Personal Wireless technology Flashcards
What are frequencies from 30 to 300 megahertz (MHz) internationally designated as?
Very high.
The ultra high frequency designation applies to frequencies from
300 to 3,000 MHz.
Which of the following frequencies has the shortest wavelength?
140 MHz.
A mode of operation in which communication is possible between two or more stations, in both
directions, using the same frequency, is called
simplex.
What communication mode(s) of operation allows two or more stations to send intelligence in
both directions but not simultaneously?
Simplex and half duplex.
Producing radio frequency (RF) energy and radiating useful signals into space is the purpose of
the
transmitter.
What type modulation produces a constant amplitude transmission?
Frequency.
The ability to maintain a constant output carrier frequency refers to a transmitter’s frequency
accuracy.
The process of mixing or combining two frequencies in a nonlinear device in an amplitude
modulated (AM) receiver is called
heterodyning.
What component of a frequency modulated (FM) receiver removes the original signal from the
sidebands and recreates the audio intelligence?
Discriminator.
What characteristic enables a receiver to reproduce a desired signal from several closely spaced
stations or from interfering frequencies?
Selectivity.
The total resistive properties of a circuit when resistance, capacitive reactance, and inductive
reactance are formulated together is called
impedance.
What transmission line is very common in both fixed and tactical application?
Flexible coax.
What field provides the basis of radio frequency (RF) communications by detaching from the
conductor and traveling through space?
Radiation.
For best communications, the transmitting antenna
and receiving antenna should have the same polarization.
What standard antenna is used for antenna gain comparison?
Isotropic.
When the gain of an anisotropic radiator is compared to the isotropic radiator, the stronger
signal of the directional antenna is expressed as
decibels (dB) gain.
What is the shortest wavelength an antenna can be made resonant?
Half.
What tuning devices are adjusted when tuning the resonant transmission line-resonant antenna
connection?
Inductors and capacitors.
What limits a direct wave to normally less than 20 miles?
Curvature of the earth.
Which type of precipitation attenuates radio frequency (RF) energy just like rain?
Fog.
What ratio is used to measure the desired signal strength relative to the background noise?
Signal-to-noise.
What combination of Air Force instructions (AFI) do you use for guidance when determining a
technical solution for personal wireless communications systems (PWCS)?
AFI 33–106 and AFI 33–201V1.
Which personal wireless communications system (PWCS) device can be used for command and
control?
Land mobile radio (LMR).
Which personal wireless communications system (PWCS) device’s original intent was for use
by family, friends, and associates to communicate among themselves within a small area?
Family radio service (FRS).
What channel access method assigns each call a certain portion of time on a designated
frequency?
Time division multiple access (TDMA).
Who is usually responsible for their air time charges and must budget accordingly?
Unit.
Cell sites are generally thought of as being a
hexagon.
Which conventional land mobile radio (LMR) device has a transmitting power of 5 or 6 watts?
Portable.
What conventional land mobile radio (LMR) device serves as the hub of a net?
Base station.
In trunked land mobile radio (LMR) systems, different user groups are known as
talkgroups.
Which trunking user equipment has the capability to monitor more than one talkgroup at a time?
Dispatch consoles.
What enhanced features of the trunking land mobile radio (LMR) allows the system manager to
completely disable radios in the field from the system terminal?
Selective radio inhibit.
In response to disaster relief operations, the Department of Defense (DOD) Policy on
Procurement of Mobile Satellite Services (MSS) was amended in 2006 to allow the DOD to use
additional MSS providers for
unclassified purposes within the CONUS.
What type areas is International Mobile Satellite Organization (Inmarsat) coverage separated
into?
Ocean.
Which International Mobile Satellite Organization (Inmarsat) system has a land mobile
terminal, typically has a one meter flat array antenna, and weights 30 to 40 pounds?
B.
