Membership
Tour
Register
Log in
Kenneth D. Frantzen
Follow
Person
Winfield, IL, US
People
Overview
Industries
Organizations
People
Information
Impact
Patents Grants
last 30 patents
Information
Patent Grant
Toll fraud control
Patent number
4,811,378
Issue date
Mar 7, 1989
American Telephone and Telegraph Company, AT&T Bell Laboratories
Richard L. Else
H04 - ELECTRIC COMMUNICATION TECHNIQUE