Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5333180 | Call message delivery system and method utilizing caller-selected system announcements | Percy B. Brown, Nga V. Chau, Tung-Hai Hsiao, Georg K. Karawas, Richard E. LeCronier +2 more | 1994-07-26 |
| 4972461 | Call message delivery system and method | Percy B. Brown, Nga V. Chau, Tung-Hai Hsiao, Georg K. Karawas, Richard E. LeCronier +2 more | 1990-11-20 |
| 4939771 | Attendant-controlled call message delivery system and method | Percy B. Brown, Nga V. Chau, A. R. Gore, Tung-Hai Hsiao, Georg K. Karawas +4 more | 1990-07-03 |