Telecommunication system and method for controlling switching of a user terminal between two networks

The Invention relates to a telecommunications system (1) and a method for controlling a change of a subscriber terminal (9) between a first network (2), which is a cellular mobile radio network , and a second network (3) a so-called WiMAX, Worldwide Interoperability for Microwave Access, radio network is. It is a so-called AAA, Authentication, Authorization and Accounting, server (18) for storing subscriber data of subscriber terminal (9) Available, both for using the first network (2) and the second network (3) is designed. The AAA server (18) is arranged in the telecommunication system (1) that both by the first network (2) and on the part of the second Network (3) in the AAA memory (18) stored subscriber data the subscriber terminal (9) can be accessed. This allows an advantageously uninterrupted and lossless switching between the two networks guaranteed (2, 3) will.