Accommodation design for wavelength and sub-λ paths in a communication network is performed. If sub-λ path accommodation is possible according to search for a wavelength path present in a single-hop logical route, the accommodation in the wavelength path is executed. If sub-λ path accommodation is possible according to search for a wavelength path present in a multi-hop logical route, a logical route is selected based on the wavelength path and the sub-λ path is accommodated in the wavelength path. Additionally, each physical route suitable for the sub-λ path accommodation is searched for. If the route can accommodate a wavelength path set in a single-hop logical route by available wavelength allocation, the sub-λ path is accommodated in the wavelength path. Furthermore, routes in consideration of overlapping of nodes, pipelines, and links and operation rate are selected based on information about the start and end nodes of each of redundant routes.

According to an example aspect of the present invention, there is provided an apparatus comprising a first part (110) which comprises a first light-based communication port (114) and a network interface (112), a second part (120) which comprises a non-volatile memory (122) and a second light-based communication port (124), and wherein the apparatus is configured to deactivate at least one of the first light-based communication port (114) and the second light-based communication port (124) responsive to determining that a read or write operation in the non-volatile memory (122) is complete.

The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate respective subcarrier frequencies which represent subchannels of an ITU channel to which client signals can be mapped. In one embodiment, subchannels are polarization interleaved to reduce crosstalk. In another embodiment, polarization multiplexing is used to increase the spectral density. Client circuits can be divided and combined with one another before being mapped, independent of one another, to individual subchannels within and across ITU channels. A crosspoint switch can be used to control the client to subchannel mapping, thereby enabling subchannel protection switching and hitless wavelength switching. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of the client circuits mapped to these subchannels across the nodes of a WDM network.

A method for the redundant transmission of data by means of light-based communication may include a data stream to be transmitted that is converted into symbols. This data stream is converted from bipolar symbols into multiple partial data streams having e.g. unipolar-positive symbols. The partial data streams are converted into multiple semi-redundant signals that are then transmitted to the receiver via multiple light-based channels. In the receiver, the received signals are converted back again analogously to when they were sent, in order to obtain the original data stream again.

A method includes: determining, by the control device, that a site receives a first service; determining that a mapping wavelength of a first service is blocked on an original routing path, where the original routing path includes a first line board connected to a first local dimension, and a wavelength occupied by the first local dimension includes the mapping wavelength of the first service; and routing, by the control device, the first service to a second line board connected to a second local dimension, where the mapping wavelength of the first service is available in the second local dimension.

This disclosure describes devices and methods related to multiplexing optical data signals. A method may be disclosed for multiplexing one or more optical data signals. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to one or more wave division multiplexer (WDM). The method may comprise combining, by the one or more WDM, the combined one or more optical data signals and one or more second optical data signals, and outputting an egress optical data signal comprising the combined one or more optical data signals and one or more second optical data signals.

An example system includes a first network device having first circuitry. The first network device is configured to perform operations including receiving data to be transmitted to a second network device over an optical communications network, and transmitting first information and second information to the second device. The first information is indicative of the data, and is transmitted using a first communications link of the optical communications network and using a first subset of optical subcarriers. The second information is indicative of the data, and is transmitted using a second communications link of the optical communications network and using a second subset of optical subcarriers. The first subset of optical subcarriers is different from the second subset of optical subcarriers.

This disclosure describes devices and methods related to multiplexing optical datasignals. A method may be disclosed. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to a first circulator. The method may also comprise combining, by the WDM, the second optical data signal and one or more third signals, and outputting an egress optical data signal to an optical switch. The method may also comprise outputting, by the optical switch, the egress optical data signal on a primary fiber.

Embodiments herein include methods and apparatuses for providing optical channel protection by a switching controller in an optical networking system. The switching controller may receive, from a light module, a digital fault status message that indicates whether a digital frame demodulated from an optical signal include a fault. The switching controller may receive from an Optical Supervisory Channel (OSC) module, an Optical Layer Defect Propagation (OLDP) status message that indicates an OSC status of the optical signal on a current optical path. The switching controller may receive, from an Optical Add Drop Multiplexer (OADM) module, an optical power status message that indicates a measured power level of the optical signal on the optical path. Based on at least one of the OLDP status, the optical power status, or the digital fault status message, the switching controller may determine the optical path as a working path or a protecting path.

Accommodation design for wavelength and sub-λ paths in a communication network is performed. If sub-λ path accommodation is possible according to search for a wavelength path present in a single-hop logical route, the accommodation in the wavelength path is executed. If sub-λ path accommodation is possible according to search for a wavelength path present in a multi-hop logical route, a logical route is selected based on the wavelength path and the sub-λ path is accommodated in the wavelength path. Additionally, each physical route suitable for the sub-λ path accommodation is searched for. If the route can accommodate a wavelength path set in a single-hop logical route by available wavelength allocation, the sub-λ path is accommodated in the wavelength path. Furthermore, routes in consideration of overlapping of nodes, pipelines, and links and operation rate are selected based on information about the start and end nodes of each of redundant routes.