Prepaid mobile subscriber identification card and method implemented thereby
US6223026A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 13, 1998 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Feb 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W8/183
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A subscriber identification SIM card for a mobile telephone comprises an advice of charge counter ACM indicating the amount corresponding to the communications carried out with the card. An EEPROM memory in the card includes a file ACMmax, indicating the maximum value of the advice of charge counter, and at least one file EF.sub.FDN indicating at least one telephone number free of charge. The invention compares the amount indicated by the advice of charge counter with the maximum amount of the advice of charge counter and blocks calls according to the result supplied. However, the invention does not block calls intended for one or more predetermined numbers stored on the card. It is thus possible to call, for example, an emergency number or the number of a server to reload the card, in the case of a prepayment card, even after the credit on the card has been used up.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.