A cellular telecommunications system having a security feature which allows only pre-authorized users to complete cellular telephone calls. The system and method recognizes a cellular radiotelephone's pre-programmed and pre-selected telephone number and an automated number identification code ...http://www.google.fr/patents/US5854975?utm_source=gb-gplus-shareBrevet US5854975 - Prepaid security cellular telecommunications system
Prepaid security cellular telecommunications system
