Abstract: A method for estimating a bandwidth limiting penalty of a chain of bandpass optical filters in an optical telecommunication system. The method is advantageous for systems carrying an optical signal at a bit rate of about 10 Gb/s, wherein average bandwidth of the filters in the chain is of the same order of magnitude as bandwidth of the optical signal. The method comprises selecting a worst case filter, checking the system by testing and/or simulating it as being provided with the selected worst case filter instead of the chain of filters, and then judging about the bandwidth limiting penalty of the chain of filters based on results of the checking.

Abstract: A technique for carrying out protection of data traffic in a multi-channel multi-section optical communications network by simultaneously using Optical Multiplexed Section (OMS) protection and Optical Channel (OCH) protection; the technique comprises selection of a working optical signal in an OCH protected optical channel, in case of a fault in a section of the network, by relying on an indication associated with OMS switching functionality that is required to overcome the mentioned fault.

Abstract: A network with nodes interconnected by optical fiber links carrying an optical communication channel having a single optical wavelength. In the network, at least two network nodes operate as transmitting nodes generating a first short pulse optical signal at different bit rates; at least one of the other network nodes operates as a receiving node and is designated to receive transmissions from at least one of the transmitting nodes via the optical channel in a form of a second short pulse optical signal. The receiving node is provided with a dispersion compensation module adapted to compensate dispersion created in the optical fiber along the optical channel between a specific transmitting node and the receiving node, thereby ensuring receipt, in a restored form, of data transmitted using the second optical signal and directed to the receiving node.

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 method and a system for performing pre-emphasis of one or more optical channels respectively carrying one or more optical signals, by effecting bit rate of the one or more of the signals, thereby adjusting BER value thereof.

Abstract: The invention proposes a technique for measuring chromatic dispersion in an optical communication line transmitting an optical signal at a predetermined optical wavelength. The technique comprises determining the sign of chromatic dispersion and includes introducing controlled changes of wavelength around the predetermined wavelength, monitoring the optical signal that has passed said line, and obtaining a first and a second signals, wherein the first signal reflects changes of the carrier wavelength, and the second signal reflects changes of delay of the optical signal transmitted via the line. The two signals are compared and the chromatic dispersion sign is determined based on the phase difference there-between.

Abstract: The invention proposes a Grouped Optical Add Drop Multiplexer (GOADM) comprising a periodic filter for forming a group of spaced optical wavelengths to be dropped or added.

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: A method and a system for performing pre-emphasis of one or more optical channels respectively carrying one or more optical signals, by effecting bit rate of the one or more of the signals, thereby adjusting BER value thereof.

Abstract: The invention proposes a Grouped Optical Add Drop Multiplexer (GOADM) comprising a periodic filter for forming a group of spaced optical wavelengths to be dropped or added.

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.