IFR FM/AM-1200A

D. Mobile Handoff
When a home repeater is busy, it will instruct a mobile unit to change
its channel to the next free repeater in the system. A handoff will
occur in this manner:
REPEATER #2 ACTION
SINCE HOME REPEATER IS BUSY,
IT CONTINUOUSLY TRANSMITS
DATA WORD:
S:0:2:2:212:5:C
INDICATING MOBILE #2121S
USING
REPEATER #2 BUT
REPEATER
#5 IS FREE
'
REPEATER #2 SEES ITS NUMBER
IN THE COAX TRANSACTION AND
CONTINUOUSLY TRANSMITS TWO
MESSAGES, FIRST:
S:0:2:2:212:1
:C
INDICATING MOBILE #212 IS USING
REPEATER #2 THEN:
S:0:5:2:91 :1 :C
WHICH TELLS MOBILE #91 TO GO
TO REPEATER #5
~
REPEATER #2 CONTINUALLY
IN USE
5-46
08
I REPEAT I
MOBILE ID #91 ACTION REPEATER #5 ACTION
FREE REPEATER TRANSMITS
DATA WORD:
S:0:5:5:255:5:C
INDICATING IT IS FREE
MOBILE OPERATOR PRESSES
PUSH-TO-TALK
AND UNIT
TRANSMITS
DATA WORD:
S:0:5:2:91
:31 :C
REPEATER
#5 RECOGNIZES
REQUEST FROM #91 AND
TRANSMITS DATA WORD:
S:0:5:2:91
:1 :C
~~
MOBILE OPERATOR BEGINS
VOICE TRANSMISSION
MOBILE OPERATOR RELEASES
PUSH-TQ- TALK AND TRANSMITS
DATA WORD:
S:0:31
:2:91:31 :C
REPEATER #5 THEN HANDSHAKES
BY
TRANSMITTING DATA WORD:
S:0:31
:2:91 :5:C
I
MOBILE UNIT REVERTS BACK TO
MONITORING ITS HOME
REPEATER
I REPEAT I
6104002
Figure 5-7 Handoff Sequence