Abstract: A signal acquisition device captures signals from a telecommunication line such as a local loop. The captured signals are spectrally analyzed using a signal-processing unit. The output of the signal-processing unit—in the form of a test spectrum—is provided to a signal identification system. The signal identification system comprises at least one of a plurality of spectra of known signals stored as templates. Using a matching algorithm, the spectrum of the test signal (unknown signal) is correlated with spectra of at least two known signals. The unknown signal is determined to be the same type as that of the known signal with whose spectrum the unknown signal produces the largest absolute correlation score. Alternatively, an unknown signals is determined to be that of a known signal if a correlation of both signals results in a score the absolute value of which is greater or equal to a predetermined threshold level.

Abstract: Telephone line service type identification is provided to a telephone technician in the field by the placement of one or more tuned circuit(s) across the telephone line. In one embodiment, an inexpensive tuned circuit such as a ceramic resonator forms a telecom service resonator ID device which is placed across a telephone line, either at the central office or at the customer premises. Injection of a test current at a predetermined frequency, and a suitable amplitude of the same indicates to the technician aspects of telecom service to that particular telephone line (e.g., the existence of POTS, ISDN, and/or xDSL) and or use of the telephone line by a home network such as HPNA. In another embodiment, a telecom service transponder ID device is formed to provide line service identification to an interrogating line technician. The telecom service transponder ID device is activated when the test signal including an appropriate frequency is present to cause excitation in the telecom service transponder ID device.

Abstract: A test system automatically locates impedance mismatched, energy reflection discontinuities (e.g., bridged taps) along a wireline communication link, by coupling a linearly stepped sinusoidal waveform to a measurement location of the wireline link. The applied waveform propagates down the link and is reflected back from the energy reflection discontinuities. A line monitoring receiver coupled to the measurement location samples the response of the line to the swept waveform. A response processor executes a frequency domain reflectometry algorithm to analyze the frequency response of the wireline to the stepped frequency waveform. It then generates an output representative of distances from the measurement location to the bridged taps.

Abstract: The system to pre-qualify copper subscriber loops for high bandwidth access service determines electrical characteristics of a subscriber line served by a central office switch from a location remote from said subscriber line absent a direct metallic connection exclusively to said subscriber line. This is accomplished where the subscriber line has subscriber equipment connected thereto at an end distant from said central office switch by establishing a communication connection through the central office switch between the service provider and the subscriber equipment connected to said subscriber line. In response to the establishment of this communication connection, electrical signals, comprising subscriber or network generated tone signals, are applied to the subscriber line to enable the service provider to determine the electrical characteristics of the subscriber line by analyzing the received tone signals.

Abstract: The invention is concerned with a method for controlling the transmission power for a session in a system for transmitting data via a telephone line by using a digital subscriber line between a user terminal and a central unit. In the method, the transmission power is increased or decreased between given limit values so that the power is kept as low as possible, while still providing sufficient transmission quality. The quality criteria according to which the transmission power is controlled consistis of the value of the Signal to Noise Ratio (S/N), and the number of bit errors BER within a given time interval.

Abstract: A method and system for determining the high speed data service capability of a subscriber line includes sending an embedded test signal to a subscriber line. A reflected signal received in response to the test signal is analyzed for determining transmission characteristics of the subscriber line. Based on the reflected signal, a determination about the high speed data service capabilities of the subscriber line is made and stored for future reference.

Abstract: A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.

Abstract: A DMT (Discrete Multi-Tone) test method is provided. The test method is employed by two test devices to estimate the theoretical and practical data rates of a cable under test for a pair of target ADSL (Asymmetric Digital Subscriber Line) DMT modems. The present DMT test can also be used to analyze the cause of, or to predict a problem, whereby a pair of ADSL DMT modems could fail to synchronize. The method includes (a) synchronizing two devices at lower frequencies; (b) measuring the frequency characteristics of the cable with test signals; (c) measuring the cable noise and interference for every sub-channel of the ADSL bandwidth; (d) determining the theoretical and practical data rates for every sub-channel, based on the measured frequency characteristics and noise characteristics, as well as modem parameters selected by the user; (e) estimating the theoretical and practical data rates for the ADSL bandwidth based on the ADSL DMT standard selected by the user.

