Optical network unit implemented with low-cost line interface cards
First Claim
1. An optical network unit for an optical access network, comprising:
- an optical receiver connected through a single-mode fiber optic link to a central office for receiving therefrom an ATM (asynchronous transfer mode) cells having a rate conforming to the transmission capacity of the single-mode fiber optic link;
a plurality of line interface cards associated respectively with drop lines connected to subscribers, each of the line interface cards comprising;
an address filter having a uniquely assigned address for extracting, from the output of said optical receiver, ATM cells having a virtual channel identifier corresponding to the assigned address;
first converting means for converting the extracted ATM cells to a signal having a rate conforming to the transmission capacity of the associated drop line;
second converting means for converting a signal from said drop line to ATM cells having a rate conforming to the transmission capacity of said single-mode fiber optic link;
interface means for interfacing the first and second converting means with said associated drop line; and
a buffer for storing the ATM cells from the second converting means;
a multiplexer for multiplexing ATM cells stored in the buffers of said line interface cards and producing an ATM cell stream; and
an optical transmitter for transmitting the ATM cell stream through said single-mode fiber optic link to said central office.
1 Assignment
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Accused Products
Abstract
In an optical network unit of an optical access network, an optical receiver is connected through a single-mode fiber optic link to a central office for receiving therefrom an ATM cells having a rate in conformance to the transmission capacity of the link. Multiple line interface cards are associated respectively with subscriber drop lines. Each of the line interface cards comprises an address filter having a uniquely assigned address for extracting, from the output of the optical receiver, ATM cells having a VCI corresponding to the assigned address, a first speed converter for converting the extracted ATM cells to a signal having a rate conforming to the transmission capacity of the associated drop line, a second converter for converting a signal from the drop line to ATM cells having a rate conforming to the transmission capacity of the single-mode fiber optic link, interface for interfacing the first and second converters with the drop line, and a buffer for storing the ATM cells from the second converter. ATM cells stored in the buffers of the line interface cards are multiplexed into an ATM cell stream and transmitted through the single-mode fiber optic link to the central office.
53 Citations
7 Claims
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1. An optical network unit for an optical access network, comprising:
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an optical receiver connected through a single-mode fiber optic link to a central office for receiving therefrom an ATM (asynchronous transfer mode) cells having a rate conforming to the transmission capacity of the single-mode fiber optic link; a plurality of line interface cards associated respectively with drop lines connected to subscribers, each of the line interface cards comprising; an address filter having a uniquely assigned address for extracting, from the output of said optical receiver, ATM cells having a virtual channel identifier corresponding to the assigned address; first converting means for converting the extracted ATM cells to a signal having a rate conforming to the transmission capacity of the associated drop line; second converting means for converting a signal from said drop line to ATM cells having a rate conforming to the transmission capacity of said single-mode fiber optic link; interface means for interfacing the first and second converting means with said associated drop line; and a buffer for storing the ATM cells from the second converting means; a multiplexer for multiplexing ATM cells stored in the buffers of said line interface cards and producing an ATM cell stream; and an optical transmitter for transmitting the ATM cell stream through said single-mode fiber optic link to said central office. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification