Physical path between transmitter and receiver is called transmission medium, it may be wireline or wireless.
Wireless (unguided) media
•Wireline (guided) medium
Fiber Medium Vs Microwave medium
Optical Fiber Communication
Transmitting information from one place to another by sending pulses of light (wavelength) through an optical fiber. Modulation used: Light Intensity Modulation
Advantages of Optical Fibers
- Very high information carrying capacity
- Less attenuation (order of 0.2 db/km)
- Small in diameter and size & light weight
- Greater safety and immune to EMI & RFI, moisture & corrosion
- It is dielectric in nature so can be laid in electrically sensitive surroundings
- Difficult to tap fibers, so secure
- No cross talk and disturbances
Disadvantages of Optical Fibers
- The terminating equipment is still costly as compared to copper equipment.
- It is delicate so has to be handled carefully
- High Cost
- Last mile is still not totally fiberised due to costly subscriber premises equipment
- Optical fiber splicing is a specialized technique and needs expertly trained manpower.
- The splicing and testing equipments are very expensive as compared to copper equipments.
Applications of Optical Fiber
- Long distance communication: Backbones
- Broadband services
- Computer data communication (LAN, WAN etc..)
- Medical Industry
- Military application