A method is provided for operating a communications device (UE) in a mobile communications network including one or more network elements (eNodeB, MME; CIoT-BS, C-SGN), which are especially for providing a wireless access interface for the communications device (UE), especially according to LTE or CIoT. The communications device (UE), during an attach procedure, transmits an information element regarding radio related capabilities of the communications device (UE) and/or regarding core network capabilities of the communications device (UE) to a network element (eNodeB; CIoT-BS) of the mobile communications network providing a wireless access interface for the communications device (UE). A method is also provided for operating a communications device (UE) in a mobile communications network including one or more network elements (eNodeB, MME; CIoT-BS, C-SGN). A mobile communications system is also provided to perform the methods.