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.

Date of Patent:
Jul. 22, 2008

Filed:

Jul. 15, 2005
Applicants:

Denis Downey, Cork, IE;

Alex Volkov, Cork, IE;

Michael Hamington, Cork, IE;

Frank O'keeffe, Cork, IE;

Yury Kharkunou, Cork, IE;

Inventors:

Denis Downey, Cork, IE;

Alex Volkov, Cork, IE;

Michael Hamington, Cork, IE;

Frank O'Keeffe, Cork, IE;

Yury Kharkunou, Cork, IE;

Assignee:

Arris International, Inc., Suwanee, GA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04J 3/06 (2006.01); H04N 7/16 (2006.01);
U.S. Cl.
CPC ...
Abstract

The clocks of one or more edgeQAM devices are synchronized with a master clock at the remotely located CMTS. A master clock signal may be transmitted via a dedicated gigabit Ethernet link. Alternatively, master clock information contained in a time synchronization message may be transmitted for use in adjusting local oscillators that drive local clocks at respective edgeQAM devices. In another embodiment, the downstream sample rate to particular edgeQAM devices may be sampled and used to lock a local clock at respective canary modems dedicated to each edgeQAM device. A canary modem's clock is compared to the master clock, and a resulting phase error is communicated to the respective edgeQAM device for use in adjusting its local clock. Or, TDMA upstream ranging burst average trends are used to estimate edgeQAM clock error. Each respective edgeQAM uses this error to adjust its clock.


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