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:
Jun. 30, 2009
Filed:
May. 28, 2004
Hirotaka Nakamura, Narashino, JP;
Junichi Kani, Narashino, JP;
Hiroo Suzuki, Yokohama, JP;
Mitsuhiro Teshima, Yokosuka, JP;
Ukyo Yamaguchi, Yachiyo, JP;
Hidetaka Onishi, Chiba, JP;
Katsumi Iwatsuki, Yokohama, JP;
Hirotaka Nakamura, Narashino, JP;
Junichi Kani, Narashino, JP;
Hiroo Suzuki, Yokohama, JP;
Mitsuhiro Teshima, Yokosuka, JP;
Ukyo Yamaguchi, Yachiyo, JP;
Hidetaka Onishi, Chiba, JP;
Katsumi Iwatsuki, Yokohama, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths λdto λdn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths λd+Δλ to λdn+Δλ, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths λuto λun or wavelengths λu+Δλ to λun+Δλ, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.