A method pertaining to a telecommunications system for handling supplementary services for a mobile unit. The system includes a public land mobile network to which the mobile unit has subscribed. The mobile telephone network includes a main switch or gateway switching center to which there...http://www.google.com/patents/US5781858?utm_source=gb-gplus-sharePatent US5781858 - Method and arrangement for handling and inspecting supplemetary services intended for a mobile telephone unit 
