Technology
Chapter 22: Telecommunication—Terms and Definitions
Alternating current: the flow of electrons in both directions along a conductor, reversing at regular
intervals.
Amplitude: the height of a wave. It measures the strength of the wave.
Amplitude modulation (AM): a system that merges a message onto a carrier wave by changing
the strength of the carrier signal.
Audience assessment: actions that study audience needs and wants. It is the first step in the
process of communication design.
Audio: sound.
Broadcast frequency: a frequency above audible sound.
Broadcast system: a system that sends radio waves through the air carrying the signal from the
sender to the receiver.
Carrier frequency: a frequency used by radio broadcast systems that radiates from the transmitter.
Casting: a process through which on-camera performers are employed.
Conductor: a metal that conducts an electrical current.
Direct current: the flow of electrons in one direction through a conductor.
Duplex system: a basic system used in mobile communication that uses two channels.
Frequency: the number of cycles that pass some point in one second.
Frequency division multiplexing (FDM): multiplexing that uses a separate frequency to transmit
each message.
Frequency modulation (FM): a system that encodes a message on a carrier wave by changing its
frequency.
Hard-wired system: a system that sends its signals through a physical channel.
Hertz: the unit of measurement for the number of cycles per second.
Induction: the process in which magnetic lines of force increase and decrease in strength, causing
electrons to flow in an adjacent wire.
Kilohertz: a basic unit of measurement in telecommunication. It equals 1000 cycles per second.
Megahertz: a basic unit of measurement in telecommunication. It equals 1 million cycles per second.
Multiplex system: a basic system used in mobile communication that uses multiple frequencies to
accommodate different types of units.
Multiplexing: a system used to increase the capacity of a waveguide.
Radio wave: a frequency within the electromagnetic spectrum, extending from around 30 hertz to
300 gigahertz.
Copyright Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Script: a document that identifies characters, develops a situation, and communicates a story.
Simplex system: a basic system used in mobile communication that uses the same channel for both
base and mobile transmissions.
Telecommunication: a communication process that depends on electromagnetic waves to carry a
message over a distance.
Time division multiplexing (TDM): multiplexing that divides time into very brief segments.
Transducer: a technological device that changes energy of one form into energy of another form.
Ultrahigh frequency (UHF): a radio frequency between superhigh frequency and very high
frequency (VHF).
Very high frequency (VHF): a radio frequency between ultrahigh frequency (UHF) and high
frequency.
Video: visual.
Copyright Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.