Transcript Optical Fiber Communication 2

Advantages and Disadvantages of
Optical Fiber Communication
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Objectives
After completion of this lecture, participants
will be able to understand:
Advantages and some Disadvantages of
Optical Fiber Communication System over
Traditional Communication System
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Advantages of Optical Fiber
Communication
1) Large Bandwidth
•
Infinite theoretical Bandwidth .
•
Optical Carrier Frequency Range: 104 GHz to 107 GHz
•
Coaxial Cable Bandwidth is up to 500 MHz.
•
Millimeter Radio Wave Bandwidth is up to 700 MHz.
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Advantages of Optical Fiber
Communication
2) Small Physical Size
•
Fiber Clad Diameter:
50 m to 400m
•
Fiber Core Diameters:
08 m to 200m
3) Light Weight
•
Light Glass or Plastic material
•
Light Plastic or Kevlar Outer Jacket
•
A few grams per meter
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Advantages of Optical Fiber
Communication
4) Electrical Isolation
Material:
Glass or Plastic (Electrical Insulator)
No earth loop problem
No interference problem
No short-circuits
No sparks
Suitable for electrically hazardous environment (shocks,
explosives)
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Advantages of Optical Fiber
Communication
5) Immunity to Interference
Optical Fiber is Dielectric Waveguide of glass material
Free from Electromagnetic Interference (EMI)
Free from Radiofrequency Interference (RFI)
Free from Electromagnetic Pulses (EMP) due to switching transients
Operation unaffected in Electrically Noisy environments
Require no shielding
Susceptible from Lightning Strikes
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Advantages of Optical Fiber
Communication
6) Immunity to Cross Talk
• No optical Interference between fibers even if many fibers are
in the same cable
•
No Electrical Signals
No Cross Talk
7) Signal Security
• Optical Signal cannot be tapped-out without cutting the fiber
(thereby shutting down/interrupting the link)
Eavesdropping is minimized
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Advantages of Optical Fiber
Communication
8) Low Transmission Loss
• ITU-T Recommendation G.651 for 850 nm:
4-8 dB/km
• Practical Range obtained:
2-4 dB/km
• ITU-T Recommendation G.651 for 1310 nm:
1-2 dB/km
• Practical Range obtained:
1-1.5 dB/km
• ITU-T Recommendation G.651 for 1550 nm:
0.5-1 dB/km
• Practical Range obtained:
0.2-0.15 dB/km
Bandwidth and Transmission distance is increased
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Advantages of Optical Fiber
Communication
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Advantages of Optical Fiber
Communication
9) Ruggedness
•
OF Cables have very high tensile strengths (typically 600 lb)
10) Flexibility
•
Can be bend or Twisted to very small radii without damage
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Advantages of Optical Fiber
Communication
11) Reliability
• Simpler Equipment
• Fewer Equipment including Repeaters (sometimes no repeaters)
• Very-low Noise and interference Environment
• Higher Bandwidths
• Better physical properties of optical fiber medium
• Higher Mean Time Before Failure (MTBF)
More Reliable Systems
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Advantages of Optical Fiber
Communication
12) Ease of Maintenance
•
Simpler Equipment
•
Less Equipment
Easy and Cost Effective maintenance
13) Low Cost
•
Lower Installation Cost
•
Lower Operating Cost
•
Lower Bandwidth Cost
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Advantages of Optical Fiber
Communication
14) High-Quality Transmission
• BER:
Typically 10-09 to 10-11 for Optical Fiber Medium
• BER:
Typically 10-05 to 10-07 for Copper and Microwave
Media
15) Environmental Stability
Retention of Transmission Characteristics under Environmental
Stresses
1. Less temperature sensitive as compare to copper.
2. Lower Corrosion Rates than copper .
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Disadvantages of Optical Fiber
Communication
1) Radiation Hardness
Fiber darkens to some degree when bombarded by high energy
radiations
2) Nonconductor
Cannot Transmit Electrical Power for energizing Telecomm
Equipment
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Disadvantages of Optical Fiber
Communication
3) Bend Strength
Lower Bend Strengths. Cables are generally designed to avoid this
situation
4) Hydrogen Absorption
H2 molecules can be absorbed and diffused in silica fibers and
produce attenuation
5) Line Transmission
Optical Fiber Communication is not a wireless system and there
is always an cable between transmitters and receivers.
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Thanks
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