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:
Jun. 09, 1987
Filed:
Mar. 20, 1984
Charles H Hustig, Hudson, WI (US);
Jeffrey L Ward, Hudson, WI (US);
Donald W Moses, Minneapolis, MN (US);
Robert S Bradford, Woodland Hills, CA (US);
Applied Spectrum Technologies, Inc., Minneapolis, MN (US);
Abstract
A high speed and relatively error free communications system is disclosed which enables the high speed transmission of data at a 19.2 kilobit per second rate. The data is transmitted over the same communications medium as voice transmissions, the data transmission being virtually imperceptible to the user of the analog telephone system. Connection to and from the data terminals is made through an RS232C interface. A spread spectrum technique is utilized which 'whitens' the signals of the data terminal regardless of whether the terminal is idle, transmitting or receiving data. Virtual error free transmission is achieved by interleaving bits, so that noise does not destroy the data, and by error detection and correction techniques which assure that the data, as received, is identical to that transmitted. By using a variable pseudo random code, privacy of data communications are enhanced and cross-talk is substantially eliminated. The resulting system is one that can use a single twisted pair wire for transmission and is capable of transmitting data at a high rate of speed while leaving the analog voice transmission resident and unaffected on the line.