Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6430279 | Method for the acceptance of calling charges for individual calls as well as telephone network and terminal unit | Rolf Stiefel | 2002-08-06 |
| 6208722 | Method of accepting charges in individual connections and a telephone network and terminal | Rolf Stiefel | 2001-03-27 |
| 6126069 | Chip card, method and system for using and paying for services | Rolf Stiefel, Ulrich Barth | 2000-10-03 |