Introduction to Data Communications
15d. Optical Fibre (cont'd)

Physical vibration will show up as signal noise!
Limited physical arc of cable. Bend it too much & it will break!
Difficult to splice

The cost of optical fibre is a trade-off between capacity and cost. At higher transmission capacity, it is cheaper than copper. At lower transmission capacity, it is more expensive.

15e. Media versus Bandwidth

The following table compares the usable bandwidth between the different Guided Transmission Media

Cable Type	Bandwidth
Open Cable	0 - 5 MHz
Twisted Pair	0 - 100 MHz
Coaxial Cable	0 - 600 MHz
Optical Fibre	0 - 1 GHz

16. Transmission Media - Unguided

Unguided Transmission Media is data signals that flow through the air. They are not guided or bound to a channel to follow. They are classified by the type of wave propagation.

16a. RF Propagation

There are 3 types of RF (Radio Frequency) Propagation:

Ground Wave,
Ionospheric and
Line of Sight (LOS) Propagation.

Ground Wave Propagation follows the curvature of the Earth. Ground Waves have carrier frequencies up to 2 MHz. AM radio is an example of Ground Wave Propagation.