A computer-implemented method to increase capacity of an optical network based on overall excess margin in the optical network includes determining an objective function based on data associated with a plurality of optical signals in the optical network, each of the optical signals between modems in the optical network, wherein an input to the objective function comprises how much margin the optical signals have until Forward Error Correction (FEC) limits are reached; performing an optimization of the objective function based on changing a plurality of parameters of the optical signals; and causing changes to settings of a subset of the modems based on the performing to change the capacity of the optical network.

A method and apparatus for communications in a passive optical network (PON) system are provided. An optical line terminal (OLT) generates a PON downstream Physical Layer (PHY) frame comprising a downstream physical synchronization block (PSBd) that comprises a wavelength identification (ID) of at least one downstream wavelength of the plurality of downstream wavelengths. The OLT sends the PON PHY frame comprising the wavelength ID in the PSBd to ONU for confirming the at least one downstream wavelength.

The drone-based radio-over-fiber system provides an unmanned aerial vehicle (AV), preferably a multi-rotor drone, connected to a base station by a tether including an optical fiber. A radio frequency-over-fiber system is used for bidirectional data communications between at least one radio frequency (RF) transmitter at the base station and at least one antenna mounted on the drone through the optical fiber in the tether. The system includes wave division multiplexers/demultiplexers that permit ultrahigh bandwidth communication over the tether. An embodiment of the system for 2?2 multiple-input, multiple-output (MIMO) signals in the 700 MHz LTE band is described.

An aspect of the present disclosure is a transmission system including a modulated wave generation unit that generates an intermediate wave, which is a coherent wave in which a frequency component of either of two signals overlays a frequency spectrum, the two signals being a main signal indicating transmitted information to be transmitted and a control signal indicating management information, which is information on communication between a transmission source of the transmitted information and a communication destination of the transmission source, and a modulation unit that modulates the intermediate wave with a signal in which a frequency component does not overlay the frequency spectrum of the coherent wave generated by the modulated wave generation unit out of the two signals that are the main signal and the control signal. In the transmission system, a frequency band of the main signal and a frequency band of the control signal do not overlap each other.

The drone-based radio-over-fiber system provides an unmanned aerial vehicle (AV), preferably a multi-rotor drone, connected to a base station by a tether including an optical fiber. A radio frequency-over-fiber system is used for bidirectional data communications between at least one radio frequency (RF) transmitter at the base station and at least one antenna mounted on the drone through the optical fiber in the tether. The system includes wave division multiplexers/demultiplexers that permit ultrahigh bandwidth communication over the tether. An embodiment of the system for 2?2 multiple-input, multiple-output (MIMO) signals in the 700 MHz LTE band is described.

A network design device includes a processor. The processor determines a second wavelength allocation based on a first wavelength allocation that indicates a wavelength allocation for a plurality of optical lines established in a wavelength division multiplexing optical network. The processor searches for a disconnection target optical line that is requested to be disconnected in order to realize a transition from the first wavelength allocation to the second wavelength allocation from among the plurality of optical lines. The processor generates procedure information that indicates a procedure of the transition from the first wavelength allocation to the second wavelength allocation based on a difference between the first wavelength allocation and the second wavelength allocation and a searched disconnection target optical line.

The drone-based radio-over-fiber system provides an unmanned aerial vehicle (AV), preferably a multi-rotor drone, connected to a base station by a tether including an optical fiber. A radio frequency-over-fiber system is used for bidirectional data communications between at least one radio frequency (RF) transmitter at the base station and at least one antenna mounted on the drone through the optical fiber in the tether. The system includes wave division multiplexers/demultiplexers that permit ultrahigh bandwidth communication over the tether. An embodiment of the system for 2?2 multiple-input, multiple-output (MIMO) signals in the 700 MHz LTE band is described.

A method and apparatus for communications in a passive optical network (PON) system are provided. An optical line terminal (OLT) generates a PON downstream Physical Layer (PHY) frame comprising a downstream physical synchronization block (PSBd) that comprises a wavelength identification (ID) of at least one downstream wavelength of the plurality of downstream wavelengths. The OLT sends the PON PHY frame comprising the wavelength ID in the PSBd to ONU for confirming the at least one downstream wavelength.

There is provided an optical transmission control device includes a memory, and a processor coupled to the memory and the processor configured to aggregate information of candidacy sections having a possibility that communication is discontinued among wavelength-multiplexed transmission sections, classify, based on the aggregated information, optical paths set between optical transmission devices into a first optical path on which, when communication in the candidacy sections is discontinued, an optical signal is not transmitted, and a second optical path on which, when the communication in the candidacy sections is discontinued, an optical signal is transmitted, and determine a wavelength allocation in a first wavelength group of the first optical path and a second wavelength group of the second optical path so that a difference in gain wavelength characteristics of the first optical path and the second optical path is equal to or less than a predetermined level.

An optical Internet Protocol (IP) router serves a cell-site over an optical communication network. The optical IP router transmits a network attach request having an optical node name over a control optical wavelength. The optical communication node receives an assignment of a data optical wavelength, a cell-site mode, and an Internet Protocol (IP) address over the control optical wavelength based on the optical node name. The optical communication node operates in the cell-site mode and responsively exchanges cell-site data having the IP address over the data optical wavelength.