers Fiber Multiplexing Switching

System Design Considerations Application Examples

Technologies Available

Transmitters (Light Sources) LED’s - 850/1310nm

Used with MMF up to 250Mb/s Short distances <1 Km

Semiconductor Lasers – 850/1310/1550nm VCSEL’s, Fabry Perot and DFB 1310/1550 can be used with MMF or SMF Short to long distances Low to High data rates (Mb/s to Gb/s)

FP and DFB Laser Spectrum

FP laser Emits multiple evenly spaced wavelengths Spectral width = 4nm

DFB laser Tuned cavity to limit output to single oscillation / wavelength Spectral width = 0.1nm

Op

tica

l Ou

tpu

tP

ow

er

(mW

)

FWHM=4nm

Op

tica

l Ou

tpu

tP

ow

er

(mW

)

FWHM=0.1nm

Wavelength(nm)

Wavelength(nm)

FP Laser Output DFB Laser Output

A B

Which Laser Type is Better?

Fabry Perot Ideal for low cost pt-pt MMF or SMF Not suitable for WDM

due to +/- 30nm variation

Dispersion is a serious issue at Gb/s rates

Distributed Feed Back Used in wavelength

division multiplexing systems

Less susceptible to dispersion than FP laser

Used for medium and long haul applications

Technologies Available

Receivers (Detectors) PIN Photodiodes

Silicon for shorter ’s (eg 850nm) InGaAs for longer ’s (eg 1310/1550nm) Good optical sensitivity

Avalanche Photodiodes (APD’s) Up to 50% more sensitivity than PIN diodes Primarily for extended distances in Gb/s rates Much higher cost than PIN diodes

Multi-Mode 50/62.5um core, 125um clad Atten-MHz/km: 200 MHz/km Atten-dB/km: 3dB @ 850nm MMF has an orange jacket

Single-Mode 9um core, 125um cladding Atten-dB/km: 0.4/0.3dB

1310nm/1550nm SMF has a yellow jacket

Laser

Laser

M uliti M ode

S ing le M ode

Core

Cross section

Cladding

LE D

Laser

M uliti M ode

S ing le M ode

Core

Cross section

Cladding

CoreCladding

Fiber Types

Degradation In Fiber Optic Cable

Attenuation Loss of light power as the signal travels

through optical cable Dispersion

Spreading of signal pulses as they travel through optical cable

Attenuation Vs. Wavelength

Light Propagation

Light propagates due to total internal reflection

Light > critical angle will be confined to the core

Light < critical angle will be lost in the cladding

Bending Loss

Bends introduce an interruption in the path of light causing some of the optical power to leak into the cladding where it is lost

Always keep a minimum bending radius of 5cm on all corners

When bundling fibers with tie wraps keep them loose to avoid introducing micro bending into the fiber

Dispersion - Single-Mode

FP and DFB lasers have finite spectral widths and transmit multiple wavelengths

Different wavelengths travel at different speeds over fiber A pulse of light spreads as it travels through an optical fiber

eventually overlapping the neighboring pulse Narrower sources (e.g DFB vs. FP) yield less dispersion Issue at high rates (>1Ghz) for longer distances (>50Km)

Time

Transmitter Receiver

Dispersion - Multi-Mode Fiber

Modal Dispersion The larger the core of the fiber, the more

rays can propagate making the dispersion more noticeable

Dispersion determines the distance a signal can travel on a multi mode fiber

Advances in Fiber Optic cable

SMF Reduction in the water peak Reduction in loss per Km Corning “SMF28e” Lucent “AllWave”

MMF Higher bandwidths Most manu’s going to 50um, graded index

fiber

Optimizing Fiber Usage

Multiplexing

TDM – Time Division Multiplexing WDM – Wave Division Multiplexing

Multiplexing - TDM

Done in the electrical domain Can TDM Video+Audio+Data OR Many

Video’s, Audio’s, Data’s Increases efficiency of each wavelength Max # of signals based on max link rate

