Abstract: A method and apparatus for filter spectrum deconvolution and reshaping include providing a filter output of a spectrum signal and determining the intensity and wavelength of the spectrum signal at each spectral peak. The filter output is characterized as an integral of convolution of a spectrum signal function and a filter function. Transformation are then performed on the filter output to deconvolve and remove the undesirable filter function and add a desirable filter function to reshape the output filter spectrum.

Abstract: A network test architecture includes a plurality of modules for performing a plurality of functions, each of the plurality of modules having a unique identifier. An additional module for performing an additional function has an additional unique identifier. A control bus is connected among the plurality of modules; a data bus is connected among the plurality of modules; and a power bus is connected among the plurality of modules. A controller controls operation, data transmission, and powering of the plurality of modules and the additional module, respectively, through the control bus, the data bus, and the power bus, the controller using the unique identifier and the additional unique identifier of the plurality of modules upon simultaneous connection of the control bus, the data bus, and the power bus to the additional module.

Abstract: A method and apparatus for providing controllable second-order polarization mode dispersion for fiber optic transmission systems are provided. A section of fixed high birefringent optical fiber, a polarization controller, and a variable differential group delay module are provided. The polarization controller is connected to the optical fiber section, and the variable differential group delay module is connected to the polarization controller. The variable differential group delay module is controlled to vary the second-order polarization mode dispersion values at an output of the high birefringent optical fiber section.

Abstract: In a method for measuring jitter, a signal under test is inputted to generate signal transition locations. A signal transition location is latched using a sampling clock signal, and the signal transition location is converted to a delay value. The delay value is converted to an edge position output, and a value of the edge position output is detected.

Abstract: A network test architecture includes a plurality of modules for performing a plurality of functions, each of the plurality of modules having a unique identifier. An additional module for performing an additional function has an additional unique identifier. A control bus is connected among the plurality of modules; a data bus is connected among the plurality of modules; and a power bus is connected among the plurality of modules. A controller controls operation, data transmission, and powering of the plurality of modules and the additional module, respectively, through the control bus, the data bus, and the power bus, the controller using the unique identifier and the additional unique identifier of the plurality of modules upon simultaneous connection of the control bus, the data bus, and the power bus to the additional module.

Abstract: A Digital Subscriber Line Access Multiplexer includes a set of line cards, a set of xDSL modem cards, a redundant xDSL modem card, a test and switching unit, a control unit, and a trunk unit. Each line card may include a switch, through which the control unit may selectively direct the line card to couple to a corresponding xDSL modem card or a redundancy bus. The test and switching unit is coupled to the redundancy bus, and includes a relay matrix and a Copper Loop Tester (CLT). In response to commands received from the control unit, the relay matrix may route redundancy bus signals to the CLT and/or the redundant xDSL modem card. The CLT performs tests to measure or determine subscriber loop electrical characteristics in response to control unit commands, and returns test results to the control unit.

Abstract: A method and system are provided for determining the identity of computer peripheral devices that are coupled to a computer or network communication system in a daisy chain configuration. The computer includes a first switch. Each of the plurality of computer peripheral devices includes a bypass board having a second switch thereon. The method includes: (a) opening the first switch and the second switches; (b) closing the first switch; (c) detecting a short circuit formed between the computer and each one of the plurality of computer devices; and (d) identifying one of the peripheral computer devices which detects the short circuit as the first identified peripheral computer device. A method and system is also provided for sharing resources in a computer system, which includes a computer and peripheral computer devices.

Abstract: A method and system is provided for monitoring the quality of signal transmissions in a communications network by calculating Quality of Services (QoS) scores and corresponding Transmission Impairment Test (TIT) scores, and then monitoring a QoS score to predict a corresponding TIT score. When the predicted TIT score goes below a minimum value, an administrator of the communications network will be informed so that the administrator can determine if services may be needed to restore the quality of signal transmissions. In an embodiment, the communications network includes a cable modem termination system (CMTS); a voice band tester (VBT) coupled to the CMTS; a cable modem tester coupled to the CMTS; and a Voice over Internet Packet (VoIP) monitoring device coupled to the CMTS and the voice band tester. The cable modem tester is located at a location remote from the VBT.

Abstract: A method and system is provided for monitoring the quality of signal transmissions in a communications network by calculating Quality of Services (QoS) scores and corresponding Transmission Impairment Test (TIT) scores, and then monitoring a QoS score to predict a corresponding TIT score. When the predicted TIT score goes below a minimum value, an administrator of the communications network will be informed so that the administrator can determine if services may be needed to restore the quality of signal transmissions. In an embodiment, the communications network includes a cable modem termination system (CMTS); a voice band tester (VBT) coupled to the CMTS; a cable modem tester coupled to the CMTS; and a Voice over Internet Packet (VoIP) monitoring device coupled to the CMTS and the voice band tester. The cable modem tester is located at a location remote from the VBT.

Abstract: A method and apparatus for providing tunable second-order polarization mode dispersion with constant mean first-order differential group delay for fiber optic transmission systems are provided. A section of fixed high birefringent optical fiber, a polarization controller, and a variable differential group delay module are provided. The polarization controller is connected to the high birefringent optical fiber section, and the variable differential group delay module is connected to the polarization controller. The variable differential group delay module is controlled to vary the second-order polarization mode dispersion values at an output of the high birefringent optical fiber section. The polarization controller is controlled to hold the mean first-order differential group delay substantially constant at the output of the high birefringent optical fiber section for each value of the second-order polarization mode dispersion at the output of the high birefringent optical fiber section.