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:
Mar. 03, 1992
Filed:
Oct. 24, 1990
Lowell G Atkinson, Indianapolis, IN (US);
Nathan W Engle, Bloomington, IN (US);
Donald L Hornback, Indianapolis, IN (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
At a telephone subscriber's premises, call identification apparatus is used to determine whether incoming calls are intended for a primary telephone station or for a secondary telephone station. The call identification apparatus monitors electrical signals present on a telephone line after the call has been answered by one of the secondary telephone stations in search of a predetermined identificattion signal. In response to the presence of the identification signal from an originating source, the apparatus disconnects all secondary stations from the telephone line, terminates the incoming call by hanging up, and dials a predetermined telephone number. After dialing the predetermined number, an authentication procedure is invoked which requires that the dialed station transmit a security code to the apparatus. If the dialed station incorrectly transmits the security code more than N times, the call is terminated. Illustratively, the primary station comprises a home security system plus the call identification apparatus within a single unit.