Page 177 - CISSO_Prep_ Guide

of signal quality over time. With analog communications, an
amplifier was used to boost the strength of the signal and allow
it to be carried long distances. With digital communications, a
repeater that will regenerate the signal is used. Regenerating the
signal also serves to reduce noise and improve the integrity of
the data. Twisting the pairs of wires also breaks up the problem
of crosstalk, where the signal from one wire may bleed onto on
the wires that are nearby.

Coaxial cable - coax is generally better than twisted pair in
capacity and distance, but it is more expensive, harder to work
with, and not as commonly used. Coax consists of two
conductors separated by an insulator and has excellent
bandwidth. Coax cable is generally connected using BNC
connectors.

Fiber Optic cable - the development of fiber optic cable led to
tremendous improvements in bandwidth and quality of network
communications. Fiber can handle traffic volumes far exceeding
any other technology. Fiber, though, is more expensive, more
difficult to work with, and less compatible with some devices.
Fiber is, however, immune to some of the problems of UTP,
such as radio frequency interference (RFI) and electromagnetic
interference (EMI).

Wireless Technologies

802.11 WLAN - the 802.11 standards (and standards in
development) for wireless local area networks are excellent for
connecting devices in a defined area. Wireless routers enable
wireless communications and also serve as an interface to wired