Communication Systems

In optical conununication, light is transmitted in the form of light puises along an opticaI fibre as transmission medium. Since, wavelength of the light is very small, it provides a very large band width and can carry a huge amount of information. And main merits of two wire transmission line or co-axial cable transmission are that they are quite cheap, very easy to install and less electrical disturbances (noise).
So, the required answer is high band width and low transmission loss.