04-12-2012, 06:33 PM
Introduction to Optical Networks
Introduction to Optical Networks.pdf (Size: 220.33 KB / Downloads: 99)
What are optical network?
Telecomm Networks build using various communication
media
- Twisted pair copper wire
- Coaxial cable
- Wireless (Radio, microwave, satellite, infrared)
- Optical fiber
Advantages of fiber
-Large Bandwidth-distance product.
- immunity to noise and intereference
- very low cost per unit bandwidth
- easy upgradability using WDM technology
- Tapping of signal from fiber without being detected - difficult
Due to all these advantages
- Optical fiber Networks have high capacity
- Can be used for providing the high bandwidth services
- Even in wireless, infrared means high bandwidth connectivity.
All the networks using optical fiber as transmission medium -
optical networks
When - transmitted signal remains in optical form till its arrival at
destination - All-optical network
Optical TDMA, CDMA implementations
- need very short pulses (can be generated by mode locked
lasers).
- Time division multiplexers/ demultiplexer requires very tight
tolerance of fiber length (due to tight timing requirments)
- Encoder and decoders will require again very tight tolerance
in fiber length used for delay lines.
- Dispersion - need to be taken care of.