Answer the two questions::: (1) Why should “overhead” in an organization’s network concern a manager? (2) What are the key security issues in using various guided and unguided media?

Transmission Media
These are the types of guided and unguided media.
• Guided
o Twisted Pair
o Coaxial
o Fiber Optic
• Unguided
o Terrestrial microwave
o Satellite microwave
o Radio
o Infrared

Guided media can use a large span of frequencies across the frequency spectrum. It is important to see the relationship of the various media. As you go higher in the spectrum of frequencies, you get more bandwidth. As you probably know already, 108 is 10 times larger than 107, so looking at the 1014 or 1015 range looks pretty big in terms of bandwidth and data rate. Looking at this, you should be able to see why fiber optics can carry so much data.

For unguided media, transmission and reception are achieved by means of an antenna. There are basically two types of configuration for wireless transmission: directional and omnidirectional. For directional configuration, the transmitting antenna puts out a focused electromagnetic beam that will be received by the receiving antenna. The transmitting and receiving antennas must therefore be carefully aligned. In the omnidirectional case, the transmitted signals spread out in all directions and can be received by many antennas.

Advantages
• Covers greater distances without installing cable
• Communicate where cable can’t go (space, swamps, mountains, oceans, etc.)
• Can go through buildings and obstacles with some frequencies
• Can support mobile transmitters and receivers (except in terrestrial microwave and some satellite systems)
Disadvantages
• More noise
• Can be hard to set up (microwave and satellite)
• Share the airwaves. A specific frequency or set of frequencies are required to legally operate.