AASTRA SIP-DECT (Release 2.1)- OM System Manual - Installation, Administration and Maintenance EN - Manual (Page 123)

SIP – DECT OM System Manual Release 2.1 7 Configuration und Administration Aspects
depl-1230/1.3 Page: 123 (196)
As the PP user moves into the next RFP zone of coverage, the PP detects that the RFP has
a better signal strength. Again the media stream from the SIP phone cannot move to the
secondary RFP, so the primary RFP uses the LAN to direct the voice to the new secondary
RFP.
7.2 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. The first RFP to complete startup will
transmit a signal on the air for the other RFPs to synchronize from. If an RFP gets in sync,
then it will transmit a signal on the air and will be the sync source for the next RFP. Only
RFPs which can receive a synchronization signal will become 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.