Abstract: The invention concerns shutting down and restarting optical amplifiers, such as Raman amplifiers, in an optical link, depending whether the optical amplifier is a transmitting side amplifier or a receiving side amplifier. For controlling the amplifiers, at least one diagnostic signal is to be transmitted via an auxiliary optical channel in the optical link, and a number of physical events simultaneously taking place are to be taken into account to conclude whether to shut down or to restart one of the optical amplifiers.

Abstract: A technique is described for controlling and optical network composed of network elements (NEs), with the aid of a network controller (NC) being in communication with the network elements. The technique includes collecting, by the network controller NC, information on the NEs therefrom, and, whenever a change in the network is requested, simulating within the NC operation of the network with the requested change and based on the collected information. The NC makes a decision on acceptability of the requested change, and may then cause implementation of the requested change in the network.

Abstract: The invention concerns shutting down and restarting optical amplifiers, such as Raman amplifiers, in an optical link, depending whether the optical amplifier is a transmitting side amplifier or a receiving side amplifier. For controlling the amplifiers, at least one diagnostic signal is to be transmitted via an auxiliary optical channel in the optical link, and a number of physical events simultaneously taking place are to be taken into account to conclude whether to shut down or to restart one of the optical amplifiers.

Abstract: A technique is described for controlling and optical network composed of network elements (NEs), with the aid of a network controller (NC) being in communication with the network elements. The technique includes collecting, by the network controller NC, information on the NEs therefrom, and, whenever a change in the network is requested, simulating within the NC operation of the network with the requested change and based on the collected information. The NC makes a decision on acceptability of the requested change, and may then cause implementation of the requested change in the network.

Abstract: A technique for maintaining a required value of power per optical communication channel in a chain of optical nodes (112, 114, 118, 116) connected by optical fiber spans (111, 119, 121), wherein at least some of the nodes include optical amplifiers (112, 114, 116) with controllable gains, the technique comprises performing automatic gain control at the optical amplifiers so that, in the frame of power gain of each particular optical amplifier (114, 116), to compensate a preceding span loss. The span loss is calculated as power loss on an optical fiber span (111,121) incoming the particular amplifier.

Abstract: The invention describes a system of two-stage optical amplifiers adapted for inserting OADM in the mid-stage, and an integrated assembly designed for implementing the amplifiers in a way suitable for forming bi-directional configurations useful in optical networks. A so-called east-west configuration for a bi-directional transmission is described, where each direction of the optical transmission is served by the two-stage optical amplifier the 1st stage of which belongs to one integrated assembly, and the 2nd stage—to another assembly.

Abstract: An optical communication switch operative in a communication network which is adapted to enable protection of a segment, or a number of segments, along an optical path in the communication network.

Abstract: The invention describes a system of two-stage optical amplifiers adapted for inserting OADM in the mid-stage, and an integrated assembly designed for implementing the amplifiers in a way suitable for forming bi-directional configurations useful in optical networks. A so-called east-west configuration for a bi-directional transmission is described, where each direction of the optical transmission is served by the two-stage optical amplifier the 1st stage of which belongs to one integrated assembly, and the 2nd stage—to another assembly.

Abstract: A technique for maintaining a required value of power per optical communication channel in a chain of optical nodes (112, 114, 118, 116) connected by optical fiber spans (111, 119, 121), wherein at least some of the nodes include optical amplifiers (112, 114, 116) with controllable gains, the technique comprises performing automatic gain control at the optical amplifiers so that, in the frame of power gain of each particular optical amplifier (114, 116), to compensate a preceding span loss. The span loss is calculated as power loss on an optical fiber span (111, 121) incoming the particular amplifier.

Abstract: An optical communication switch operative in a communication network which is adapted to enable protection of a segment, or a number of segments, along an optical path in the communication network.