Granted Patent
Utility
US 6,681,111 · App. 09/834,952
Roaming service system for GSM service subscriber in CDMA service area, and method for registering locations and transmitting and receiving signals and short messages using the system
Inventors:
Byung-Ik Ahn, Chan Ho Yun, Yuon-Pil Jeung, Kwang-Wuk Lee, Cheol-Hyun Kang, Seong-Jin Choi
Patented Case
View Patent ↗
Granted: Jan 20, 2004
Filed: Apr 16, 2001
Inventors
Byung-Ik Ahn
Chan Ho Yun
Yuon-Pil Jeung
Kwang-Wuk Lee
Cheol-Hyun Kang
Seong-Jin Choi
Assignee (at issue)
Korea Telecom Freetel Co., Ltd.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.