Abstract: A test system and method for performing DSL assessments of a telephone line along a prescribed test path is disclosed. The disclosed test system and method includes a loop diagnostic test unit adapted for testing said telephone line using narrow-band and mid-band frequency test signals; a test system controller and a test system server to provide the DSL assessments to a user via an appropriate interface. In addition, the disclosed analysis methods utilize primary line condition information, secondary line condition information, historical line information, together with real-time measurements and external data inputs to perform line imbalance analysis, fault identification analysis, trend analysis, and jurisdictional analysis all of which have relevance to quality, performance and assurance of DSL service through the telephone line.

Abstract: A telephone line test system that may be used to compute line length of subscriber lines connected to a central office or other distribution point. When initially installed, the test system may automatically compute CO limits. The CO limits are computed from single-ended measurements on subscriber lines and represent electrical effects of the path between a test head and the distribution point. These CO limits are used to more accurately compute the length of lines connected to the distribution point using measurements made by the test system. Because the process uses single-ended measurements, it may be run in background mode during the initial installation of the test system or at any subsequent time it is desired to update the CO limits.

Abstract: In an apparatus and method for testing a VoIP network, a special mode sequence and a telephone number are transmitted on the VoIP network. In response to the transmission of the special mode sequence and the telephone number, a network connection is established on the VoIP network. Test data is transmitted from a first endpoint of the network connection to a second endpoint of the network connection. In response to the transmission of the test data, either the same or similar test data is returned to the first endpoint. The transmitted and returned test data are processed to determine at least one of: an amount of network delay in the transmitted and returned test data, an amount of jitter in the rate of the returned test data, and an amount of lost test data between the transmitted test data and the returned test data.

Abstract: The present invention provides a method and apparatus for estimating the insertion loss of a telephone line. A complex waveform is applied to each wire of the telephone line being tested. Real and imaginary components of the resultant waveform are measured at a plurality of frequencies. Insertion loss of the line is estimated from a series of single-ended voltage measurements made at a plurality of frequencies. These measurements are captured and used to estimate the insertion loss of the telephone line.

Abstract: A system and method for performing DSL assessments of a telephone line along a prescribed test path is disclosed. The disclosed system includes a loop diagnostic test unit adapted for testing said telephone line using narrow-band and mid-band frequency test signals; a test system controller and a test system server to provide the DSL assessments to a user via an appropriate interface. In addition, the disclosed methods include the basic steps of: accessing the telephone line along the test path that includes selected hardware such as a voice switch test bus, central office splitter, service provider instruments and terminations; ascertaining various line characteristics along the test path using mid-band and narrow-band frequency signals; analyzing the line characteristics to identify line conditions that affect DSL service; and determining the impact of the line conditions on DSL service.

Abstract: A system and method for performing DSL assessments of a telephone line along a prescribed test path is disclosed. The disclosed system includes a loop diagnostic test unit adapted for testing said telephone line using narrow-band and mid-band frequency test signals; a test system controller and a test system server to provide the DSL assessments to a user via an appropriate interface. In addition, the disclosed methods include the basic steps of: accessing the telephone line along the test path that includes selected hardware such as a voice switch test bus, central office splitter, service provider instruments and terminations; ascertaining various line characteristics along the test path using mid-band and narrow-band frequency signals; analyzing the line characteristics to identify line conditions that affect DSL service; and determining the impact of the line conditions on DSL service.

Abstract: A system for determining insertion loss of a telephone line under test (LUT) is responsive to electrical stimulation of an input of the LUT at each frequency of a first plurality of discrete frequencies for determining values of at least two of Rs, Cs, Rp and Cp at each frequency, wherein Rs and Cs represent an equivalent series RC input impedance of the LUT and Rp and Cp represent an equivalent parallel RC input impedance of the LUT. The system determines an insertion loss value of the LUT as a function of a value of one of Rs, Cs, Rp and Cp determined at one frequency of the first plurality of frequencies and a value of another one of Rs, Cs, Rp and Cp at another frequency of the first plurality of frequencies.

Abstract: A system for determining insertion loss of a telephone line under test (LUT) predicts a length d of the LUT at each of a number of discrete frequencies. The system determines for each predicted length d a running standard deviation that is a function of the predicted length(s) d at and below the frequency where the predicted length d was determined; and determines a mean length (dm) of the LUT as a function of the lengths d of the LUT determined for each frequency at and below the pair of adjacent frequencies where the largest difference between running standard deviations occurs. The system determines a gauge of the LUT as a function of the running standard deviation the one of said pair of adjacent frequencies; and determines an insertion loss value of the LUT as a function of the gauge and the mean length dm.

Abstract: A system for qualifying subscriber lines in a telephony system for high speed data services. The system includes a measurement unit that makes one ended electrical measurements on the subscriber lines. Measurements on the subscriber lines are used to predict which of the lines can carry signals used in high speed data services. The predictions are used in marketing select data transmission services.

