A radio that has no direct connection to the IP Dect Master. It needs (either directly or indirectly) access to a base station that provides the channel to the PBX. A repeater increases the systems coverage thus, it does not add to the number of concurrent calls possible.
A repeater needs a sync-source (as any radio does). However, the radio serving as synchronization chain is also used to access the voice channel to the PBX. That is, calls travelling across a repeater will always also be handled by the repeaters sync source.
Note that in our current IP-DECT solution (IP1202), there are no repeaters.