TDMMultiplexed signal

Signal 1

Signal 2

Signal 3

Signal 4

TimeDivisionMultiplex

Signal 1

Signal 2

Signal 3

Signal 4

TimeDivision

De-multiplexSingle-mode Fiber

Multiplexing - TDM Latest developments in TDM

No synchronization required between signals – All signals 100% independent

Low latency (<10us) Small form factor (4/8 Ch in 1/2, 3RU card slot) 8 Ch SDI TDM mux

128 SDI per fiber (CWDM), 320 SDI per fiber (DWDM) 2 Ch HDSDI TDM mux

32 HD per fiber (CWDM), 80 HD per fiber (DWDM) 256 AES per fiber (CWDM), 640 AES (DWDM) RGBHV over 1 fiber/1 wavelength vs 3 fibers

Wavelengths travel independently Data rate and signal format on each

wavelength is completely independent Designed for SMF fiber

Signal 1

Signal 2

Signal 3MUX

Signal 1

Signal 2

Signal 3

DEMUX

WDMMultiplexed signal

Single-mode Fiber

Signal 4 Signal 4

Multiplexing - WDM

Multiplexing - WDM

WDM – Wave Division Multiplexing Earliest technology Mux/Demux of two optical wavelengths

(1310nm/1550nm) Wide wavelength spacing means

Low cost, uncooled lasers can be used Low cost, filters can be used

Limited usefulness due to low mux count

Multiplexing - DWDM

DWDM – Dense Wave Division Multiplexing Mux/Demux of narrowly spaced wavelengths

400 / 200 / 100 / 50 GHz Channel spacing 3.2 / 1.6 / 0.8 / 0.4 nm wavelength spacing

Up to 160 wavelengths per fiber Narrow spacing = higher cost implementation

More expensive lasers and filters to separate ’s Primarily for Telco backbone – Distance Means to add uncompressed Video signals to

existing fiber

Multiplexing - CWDM

CWDM – Coarse Wave Division Multiplexing Newest technology (ITU Std G.694.2) Based on DWDM but simpler and more robust Wider wavelength spacing (20 nm) Up to 18 wavelengths per fiber Uses un-cooled lasers and simpler filters Significant system cost savings over DWDM DWDM can be used with CWDM to increase

channel count or link budget

CWDM Optical Spectrum

20nm spaced wavelengths

DWDM vs. CWDM Spectrum

1470 1490 1510 1530 1550 1570 1590 1610

Wavelength

dB

1.6nm Spacing

Optical Routing - Definitions

Optical Routers – Optical IN , Optical OUT Photonic Routers – Optical IN & OUT but

100% photonic path OOO- Optical to Optical to Optical switching

Optical switch fabric OEO- Optical to Electrical to Optical

conversion Electrical switch fabric Regenerative input and outputs

Photonic Technologies

MEMS (Micro Electro-Mechanical System) Liquid Crystal MASS (Micro-Actuation and Sensing

System )

MEMS Technology

Steer the Mirror Tilted mirrors shunt light in various directions 2D MEMS

Mirrors arrayed on a single level, or plane Off or On state: Either deployed (on), not deployed (off)

3D MEMS Mirrors arrayed on two or more planes, allowing light to

be shaped in a broader range of ways Fast switching speed (ns) Photonic switch is 1:1 IN to OUT (i.e. no broadcast

mode)

Liquid Crystal Technology

Gate the light No Moving Parts Slow switch speed Small sizes (32x32) Operation based on polarization:

One polarization component reflects off surfaces

Second polarization component transmits through surface

MASS Technology

Steer the fiber Opto-mechanics uses piezoelectric actuators Same technology as Hard Disk Readers and

Ink Jet Printer Heads Small-scale opt mechanics: no sliding parts Longer switch time (<10msec)

OE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EOOE EO

X

EQEQEQEQEQEQEQEQEQEQEQEQEQEQEQEQ

CPUMonitoringInterface

LocalIndication

FiberInputs

ElectricalInputs

FiberOutputs

ElectricalOutputs

OEO Technology

High BW Electrical

XPNT

OEO Routing

Optical <> Electrical conversion at inputs/outputs Provides optical gain (e.g. 23 dB)

High BW, rate agnostic electrical switching at core SD, HD, Analog Video (digitized), RGBHV, DVI

