Transcript All Optical Networks

All Optical Networks
Samir Chatterjee & Suzanne Pawlowski
Presenter: Pengfei Liu
Outline
To present a general overview of optical
networks;
 To discuss how all-optical networks can
be integrated into existing and future
broadband network architectures;

All-optical

Current fiber networks use electronic
switching and are therefore limited to
electronic speeds of a few gigabits per
second. For higher speeds, it is
important that the signal remain photonic
throughout its path. Such networks,
which use optical switching and routing,
are called all-optical.
Drivers for Optical Networks

Internet and Web
browsing.
Bandwidth requirement *8
More users
Response time

Graphics and
visualization.
2000*2000 12-bit color
pixels/frame & 24 frame/sec
adds up to 1Gbps
Drivers for Optical Networks

Medical image
access and
distribution.
 Multimedia
conferencing.
Video: 10-40Mbps HDTV
2-6Mpbs MPEG

Broadband
services to the
home.
Optical Transmission System

Three basic
elements
Light Source: infrared lightemitting diodes( LEDs )
or Injection Laser
diodes( ILDs )
Transmission medium:singlemode or multimode fiber,
ultra-thin glass fiber.
Detector: photodiode and
phototransistor
Optical fiber principles


Central core,
surrounded by a
cladding layer, which is
covered by protective
jacket
ray of light travels
through by reflecting
along the interface
between the two
transparent mediums.
Optical fiber principles

Total Internal Reflection
Total internal reflection causes the light to be
guided down the fiber. Total internal reflection
is directly related to the fact that the refractive
index of the cladding( n1 ) is less than the
refractive index of the core( n2 ).
n1 < n2
Optical Networking Technology

Erbium-doped fiber
amplifier( EDFA )
Optical signals are
regenerated
electronically to
overcome the
attenuation inherent in
the silica fiber as well as
other losses due to
optical components
along the line.
Optical Networking Technology

Wavelength
division
multiplexing(WDM)
All-optical networks

Tree dominant types of optical networks
All-optical networks
All-optical networks
Optical Services

Network services are provided in the form of layers of
various protocols.
Optical Services
UNI( User Network Interface )
ON( Optical Network )
Circuits (POTS, T-1, SONET),
Datagram (IP with its best-effort service)
Virtual circuits (frame-relay and ATM).
Conclusion
Briefly reviewed the state of the
technology and possible future directions
for fiber-optic networks.
 There’s still a long way to go.

End of Presentation