Method and structure for detecting a customer premises equipment alerting signal
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jan 19, 1999
Issued Date -
N/A
app pub date -
Aug 29, 1996
filing date -
Feb 13, 1995
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A method and device for detecting a customer premises equipment alerting signal (CAS) tone in a telephone system which has both caller identification and call waiting. The present invention distinguishes between valid CAS tones transmitted by the telephone company central office and invalid CAS tones which are caused by music or a human voice. The present invention samples detected tone during a plurality of sample periods. The change of frequency, as well as the direction of frequency change, between successive sample periods is calculated. The number of transitions in the direction of frequency change are counted and used to determine whether the detected tone corresponds to a valid CAS tone or an invalid CAS tone.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully