Codan Radio P25 Training Guide - Manual (Page 39)

P25 RADIO SYSTEMS | TRAINING GUIDE
Chapter 3: P25 Technical Information Page 31
Unit ID
The Unit ID is a 24 bit user programmable fi eld that is used for both group and individual calling. The
Unit ID is used as both a Source ID (from the sending unit) and a Destination ID (in the receiving unit
in an individual call).
The Unit ID is different from the Electronic Serial Number (ESN) embedded in the radio. The ESN is
only programmable by the manufacturer of the radio.
The Unit ID ranges from hexadecimal $000000 to $FFFFFF and contains 16,777,216 addresses.
The Unit ID’s should be programmed into the radios using a national, corporate or agency wide unit
identifi cation scheme.
The following Unit ID’s have specifi c functions:
$000000 no-one. This value is never assigned to a radio unit
$000001 to $98967F for general use.
$989680 to $FFFFFE for talk group use or other special purposes.
$FFFFFF designates everyone. Used when implementing a group call with a TGID.
Source ID
The Link Control Word (LDU1) contains the 24 bit Source ID fi eld. The Source ID is the Unit ID of the
SENDING unit. The Source ID is typically sent in all voice messages and is used for both group and
private calling.
(See Chapter 4; Figure 4-6)
Destination ID
The Link Control Word (LDU1) contains the 24 bit Destination ID fi eld. The Destination ID is used for
private voice messages only (called private or individual calling). The Destination ID is the Unit ID of
the intended recipient of the individual call.
(See Chapter 4; Figure 4-6)