Changing terminals during a call

By providing a system comprising four system-parts like a GSM-handset, a DECT-handset, a pc and a switch with a detector for detecting a request change signal originating from or sent to one of said system-parts and by in response to said detecting during a call with a further terminal changing a first system-part into a second system-part whereby during a time-interval both system-parts are involved in said call, the change can be made without a user missing a moment of said call, and the system becomes more user-friendly, especially when said time-interval can be adapted or depends upon the kinds of signals which are exchanged or the kinds of terminals which are used.