Abstract: A remote test unit and method of operation are provided for utilizes the ability of an access matrix ability to route signals. The Remote Test Unit can emulate a central Digital Subscriber Line Modem (DSLM-C) for testing customer premises equipment containing a remote Digital Subscriber Line Modem (remote Digital Subscriber Line Modem). The Remote Test Unit can also emulate a remote Digital Subscriber Line Modem for testing central offices equipment including a digital subscriber line access multiplexer (DSLAM) containing a central Digital Subscriber Line Modem. The Remote Test Unit can also emulate a concentrator connected to the DSLAM, a router connected to the concentrator, an Internet service provider (ISP) connected to the router, and a web site connected to the Internet service provider over the Internet.

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 utilizing tunable differential group delay with at least a component of a fiber optic transmission system includes providing a tunable differential group delay system that is optically connected to a component of the fiber optic transmission system. The tunable differential group delay system is then controlled to insert differential group delay into the component of the fiber optic transmission system.

Abstract: A remote test unit (RTU) and method of operation are provided for utilizes the ability of an access matrix ability to route signals. The RTU can emulate a central Digital Subscriber Line Modem (DSLM-C) for testing customer premises equipment containing a remote Digital Subscriber Line Modem (DSLM-R). The RTU can also emulate a DSLM-R for testing central offices equipment including a digital subscriber line access multiplexer (DSLAM) containing a DSLM-C. The RTU can also emulate a concentrator connected to the DSLAM, a router connected to the concentrator, an Internet service provider (ISP) connected to the router, and a web site connected to the ISP over the Internet. The RTU can further test, using emulation, ISO/OSI layers defined in the ISO/OSI reference model which are connected to the DSLAM.

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 apparatus for utilizing tunable differential group delay with at least a component of a fiber optic transmission system includes providing a tunable differential group delay system that is optically connected to a component of the fiber optic transmission system. The tunable differential group delay system is then controlled to insert differential group delay into the component of the fiber optic transmission system.

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 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 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 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 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 for detecting the presence of a bridge tap and other types of fault in a transmission line. Initially, test signals of predetermined frequencies are transmitted into a transmitting end of the transmission line. The test signals are received at a receiving end of the transmission line and the amplitudes of the received signal are measured. A frequency response of the transmission line is computed based on the measured amplitudes. The frequency response is then analyzed for the presence of a frequency-domain signature that corresponds to one of the detectable types of fault. The presence of a bridge tap or another type of fault is identified based on the detected frequency-domain signature. The frequency-domain signature associated with a bridge tap can comprise a set of one or more attenuation dips in the frequency response, with each attenuation dip corresponding to a local minima in the frequency response.

Abstract: A method for detecting the presence of a bridge tap and other types of fault in a transmission line. Initially, test signals of predetermined frequencies are transmitted into a transmitting end of the transmission line. The test signals are received at a receiving end of the transmission line and the amplitudes of the received signal are measured. A frequency response of the transmission line is computed based on the measured amplitudes. The frequency response is then analyzed for the presence of a frequency-domain signature that corresponds to one of the detectable types of fault. The presence of a bridge tap or another type of fault is identified based on the detected frequency-domain signature. The frequency-domain signature associated with a bridge tap can comprise a set of one or more attenuation dips in the frequency response, with each attenuation dip corresponding to a local minima in the frequency response.