User's Manual

148 Glossary
DRAFT 2
15 Glossary
A
APCO The Association of Public Safety
Communications Officials.
The APCO Project 25 standards
committee (
http://www.apcointl.org/)
defined a digital radio standard. The
standard is often referred to as ‘APCO’
or ‘P25’.
C
channel In a conventional system, a channel is a
pair of frequencies used to transmit and
receive radio signals.
In a P25 trunking system, a channel is a
group of radio users.
control
channel
In a P25 trunking system, the control
channel is used by the trunking site to let
the radio units in the site’s coverage
area know when they can transmit their
call information.
conventional
operation
In conventional operation, the radio is
tuned to a programmed channel, and
communicates with other radios either
on that channel, or through a repeater
system.