A mobile terminal device determines whether it is located in the local radio area of the network or in another radio area and the determined radio area is indicated to an application of the network. The application is used to control a communication request addressed to the mobile terminal device. Communication requests coming in on the network can be directly switched to the local radio area using the application or can be directly forwarded to the mobile radio address in the mobile radio network of which the mobile terminal device is located, thereby avoiding or substantially reducing roaming or forwarding of communication requests from the local radio area to another radio area and thereby achieving an economical operation of mobile telephone terminal devices with local radio area.