Method for optimizing data transmission in a packet switched wireless data transmission system

The invention relates to a method for optimizing the transfer of information between one or more applications run in a mobile terminal (MT) and a packet-switched network (NW). There are at least two PDP contexts (PDP-PDP) available in the packet-switched network (NW), which have at least partly different data transfer properties, whereby the PDP contexts (PDP-PDP) can provide at least partly different qualities of service for the transfer of information. In this method at least one application connection is established for at least one of said applications, for which application connection a quality of service is specified. In addition, this method is characterized in that at least one data flow is formed of the information to be transferred in the application connection, and one of the PDP contexts (PDP-PDP) is selected for each data flow of the application connection. The method is also characterized in that when the quality of service specified for the application connection changes, it is examined on the basis of the properties of the PDP contexts (PDP-PDP) available in the packet-switched network (NW) which of the PDP contexts (PDP-PDP) is suitable for use by the application connection with the changed quality of service, and the one of the PDP contexts (PDP-PDP), the data transfer properties of which are closest to the changed quality of service is selected for the application connection.