[attachment=2511]

Fiber-Optic Communication Systems An

Introduction

---

Presented By
Xavier Fernando
Ryerson University

---

Why Optical Communications?
¢ Optical Fiber is the backbone of

modern communication networks
“ Voice (SONET/Telephony) - The

largest traffic
“ Video (TV) over Hybrid Fiber

Coaxial (HFC)
“ Fiber Twisted Pair for Digital

Subscriber Loops (DSL)
“ Multimedia (Voice, Data and Video)

over DSL or HFC

Why Optical Communications?
¢ Lowest attenuation à attenuation

in the optical fiber (at 1.3 µm and 1.55

µm bands) is much smaller than electrical

attenuation in any cable at useful

modulation frequencies
“ Much greater distances are

possible without repeaters
“ This attenuation is independent of

bit rate
¢ Highest Bandwidth (broadband) à

high-speed
“ Single Mode Fiber (SMF) offers the

lowest dispersion à highest bandwidth à

rich content
¢ Upgradability: Optical

communication system can be upgraded to

higher bandwidth, more wavelengths by

replacing only the transmitters and

receivers
¢ Low Cost for fiber

Why Opti-Comm for you?
¢ Most of you will eventually work

in Information and Communications

Technology (ICT) area
“ 138,000 ICT engineers hired in US

in 2006 compared to 14000 in biomedical
(http://bls.gov/oco/ocos027.htm)
¢ Canada produces 40% of the worlds

optoelectronic products (Nortel, JDS

Uniphase, Quebec Photonic Cluster¦)

Different Scenarios
¢ Digital fiber optic (SONET)

systems in the backbone“ Mostly deployed
¢ Dynamic multi-access Ethernet

systems “ LAN, GPON, EPON Access Networks
¢ Microwave (analog) fiber optic

(MFO) Systems “ CATV, Satellite base

stations
¢ Radio over fiber systems for

wireless communications (ROF)
¢ Infrared optical-wireless systems

(Free Space Optics, IrDA)

Synchronous Optical Networks
¢ SONET is the TDM optical network

standard for North America (called SDH in

the rest of the world)
¢ We focus on the physical layer
¢ STS-1, Synchronous Transport

Signal consists of 810 bytes over 125 us
¢ 27 bytes carry overhead

information
¢ Remaining 783 bytes: Synchronous

Payload Envelope