Membership
Tour
Register
Log in
Chao-Jan Cheng
Follow
Person
Belleville, CA
People
Overview
Industries
Organizations
People
Information
Impact
Patents Grants
last 30 patents
Information
Patent Grant
Call progress signal monitor and method for telephone systems
Patent number
4,528,664
Issue date
Jul 9, 1985
Northern Telecom Limited
Chao-Jan Cheng
H04 - ELECTRIC COMMUNICATION TECHNIQUE