A system, wherein a mobile station can switch to an IP access protocol, whereupon data transmitted between the mobile station and a mobile services switching centre change over from a base station system, reached using radio communication, to being transmitted through an interworking unit (40) coupled...http://www.google.de/patents/US7502626?utm_source=gb-gplus-sharePatent US7502626 - System and device for accessing of a mobile communication network
