Telecommunications system
US7551933B2 · kind B2 · utility
2Cited by
36References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2002 |
| Grant date | Jun 23, 2009 |
| Priority date | — |
| Expiry date | Jul 17, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W4/14
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a telecommunications system such as a global mobile telephone network in which each subscriber unit includes a Subscriber Identity Module (SIM card), each SIM card has fixed memory locations, to which data can be addressed over the air. Some of the locations can not be overwritten from the subscriber unit but can be accessed therefrom on the entry of short simple codes, each associated with one of the locations. Further fixed memory locations can be read over the air only when the subscriber enters a personal identification number. Locking control files are used to control read/write access to the locations respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.