Abstract: A method for increasing bandwidth utilization of a transmission channel having a first bandwidth capacity and operative at a first transmission rate, the method including the steps of providing one or more input bit streams each having a transmission rate that does not exceed that of the first transmission rate, dividing the one or more input bit streams into a plurality of sub-streams, each having a bandwidth lower than the first bandwidth capacity, selecting a group of sub-streams out of the plurality of sub-streams which group has a combined bandwidth just lower than the first bandwidth capacity, carrying the selected group of sub-streams over the transmission channel, and assembling the selected group of sub-streams into an output bit stream.

Abstract: There is proposed a technique for counting channels at a node of a multi-channel optical network, where the node is connected to a following node and a preceding node by an optical communication line carrying a plurality of information optical channels. The technique comprises exchanging of information structures between the nodes, such that each of the information structures specifies particular optical information channels which are currently in use at a predetermined network section or node.

Abstract: A method is described for fast rerouting, in case of a fault, packets of MPLS traffic in a ring-like network configuration, where the MPLS traffic is formed by one or more Label Switched Paths (LSPs) entitled to protection. The method comprises rerouting the MPLS packets to a protection path in the ring, providing the rerouted MPLS packets with additional labels to their respective label stacks, and then detecting the additional labels at network nodes included in the protection path. Detection of the additional labels further allows determining egress nodes of the rerouted MPLS packets and outputting the rerouted MPLS packets at their corresponding egress points from the protection path.

Abstract: Technology is proposed for estimating one or more characteristics of a main signal transmitted via a communication link, wherein the main signal is composed from a number of component signals possibly comprising respective data signals and transmitted via a number of respective communication channels. The technology comprises providing an analyzing circuit independent from the communication link, transmitting a probe data signal in the analyzing circuit, monitoring a bit error rate (BER) parameter associated with the probe data signal and introducing into the analyzing circuit at least a portion of energy of the main signal as an interference signal. The technology allows judging about characteristics of the main signal based on changes in the monitored BER parameter of the probe data signal.

Abstract: A method for managing congestion on a network, the method including establishing a buffer (20) threshold bounding a first and a second buffer region (22, 24, 26), maintaining a rejection indicator for each of a plurality of network connections (24), and preventing the buffering (26) of a transmission bound for a first of the plurality of network connections if the buffer threshold is exceeded.

Abstract: A method is proposed for improving protection of data traffic in an optical ring network, where the data is arranged in SDH/SONET frames and the network supports a standardized MS-SPRING/BLSR protocol. The method comprises providing means to distinguish between a first kind and a second kind of coded protocol messages. The first kind of the messages is a bridge request message sent from node P (a first node) to node Q (a second node) and signaling about a unidirectional signal failure or degradation between the node P and Q, and the second kind of the messages is an acknowledgement message sent from node Q to node P in response to the bridge request message.

Abstract: An optical transponder capable of effecting performance monitoring on the electrical signal equivalents of at least two different optical signal types each uniquely identifiable in terms of transmission protocol and/or bit rate. The optical transponder includes an optical/electrical (O/E) receiver module for converting an ingressing optical signal from an optical signal source into an electrical signal; a performance monitoring module for effecting performance monitoring on the electrical signal; and an electrical/optical (E/O) transmitter module for regenerating an egressing optical signal from the electrical signal for feeding to an optical signal destination.

Abstract: Dividing a multiplexed optical signal transmitted along a first transmission path into two portions and diverting one of the two portions to a second transmission path and forwarding the other portion of the multiplexed optical signal along that first transmission path, while the energy of the diverted portion comprises the entire spectrum of the multiplexed optical signal. Preferably, the diverted first portion is further divided into at least two parts, each comprising a wavelength range substantially different than the others, and at least one of the two parts is forwarded towards an optical receiver.

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 method for routing of incoming prioritized telecommunication traffic in a telecommunication network by applying an algorithm of finding optimal path to an augmented graph built for said telecommunication network. The telecommunication network is represented as a network graph comprising nodes (A, B, C, D, E) and real links (AB, BC, CD, ED, AE) bridging the nodes, while the augmented graph is a graph built on the basis of the network graph by adding to it virtual links (ABC1, . . . , EDC3). The augmented graph comprises nodes and edges, wherein the edges of the augmented graph are weighed to reflect priority of the telecommunication traffic presently taking place there-through. For placing a new call according to the method, a pathfinder optimization algorithm is applied to the augmented graph to determine an optimal pathfinder solution, having the minimal total weight, for routing the new call in the augmented graph.

