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:
Feb. 03, 2004
Filed:
Sep. 07, 2001
Chien-Cheng Tung, Fremont, CA (US);
XiaoHua Luo, San Jose, CA (US);
Anthony L. Mazzarini, San Jose, CA (US);
PCTEL,Inx., Chicago, IL (US);
Abstract
A computer having a modem is programmed with software (also called a “on-hook/off-hook detector”) that detects a change in status (e.g., on-hook or off-hook) of a device (e.g., a telephone having a handset) by measuring a change in the signal power of a signal flowing through a telephone line connecting the modem and the device. In particular, the computer programmed with the on-hook/off-hook detector detects a status of a telephone handset by measuring power of a reference signal and measuring power of an instantaneous signal on the connection and comparing these two measurements. The reference signal is a constant signal whose power does not change. Then, the computer programmed with the on-hook/off-hook detector is able to detect whether there has been a change in status of the telephone handset by comparing the detected status with a previous status of the telephone handset. The on-hook/off-hook detector may be executed in a central processing unit (CPU) of a computer or in a digital signal processor (DSP) of a modem.