Abstract: A longitudinal balance test circuit connects to the tip and ring lines of a pair of telephone wires. It also connects to a shield conductor that extends with the tip and ring lines. The test circuit includes a transformer which has two windings. One winding connects to the tip and ring lines, and it also connects to the shield conductor. The other winding connects to a signal generator that provides an alternating current test voltage with which to test longitudinal balance of the tip and ring lines. A method of testing a telephone line for longitudinal balance comprises: measuring an alternating current test signal applied to a telephone line under test; measuring stressed noise of the telephone line in response to the applied. alternating current test signal; calculating, in response to the measured alternating current test signal and the measured stressed noise, an adjusted value related to longitudinal balance regardless of the length of the telephone line under test; and displaying the adjusted value.

Abstract: A method and apparatus for measuring call setup time is presented. A first device in a network sends a signal to a second device. The first device monitors for a response from the second device and adjusts an answer tone setting for the second device based on the response. After which, the first device calculates an elapsed time between sending the signal and a receipt of the response.

Abstract: Telephone line service type identification is provided to a telephone technician in the field by the placement of one or more tuned circuit(s) across the telephone line. In one embodiment, an inexpensive tuned circuit such as a ceramic resonator forms a telecom service resonator ID device which is placed across a telephone line, either at the central office or at the customer premises. Injection of a test current at a predetermined frequency, and a suitable amplitude of the same indicates to the technician aspects of telecom service to that particular telephone line (e.g., the existence of POTS, ISDN, and/or xDSL) and or use of the telephone line by a home network such as HPNA. In another embodiment, a telecom service transponder ID device is formed to provide line service identification to an interrogating line technician. The telecom service transponder ID device is activated when the test signal including an appropriate frequency is present to cause excitation in the telecom service transponder ID device.

Abstract: A method detects a fault in a subscriber line having two wires with separate input impedances. The method includes driving the subscriber line from one end with an alternating voltage, making one-ended electrical measurements on the driven liner and determining from the measurements a quantity proportional to the phase difference of the two input impedances. The method also includes identifying a fault in response to the phase difference having a signature associated with presence of a fault in the line.

Abstract: A method and automatic test system for determining qualification of a twisted pair transmission line to propagate data signals. The method includes measuring phase imbalance in the twisted pair transmission line. The phase imbalance is determined by resistance imbalance in the twisted pair transmission line. The resistance imbalance is determined by applying a common mode voltage to the twisted pair transmission line; and, determining phase imbalance in the twisted pair in response to the applied common mode voltage. The method includes applying a common mode voltage to the twisted pair transmission line; determining phase imbalance if the twisted pair in response to the applied common mode voltage; detecting a peak in the determined phase imbalance; determining a frequency of the detected peak; determining line qualification in accordance with the determined frequency.

Abstract: To facilitate the use of relatively high frequency data transmission services over a wireline communication resource originally deployed to support low frequency voice band services, an assessment of the wireline communication resource (50-52) is based on attenuation of high frequency test signals, of known original level, that are generated (18) injected into the wireline communication resource from a test point (12). A detector (60) at a potential point of service, e.g. at a customers' premises (14), detects an attenuated level of the test signals and generates a control signal (70, 82), such as a drive current, indicative of the attenuation caused by the wireline communication resource (50-52). The control signal (70, 82) is then indirectly communicated back to the test point (12) in a coded form, and preferably within a voice band transmission.

