01-03-2010, 07:46 PM
Fiber-Optic Communication Systems An Introduction.ppt (Size: 1.07 MB / Downloads: 342)
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 àattenuation
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) ÃÂ
high-speed
“ Single Mode Fiber (SMF) offers the
lowest dispersion àhighest bandwidth ÃÂ
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://www.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