A coherent passive optical network includes a downstream transceiver and first and second upstream transceivers in communication with an optical transport medium. The downstream transceiver includes a downstream processor for mapping a downstream data stream to a plurality of sub-bands, and a downstream transmitter for transmitting a downstream optical signal modulated with the plurality of sub-bands. The first upstream transceiver includes a first local oscillator (LO) for tuning a first LO center frequency to a first sub-band of the plurality of sub-bands, and a first downstream receiver for coherently detecting the downstream optical signal within the first sub-band. The second upstream transceiver includes a second downstream receiver configured for coherently detecting the downstream optical signal within a second sub-band of the plurality of sub-bands. The downstream processor dynamically allocates the first and second sub-bands to the first and second transceivers in the time and frequency domains.

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 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 method in a first level aggregation node of a transport network is disclosed. The transport network comprises the first level aggregation node, a second level aggregation node and a Passive Optical Network. T the method comprises receiving, from the second level aggregation node, a plurality of wavelength division multiplexing (WDM) channels having wavelengths in a first spectrum section and generating at least one passive optical channel having a wavelength in a second spectrum section, different to the first spectrum section. The method further comprises combining at least some of the WDM channels received from the second level aggregation node with the at least one passive optical channel, and forwarding the combined WDM channels and passive optical channel to a termination node in the Passive Optical Network. Also disclosed are a method in a termination node of a transport network, a first level aggregation node, a termination node and a computer program.

A data storage system is disclosed that includes a recirculating loop storing data in motion. The data may be carried by a signal via the loop including one or more satellites or other vessels that return, for example by reflection or regeneration, the signals through the loop. The loop may also include a waveguide, for example an optical fiber, or an optical cavity. Signal multiplexing may be used to increase the contained data. The signal may be amplified at each roundtrip and sometimes a portion of the signal may be regenerated.

Technologies for connecting data cables in a data center are disclosed. In the illustrative embodiment, racks of the data center are grouped into different zones based on the distance from the racks in a given zone to a network switch. All of the racks in a given zone are connected to the network switch using data cables of the same length. In some embodiments, certain physical resources such as storage may be placed in racks that are in zones closer to the network switch and therefore use shorter data cables with lower latency. An orchestrator server may, in some embodiments, schedule workloads or create virtual servers based on the different zones and corresponding latency of different physical resources.

A service data processing method and apparatus is disclosed. A data frame is divided into code blocks with smaller granularity, and service data is mapped to a corresponding quantity of code blocks in the data frame based on a service requirement. In addition, the data frame is used to indicate a location of a code block carrying the service data. In one manner, a code block in a payload area of the data frame is divided into a data code block and an overhead code block, and the overhead code block is used to indicate a location of a data code block carrying the service data. In the another manner, an indication field is configured in an overhead area of the data frame to indicate a location of a code block that carries the service data and that is in the payload area of the data frame.

Embodiments are generally directed apparatuses, methods, techniques and so forth to select two or more processing units of the plurality of processing units to process a workload, and configure a circuit switch to link the two or more processing units to process the workload, the two or more processing units each linked to each other via paths of communication and the circuit switch.

An electro-optical (EO) interconnect assembly includes an optical fiber, and first and second EO transceivers. The first and second EO transceivers, which are coupled to respective ends of the optical fiber, are configured to (i) connect to respective first and second network devices, (ii) exchange electrical signals with the first and second network devices, (iii) convert between the electrical signals and optical signals, and exchange the optical signals with one another over the optical fiber, and (iv) conduct with one another, over the optical fiber, a secure challenge-response transaction, and to initiate a responsive action upon failure of the challenge-response transaction.

A transmission device, includes a first wavelength converter configured to convert a second wavelength-multiplexed signal in a first wavelength band to a second wavelength band different from the first wavelength band, and a multiplexer configured to transmit, after the conversion, a wavelength-multiplexed signal obtained through multiplexing of a first wavelength-multiplexed signal in the first wavelength band, a first supervisory control signal light ray that is a control signal for the first wavelength-multiplexed signal, the second wavelength-multiplexed signal in the second wavelength band, and a second supervisory control signal light ray that is a control signal for the second wavelength-multiplexed signal, wherein the first supervisory control signal light ray and the second supervisory control signal light ray each have a wavelength in a wavelength band different from the first wavelength band and the second wavelength band.