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:
Sep. 04, 2012
Filed:
Dec. 20, 2010
Tohru Kazawa, Kokubunji, JP;
Kenichi Sakamoto, Kokubunji, JP;
Ryosuke Nishino, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a PON system with WDM, at the time of initial setting, each ONU negotiates with an OLT, and automatically acquires a wavelength which can be used by the ONU. One wavelength for negotiation of assigned wavelength is fixed as a default, and a newly connected ONU first uses the wavelength. The OLTincludes a plurality of light sources for downstream communication. The ONUincludes a wavelength variable filter selectively receiving one of wavelengths of downstream communication, and a wavelength variable light source selectively emitting light of one of plural wavelengths for upstream communication. The ONUuses a transmission wavelength (for example, λu) for negotiation and transmits a wavelength assignment requestto the OLT. The OLTselects a wavelength λuto be assigned from unused wavelengths, and transmits wavelength information to the ONU. The OLTand the ONUcommunicates using the notified wavelengths.