Fast switching (<10us) Full broadcast mode

One IN to ANY/Many outputs Build-in EO / OE to interface with coax plant

Save converter costs

Regeneration - Optical vs Photonic

Photonic is a lossy device that provide no re-amplification or regeneration Signal coming in at –23dBm leaves at –

25dBm OEO router provides 2R or 3R (re-amplify,

reclock, regenerate) Signals come in at any level to –25dBm Leave at –7dBm (1310nm) or 0dBm (CWDM)

Applications - Design Considerations

Types of signals Signal associations Fiber infrastructure Distance/Loss Redundancy Remote Monitoring

Types of Signals

SDI

HDSDI

ANALOG

DVB-ASI

RGB

RS232/422/485

GPI/GPO

10/100 ETHERNET

GBE

FIBER CHANNEL

70/140 MHz I/F

L-BAND

CATV

SONET OC3/12

T1/E1

DS3/E3

AES

ANALOG

DOLBY EINTERCOM

OPTICAL

ROUTING

WDM

CWDM

DWDM

VIDEO

AUDIO

CONTROL

DATACOM

RF

TELECOM

MULTI

WAVELENGTH

MULTI

FIBEROR

FacilityLINKFacilityLINK - Fiber Optics Platform - Fiber Optics Platform

SPLITTERS

+

PROTECTION

SWITCHING

Design Considerations

Signal associations Video, audio, data Together or separate - Issues

Fiber infrastructure MMFor SMF Many fibers or one fiber Single clean run for your use (e.g. put in for you) Leased fiber (multiple patches, fusion splices)

Distance/Loss Total path loss = (fiber+connectors+passives) Distance can be deceiving - patches, connections,

fusion splices

Design Considerations

Fault Protection Protection against fiber breaks Important in CWDM and DWDM systems Need 2:1 Auto-changeover function with

“switching intelligence” Measurement of optical power levels on fiber Ability to set optical thresholds Revert functions to control restoration

Remote monitoring is key due to distance issues Monitor

Input signal presence and validity Laser functionality and bias Optical Link status and link errors Pre-emptive Monitoring

Input cable equalization level CRC errors on coax or fiber interface Optical power monitoring

Data logging of all error’d events Error tracking and acknowledgment

Design Considerations

Diagnostics Interface

Design Examples – Single Link

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

HD OE

Dispersion

40 Km’s

SDI @ 270Mb/s

HDSDI @ 1.485Gb/sHD EO

SD OE40 Km’s

SD EO

-7dBm @ 1310nm

-23dBm

-32dBm

Loss Budget

-7dBm @ 1310nm

SD HD HD

FP DFB

TX Power (dBm) -7 -7 0

RX Sens (dBm) -32 -23 -23

Available Budget 25 16 23

Distance (Km) 40 40 40

Fiber Loss (0.35dB/km@1310)

