Long-distance synchronous transmission method using optical fiber
AssigneeEkinops
InventorsJean-Luc Pamart, Francois-Xavier Ollivier, Jerome Robillart
Life of this patent
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Abstract
A process for transmitting data on an optical fiber including multiplexing in wavelength signals coming from a plurality of monochrome transmitters, each of which has its own wavelength, and modulating information to be transmitted by a carrier realized per channel, wherein timing (clocking) of each transmitter is controlled by a common clock.
Claims21
A process for transmitting data on an optical fiber comprising:
- wavelength division multiplexing of signals coming from a plurality of monochrome transmitters, each of which has its own wavelength and a slave local clock,
- modulating information to be transmitted by a carrier realized per channel, and
- reformatting a non-return to zero (NRZ) formatted, multiplexed signal to a return to zero (RZ) multiplexed signal or to carrier suppression return to zero (CS-RZ) multiplexed signal with an optical gate comprising an electro-optical modulator and a clock,
- wherein said reformatting is common and simultaneous for all carriers in the multiplexed signal, and
- wherein each slave local clock from each transmitter is controlled by a synchronization circuit comprising a master clock and a phase locked loop (PLL), said master clock controlling the clock of said optical gate and each slave local clock by using said phase locked loop which supplies the synchronization signal for each of the transmitters.
An apparatus for transmitting data on an optical fiber comprising a plurality of monochrome transmitters, each of which has its own transmission wavelength, with each transmitter having a local slave clock;
- a multiplexer for wavelength division multiplexing signals coming from said plurality of monochrome transmitters;
- an optical gate that comprises an electro-optical modulator and a clock and that receives multiplexed non-return to zero (NRZ) formatted signals and that reformats said multiplexed non-return to zero (NRZ) formatted signals to multiplexed return to zero (RZ) signals or to multiplexed carrier suppression return to zero (CS-RZ) signals, said reformatting being common and simultaneous for all carriers in the multiplexed signal;
- and
- a synchronization circuit comprising a master clock controlling the clock of said optical gate and each slave local clock with a phase locked loop which supplies the synchronization signal for each of the transmitters.
A counter-reaction circuit for an apparatus that transmits data on an optical fiber comprising a plurality of monochrome transmitters, each of which has its own transmission wavelength, with each transmitter having a local slave clock;
- an optical gate that comprises an electro-optical modulator and a clock and that receives multiplexed non-return to zero (NRZ) formatted signals and that reformats said multiplexed non-return to zero (NRZ) formatted signals to multiplexed return to zero (RZ) signals or to multiplexed carrier suppression return to zero (CS-RZ) signals;
- and an automatic controller of each transmitter phase comprising a master clock and a phase locked loop (PLL), said master clock controlling the clock of said optical gate and each slave local clock by using said phase locked loop which supplies the synchronization signal for each of the transmitters, wherein said counter-reaction circuit generates a frequency marker for injecting a disturbing spectral signal of each transmitter and further comprises a detector of an output signal from the optical gate which acts on the automatic controller of each transmitter phase to produce a selected spectral transformation of each marker.
Dependencies are inferred from the claim text.