Systems and methods for identifying a pair of nodes of a plurality of nodes of a virtual optical network (VON); identifying i) an optical route between the pair of nodes and ii) a desired availability of the optical route; determining a probability density function (PDF) of a signal-to-noise ratio (SNR) of a signal of the optical route; determining a SNR threshold such that an integration of the PDF of the SNR of the signal above the SNR threshold corresponds to the desired availability of the optical route; determining a plurality of spectral efficiencies that corresponds to the SNR threshold, each spectral efficiency of the plurality of spectral efficiencies associated with a respective modulation format of a plurality of modulation formats; and identifying a particular modulation format of the plurality of modulation formats that corresponds to a maximum spectral efficiency of the plurality of spectral efficiencies.

In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for dividing an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, and setting a plurality of optical frequency regions; and an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions.

Embodiments of the present invention provide an optical network unit ONU registration method, apparatus, and system, to resolve a problem in the prior art that a registration process is cumbersome. The method includes: receiving an uplink optical signal, where the uplink optical signal carries ONU authentication information; sending the optical signal to a corresponding MAC module separately according to a wavelength of uplink light; extracting, by the MAC module, the ONU authentication information, and sending the extracted ONU authentication information to a processor; and receiving, by the processor, the ONU authentication information, and determining whether the ONU authentication information is consistent with ONU authentication information configured by an OLT, where if the ONU authentication information is consistent with the ONU authentication information configured by the OLT, an ONU is registered successfully.

A design method for a quasi-coarse wavelength division multiplexing optical network is provided. A spectral grid of an optical channel has a pre-set fixed bandwidth, and the pre-set fixed bandwidth is at least 200 GHz. A modulation format of the optical channel is adaptively selected according to actual rate requirements and physical channel conditions, thus selecting an optimal modulation format achieve a tradeoff between the total cost of IP router ports and regenerators and the served number of traffic demand. The above technical solution effectively resolves the technical problems in the prior art of high construction costs and low spectral efficiency of elastic optical networks.

An optical signal monitor, including: a storage that holds a threshold value set for each of determination areas having a bandwidth set in accordance with an average grid of dummy light; a measurement section that sequentially measures an optical intensity of an inputted wavelength-multiplexed optical signal with respect to each of measurement areas obtained by dividing the determination area into areas with a bandwidth sufficiently smaller than a grid width of a monitoring-target optical signal composing the wavelength-multiplexed optical signal, and output measured values; and a section that determines that dummy light corresponding to the determination area needs introducing if each of measured values in the determination area is smaller than a threshold value, and, determines that dummy light corresponding to the determination area does not need introducing if at least one of the measured values in the determination area is equal to or larger than the threshold value.

An optical transmitter module includes: a low-speed light emitting device that emits an optical signal at a first given wavelength; a high-speed light emitting device that emits an optical signal at a second given wavelength; and a first filter that transmits one and reflect the other of the first- and second-given-wavelength optical signals to send the optical signal to an optical receiver module. The optical receiver module includes: a low-speed light receiving device that receives the optical signal at the first given wavelength; a high-speed light receiving device that receives the optical signal at the second given wavelength; and a second filter that transmits one and reflects the other of the first- and second-given-wavelength optical signals to send the first-given-wavelength optical signal to the low-speed light receiving device, and the second-given-wavelength optical signal to the high-speed light receiving device.

In one embodiment, a method for passive optical network (PON) communication includes broadcasting, by an optical line terminal (OLT), a first message including a first start time of a first quiet window and a first allocation identification number (Alloc-ID), where the first Alloc-ID indicates a first supported upstream line rate associated with the first quiet window. The method also includes receiving, by the OLT from a first optical network unit (ONU) during the first quiet window, a first serial number response, wherein a first transmitting upstream line rate of the first ONU is equal to the first supported upstream line rate.

Consistent with the present disclosure, an optical communication system is provided in which data is carried over optical signals including subcarriers. The subcarriers may be modulated with the standard modulation formats noted above, but the modulation formats are selectively assigned to the subcarriers, such that some subcarriers are modulated with different standard modulation formats than others. As used herein, a standard modulation format is one of BPSK, and n-QAM, where n is an integer greater than one. Such n-QAM modulation formats include of 3-QAM, 4-QAM (QPSK), 8-QAM, 16-QAM, 64-QAM, 128-QAM, and 256-QAM. By selecting the number of subcarriers and the types of modulation formats employed, an optical signal with an effective SE that is between that of the standard modulation formats can be generated for transmission over a distances that more closely matches the link distance. Such custom or intermediate SE signals can be tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links. As a result, more efficient data transmission can be achieved.

A computer implemented method of configuring an optical path includes selecting with one or more processors a wavelength for the optical path, generating with one or more processors, a first request for a first type of node in the optical path, generating with one or more processors a second request for a second type of node in the optical path, the second type of node having different data plane capabilities than the first type of node, wherein the first and second requests are generated as a function of a joint configuration model accommodating both types of nodes, and sending the first request from the one or more processors to the first type of node and the second request to the second type of node to configure the optical path.

One embodiment of the present invention provides an optical transceiver. The transceiver can include a transmitter and a receiver. Each of the transmitter and receiver can include a plurality of space-division multiplexing (SDM) channels configured to transmit or receive spatially separated optical signals. A respective SDM channel can include a plurality of wavelength channels and an optical wavelength multiplexer or demultiplexer configured to multiplex or demultiplex optical signals to or from the plurality of wavelength channels.