Section: Information System Operations, Maintenance and Support
Explanation/Reference:
Fiber optics cables are used for long distance, hard to splice, not vulnerable to cross talk and difficult to tap.
It supports voice data, image and video.
For your exam you should know below information about transmission media:
Copper Cable
Copper cable is very simple to install and easy to tap. It is used mostly for short distance and supports
voice and data.
Copper has been used in electric wiring since the invention of the electromagnet and the telegraph in the
1820s.The invention of the telephone in 1876 created further demand for copper wire as an electrical
conductor.
Copper is the electrical conductor in many categories of electrical wiring. Copper wire is used in power
generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless
types of electrical equipment. Copper and its alloys are also used to make electrical contacts. Electrical
wiring in buildings is the most important market for the copper industry. Roughly half of all copper mined is
used to manufacture electrical wire and cable conductors.
Copper Cable
Coaxial cable
Coaxial cable, or coax (pronounced 'ko.aks), is a type of cable that has an inner conductor surrounded by a
tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an
insulating outer sheath or jacket. The term coaxial comes from the inner conductor and the outer shield
sharing a geometric axis. Coaxial cable was invented by English engineer and mathematician Oliver
Heaviside, who patented the design in 1880.Coaxial cable differs from other shielded cable used for
carrying lower-frequency signals, such as audio signals, in that the dimensions of the cable are controlled
to give a precise, constant conductor spacing, which is needed for it to function efficiently as a radio
frequency transmission line.
Coaxial cable is expensive and does not support many LAN's. It supports data and video.
Coaxial Cable
Fiber optics
An optical fiber cable is a cable containing one or more optical fibers that are used to carry light. The optical
fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable
for the environment where the cable will be deployed. Different types of cable are used for different
applications, for example long distance telecommunication, or providing a high-speed data connection
between different parts of a building.
Fiber optics used for long distance, hard to splice, not vulnerable to cross talk and difficult to tap. It
supports voice data, image and video.
Radio System
Radio systems are used for short distance, cheap and easy to tap.
Radio is the radiation (wireless transmission) of electromagnetic signals through the atmosphere or free
space.
Information, such as sound, is carried by systematically changing (modulating) some property of the
radiated waves, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an
electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in
the waves can be extracted and transformed back into its original form.
Fiber Optics
Microwave radio system
Microwave transmission refers to the technology of transmitting information or energy by the use of radio
waves whose wavelengths are conveniently measured in small numbers of centimeter; these are called
microwaves.
Microwaves are widely used for point-to-point communications because their small wavelength allows
conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving
antenna. This allows nearby microwave equipment to use the same frequencies without interfering with
each other, as lower frequency radio waves do. Another advantage is that the high frequency of
microwaves gives the microwave band a very large information-carrying capacity; the microwave band has
a bandwidth 30 times that of all the rest of the radio spectrum below it. A disadvantage is that microwaves
are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio
waves can.
Microwave radio transmission is commonly used in point-to-point communication systems on the surface of
the Earth, in satellite communications, and in deep space radio communications. Other parts of the
microwave radio band are used for radars, radio navigation systems, sensor systems, and radio
astronomy.
Microwave radio systems are carriers for voice data signal, cheap and easy to tap.
Microwave Radio System
Satellite Radio Link
Satellite radio is a radio service broadcast from satellites primarily to cars, with the signal broadcast
nationwide, across a much wider geographical area than terrestrial radio stations. It is available by
subscription, mostly commercial free, and offers subscribers more stations and a wider variety of
programming options than terrestrial radio.
Satellite radio link uses transponder to send information and easy to tap.
The following answers are incorrect:
Copper Cable- Copper cable is very simple to install and easy to tap. It is used mostly for short distance
and supports voice and data.
Satellite Radio Link - Satellite radio link uses transponder to send information and easy to tap.
Coaxial cable - Coaxial cable are expensive and does not support many LAN's. It supports data and video
The following reference(s) were/was used to create this question:
CISA review manual 2014 page number 265
