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. 10, 2007
Filed:
Dec. 22, 2003
Jun-ichi Kani, Yokohama, JP;
Katsumi Iwatsuki, Yokohama, JP;
Jun-ichi Kani, Yokohama, JP;
Katsumi Iwatsuki, Yokohama, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In an optical wavelength division multiplexed access system, a center unit (OSU) and n optical network units (ONUs) are connected together via a wavelength splitter and optical fiber transmission lines, and downstream optical signals from the OSU to the ONUs and upstream optical signals from the ONUs to the OSU are transmitted in both directions, the wavelength spacing Δλd (optical frequency spacing Δfd) of the downstream optical signals is set to twice or more the wavelength spacing Δλu (optical frequency spacing Δfu) of the upstream optical signals, each ONU transmits an upstream optical signal whose optical spectral width is twice or more Δλu (Δfu), and the wavelength splitter spectrum slices the upstream signals transmitted from the ONUs into wavelengths (optical frequencies) whose optical spectral widths are mutually different within Δλu (Δfu), and wavelength-division multiplexes them and transmits to the OSU.