Mumbai University > Electronics and telecommunication > Sem 7 > optical communication and networks

Marks: 05

Years: MAY 2014

1. The concept of the Bandwidth distance product is helpful for comparing the performance of different types of fibre optic links. However the achievable bandwidth distance product is independent of the chosen fibre length.

2. It can be true for a link based on multimode fibre, the capacity of which is limited by intermodal dispersion on the other hand, in a link based on the single dispersion compensation; a doubling of the data rate may enforce a reduction in fibre length by a factor of 4.

3. The Bandwidth distance product is then effectively reduced by a factor of 2.

4. As the data rate goes up (MHz), the distance that can be transmitted (km) goes down.

5. Thus a higher fibre bandwidth enables us to transmit at a higher data rates or for longer distances.

6. A bandwidth of 400 MHz-km means that a 400 MHz signal can be transmitted for 1 km.

7. The manufacturers normally specify optical fibre bandwidth as Bandwidth distance product.

8. It is stated in MHz.km of GHz.km and it is a figure of merit and it is used in predicting the effective fiber bandwidth for other lengths.