Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7991131 | Control of prepaid balance status notification | William Dale Bartter, Yigang Cai | 2011-08-02 |
| 6683871 | Internet protocol telephony | Chinmei Chen Lee, Milo Orsic | 2004-01-27 |
| 4979206 | Directory assistance systems | Frederick W. Padden | 1990-12-18 |
| 4958341 | Integrated packetized voice and data switching system | Jayant G. Hemmady, William P. Lidinsky, Scott B. Steele, Roanld C. Weddige | 1990-09-18 |
| 4872160 | Integrated packetized voice and data switching system | Jayant G. Hemmady, William P. Lidinsky, Scott B. Steele, Ronald C. Weddige | 1989-10-03 |
| 4371758 | Defective short holding-time trunk identifying method | — | 1983-02-01 |