The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 09, 1991
Filed:
Jun. 28, 1989
Applicant:
Inventor:
Charles A Baldi, Loudon County, VA (US);
Assignee:
International Telesystems Corp., Herndon, VA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01L / ;
U.S. Cl.
CPC ...
3645135 ; 381 46 ; 379 34 ;
Abstract
This telephone solicitation system provides automatic dialing and call-progress detection. Audio signals on the line are analyzed to recognize network operation tones, noise bursts, and speech. A 'sample' is the total number of crossings during a 25 millisecond period. A 'window' is a sequence of eight samples analyzed for spectral and time patterns.