Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5699417 | Text transmission using DTMF signalling | — | 1997-12-16 |
| 5680447 | Circuit and method for responding to third party calls in a telephone system having call waiting | Robert L. Diamond, Steven L. Landry | 1997-10-21 |