Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7333472 | Internet protocol telephony exchange system and call control method thereof | Doo-Yong Yang, Sung Chul HONG, Tae-Hong Ahn | 2008-02-19 |
| 6970720 | Service apparatus for a public and private mobile communication network | Gui-Jung Lee, Doo-Yong Yang | 2005-11-29 |