Handover between mobile communication networks

The invention relates to a method for handing over a connection between a first (NW1) and a second mobile communication network (NW2) in a wireless terminal (MS1). In the method, at least one data transmission connection is established for the purpose of transmitting information between the wireless terminal (MS1) and one said mobile communication network (NW1, NW2). In the first mobile communication network, the connection type is either connection-oriented (HSCSD) or connectionless (GPRS), and in the second mobile communication network (NW1, NW2), at least two traffic classes with different transmission features are defined and one of them is selected for the data transmission connection of the second mobile communication network (NW1, NW2). In the method, it is also examined what active data transmission connections the wireless terminal (MS1) has to the mobile communication network (NW1, NW2) handing over the connection. When handing over a connection from the first mobile communication network (NW1) to the second mobile communication network (NW2), the connection type of each active data transmission connection is examined, the traffic class corresponding to each active data transmission connection type is defined in the second mobile communication network (NW2), and a connection according to the defined traffic class is established for each data transmission connection in the second mobile communication network (NW2). When handing over a connection from the second mobile communication network (NW2) to the first communication network (NW1) the traffic class of each active data transmission connection is examined, the connection type corresponding to each active data transmission traffic class is defined in the first mobile communication network (NW1), and a connection according to the defined connection type is defined for each data transmission connection in the first mobile communication network (NW1).