Issued Patents All Time
Showing 51–53 of 53 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5297231 | Digital signal processor interface for computer system | — | 1994-03-22 |
| 5291543 | Cellular telephone real time account administration system | David Freese, Mark J. Nielsen | 1994-03-01 |
| 5148472 | Cellular telephone call administration system | David Freese, Mark J. Nielsen | 1992-09-15 |