Avaya DECT R4 Installation And Administration Manual page 32

Avaya IP-DECT System Description
Air synchronization
IP-DECT base stations use the DECT air interface to synchronize to each other. This makes it
possible to fulfill the Common Alerting Protocol (CAP) standard and to use the existing
portables.
Configure one IPBS as a synchronization master. From this sync master all other IP base
stations adjust their internal crystal oscillator to have the same frequency drift as the master. All
base stations need not be within coverage of the master base, a IPBS running in slave mode
can synchronize to another IPBS in slave mode.
You need not configure which IPBS to synchronize to. This is handled automatically by
introducing a proprietary message called "air sync hop" that is sent from the IPBSs.
Figure 8: Air and speech sync radius.
-68 dBm
-80 dBm
A single IPBS failure may spread to other IPBSs. Therefore, for critical systems you need to
install the IPBSs within coverage of at least two alternative IPBSs to sync with.
It is also possible to configure one backup sync master in case of failure of the sync master.
Speech radius: The radius of the circle (circular radiation patterns of the IPBS antennas are
assumed), around a particular IPBS, in which portable parts can communicate with that IPBS.
See figure 8: Air and speech sync radius.
Note:
The signal strenth must be at least -68 dBm for good speech quality. The -68 dBm
Note:
circles must overlap to ensure seamless handover between 2 base stations (The
handset should receive the next base station with -62 dBm at the -68 dBm circle
of the first base station).
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Avaya DECT R4 - System Description
Air Sync Coverage
Speech Coverage
Figure 3.
-80 dBm
-68 dBm
02/2016