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.

The invention is a datacenter network comprising a plurality of switches. The switches comprise edge switches and aggregation switches associated with sliceable bandwidth variable transceivers (S-BVT). An intermediate passive optical layer is communicatively coupled to the edge switches and the aggregation switches via fiber optic links associated with the S-BVTs. Furthermore, the intermediate passive optical layer is inserted between the edge and aggregation layers in order to combine the signals from each tier. The intermediate passive optical layer comprises a passive fiber coupler that combines the links between switches and each S-BVT receiver receives the signals sent from all S-BVT transmitters connected to the intermediate passive optical layer. The datacenter network is adapted to adjust the local oscillator wavelength of each S-BVT receiver and the wavelength and slice allocation of each S-BVT transmitter, thereby permitting dynamically allocating different resources to each link.

A control circuit, comprising a processor, and a computer readable medium is described. The computer readable medium stores logic that causes the processor to analyze performance data of a link carrying data encoded in a first modulation format with a degradation prediction algorithm to determine a predicted level of degradation of the link. The processor provides first control signals to a transmitter block, and second control signals to a receiver block based upon the predicted level of degradation of the link over time. The first control signals cause the transmitter block to encode data to be transmitted over the link in a second modulation format. The second control signals cause the receiver block to decode data received from the link using the second modulation format. The first and second modulation formats conform to requirements of a same m-quadrature amplitude modulation protocol.

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.

The invention is a datacenter network comprising a plurality of switches. The switches comprise edge switches and aggregation switches associated with sliceable bandwidth variable transceivers (S-BVT). An intermediate passive optical layer is communicatively coupled to the edge switches and the aggregation switches via fiber optic links associated with the S-BVTs. Furthermore, the intermediate passive optical layer is inserted between the edge and aggregation layers in order to combine the signals from each tier. The intermediate passive optical layer comprises a passive fiber coupler that combines the links between switches and each S-BVT receiver receives the signals sent from all S-BVT transmitters connected to the intermediate passive optical layer. The datacenter network is adapted to adjust the local oscillator wavelength of each S-BVT receiver and the wavelength and slice allocation of each S-BVT transmitter, thereby permitting dynamically allocating different resources to each link.

A system and a method of dynamic bandwidth allocation in the passive optical network comprising a SDN controller (112) to switch a first subscriber of the subscriber group (102) from a first passive optical network (PON) port to a second PON port at the OLT (116) when a first bandwidth availability at the first PON port is less than a predefined bandwidth and a second bandwidth availability at the second PON port is more than the predefined bandwidth. In particular, the predefined bandwidth is a required bandwidth by the first subscriber.

Methods for configuring an optical link in which a distribution of transmission data rates and line rates are configured for a predetermined amount of optical bandwidth to maximize transmission capacity. In these methods, a controller of an optical network obtains input parameters that include a signal-to-noise ratio (SNR) for optical signals and an allocated bandwidth of the optical link, further obtains, for each line rate, a mapping of transmission data rates along a frequency spectrum of the allocated bandwidth compatible with the SNR, and generates a channel plan in which a number of traffic modes and a distribution of a plurality of channels in the allocated bandwidth are set to maximize transmission capacity. The plurality of channels is used for transmitting the signals on the optical link. The controller configures at least one optical network element in the optical network to establish the optical link based on the channel plan.

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.

A transmitter block, comprising an optical source, a modulator, a transmission circuit and a control circuit. The optical source has a laser providing an optical signal. The modulator is configured to encode data into the optical signal using an m-quadrature amplitude modulation format. The transmission circuit has circuitry to receive data to be encoded into the optical signal. The transmission circuit has at least one drive circuit supplying driver signals to the modulator to cause the modulator to encode data into the optical signal using the m-quadrature amplitude modulation format. The control circuit supplies control signals to the transmission circuit to cause the transmission circuit to change the m-quadrature amplitude modulation format from a first m-quadrature amplitude modulation format to a second m-quadrature amplitude modulation format based upon predicted degradation of a link to receive modulated data from the modulator.

A status control method, applied to an optical network unit (ONU) or an optical network terminal (ONT) of a passive optical network (PON) includes: receiving a first downlink data frame, where the first downlink data frame includes data of N different rates and indication information, the indication information includes length information of data of each rate in the first downlink data frame, and N≥2; determining length information of first data in the data of the N different rates, where a rate of the first data is higher than a working rate of a clock and data recovery (CDR) module; and generating control information based on the length information of the first data, to control the CDR module to be in a specified state within a period of time corresponding to the length information of the first data.