Handover and interworking in radio system

Abstract

The invention relates to radio systems and particularly to a handover and interworking between two radio systems utilizing different link protocols. According to the invention, in a handover the radio link protocol of the old (handover source) radio system is also retained after the handover in the new (target) radio system. The 'old' radio link protocol is merely adapted to a physical traffic channel of the new radio system. One manner of implementing the adaptation to the traffic channel is to set up the radio link protocol of the 'new' radio system between the mobile station and the interworking function and to transmit the radio link protocol frames of the “old” radio system within the radio link protocol of the new radio system. Due to this simple but effective arrangement, possibly ongoing sequences of selective retransmissions and retransmission requests of the old radio link protocol are not interrupted or disturbed, wherefore it is also possible to avoid the manipulation of buffer synchronization which might possibly lead to retransmission complications and loss or doubling of data as a result of the handover.