A communication system transmits relay data through a communication path including a plurality of sections in which different communication schemes are used. A relay communication device is provided between a first section and a second section which are adjacent sections. The relay communication device includes a receiving unit receiving the relay data from the first section through a frame of a first communication scheme, and a relaying unit configuring, in a frame of a second communication scheme used to transmit the relay data to a relay destination, signal quality information representing signal quality calculated for a physical link in each of the sections through which the relay data is transmitted before arriving at the relay communication device, and outputting the frame of the second communication scheme to the second section.

A communication system transmits relay data through a communication path including a plurality of sections in which different communication schemes are used. A relay communication device is provided between a first section and a second section which are adjacent sections. The relay communication device includes a receiving unit receiving the relay data from the first section through a frame of a first communication scheme, and a relaying unit configuring, in a frame of a second communication scheme used to transmit the relay data to a relay destination, signal quality information representing signal quality calculated for a physical link in each of the sections through which the relay data is transmitted before arriving at the relay communication device, and outputting the frame of the second communication scheme to the second section.

In a case where a failure occurs in a part of an optical fiber in an optical cable, when attempting to switch to a redundant configuration, the stable use of an optical transmission system is impaired, so that the wavelength band cannot be used effectively. Accordingly, the optical transmission system of the present invention includes a first optical device configured to change the transmission line of a wavelength band signal propagating through a first optical transmission line to a second optical transmission line that is the same path as the first optical transmission line, in the stage before a faulty part in the first optical transmission line, and a second optical device configured to change the transmission line of the wavelength band signal from the second optical transmission line to the first optical transmission line, in the stage after the faulty part.

Provided are a communication device, a communication controlling method, and a non-transitory computer-readable medium storing a communication controlling program that each make it possible to grasp the condition of communication quality. A communication device (1) includes acquiring means (2) configured to acquire quality information concerning a burst error that has occurred in an optical communication line. The communication device (1) includes estimating means (3) configured to estimate a first index value based on the quality information acquired by the acquiring means (2), the first index value indicating a degree of influence of the burst error on communication quality in a first communication device.

Provided are a communication device, a communication controlling method, and a non-transitory computer-readable medium storing a communication controlling program that each make it possible to grasp the condition of communication quality. A communication device (1) includes acquiring means (2) configured to acquire quality information concerning a burst error that has occurred in an optical communication line. The communication device (1) includes estimating means (3) configured to estimate a first index value based on the quality information acquired by the acquiring means (2), the first index value indicating a degree of influence of the burst error on communication quality in a first communication device.

Disclosed herein are methods, devices, and system for beam forming and beam steering within ultra-wideband, wireless optical communication devices and systems. According to one embodiment, a free space optical (FSO) communication apparatus is disclosed. The FSO communication apparatus includes a semiconductor optical device configured to have a transient response time of less than 500 picoseconds (ps), a lens, and a first band select filter.

Disclosed herein are methods, devices, and system for beam forming and beam steering within ultra-wideband, wireless optical communication devices and systems. According to one embodiment, a free space optical (FSO) communication apparatus is disclosed. The FSO communication apparatus includes a semiconductor optical device configured to have a transient response time of less than 500 picoseconds (ps), a lens, and a first band select filter.

An amplified optical link having a fault-protection capability that is based, at least in part, on the ability to selectively and independently power up and down different groups of optical amplifiers within the link. In an example embodiment, the optical link is implemented using an optical fiber cable having an electrical power line and arrays of optical amplifiers connected between successive optical fiber segments to form a plurality of disjoint groups of parallel optical paths between the ends of the optical fiber cable. The electrical power line is operable to selectively power, as a group, the optical amplifiers of at least some of the disjoint groups. In various embodiments, different optical paths can be implemented using different respective strands of a single-core optical fiber, different respective cores of a multi-core optical fiber, and/or different respective sets of spatial modes of a multimode optical fiber.

Disclosed is a method of operating an array of receiver devices as a phased array. The receiver devices are in a fixed mutual relationship within a zone and each receiver device comprises a photovoltaic element. The method involves receiving a signal from within the zone at a plurality of the receiver devices to generate a plurality of received signals and processing the received signals using at least one phase difference therebetween. The method also involves directing a beam of light from a unit located within the zone to the photovoltaic elements, thereby providing power to said receiver devices. The invention extends to an array of transmitter devices and to an array of both transmitter and receiver devices.

Disclosed is a method of operating an array of receiver devices as a phased array. The receiver devices are in a fixed mutual relationship within a zone and each receiver device comprises a photovoltaic element. The method involves receiving a signal from within the zone at a plurality of the receiver devices to generate a plurality of received signals and processing the received signals using at least one phase difference therebetween. The method also involves directing a beam of light from a unit located within the zone to the photovoltaic elements, thereby providing power to said receiver devices. The invention extends to an array of transmitter devices and to an array of both transmitter and receiver devices.