Abstract: Faults or degradation of performance of a voice/data communication network (2) are identified without the need to dispatch service personnel by selectively testing isolated sections of the communication network. For some of these tests, the communication network address of a customer's modem under test (106, 114, 60, 66) is retrieved from a database (88) for use in directing these tests to the customer's modem (106, 114, 60, 66) and for emulating the customer's modem (106, 114, 60, 66) during one or more of the tests.

Abstract: A system for identifying service affecting conditions on a subscriber line in the access portion of a broadband network, particularly an ADSL network. A measurement unit provides information on the line that aids in identifying projected performance. Information from a modem on the subscriber line indicative of actual performance is obtained and compared to the predicted values. Deviations are used to identify service affecting conditions and, depending on the nature of the deviations, the type of condition affecting service on the line. The physical measurements are used to identify the length of the subscriber line. Modem information is obtained through the MIB and allows determination of the bit loading on the line. Interference sources are identified by comparing the actual bit loading to bit loading expected for a line corresponding to the measured length.

Abstract: A digital wideband node (DWN) (28, 48) is coupled to a remote terminal (RT) (22, 42) that in turn is coupled to a subscriber's telephone line (26, 46). The DWN (28, 48) is configured to (1) pass a subscriber's telephone number signal directly to the RT (22, 42) whereupon a test path (25, 45) is formed with the subscriber's telephone line (26, 46), (2) pass POTS test signals directly to the RT (22, 42) for testing the subscriber's telephone line (26, 46) via the test path (25, 45) and (3) process wideband test control signals into wideband test signals which are conveyed to the RT (22, 42) for wideband testing of the subscriber's telephone line (26, 46) via the test path (25, 45).

Abstract: First and second test devices communicatively coupled to a hybrid fiber/coax (HFC) plant are operative for transmitting data packets of a simulated Voice over Internet Protocol (VoIP) telephone call therebetween without the use of a physical telephone at either test device. Each test device is operative for analyzing data packets received or transmitted thereby and for transmitting its analysis of the received or transmitted data packets to a call management system and a test controller.

Abstract: The system and method of determining insertion loss of a telephone line under test (LUT) determines a first insertion loss as a function of plurality of different equivalent circuit values of the LUT determined at a plurality of different frequencies of a first set of discrete frequencies. A running standard deviation (rSTD) of a predicted length d of the LUT at each frequency of a second set of discrete frequencies is determined from the predicted lengths d of the LUT at and below said frequency. A second insertion loss is determined based on the pair of adjacent discrete frequencies of the second set of discrete frequencies that have the largest difference between their rSTDs. Based on a comparison of the first and second insertion losses to an expected insertion loss, one of these insertion losses is deemed to be the actual insertion loss of the LUT.

Abstract: The system and method of determining insertion loss of a telephone line under test (LUT) determines a first insertion loss as a function of plurality of different equivalent circuit values of the LUT determined at a plurality of different frequencies of a first set of discrete frequencies. A running standard deviation (rSTD) of a predicted length d of the LUT at each frequency of a second set of discrete frequencies is determined from the predicted lengths d of the LUT at and below said frequency. A second insertion loss is determined based on the pair of adjacent discrete frequencies of the second set of discrete frequencies that have the largest difference between their rSTDs. Based on a comparison of the first and second insertion losses to an expected insertion loss, one of these insertion losses is deemed to be the actual insertion loss of the LUT.

Abstract: In an apparatus and method for testing a VoIP network, a special mode sequence and a telephone number are transmitted on the VoIP network. In response to the transmission of the special mode sequence and the telephone number, a network connection is established on the VoIP network. Test data is transmitted from a first endpoint of the network connection to a second endpoint of the network connection. In response to the transmission of the test data, either the same or similar test data is returned to the first endpoint. The transmitted and returned test data are processed to determine at least one of: an amount of network delay in the transmitted and returned test data, an amount of jitter in the rate of the returned test data, and an amount of lost test data between the transmitted test data and the returned test data.

Abstract: A receiver for frequency shift keyed data transmission implemented using degenerate digital signal processing techniques, whereby complex circuitry can be avoided in favor of low cost, readily manufactuable logic gates.

Abstract: An electronic relay matrix (22) is connectable between a plurality of customer telephone lines and a plurality of testers (2, 201-203) The electronic relay matrix (22) includes a line matrix (80) having a plurality of relay assemblies (821-8250) Each relay assembly (82) in a relaxed state connects together the line-side (12) and the drop-side (8) of one of the customer telephone lines. Each relay assembly (82) is adjustable to enable one of the plurality of testers (2, 201-203) to be connected to the drop-side (8) and/or the line-side (12) of a desired customer telephone line.