Patent ID: 6639703
Filing Date: 2003-10-28
Classification: H04B,H04J

Abstract:
A receiver transponder used in an optical add/drop node, comprises:a plurality of optoelectric converters configured to convert received optical signals to electric signals, a first one of the optoelectric converters being connected to an optical fiber carrying light signals from a first direction, a second one of the optoelectric converters being connected to another optical fiber carrying light signals from a second direction opposite the first direction; an electronic switch being coupled to the plurality of optoelectric converters and having a plurality of input terminals, a signal output terminal, and a control input terminal, each of the first and second optoelectric converters having output terminals connected to the input terminals of the electronic switch, the control input terminal receiving a signal to control the electronic switch to select one of the input terminals from which one of the electric signals is switched to the signal output terminal; and a reshaping circuit connected to the output terminal of the electronic switch for reshaping the signal output from the electronic switch; wherein the reshaping circuit is configured to filter the signal output from the electronic switch from a supervisory channel.