IJSRP, Volume 3, Issue 3, March 2013 Edition [ISSN 2250-3153]
The spectrum licensing issues and interference at unlicensed ISM bands limits the market penetration. Though emerging license-free bands appear promising, they still have certain bandwidth and range limitations. The advantage of FSO communication over Fiber Optic communication (FO) is that, there is no time and money wasting trench digging involved, for laying the optical fiber cables underground and no acquiring of road digging permission from the municipality , because the optical carrier signal travels through the atmosphere. Optical wireless (FSO) can augment RF and milli meter wave links with very high (>1 Gb/s) bandwidth. In fact, it is widely believed that optical wireless is best suited for multi-Gb/s communication. As this is a telecommunication technology that transmits data in the form of optical signals across the air and, as such, can be considered as a wireless (line-of-sight) transmission system; which is being capable of handling data rates at the Gbps level, does not require licensing, and can be deployed at one-fifth of the cost of fiber; also, the narrow beams employed in the transmission of signals are very difficult to be affected by jamming ,interception or interference. This article reviews the FSO Link suitability for achieving reduced error communication. With its high-data-rate capacity and wide bandwidth on unregulated spectrum, FSO communication is a promising solution for the “last mile” problem, however its performance is highly vulnerable to adverse atmospheric conditions. A number of phenomena in the atmosphere, such as absorption, scattering, and turbulence, can affect beam attenuation, but in the case of wavelengths typical of FSO systems operation, only scattering and turbulence are appropriate to be taken into consideration.