The present invention relates to a method for synchronization of real-time signals between core network and air interface in a UMTS Terrestrial Radio Access Network (UTRAN). The synchronization of the signals is needed to make a feasible connection between user equipment and a core network. This is achieved by using the timing knowledge from the protocols that are to be synchronized, and recalculating synchronization parameters for both uplink and downlink transmission. By using frame numbers instead of time of arrivals of frames, the present invention gives better control of timing and avoids long delays, and handles the problems with time alignments.