Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4821256 | Method for monitoring information transmission in connected through four-wire connecting paths, more particularly semipermanently connected through connecting paths in digital time multiplex exchanges | Lothar Schmidt, Gerhard Schaich | 1989-04-11 |