ASTRO XTS 2500/XTS 2500I Model III 124
Glossary
This is a list of specialized terms used in this manual.
ACK Acknowledgment of communication.
Active Channel A channel that has traffic on it.
Analog Signal An RF signal that has a continuous nature 
rather than a pulsed or discrete nature.
ASTRO 25 Trunking Motorola standard for wireless digital trunked 
communications.
ASTRO 
Conventional
Motorola standard for wireless analog or 
digital conventional communications.
Call Alert Privately page an individual by sending an 
audible tone.
Carrier Squelch Feature that responds to the presence of an 
RF carrier by opening or unmuting (turning 
on) a receiver's audio circuit. A squelch circuit 
silences the radio when no signal is being 
received so that the user does not have to 
listen to noise.
Central Controller  A software controlled, computer-driven device 
that receives and generates data for the 
trunked radios assigned to it. It monitors and 
directs the operations of the trunked 
repeaters.
Channel A group of characteristics such as transmit/
receive frequency pairs, radio parameters, 
and encryption encoding.
Control Channel In a trunking system, one of the channels that 
is used to provide a continuous, two-way/data 
communications path between the central 
controller and all radios on the system.
Conventional Typically refers to radio-to-radio 
communications, sometimes through a 
repeater. (See Trunking.)
94C06.book  Page 124  Wednesday, June 23, 2010  11:41 AM