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:
May. 10, 1994
Filed:
May. 07, 1992
Gordon Bremer, Clearwater, FL (US);
Kurt E Holmquist, Largo, FL (US);
Donald R Laturell, Tampa, FL (US);
Kenneth Martinez, Tampa, FL (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In the public switched telephone network, an originating modem can identify an answering modem, e.g., as to the type of modem it is, by detection of a low-level identification signal sent from the answering modem. The low-level identification signal is hidden within an industry standard 'answer tone,' e.g., a CCITT V.25 answer tone of 2100 Hz. If the low-level identification signal is detected by the originating modem, the industry standard 'handshaking' procedure is terminated and a non-standard handshaking procedure is implemented. If the identification signal is not detected by the originating modem, the industry standard handshaking procedure is simply completed.