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. 05, 2005
Filed:
Apr. 02, 2002
Farrokh Rashid-farrokhi, Pleasanton, CA (US);
Jalil Kamali, San Jose, CA (US);
Farrokh Rashid-Farrokhi, Pleasanton, CA (US);
Jalil Kamali, San Jose, CA (US);
Centillium Communications, Inc., Fremont, CA (US);
Abstract
SELP techniques that provide an accurate estimate of the length of a transmission medium (e.g., subscriber loop in a DSL system) are disclosed. A probe signal is transmitted over the transmission medium at one or more frequencies. A reflected version of the probe signal is then received. Transmission medium impedance is determined based on the ratio of the reflected version of the probe signal and the transmitted probe signal. An estimate of transmission medium length is determined by comparing its impedance to a plurality of predetermined impedances, each of which is associated with a transmission medium having known length. Thus, the length of the systems transmission medium is identified. The transmission medium impedance can also be used to identify the presence of load coils and short circuits in the transmission medium.