User's Manual

Radio Activity S.r.l. 21 / 44
3
rd
choice
Internal ref (full)
4
th
choice
Internal ref (full)
PPS to rear plug
Insulated
3.3.3.2 GPS sharing in RF linked stations
The main synchronization source in a RF linked simulcast network should be the GPS. In case of GPS failure,
the link transceiver is able to recover a time and frequency reference from the DMR signaling coming from
the Master station. This reference isn’t as precise as the GPS one but it is enough accurate to assure simulcast
operation with small degradations in the overlap area.
KAIROS has the ability to automatic switch the synch source selecting the best available. The GPS sharing
configuration is identical of the previous figure “GPS/PPS sharing example” where:
Slave
Master
A
Link transceiver
Link transceiver
B
Broadcast simulcas
t transceiver
Broadcast simulcast transceiver
C
-
Additional link receivers
D
Broadcast simulcast transceiver
Broadcast simulcast transceiver
The Broadcast transceiver can be equipped of the GPS receiver in case it is needed a redundancy in the GPS
signal (position “B” of the previous table).
Since the frontal led “RX1” flashes green synchronously with the PPS signal, this led should flash in the same
instant on all the equipments connected together. This immediately gives a feedback about the right
connection in the rack.
This configuration requires the following setup in the equipments:
KAIROS “A”:
Slave
Master
1
st
choice
Internal PPS (GPS/GLONASS)
Internal PPS (GPS/GLONASS)
2
nd
choice
External PPS (full)
External PPS (full)
3
rd
choice
RF link
(DMR)
Internal ref (full)
4
th
choice
Internal ref (full)
Internal ref (full)