Abstract: Example embodiments of the present invention relate to increasing an aggregate capacity of a network without using a centralized switch fabric. A method and corresponding apparatus in an example embodiment of the present invention relates to increasing overall aggregate capacity of a switching system. The example embodiment includes a first switching shelf having a first predetermined aggregate capacity, and multiple second switching shelves having a second predetermined aggregate capacity. The second predetermined aggregate capacity is less than the first predetermined aggregate capacity. The example embodiment increases the overall aggregate capacity as a function of connections between the first switching shelf and the multiple second switching shelves. The shelves are interconnected with interconnection links and can be configured to connect to additional shelves as the switching system grows to larger sizes. Embodiments can increase capacity while reducing cost within a network node.

Abstract: A system supports 50 ms protection switching times independent of network architecture. The system includes multiple protection switch fabrics to perform facility protection switching for the signals and a central switch fabric to switch a subset of the signals in a non-facility protection switching manner among the protection switch fabrics. Linear and ring network configurations are supported by the system. The system has flexibility to perform Linear Automatic Protection Switching (LAPS), Unidirection Path Switched Ring (UPSR) protection switching, and Bidirectional Line Switched Ring (BLSR) protection switching without burdening the central switch fabric with unnecessary or redundant traffic.

Abstract: A cable tray is provided comprising a housing defining an interior portion, the housing having at least one positioned opening formed therein and also having plural, open ends in communication with the interior portion and the at least one positioned opening for passage of at least one cable therethrough. The housing is adapted to be coupled to at least one external surface, such that at least one of the plural, open ends substantially aligns with at least one open end of a housing of at least one further cable tray.

Abstract: A communication system includes a first ingress content processor that receives information associated with a first traffic type. The first ingress content processor places the information associated with the first traffic type into a system cell having a common system cell format. A second ingress content processor receives information associated with a second traffic type. The second ingress content processor places the information associated with the second traffic type into a system cell having the common system cell format. A switch fabric receives system cells from the first and second ingress content processors. System cells from the first ingress content processor are automatically sent to the switch fabric while system cells from the second ingress content processor are required to be scheduled before being sent to the switch fabric.

Abstract: A cable tray is provided comprising a housing defining an interior portion, the housing having at least one positioned opening formed therein and also having plural, open ends in communication with the interior portion and the at least one positioned opening for passage of at least one cable therethrough. The housing is adapted to be coupled to at least one external surface, such that at least one of the plural, open ends substantially aligns with at least one open end of a housing of at least one further cable tray.

Abstract: A chromatic dispersion compensation system for an optical transmission system incorporates circuitry which determines the length of an optical fiber extending between an output amplifier and an input amplifier. Based on fiber type, the total chromatic dispersion on the fiber is determined. Compensation can then be automatically implemented.

Abstract: In today's reconfigurable optical add/drop multiplexer (ROADM) based optical node, ROADMs multiplex (and demultiplex) colored optical signals to form wavelength-division multiplexed (WDM) signals. Transponders connected to the ROADMs' add/drop ports convert noncolored optical signals to colored optical signals (and vice versa). Dedicating transponders to given ports degrades the node's ability to route around network failures. Example embodiments of the invention include an optical node and corresponding method for routing optical signals within an optical node that compensate for this inflexibility. The optical node may include two ROADMs to transmit respective WDM signals onto at least two internode network paths and a routing module that can direct channels of the same wavelength along different internode network paths.

Abstract: A chromatic dispersion compensation system for an optical transmission system incorporates circuitry which determines the length of an optical fiber extending between an output amplifier and an input amplifier. Based on fiber type, the total chromatic dispersion on the fiber is determined. Compensation can then be automatically implemented.

Abstract: A method and apparatus are provided for horizontally slicing a multi-stage switching fabric having transmission inputs and transmission outputs to and from the switch fabric. The switching fabric includes switch elements arranged in at least first and second stages, each switch element having element inputs and outputs with each switch element being configured to join one of the element inputs with an associated one of the element outputs. The switch fabric includes a first logic device that contains a stage-1 subset of the switch elements that is arranged within, and configured to operate as part of, the first stage. The first logic device also contains a stage-2 subset of the switch elements arranged within, and configured to operate as part of, the second stage. The switch fabric includes a second logic device that contains a stage-1 subset of the switch elements that is arranged within, and configured to operate as part of, the first stage.

Abstract: A method and apparatus are provided for horizontally slicing a multi-stage switching fabric having transmission inputs and transmission outputs to and from the switch fabric. The switching fabric includes switch elements arranged in at least first and second stages, each switch element having element inputs and outputs with each switch element being configured to join one of the element inputs with an associated one of the element outputs. The switch fabric includes a first logic device that contains a stage-1subset of the switch elements that is arranged within, and configured to operate as part of, the first stage. The first logic device also contains a stage-2 subset of the switch elements arranged within, and configured to operate as part of, the second stage. The switch fabric includes a second logic device that contains a stage-1 subset of the switch elements that is arranged within, and configured to operate as part of, the first stage.

Abstract: A node for managing an optical signal includes a first system optics card for providing channels to be transported over a first optical transport link and receives channels from a second optical transport link. Channels received over the second optical transport link are provided to an optical converter card for transport to a client device, for feedback onto the first optical transport link, or pass through to a second system optics card of the node. The first system optics card is capable of dropping network channels from the second transport link to associated client devices through optical converter cards and add client channels received from optical converter cards to the first transport link. The first system optics card may include one or more express input and output ports to couple with one or more other system optics cards in order to provide multiple degrees of communication capability.

