User Manual

OpenMobility SIP Installation, Administration and Maintenance
Aastra DeTeWe Doc-ID: pm-0504 28.11.2006 Page: 14 (52)
2.5 RFP Synchronization
To guarantee a seamless handover if a caller moves from one RFP zone of
coverage to another RFP zone of coverage, an accurate synchronization of
the RFPs is necessary.
The RFPs are synchronized over the air interface. During start up one RFP
will be the first, which transmits a signal on the air. The other RFPs only
receive the signal until their are synchronous. If a RFP gets in sync then it will
transmit a signal on the air and will be the sync source for the next RFPs.
Only RFPs which can receive each other will be synchronized.
For the RFP to sync to another RFP the signal strength cannot drop below
–70 dBm. You must consider this requirement during the site survey.
The first active RFP will be chosen by the ADMM.
R 111 R 110 R 109 R 108
R 106
R 101 R 102 R 103 R 104 R 105
R 107
Unsynchronized RFP,
which does not receive a
signal from another RFP
Unsynchronized RFP,
which receives a signal
from another RFP and
tries to get synchronized
Synchronized RFP,
which receives and
transmits a signal on the
air interface
As long as a RFP is not in sync, no calls can be established using this RFP.
If a RFP loses the synchronization the RFP does not accept new calls (“busy
bit”). There is a delay of maximum 3 minutes until the active calls on this RFP
are finished. Then it tries to get synchronized again.
An IP DECT installation is more reliable if a RFP can receive the signal from
more than only one RFP, because the other signals are also used for
synchronization.