Motorola APX 900 User Manual page 143

Selective Call
A feature that allows you to call a selected individual, intended to provide privacy and to eliminate
the annoyance of having to listen to conversations of no interest to you.
Selective Switch
Any digital P25 traffic having the correct Network Access Code and the correct talkgroup.
Squelch
Muting of audio circuits when received signal levels fall below a pre-determined value. With
carrier squelch, all channel activity that exceeds the preset squelch level can be heard.
Synchronous Serial Interface (SSI)
DSP interface to peripherals that consists of a clock signal line, a frame synchronization signal
line, and a data line.
Standby
An operating condition whereby the radio's speaker is muted but still continues to receive data.
Status Calls
Pre-defined text messages that allow the user to send a conditional message without talking.
Tactical/non-revert
The user will talk on the channel that was selected before the radio entered the emergency state.
TalkAround
Bypassing a repeater and talking directly to another unit for local unit-to-unit communications.
Talkgroup
An organization or group of radio users who communicate with each other using the same
communications path.
TMS
Text Messaging Service.
Trunking
The automatic sharing of communications paths between a large number of users. Allows
users to share a smaller number of frequencies because a repeater or communications path
is assigned to a talkgroup for the duration of a conversation.
Trunking Priority Monitor scan list
A scan list that includes talkgroups that are all from the same trunking system.
USK
Unique shadow key.
UTC
MN003441A01-AP
Glossary
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