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, 1996
Filed:
Sep. 30, 1994
Applicant:
Inventors:
David T Gustafson, Gilbert, AZ (US);
Paul R Kennedy, Mesa, AZ (US);
Shirley H Lee, Chandler, AZ (US);
James B Piket, Gilbert, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04Q / ;
U.S. Cl.
CPC ...
379 59 ; 455 331 ; 380 28 ;
Abstract
A cellular voice privacy arrangement includes a digital privacy unit which is part of each subscriber's fixed equipment. The digital privacy unit includes suitable analog to digital and digital to analog converters. A vocoder, digital signal processor and modem provide the privacy. The identification numbers of each terminal (phone) are exclusive-ORed to form a scramble variable. Vocoder data (voice coded information) is exclusive-ORed with the scramble variable to provided scrambled data for transmission.