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. 01, 1998
Filed:
Aug. 05, 1996
Kenichi Yoneyama, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A wavelength division multiplexing transmission system includes a light transmitter (20, 20A), a light receiver (30), and an optical transmission path (40) for connecting the light transmitter and the light receiver. The wavelength division multiplexing transmission system also includes a feedback section (80) for connecting to the light receiver and the light transmitter. The light receiver has a power level detecting unit (36) which detects received light power levels of demultiplexed light signals to produce detected light power level signals. An encoding unit (37) encodes the detected light power level signals into an output light power level signal. The feedback section therefore transmits the output light power level signal as a transmission light power level signal from the light receiver to the light transmitter. The light transmitter includes a decoding circuit (27) for decoding the transmission light power level signal into input light power level signals as replicas of the detected light power level signals. A power control unit (24, 24A) is responsive to the input light power level signals to control light sources (22-1 to 22-m) to change controllable original light power levels of original light signals so that the demultiplexed light signals have the received light power levels each of which becomes a predetermined light power level.