Wavelength division multiplexed passive optical network
First Claim
1. A method for transmitting and receiving data across a wavelength division passive optical network, comprising the steps of:
- generating a first laser beam having a first wavelength;
generating a second laser beam having a second wavelength;
modulating said first laser beam with first downstream data;
modulating said second laser beam with second downstream data, wherein said modulated second laser beam has a constant intensity;
multiplexing said modulated first laser beam and said modulated second laser beam into a multiplexed laser beam;
transmitting said multiplexed laser beam;
receiving said multiplexed laser beam;
demultiplexing said multiplexed laser beam into a third laser beam having said first wavelength and modulated with said first downstream data and a fourth laser beam having said second wavelength and modulated with said second downstream data;
receiving said third laser beam at a first receiver;
splitting said fourth laser beam into a fifth laser beam and a sixth laser beam;
receiving said fifth laser beam at a second receiver;
modulating said sixth laser beam with upstream data;
transmitting said modulated sixth laser beam; and
receiving said modulated sixth laser beam at a third receiver.
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Accused Products
Abstract
Data is transmitted between a central office and customer premises by a wavelength division multiplex passive optical network. Two laser beams with separate wavelengths are transmitted from the central office to an optical network unit in the customer premises. Both laser beams carry downstream data. One laser beam is intensity modulated by on/off keying. The other laser beam is phase modulated by differential phase shift keying, which maintains a constant optical intensity. The first laser beam is received by a first optical receiver, which demodulates the first downstream data. The second laser beam is split in two. One laser beam is sent to a second optical receiver, which demodulates the second downstream data. The other laser beam is sent to a reflective semiconductor amplifier, which modulates the beam with upstream data and transmits the beam back to a receiver in the central optical system.
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Citations
20 Claims
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1. A method for transmitting and receiving data across a wavelength division passive optical network, comprising the steps of:
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generating a first laser beam having a first wavelength; generating a second laser beam having a second wavelength; modulating said first laser beam with first downstream data; modulating said second laser beam with second downstream data, wherein said modulated second laser beam has a constant intensity; multiplexing said modulated first laser beam and said modulated second laser beam into a multiplexed laser beam; transmitting said multiplexed laser beam; receiving said multiplexed laser beam; demultiplexing said multiplexed laser beam into a third laser beam having said first wavelength and modulated with said first downstream data and a fourth laser beam having said second wavelength and modulated with said second downstream data; receiving said third laser beam at a first receiver; splitting said fourth laser beam into a fifth laser beam and a sixth laser beam; receiving said fifth laser beam at a second receiver; modulating said sixth laser beam with upstream data; transmitting said modulated sixth laser beam; and receiving said modulated sixth laser beam at a third receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A wavelength division multiplex passive optical network comprising,
a central optical system further comprising: -
an optical source adapted to generate a first laser beam having a first wavelength and a second laser beam having a second wavelength; a first optical modulator adapted to modulate said first laser beam with first downstream data; a second optical modulator adapted to modulate said second laser beam with second downstream data, wherein said modulated second laser beam has a constant intensity; a multiplexer adapted to multiplex said modulated first laser beam and said modulated second laser beam into a multiplexed laser beam; and a first receiver adapted to receive an upstream laser beam having said second wavelength, said upstream laser beam modulated with upstream data, wherein said upstream laser beam is based at least in part on said modulated second laser beam; a remote node further comprising; a demultiplexer adapted to receive said multiplexed laser beam;
adapted to demultiplex said multiplexed laser beam into a third laser beam having said first wavelength and modulated with said first downstream data and a fourth laser beam having said second wavelength and modulated with said second downstream data; and
adapted to transmit said third laser beam and said fourth laser beam; andan optical network unit further comprising; a second receiver adapted to receive said third laser beam; a splitter adapted to split said fourth laser beam into a fifth laser beam and a sixth laser beam; a third receiver adapted to receive said fifth laser beam; a third modulator adapted to modulate said sixth laser beam with upstream data; and a reflector adapted to reflect said sixth laser beam modulated with said upstream data to generate said upstream laser beam. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification