Granted Patent
Utility
US 5,644,623 · App. 08/594,583
Automated quality assessment system for cellular networks by using DTMF signals
Inventor:
Kenneth G. Gulledge
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Jan 31, 1996
Inventor
Kenneth G. Gulledge
Assignee (at issue)
SAFCO Technologies, Inc.
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.