Advantages of FSO | Disadvantages of FSO, Free Space Optics
This page covers advantages and disadvantages of FSO (Free Space Optics). It mentions benefits or advantages of FSO and drawbacks or disadvantages of FSO.
What is FSO ?
It is wireless optical technology which transmits data via laser beams. It uses light waves to transmit/receive data in LOS (Line of Sight) path between buildings. Unlike OFC (Optical Fiber Cable), it uses air for data transportation using light. OFC uses cable as medium for data transportation using light.
The figure depicts block diagram of FSO (Free Space Optics). As shown there are three components of FSO system viz. transmitter, channel and receiver. Transmitter consists of data source encoder, LED/LD and lense or mirror. Receiver consists of photo detector, signal processor and decoder.
Following are the features or characteristics of FSO.
• Frequency : Greater than 300 GHz
• Bandwidth : tens of GHz
• Transmission power : Dozens of watts
• Receiver Noise figure : About 15 dB
• Receiver Sensitivity : About -56 dBm
Benefits or advantages of FSO
Following are the benefits or advantages of FSO:
➨As it uses air as transport medium, no permission is needed for transmission of laser beams. Hence it is license free operation.
➨Installation is easier and fast. Moreover maintenance time is short.
➨The cost is moderate.
➨It has ability to operate at higher power levels.
➨It offers higher bit rates and lower bit error rates (BERs).
➨The system is immune to EM (Electromagnetic) interference.
Drawbacks or disadvantages of FSO
Following are the drawbacks or disadvantages of FSO:
➨Spreading loss is higher and there is atmospheric loss due to water and carbon dioxide molecules.
➨Power consumption is higher.
➨It is easy to intercept due to its propagation medium and hence it is less secure than OFC.
➨Transmitter and receiver should be in LOS (Line of Sight) to each other for its operation.
➨The FSO transmitted signal gets blocked due to trees, animals, buildings and other atmospheric conditions. Birds and scintillation cause beam interruptions. Hence availability of FSO link depends on weather.