optical networking in wireless mobile networks

1. Optical Networking
.

2. Contents
• Optical network definition
• Components of optical network
• Optical fibre
• SONET
• Advantages
• Disadvantages

3. Optical Network
• An optical Network is a communication network in
which information is transmitted as optical or
Infrared radiation transmission (IR) signals.
• It is also called Photonic Network
• Form of optical communication that relies on optical
amplifiers , Lasers or LEDs and Wave division
Multiplexing(WDM) to transmit large quantities of
data generally across Fibre-optic cables.

4. Components of Optical Network System
• Fiber. Multi-mode or single-mode.
• Laser or LED light source.
• Multiplexer/demultiplexer, also called mux/demux,
filter, or prism. These can include Optical Add/Drop
Multiplexer (OADM) and Reconfigurable Optical
Add/Drop Multiplexer (ROADM).
• Optical switch, to direct light between ports without an
optical-electrical-optical conversion
• Optical splitter, to send a signal down different fiber
paths.
• Optical amplifier.

5. Optical Fiber
• An optical fiber is made of
three sections:
– The core carries the
light signals
– The cladding keeps the light
in the core
– The coating protects the glass
5
CladdingCore
Coating

6. Optical Fiber (cont.)
• Single-mode fiber
– Carries light pulses by
laser along single path
• Multimode fiber
– Many pulses of light
generated by LED
travel at different
angles
SM: core=8.3 cladding=125 µm
MM: core=50 or 62.5 cladding=125 µm

7. 7.7
Bending of light ray

8. 7.8
Propagation modes

9. Figure Modes

10. SONET
• Synchronous Optical Network (SONET)
• The ANSI standard for synchronous data transmission on
optical media.
• Provide end-to-end circuit-switched connections
• Provide efficient mechanism for multiplexing low-speed
connections into higher-speed connections
– Define a base rate of 51.84 Mbps and a set of multiples of the base rate
known as "Optical Carrier levels (OCx)"
• Provide efficient way to extract low-speed streams from a
high-speed stream at intermediate nodes
• High availability (99.99% to 99.999%)
– Rapid service restoration in the event of failures

11. 11
SONET Transmission Rates
OC-1 = 51.84 Mbps
OC-3 = 155.52 Mbps
OC-12 = 622.08 Mbps
OC-24 = 1.244 Gbps
OC-48 = 2.488 Gbps
OC-192 = 9.953 Gbps
OC-768 = 39.814 Gbps

12. 12
SONET Elements
• Terminal multiplexers (TMs): nodes at the ends of
point-to-point links, multiplex and demultiplex traffic
streams
• Add/drop multiplexers (ADMs):drop/add one or
more low-speed streams from/to a high-speed
stream, allow the remaining traffic to pass through
– Deployed in linear and ring networks
• Digital crossconnects (DCSs): large number of ports,
extract and switch lower-speed streams
(44.736Mbps and 1.544Mbps), interconnect SONET
rings

13. Advantages
• Bandwidth - Fibre optic cables have a much greater bandwidth than metal cables
• Low Power Loss - An optical fibre offers low power loss. This allows for longer
transmission distances. In comparison to copper; in a network, the longest
recommended copper distance is 100m while with fibre, it is 2000m.
• Interference - Fibre optic cables are immune to electromagnetic interference. It
can also be run in electrically noisy environments without concern as electrical
noise will not affect fibre.
• Size - In comparison to copper, a fibre optic cable has nearly 4.5 times as much
capacity as the wire cable has and a cross sectional area that is 30 times less.
• Weight - Fibre optic cables are much thinner and lighter than metal wires. They
also occupy less space with cables of the same information capacity. Lighter
weight makes fibre easier to install.
• Safety - Since the fibre is a dielectric, it does not present a spark hazard.
• Security - Optical fibres are difficult to tap.
• Flexibility - An optical fibre has greater tensile strength than copper or steel fibres
of the same diameter.
• Cost - The raw materials for glass are plentiful, unlike copper. This means glass can
be made more cheaply than copper.

14. Disadvantage
• Cost - Cables are expensive to install but last
longer than copper cables.
• Transmission - transmission on optical fibre
requires repeating at distance intervals.
• Fragile - Fibres can be broken or have
transmission loses when wrapped around curves
of only a few centimetres radius. However by
encasing fibres in a plastic sheath, it is difficult to
bend the cable into a small enough radius to
break the fibre.
• Protection - Optical fibres require more
protection around the cable compared to copper.

15. Thank You