A method for providing a data connection between a mobile terminal and a first core network of a first cellular network, the mobile terminal comprising a processing unit, a memory unit, and a first authentication module and a second authentication module, wherein the first authentication module comprises a first user profile with first authentication information for access to the first cellular network, wherein the second authentication module comprises a second user profile with second authentication information for access to a second cellular network, wherein the process comprises the following steps: Establishing the data connection using an access network of the second cellular network using the second authentication information, Transmission of at least parts of the first authentication information to the first core network via the access network of the second cellular network, Authentication of the first user profile at the first core network, in particular at the first core network of the first cellular network, using the at least parts of the first authentication information; Providing the data connection using the transmitted first authentication information; wherein the mobile terminal is set up to communicate via a cellular mobile radio channel and via a WiFi connection, characterized in that the establishment of the connection via the access network is initiated in addition to the WiFi connection to increase the bandwidth. wherein the first authentication module comprises a first user profile with first authentication information for access to the first cellular network, wherein the second authentication module comprises a second user profile with second authentication information for access to a second cellular network, wherein the process comprises the following steps: Establishing the data connection using an access network of the second cellular network using the second authentication information, Transmission of at least parts of the first authentication information to the first core network via the access network of the second cellular network, Authentication of the first user profile at the first core network, in particular at the first core network of the first cellular network, using the at least parts of the first authentication information; Providing the data connection using the transmitted first authentication information; wherein the mobile terminal is set up to communicate via a cellular mobile radio channel and via a WiFi connection, characterized in that the establishment of the connection via the access network is initiated in addition to the WiFi connection to increase the bandwidth. Establishing the data connection using an access network of the second cellular network using the second authentication information, Transmission of at least parts of the first authentication information to the first core network via the access network of the second cellular network, Authentication of the first user profile at the first core network, in particular at the first core network of the first cellular network, using the at least parts of the first authentication information; Providing the data connection using the transmitted first authentication information; wherein the mobile terminal is set up to communicate via a cellular mobile radio channel and via a WiFi connection, characterized in that the establishment of the connection via the access network is initiated in addition to the WiFi connection to increase the bandwidth.