Self-healing passive optical network
First Claim
1. A passive optical network comprising:
- a central office;
a plurality of optical network units, each of the optical network unit including;
a first upstream light source for outputting an upstream optical signal;
a circulator having a first to a third port, for outputting the upstream optical signal input to the first port to the second port connected to a distribution optical fiber, for outputting the returning upstream optical signal input to the second port to the third port;
an optical receiver for receiving the upstream optical signal output from the third port of the circulator, and converting the received upstream optical signal into an electrical signal to be output;
a second upstream light source for outputting an upstream optical signal; and
a first switch for connecting the first upstream light source to the circulator in a normal state, for connecting the circulator to the second upstream light source when an abnormality has occurred at the first upstream light source;
a remote node connected to the central office through a main optical fiber, the remote node transmitting one portion of power of the upstream optical signal, which has input from each of the optical network units, to the central office, and returning a remaining portion of the power of the upstream optical signal to the optical network unit; and
a plurality of distribution optical fibers connecting the plurality of optical network units to the remote node,wherein each of the optical network units transmitting the upstream optical signal to the remote node through a corresponding distribution optical fiber, and detecting abnormality occurrence from a state of the upstream optical signal returning from the remote node.
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Accused Products
Abstract
A self-healing passive optical network is disclosed. The network includes a central office and a remote node connected to the central office through a main optical fiber. The remote node transmits one portion of power of the upstream optical signal, which has been input from each of the optical network units, to the central office, and returning a remaining portion of the power of the upstream optical signal to the optical network unit. The network also includes a plurality of optical network units connected to the remote node through a plurality of distribution optical fibers. Each of the optical network units transmits an upstream optical signal to the remote node through the directly connected distribution optical fiber, and detects abnormality occurrences from a state of the upstream optical signal returning from the remote node.
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Citations
11 Claims
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1. A passive optical network comprising:
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a central office; a plurality of optical network units, each of the optical network unit including;
a first upstream light source for outputting an upstream optical signal;
a circulator having a first to a third port, for outputting the upstream optical signal input to the first port to the second port connected to a distribution optical fiber, for outputting the returning upstream optical signal input to the second port to the third port;
an optical receiver for receiving the upstream optical signal output from the third port of the circulator, and converting the received upstream optical signal into an electrical signal to be output;
a second upstream light source for outputting an upstream optical signal; and
a first switch for connecting the first upstream light source to the circulator in a normal state, for connecting the circulator to the second upstream light source when an abnormality has occurred at the first upstream light source;a remote node connected to the central office through a main optical fiber, the remote node transmitting one portion of power of the upstream optical signal, which has input from each of the optical network units, to the central office, and returning a remaining portion of the power of the upstream optical signal to the optical network unit; and a plurality of distribution optical fibers connecting the plurality of optical network units to the remote node, wherein each of the optical network units transmitting the upstream optical signal to the remote node through a corresponding distribution optical fiber, and detecting abnormality occurrence from a state of the upstream optical signal returning from the remote node. - View Dependent Claims (2, 3)
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4. A passive optical network comprising:
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a central office; a remote node including a wavelength division multiplexer and a plurality of optical distributors, the wavelength division multiplexer having a multiplexing port connected to the central office through a main optical fiber and a plurality of demultiplexing ports connected to a plurality of distribution optical fibers, the wavelength division multiplexer multiplexing a plurality of upstream optical signals input to the demultiplexing ports to output the multiplexed signal to the multiplexing port, and the optical distributors disposed on the distribution optical fibers, having multiple pairs of the optical distributors, passing input upstream optical signals when the upstream optical signals have specific wavelengths assigned to the optical distributors, and transmitting the upstream optical signals to other optical distributors when the upstream optical signals do not have specific wavelengths assigned to the optical distributors; and a plurality of optical network units connected to the distribution optical fibers, having multiple pairs of the optical network units, and having a first upstream light source for outputting an upstream optical signal and a first optical switch, the first optical switch transmitting the upstream optical signal to a directly connected distribution optical fiber in a normal state, and the first optical switch transmitting the upstream optical signal through a distribution optical fiber connected to a corresponding optical network unit when an abnormality occurs at the distribution optical fiber. - View Dependent Claims (5, 6, 7, 8)
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9. An optical network unit for an optical network comprising:
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an interface for a distribution optical fiber, an upstream light source for outputting an upstream optical signal; and a controller, a circulator having a first to a third port, for outputting the upstream optical signal input to the first port to the second port connected to the distribution optical fiber, for outputting the returning upstream optical signal input to the second port to the third port; an optical receiver for receiving the upstream optical signal output from the third port of the circulator, and converting the received upstream optical signal into an electrical signal to be output; second upstream light source for outputting an upstream optical signal; a first switch for connecting the first upstream light source to the circulator in a normal state, for connecting the circulator to the second upstream light source when an abnormality has occurred at the first upstream light source; a beam splitter for splitting the portion of power of the upstream optical signal; and a second switch for providing the optical receiver with one portion of the split power in order to check whether or not an abnormality occurs at the first upstream light source, wherein the optical network unit transmits the upstream optical signal via the interface and receives a return signal based upon the upstream optical signal, the controller being arranged to detect an abnormality occurrence from a state of the return signal. - View Dependent Claims (10, 11)
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Specification