Issued Patents 2004
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6731738 | Call tones in communication networks | Chaoxin Qiu, Shannon P. Silvus, Michael J. Gettles, William Douskalis | 2004-05-04 |
| 6728362 | Continuity testing with call tone messaging in communication networks | Chaoxin Qiu, Shannon P. Silvus, Michael J. Gettles, William Douskalis | 2004-04-27 |