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:
Oct. 20, 2009
Filed:
Apr. 12, 2006
Charles Nicholls, Nepean, CA;
Brian Lehman, Nepean, CA;
Gregory Carleton, Ottawa, CA;
Nortel Network Limited, St. Laurent, CA;
Abstract
Systems and methods are disclosed to maintain synchronous communications that uses a global positioning system satellite, a primary communication unit, and a secondary communication unit. The satellite based time reference broadcasts a reference signal to the primary communication unit and the secondary communication unit. The primary communication unit contains a high quality oscillator, and operates a virtual model of a secondary oscillator which is located in the secondary communication unit. The primary and secondary units have synchronous communications with each other by using a global positioning system satellite broadcast as a reference signal. If the secondary unit loses its signal from the global positioning system, the secondary oscillator enters a holdover state and transmits a notification of the holdover state to the primary communications unit. The primary communication unit then transmits time insensitive synchronization data based upon the virtual model through the packet switched network to the secondary communications unit to maintain synchronization.