The invention relates to a method and a system for automated call diversion of calls intended for a mobile radio device (1) to a second network connection (5). The invention is characterized in that a detection module of a customer premises equipment (2) detects the mobile radio device (1) as soon as it is located in the sphere of influence (14) of an interface (4) between the mobile radio device (1) and the customer premises equipment (2), whereby identification data of the mobile radio device are transmitted via the interface. Based on the identification data of the mobile radio device, call diversion of calls intended for the mobile radio device to the second network device is activated as long as the mobile radio device (1) is located in the sphere of influence (14) of the interface between the mobile radio device (1) and the customer premises equipment (2).