Abstract: A network design that reduces the number of wavelengths needed to support communications in a Wavelength Division Multiplexing (WDM) network is disclosed. Wavelengths are reused in isolated sub-networks that do not share common network paths, allowing for the reduction in cost of the WDM equipment supporting the communications in the network.

Abstract: Optical networks are increasingly employing optical network nodes having multiple interfaces to allow a node to direct optical signals received at any interface to any other interface connected to the node. Constructing a larger wavelength selective switching (WSS) module used in such a node can be complex and expensive. A method an apparatus for constructing a large WSS using parallelism is provided. In example embodiments, a larger WSS may include multiple parallel non-cascaded smaller WSSs and an optical coupler configured to optically couple the multiple parallel, non-cascaded smaller WSSs. This technique may be used to construct both N×1 and 1×N WSSs. Because the technique employs multiple parallel, non-cascaded WSSs, all inputs of a larger N×1 WSS and all outputs of a larger 1×N WSS are available receive or transmit external signals rather than being rather than being unavailable due to, for example, cascading smaller WSS devices together.

Abstract: Optical networks are increasingly employing optical network nodes having multiple interfaces to allow a node to direct optical signals received at any interface to any other interface connected to the node. Constructing a larger wavelength selective switching (WSS) module used in such a node can be complex and expensive. A method an apparatus for constructing a large WSS using parallelism is provided. In example embodiments, a larger WSS may include multiple parallel non-cascaded smaller WSSs and an optical coupler configured to optically couple the multiple parallel, non-cascaded smaller WSSs. This technique may be used to construct both N×1 and 1×N WSSs. Because the technique employs multiple parallel, non-cascaded WSSs, all inputs of a larger N×1 WSS and all outputs of a larger 1×N WSS are available receive or transmit external signals rather than being rather than being unavailable due to, for example, cascading smaller WSS devices together.

Abstract: A reconfigurable optical add drop multiplexer (ROADM) includes local interfaces at which optical signals of different wavelengths are locally input into the ROADM, and a network interface configured to connect the ROADM to a network from which multiplexed optical signals of different wavelengths are transmitted to the network. In a first configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a first minimum frequency difference. In a second configuration, the ROADM is configured to transmit from the network interface to the network multiplexed signals of different wavelengths having a second minimum frequency difference. The second minimum frequency difference is greater than the first minimum frequency difference. This arrangement reduces the power of four wave mixing cross products produced when optical signals of three wavelengths are multiplexed and transmitted from the ROADM to NZDSF or DSF fiber types.

Abstract: In today's reconfigurable optical add/drop multiplexer (ROADM) based optical node, transponders associated with the ROADMs' add/drop ports are dedicated to a given network node interface. Dedicated transponders reduce the flexibility to route around network failures. Example embodiments of the invention includes an optical node and corresponding method for routing optical signals within an optical node. The optical node may include at least two ROADMs to transmit respective wavelength division multiplexed (WDM) signals onto at least two inter-node network paths and at least one add/drop module including add ports to direct add wavelengths received from tributary network paths to each of the ROADMs via intra-node network paths to allow the wavelengths to be available to be added to the inter-node network paths.

Abstract: An example embodiment of the invention includes a method and apparatus for supporting fiber span loss and dispersion measurements in the presence or absence of dispersion compensation elements (DCE). The technique may be used to configure a network link by accessing an optical signal at an ingress side of a connection point for a DCE coupling an egress side of a fiber span at the ingress side of the DCE to an optical amplifier at a connection point for an egress side of the DCE. The technique may include determining chromatic dispersion of the fiber span based on the optical signal and reporting information associated with chromatic dispersion. As a result, the technique may be used, for example, during initial system installation when user data signals and the DCE are not present as well as after the network begins carrying user traffic and after a DCE has been installed.

Abstract: In a network environment, a first master timing generator generates a first frame reference signal and a second master timing generator generates a second frame reference signal. A first data source generates a first data source signal, a first frame source signal, and a first clock source signal in response to a selected one of the first and second frame reference signals. Similarly, a second data source generates a second data source signal, a second frame source signal, and a second clock source signal in response to a selected one of the first and second frame reference signals. A timing recovery circuit generates a recovered reference signal and a recovered clock signal in response to a selected one of the first and second frame reference signals. A phase aligner stores the first data source signal in response to the first frame source signal and the first clock source signal.

Abstract: According to a first embodiment of the present invention, reconfigurable resources within a reconfigurable test unit are configured to test or monitor a first function associated with a system under test. Following the completion of the testing or monitoring of the first function, the reconfigurable resources within the reconfigurable test unit are configured to test or monitor a second function associated with the system under test, wherein the second function may be substantially different than the first function. The method and apparatus so described allows for the testing of systems using a minimal amount of hardware and software resources within a reconfigurable test unit.

Abstract: A reconfigurable optical add drop multiplexer core device includes a light distributor, a light combiner, and first and second sets of add and drop ports. The light distributor is configured to receive an optical signal along a primary input of the reconfigurable optical add drop multiplexer core device and to distribute the received optical signal along a plurality of subtending outputs. The light combiner is configured to receive optical signals along a plurality of subtending inputs, to combine the received optical signals into a combined signal, and to output the combined signal. The add and drop ports in the first set function as add and drop ports, respectively, and the add and drop ports in the second set function as both add and drop ports, respectively, and as express ports connectable to another reconfigurable optical add drop multiplexer core device.