Abstract: The present invention relates to a method for improving service level selection in a communication network system, in which an interworking function (IWF) is arranged between a user terminal (MS) and the network(s) in question, and wherein High Speed Circuit Data (HSCD) are specified, and for the purpose of making this selection in a more expedient manner and allow the user to allocate bandwidth in a more flexible and dynamic way, it is according to the present invention suggested that the interworking function (IWF) is used for signalling to the user terminal (MS) when a change in level selection may be useful.

Abstract: A payload data connection arrangement within a core network in a cellular mobile communication network reduces the number of transcodings and reduces the number of transmission devices that are linked in by a more flexible handling of interworking functions. This is achieved by comparing possible payload connections between a core network and access networks for both legs of a call. Based on the result of the comparison, only those devices are linked in that are technically necessary. Methods and devices that are used to set-up data connections with said benefits are illustrated and described.