Abstract: The invention presented herein is directed to a remotely addressable maintenance unit (RAMU) working in conjunction with a test head at the central office for detecting and locating faults in digital subscriber loop (DSL) and/or plain old telephone system (POTS) environments. The RAMU includes circuitry for setting and resetting one or more relays for either normal or testing/maintenance mode. The present invention provides a system and method for addressing the RAMU by applying either positive or negative voltages from the tip to ground, from ring to ground, and from tip and ring to ground. In this manner, individual RAMUs can be defined/designed to respond in certain voltage levels and polarities. Accurate fault detection and sectionalization is achieved by the combination of the addressing capabilities enumerated herein, and the impedance signature designed into the RAMU, working in concert with a test head in the central office.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist. Therefore, a channel check test system includes a transmitting side DCME for inserting a nonlinear quantized input test pattern into a channel to be tested, and a receiving side DCME.

Abstract: The present invention provides for an apparatus and a method for testing, configuring, and evaluating a transmission line. The apparatus of the present invention comprises a Universal Telephone Equipment Terminator (UTET) capable of implementing at least one of a test, configuration, and emulation on the transmission line.

Abstract: A line test apparatus includes a hand-held body having a sensor probe tip for capacitively or inductively sensing the presence of an audio signal within a conductor under test, or within a conductor pair under test. The probe tip delivers an electrical input signal to an amplifier housed within such body; the electrical amplifier serves to amplify the signal and produces an amplified electrical output signal at an output terminal thereof. A vibratory element is electrically coupled to the output terminal of the amplifier for vibrating with an intensity corresponding to the magnitude of the sensed audio signal. Other output transducers, such as LEDs and/or a loudspeaker, may also be included for providing visual and/or audible output signals indicating the presence and magnitude of the sensed audio signal.

Abstract: A communications system is tested to simulate a realistic conversation. A first measurement device make a call, through the system it is testing, to a second measurement device and the two devices converse using predetermined speech generated dynamically by each device in response to the signals received from the other, to simulate aspects of conversation over non-perfect communications system link. The progress of the conversation will therefore take different courses according to the quality of the link. For example, if an expected signal is detected by one device, it transmits an appropriate predetermined response to the other device. However, if the expected signal is corrupted, or not received at all, different predetermined responses (or no response at all) are transmitted to the other device. This in turn may cause the other device to repeat the original signal.

Abstract: There is described a key telephone system which enables rewriting of the main program of the key telephone system, recovery of the key telephone system from a failure, and maintenance of the key telephone system such as diagnosis in an immediate, flexible, and inexpensive manner, a maintenance method for the key telephone system, and a medium on which is recorded a program for carrying out the maintenance method. A program to be rewritten is downloaded from an external device to a second storage means. After an existing program of a storage means has been saved into the second storage means, the downloaded program stored in the second storage means is transmitted and rewritten into the storage means. Failure information recording means records information regarding at least failures that occur at the time of downloading the program, failures that occur at the time of saving the existing program, and failures that occur at the time of rewriting the downloaded program.

Abstract: A communication line tester system and method allows for effective measurement and presentation of communication line characteristics. The communication line tester includes a transmitter, an analog-to-digital converter and a main processor. The transmitter is electrically coupled to the communication line. The analog-to-digital converter is electrically coupled to the communication line. The main processor is electrically coupled to the analog-to-digital converter. The main processor include a pseudo-random code processor configured to generate pseudo-random coded signals for transmission by the transmitter on to the communication line and to decode pseudo-random coded signals received by the main processor from the analog-to-digital converter.

Abstract: A two-ended, line-driving and receiving/tone signal analysis system performs line connection verification applying a low-distortion, low-amplitude test signal to one end of a cable pair under test and monitoring the response of a remote end wireline pair. Preferably the test signal frequency is on the order of 110 Hz, which avoids domestic and foreign AC power signal frequencies and is spectrally equidistant from their harmonics. It also avoids ringing frequencies for POTS lines, and remains safely below the 350 Hz lower limit of POTS and other telephone line system services. In response to application of the 110 Hz test signal to tip and ring segments of a wireline pair at one end of the cable bundle, the energy of the 110 Hz component, as well as that of two other ‘spectrally nearby’ (slightly higher at 112 Hz and slightly lower at 108 Hz), are measured at a tip and ring pair at the far end of the cable plant.