Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4875038 | Frequency division multiplexed acknowledge back paging system | Kazimierz Siwiak, Francis R. Steel | 1989-10-17 |
| 4868560 | Voice paging system providing deferred paging capability | Gary A. Oliwa | 1989-09-19 |
| 4825193 | Acknowledge back pager with adaptive variable transmitter output power | Kazimierz Siwiak, Francis R. Steel | 1989-04-25 |