Operating instructions

SRM9020plus ~ Trunked Operating Instructions
© Comgroup Australia 2010 Page 23 TNM-U-E-0085 Issue 1.0b
PSTN
Public Switched Telephone Network — the telephone system.
PTT/Pressel
Press-to-Talk. Hold down the Press-to-talk switch on the
microphone for the duration of the transmission.
RF
Radio Frequency.
SDM
An Alphanumeric Short Data Message sent to/from the radio.
Status
Message
A number code that transmits the “status” of the mobile to the
controller automatically. The number refers to a pre-
programmed text message.
Traffic
Channel
A radio channel used for sending speech transmissions.
A traffic channel is only allocated for the duration of the call. It
then becomes available for use by others.
Trunked
Operation
The automated sharing of a number of channels between a
larger number of users.