Abstract: 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 (ANI). The pre-selected telephone number is reserved to the pre-paid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation by the pre-paid service provider. This system also allows pre-authorized users to receive and pay for incoming calls as well as purchase additional airtime and monthly access fees with convenient pre-paid cards.

Abstract: 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 (ANI). The pre-selected telephone number is reserved to the pre-paid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation by the pre-paid service provider. This system also allows pre-authorized users to receive and pay for incoming calls as well as purchase additional air time and monthly access fees with convenient pre-paid cards.

Abstract: 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 (ANI). The pre-selected telephone number is reserved to the prepaid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation by the pre-paid service provider. This system also allows pre-authorized users to receive and pay for incoming calls as well as purchase additional air time and monthly access fees with convenient prepaid cards.

Abstract: 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 a pre-selected telephone number and a automated number identification code (ANI). The pre-selected telephone number is reserved to the pre-paid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation by the pre-paid service provider.

Abstract: 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 (ANI). The pre-selected telephone number is reserved to the pre-paid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation by the pre-paid service provider. This system also allows pre-authorized users to receive and pay for incoming calls as well as purchase additional air time and monthly access fees with convenient pre-paid cards.

Abstract: A cellular telecommunications system having a security feature which allows only pre-authorized users no complete cellular telephone calls. The system and method recognizes a cellular radiotelephone's pre-programmed a pre-selected telephone number and a automated number identification code (ANI). The pre-selected telephone number is reserved to the pre-paid cellular telecommunications system. The cellular radiotelephone transmits the ANI and a dialed number identification system code (DNIS) to a cellular switch, which contacts a host computer for call validation the pre-paid service provider.

Abstract: A pulse sample demodulator which has a first sample and hold circuit detects the peak amplitude of the time varying waveform during a short sampling interval. The first sample and hold circuit is triggered by narrow pulses produced by a circuit responsive to the occurrence of each peak in the time varying waveform. A second sample and hold circuit, sampling during an interval not coincident with the first sampling interval, receives the information stored in the first sample and hold circuit; but sampling at a different interval, it does not receive the time varying signal applied to the first sample and hold circuit, which would otherwise appear as ripple in the output of the demodulator.