Overload balancing is the process to setup a DECT connection (for a call or other administrative or customer purpose) not at the current base station, which is fully loaded with active DECT or media connections, but via a neighbour base station, which has free resources to setup/accept the new DECT connection.
While handover and roaming is possible between base stations of different DECT managers, overload balancing is only possible inside the area of one DECT manager.
Handover and overload balancing can only be provided by synchronised base stations. In some cases, not all base stations connected to one DECT manager can be synchronised for location specific reasons. To organize synchronisation just within a subset of base stations connected to one DECT manager, you can form clusters, within a DECT manager. A DECT manager can offer multiple clusters with base stations synchronised within the cluster, but not synchronised along different clusters.
In multiple DECT manager installations, cross-cluster synchronisation is possible via DECT manager synchronisation