A method for data transmission in which data is emitted and/or received by a communication device in a first radio network formed according to a first standard in a first operating mode and data is emitted and/or received in a second radio network formed according to a second standard in a second operating mode. The communication device detects whether it is inside or outside a receiving region of the first radio network. The communication device is operated in the first operating mode if it is inside the receiving region of the first radio network, and the communication device is operated in the second operating mode if it is outside the receiving region of the first radio network. The second standard is an IEEE 802.11p standard and the first standard is a standard of the IEEE 802.11 regulation that is different from the IEEE 802.11p standard. The communication device takes part in an ad-hoc communication in the second operating mode.