Abstract: A method for data transport that includes providing a branch terminal between a first and second trunk terminal, wherein a branching unit is present at an intersect between the first and second trunk terminal and the branch terminal. The branching unit includes a reconfigurable add/drop multiplexers (ROADM) at least one attenuator. A signal is sent from a second terminal of the first and second trunk terminal to the branding unit. The signal may include a branch traffic component trunk traffic component. The branching unit includes at least one attenuator for attenuating the trunk traffic component so that the trunk traffic component of the signal cannot be detected at the branch terminal.

Abstract: A method for data transport that includes providing a branch terminal between a first and second trunk terminal, wherein a branching unit is present at an intersect between the first and second trunk terminal and the branch terminal. The branching unit includes a reconfigurable add/drop multiplexers (ROADM) at least one attenuator. A signal is sent from a second terminal of the first and second trunk terminal to the branding unit. The signal may include a branch traffic component trunk traffic component. The branching unit includes at least one attenuator for attenuating the trunk traffic component so that the trunk traffic component of the signal cannot be detected at the branch terminal.

Abstract: An optical communication system includes a digital signal processer coupled to the coherent receiver, said coherent receiver including a nonlinearity compensation module for compensating for nonlinear effects in fiber in the optical link for increasing capacity or transmission distance of the fiber, the nonlinearity compensation module includes a spectral slicing of the signal into bands, computing nonlinear interaction between the bands with parameters opposite to those of the fiber to reverse the non-linear effects in the fiber, and only certain nonlinear interactions between bands are considered thereby reducing complexity of the nonlinearity compensation.

Abstract: Exemplary embodiments include a method and systems for impairment compensation in a communication system. The systems can include an electronic phase conjugation system that receives an incoming optical signal from a first section of a fiber optic link, converts the incoming optical signal to an in-phase electric signal and a quadrature electrical signal, and generates a phase conjugated outgoing optical signal from the in-phase and quadrature electrical signals. The phase conjugated outgoing optical signal compensates for impairment of the fiber in the communication system.

Abstract: An optical communication system includes a digital signal processer coupled to the coherent receiver, said coherent receiver including a nonlinearity compensation module for compensating for nonlinear effects in fiber in the optical link for increasing capacity or transmission distance of the fiber, the nonlinearity compensation module includes a spectral slicing of the signal into bands, computing nonlinear interaction between the bands with parameters opposite to those of the fiber to reverse the non-linear effects in the fiber, and only certain nonlinear interactions between bands are considered thereby reducing complexity of the nonlinearity compensation.

Abstract: Exemplary embodiments include a method and systems for impairment compensation in a communication system. The systems can include an electronic phase conjugation system that receives an incoming optical signal from a first section of a fiber optic link, converts the incoming optical signal to an in-phase electric signal and a quadrature electrical signal, and generates a phase conjugated outgoing optical signal from the in-phase and quadrature electrical signals. The phase conjugated outgoing optical signal compensates for impairment of the fiber in the communication system.