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: 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.

Abstract: A delay-line time-domain reflectometer includes a return detector configured to process a discharge pulse produced by discharge of a line capacitor, formed by the physical relationship of a pair of conductive wires forming a telephone line, from a predetermined DC voltage. The return detector includes a number of neural networks configured to process the discharge pulse under the control of a controller. The neural networks enable the controller to characterize the loop configuration of the telephone line, where the loop configuration includes the length of the telephone line, the position of any bridged tap connected to the telephone line and/or the length of any bridged tap connected to the telephone line.

Abstract: An apparatus for testing a telephone line (12) includes a charge generator (4) for selectively charging a line capacitor (16) formed by the physical relation of at least two electrically conductive leads (8, 10) of the telephone line (12) to a predetermined DC voltage. A line clamp (6) selectively connects the leads (8, 10) together and a return detector (18) receives a discharge pulse (22) produced by discharge of the line capacitor (16) in response to the line clamp (6) connecting the leads (8, 10) together. The return detector (18) detects an end-of-line pulse (28) and/or a bridged-tap pulse (32) superimposed on the discharge pulse (22) and outputs an analog return signal as a function thereof.

Abstract: A telephony test system (34) has a communication interface (52, 54, 56) connected to communicate with a remote terminal (16). In response to receiving an electrical test request signal from the remote terminal (16), a controller (50) causes an analog-to-digital converter (DAC) (70) to produce an analog signal which is supplied to a high voltage amplifier (124) which amplifies and supplies the amplified analog signal to customer telephony equipment (6). Controller (50) measures the response of customer telephony equipment (6) to the amplified analog signal and determines from the response and the amplified analog signal an electrical power dissipated by the high voltage amplifier during supply of the amplified analog signal. Controller (50) controls a power supply to adjust the voltage supplied to the high voltage amplifier (124) to avoid electrical power dissipated thereby during supply of the amplified analog signal from exceeding a desired maximum electrical power dissipation.

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.

Abstract: One or more pieces of equipment of a hybrid fiber-coaxial (HFC) network has a frequency agile transponder connected thereto. Each frequency agile transponder includes a transmitter (T) and a receiver (R) which are connectable to a coaxial line of the HFC network. Bidirectional communications can occur between a controller and each frequency agile transponder via the HFC network. The frequency agile transponder has analog inputs/outputs connectable to test points of the one or more pieces of equipment of the HFC network. The frequency agile transponder can test the test points and supply to the controller the results of the test. The transmit and receive center frequencies of the transmitter and receiver of the frequency agile transponder can be selectively and remotely adjusted by the controller to avoid signals at carrier frequencies utilized to transmit program material, data signals and/or telephony signals.

Abstract: A remote telephone testing device (22) includes a transmitter (30), a receiver (24), a controller (26) and a test circuit (28). In response to the receiver (24) receiving a test signal from a test system (20) via a telephone network (2, 4, 6, 8), the controller (26) communicatively isolates telephone equipment (10) of a subscriber (S) from the telephone network (2, 4, 6, 8) and connects the test circuit (28) to the telephone equipment (10). The test circuit (28) tests the telephone equipment (10) and conveys one or more results of such test to the controller (26) which relays the one or more results to the test system (20) via the transmitter (30). When testing is complete, the telephone equipment (10) is isolated from the test circuit (28) and is communicatively connected to the telephone network (2, 4, 6, 8).

Abstract: A telephone test system (2) includes a controller (4), a programmable gate array (PGA) (24) and a digital signal processor (DSP) (26) connected by a common bus (20). The PGA (24) includes an output connected to an input of a digital-to-analog converter (DAC) (36) and input connected to an output of an analog-to-digital converter (ADC) (32). A driver circuit (46) is connected between the DAC (36) and a telephone circuit (60) and between the ADC (32) and the telephone circuit (60). Under the control of the DSP (26), the driver circuit (46) generates voltages to the telephone circuit (60) and samples the response of the telephone circuit (60) to such generated voltages. The driver circuit (46) includes control inputs for receiving from the PGA (24) an impedance adjust signal (D) and a resistance adjust signal (R). An output impedance (124) of the driver circuit (46) connected to the telephone circuit (60) is adjustable as a function of the impedance adjust signal (D) and/or the resistance adjust signal (R).

Abstract: A broadband network for providing broadband signals, such as cable television signals, to a subscriber location includes a network interface device installed at the subscriber's end of the broadband network. The network interface device includes circuitry that provides for the selective provisioning of services to the subscriber location from the broadband network and a test circuit that can be selectively connected for testing signals appearing on the broadband network.

Abstract: A channel unit network having a two-wire port for interconnecting a two-wire, bidirectional signal transmitting means with a four-wire digital transmitting means in a communication system to create a precision bidirectional simulated two-wire cable pair with an extended operation range over a transmission medium includes a signal processing circuit, tip and ring switch mode driver, a negative inductor circuit, a negative capacitor circuit, and a 200 Hz impedance circuit. The negative conductor circuit and the negative capacitor circuit are used to generate respective negative inductance and negative capacitance at 24 Hz in order to maintain loop stability. The 200 Hz impedance circuit is used to generate a positive impedance at a frequency of approximately 200 Hz so as to prevent overloading of external telephone communication testing circuitry.

Abstract: A channel unit network for interconnecting a two-wire, bidirectional signal transmitting means with a four-wire digital transmitting means in a communication system to create a precision bidirectional simulated two-wire cable pair over a transmission medium includes tip and ring switch mode drivers, a signal processing circuit, a decoupling circuit, and tip and ring balance amplifiers. The decoupling circuit is used for splitting off "voice band" frequency signals from incoming tip and ring "DC band" signals from the two-wire means. The signal processing circuit performs both analog-to-digital conversions and digital-to-analog conversions.

Abstract: A metallic channel unit network for interconnecting a two-wire, bidirectional signal transmitting means and a four-wire signal transmitting means in a communication system includes a voice hybrid driver, A/D signal processing circuit, D/A signal processing circuit, tip and ring switching drivers, and tip and ring sensing amplifiers. The metallic channel unit network is suitable for use with substantially all of the different alarm-signalling techniques utilized by the various alarm companies for connecting their equipment to a channel bank multiplexer coupled to the four-wire means. The metallic channel unit network provides an apparent metallic cable pair over the digital carrier in the frequency range of DC to 3.5 KHz with an amplitude variation between +200 to -200 VDC.