14 14 14

Connectors 4 4 4

Connector Loss 1 1 1

Total Loss 15 15 15

Headroom 10 1 8

SD HD HD

FP DFP

FP Line width (nm) 4 4 0.2

Dispersion (ps/nm.km) 2 2 2

Distance (km) 40 40 40

Dispersion (ps) 320 320 16

RX Jitter Tolerance (UI) 0.4 0.4 0.4

RX Jitter Tolerance (ps) 1480 270 270

Headroom (ps) 1160 -50 254

Post House Facility link - Legacy

E to O

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

HIPPI @

1.2Gb/s

E to O

O to O

O to O

O to E

Location #1 Location #2

O to ERS422

2 Km’s

1510

WDM

1530

1550

1570

1510

1530

1550

1570

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

HIPPI @

1.2Gb/s

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

HIPPI @

1.2Gb/s

O to E

E to O

E to O

O to O

O to O

1510

1530

1550

1570

1510

1530

1550

1570

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

SONET OC3 @155Mb/s

HIPPI @

1.2Gb/s

E to O RS4221310 1310

SONET OC3 @155Mb/s

SONET OC3 @155Mb/s

SONET OC3 @155Mb/s

1310

1310

1310

1310

1310

1310

CWDM M4 CWDM D4

CWDM M4 CWDM D4

WDM

O to E

ATMSwitch

ATMSwitch

ATMSwitch

O to E

ATMSwitch

Post House Facility Link – New

AES

E to O

O to E

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

E to O

O to E

Mux + EO

OE+Demux

O to E

E to O

Location #1 Location #2

RS422RS422

2 Km’s

SDI @ 270Mb/s

HDSDI @ 1.485Gb/s

GBE

AES

Gbe

RS422 RS422

Analog Video

Analog Audio

1310

CWDM

M16

CWDM D16

Gbe

O to E

E to O

Demux+OE

EO + Mux

Analog Video

Analog Audio

Mux + EO

OE+Demux

Analog Video

Analog Audio

Demux+OE

EO + Mux

10/100 10/100

Mux +EO

Demux +OE

10/100 Mb/s Ethernet

Demux +OE

Mux + EO

Analog Video

Analog Audio

10/100 Mb/s Ethernet

GBE

Co

ars e

WD

M

Co

ars e

WD

M

Coax to Fiber

Coax to Fiber

Coax to Fiber

Coax to Fiber

CH 1

CH 2

CH 3

CH 4A

udio

Mux

SDI Videowith

Embedded

Audio

6 AES Audiofor

Radio

Fiber to Coax

Fiber to Coax

Fiber to Coax

Fiber to Coax

NTSC Enc

NTSC Enc

NTSC Enc

NTSC Enc

Audio

Dem

ux

AnalogVideoand

Audio

Fiber STL Monitoring

Points

6 AES Audiofor

RadioMonitoring andControl

Cat 5 to Fiber Fiber to Cat 5

BROADCAST CENTERBROADCAST CENTER CN TOWERCN TOWER

XX22

RF Over fiber optics -Applications

Typical Satellite Application With SNMP Monitoring

LB LB EOEO

LB OELB OE

LB OELB OE

Satellite Satellite ReceiverReceiver

VerticVerticalal

HorizontHorizontalalLNB LNB

PowerPower

L-Band Downlink (950Mhz – 2250Mhz)

IF OEIF OEC or KuC or Ku

Up ConvUp ConvIF EOIF EO

Video ModVideo Mod

IF Uplink (70/140Mhz)

HPAHPA

LB LB EOEO

Remote SNMP

Monitoring & Control

Satellite Satellite ReceiverReceiver

Satellite Satellite ReceiverReceiver

Satellite Satellite ReceiverReceiver

Satellite Satellite ReceiverReceiver

BPX-RFBPX-RF DA8-RFDA8-RFRouterRouter

Satellite Satellite ReceiverReceiver

Satellite Satellite ReceiverReceiver

DA-RFDA-RF

BPX-RFBPX-RF

Video ModVideo Mod

DA-RFDA-RFBPX-RFBPX-RF

Ethernet Ethernet / SNMP/ SNMP

Ethernet Ethernet / SNMP/ SNMP

Ethernet Ethernet / SNMP/ SNMP

Large Video MAN – Fully protected

RSK

Pac TV

RSH

OneWilshire

VideoMan Nodes Layout

DT11/17/03

25 mi

25 mi

KNBC KRCAKVEA

BT

DirectTV

KCBS CNN9 Net

Australia

Intelsat

JapanTelecom

FoxSports

VYVXFiber

KSCI

KTTV

RSE

Fox

NCTC

4 mi

0.5

10.5

10.5

1.5

0.5

0.8

Extra 2.3

2.3 2.92.3

7.3

Ent ..Tonight

KTLA

CBS2.1

1.51.1 1.1

1.1

2.7

E!

0

0.5

6.2

0.7

Globesat

0.75KMEX

7.25

8 mi

5.5 mi

11 mi

13.5 mi

9.8 mi

KABCProspect

8 mi5.5 mi

LA Zoo

TVGaming 7.25 Dodger

Stadium2.5

5.75

7.5

KABCCircle seven

Summary

Fiber is an ideal transport medium No magic involved in using fiber

optics Many solution options available Proper upfront system design

upfront prevents many headaches

Questions

Eric Fankhauserericf@evertz.comwww.evertz.com