Communication is carried out on the basis of an optimum speech coding scheme that is matched to the speech coding schemes provided by the radio zones, and to the speech coding capabilities of the mobile stations. To achieve this, when a traffic channel is set up between a mobile station and a switch,...http://www.google.com/patents/US5991642?utm_source=gb-gplus-sharePatent US5991642 - Mobile communication system having a control station which selects speech coding schemes for a mobile station