Abstract: A technique for handling an optical pulse signal, wherein the handling includes one or more operations out of: pulse shaping, treatment of nonlinearity and monitoring; the technique uses a device capable of performing a cascaded second harmonic generation (SHG) with respect to a particular fundamental harmonic (FH), and comprises: selecting in the device a particular optical path length suitable for performing at least one of the above operations with respect to an incoming optical pulse signal carried by a wavelength defined by the particular fundamental harmonic (FH), conveying the incoming optical pulse signal carried by the defined wavelength along the selected optical path in the device, obtaining from the device an output optical pulse signal at the fundamental harmonic (FH), wherein the treatment of nonlinearity and/or the pulse shaping are performed, and/or obtaining an output optical pulse signal at the second harmonic (SH) for further monitoring it and judging about the input optical pulse signal

Abstract: A method for utilizing a Spanning Tree Protocol (STP) in an Ethernet network wherein a number of VLANs are defined and a plurality of Ethernet switching nodes (A, B, C D E, F, G H) are interconnected via their ports (A1, . . . ,H4) so that each of the ports is initially assigned to one or more VLANs, and each of the VLANs is intended to enable traffic between two or more edge ports (D3, B3). The method comprises also-called pruning procedure initiated upon establishing a new STP topology (30) related to one or more VLANs. This procedure concerns a broadcast domain of at least one of the VLANs and is aimed at obtaining a sub-tree for each pruned VLAN in the new STP topology. The sub-tree is usually shrunk, bound by the edge ports assigned to the corresponding pruned VLAN, and thus eliminates broadcast traffic of the pruned VLAN to any Ethernet switch extending beyond the obtained sub-tree.

Abstract: A method of transmitting signals along a communication path, by a first compression/decompression unit, which method comprises receiving first signals from a first direction along the path, determining based on the received first signals whether a second decompression unit is located along the path in the first direction, receiving second signals from a second direction. In the case it is determined that a second decompression unit is located along the path in the first direction, selecting a compressed or decompressed format for transmission of the second signals responsive to at least one additional parameter, such that the determination that a second decompression unit is located along the path in the first direction does not always bring about selecting the compressed format. Then, the second signals are transmitted in the selected format.

Abstract: A method and a system for traffic management in an optical network, based on measuring chirp of optical signals transmitted along an optical path extending 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: A method and an inter-chip communication port for supporting a concatenated type of a high order SDH/SONET signal, with processing Transport Overhead bytes (TOH) and Path Overhead bytes (POH) thereof, in a structure which comprises a group of chips, wherein each of the chips is capable of supporting a lower order SDH/SONET signal with processing its TOH and POH, while one of them named a master chip is operative to coordinate operation of the remaining chips named slaves so as to cause them working in accord as one unit.

Abstract: An optical switching apparatus in an optical communication network selectively combines and separates series of optical signal samples using OTDM and/or WDM. In upstream communication, the optical switching apparatus optically converts n series of upstream optical signal samples having the upstream optical signal samples carried over channel wavelengths &lgr;1, . . . ,&lgr;n at data rates DR1, . . . ,DRn respectively into a combined series of upstream optical signal samples having the upstream optical signal samples carried over a channel wavelength &lgr;D at a combined data rate DRc which is greater than any one of the data rates DR1, . . . ,DRn. The combined series of upstream optical signal samples is then routed to a destination route.

Abstract: This invention discloses a wave division multiplexing communications system including a pluarity of optical transmitters, each of said optical transmitters further including a distributed feed back laser characterized in that it has a dispersion penalty of less than 2 dB when used for transmission into an optical fiber having chromatic dispersion of 1800 ps/nm, a driver operative for receiving a communications signal input and providing electrical power to said distributed feed back laser in accordance therewith and a wave division multiplexer receiving outputs from said plurality of optical transmitters comprising thin film dielectric layers and having a maximum power insertion loss of 4.5 dB.

Abstract: A switching core controller for controlling one or more Digital Cross-connect Systems (DCSs). A method for operating a switching core for pre-provisioning communication paths in anticipation of incoming calls. A method for routing a call to effect load balancing between mediation devices of a logical entity of at least two mediation devices.

Abstract: A switching system for a telecommunications network, including a switching matrix, a transport interface for receiving signals from a plurality of I/O ports, the signals being arranged in channels of at least a first and a second format, a plurality of cross-connections for switching the signals between the I/O ports via the switching matrix; and a server operatively associated with the switching matrix and including format exchanging circuitry operable to receive a signal arranged in the first format and to rearrange the signal into the second format, thus producing a converted signal, and to transmit the converted signal to the switching matrix for eventual output.