Abstract: A method and system for testing trunks and modems of communication lines includes identifying a trunk and a modem in a communication line from trunk signaling (SS7) data. Historic performance data of the modem in the communication line is then measured. The historic performance data includes the time the modem is connected with the trunk, the speed at which data is communicated through the modem and the trunk in the communication line, and the rate at which the modem connects with the trunk. The performance data of the modem is then correlated with the trunk signaling data to associate the performance data of the modem with the trunk in the communication line. The performance data of the modem is then analyzed to determine if the communication line is operating improperly. The analysis is performed to determine whether the trunk or the modem is operating improperly.

Abstract: A digital subscriber line (xDSL) communication system (10) is disclosed that allows xDSL communication across a local loop. The system (10) includes a local loop termination point (14) and customer premises equipment (12) connected to a twisted pair telephone line (16). Loop integrity test devices (22, 24) for xDSL communication are located at the local loop termination point (14) and the customer premises equipment (12) and are coupled to the telephone line (16). The loop integrity test devices (22, 24) are respectively operable to transmit test signatures across the telephone line (16), to receive and evaluate test signatures from the telephone line (16), and to indicate whether the telephone line (16) can support xDSL communication based upon evaluation of test signatures.

Abstract: A sensor capable of being coupled to a transmission line and monitoring a foreign voltage on the transmission line includes a voltage monitoring circuit. The voltage monitoring circuit is adapted to operate in a foreign voltage detection mode in response to receiving a first logic signal and a foreign voltage measurement mode in response to receiving a second logic signal. A method for operating a circuit to detect and measure a foreign voltage on a transmission line includes providing a first logic signal to configure the circuit to detect the foreign voltage. The foreign voltage is detected on the transmission line in the circuit. A second logic signal is provided to configure the circuit to measure the foreign voltage, and the foreign voltage is measured.

Abstract: The present invention is embodied in a system and method for protecting an electronic device connected to a telephone line. The system includes a detector, sensor and protector. The detector determines a resistance built-in to the telephone line, the sensor utilizes the resistance of the telephone line to determine if the telephone line is a digital line and the protector prevents the electronic device from prolonged connection with the telephone line if it is a digital line.

Abstract: A method that uses a test system at one end of a communication link to test the communication link for high speed service by coupling the test system to the communication link, placing a telephonic call to telephonic equipment located at an other end of the communication link and testing the communication link with the test system after the call has been terminated at the telephonic equipment.

Abstract: A telephone line measurement circuit is disclosed for detecting a variation of a characteristic between a first and a second leads of a telephone line. The circuit comprises a first circuit having a first and a second inputs and an output. The circuit also has a second circuit having a first and a second inputs and an output. The first input of the first circuit and the second input of the second circuit are coupled to the first lead of the telephone line and the second input of the first circuit and the first input of the second circuit are coupled to the second lead of the telephone line. The outputs of the first and the second circuits are then coupled together to provide an output for the measurement circuit.

Abstract: A cross connect physical layer switching system is integrated into a central office and facilitates delivering data services, such as digital subscriber line (DSL) service, to subscribers over a shared data and voice line. The cross connect physical layer switching system may be placed between a splitter and the shared line to allow a remote test unit to be controllably connected to the shared line to permit testing of the shared line by a competitive local exchange carrier (CLEC). By placing the physical layer switching system in the CO, both the CLEC and the incumbent local exchange carrier (ILEC) have fill access to the test head (RTU) and full spectrum testing of the line. This allows test access to continue to be done remotely as in an unshared line environment.

Abstract: An adapter/converter circuit converts transmissions by a mobile telephone built for one standard (e.g., PCS) from the telephone transmit/base station receive frequency of that one standard to the telephone transmit/base station receive frequency of another standard (e.g., cellular), and converts transmissions by a base station or similar device (e.g., a base station simulator) from the telephone receive/base station transmit frequency of the one standard to the telephone receive/base station transmit frequency of the other standard. The two frequency conversions occur simultaneously on two parallel legs under the control of a PLL dual frequency synthesizer, which is in turn controlled by user input (in the case where the adapter is used to allow, e.g., PCS telephones to be tested on cellular test equipment) or by the base station (in the case where the adapter is used to allow, e.g., PCS telephones to be used with a cellular base station).

Abstract: A subscriber circuit allowing a reliable and proper subscriber line test is disclosed. The subscriber circuit includes a splitter and a feeder for feeding a current to subscriber equipment through a subscriber line. A path selector is provided to select one of a first path and a second path between the subscriber line and the feeder. The first path has the splitter inserted therein and the second path has no splitter inserted therein. The path selector normally selects the first path. When the subscriber line test instruction is received, the path selector selects the second path.

Abstract: An in-line data protector for preventing a test set from accessing a telephone line under a predetermined condition is disclosed. The in-line data protector selectively connects the test set and the telephone line responsive to detection of a data signal on the telephone line. The in-line data protector includes a power circuit for providing general operating power, a processor connected to the telephone line, and a relay serially connected between the telephone line and the test set. When general operating power is received, the processor analyzes the telephone line by emulating a single band filter. By using a single band filter, a very good determination can be made as to whether a signal on the telephone line is a data signal or a voice signal. If the signal is not a data signal, the processor instructs the relay to close, thereby connecting the telephone line to the test set.

Abstract: A graphics overlay for displaying the location of a traced connector port in a telecommunications patching system. The graphics overlay is the visible portion of a tracing interface module that is viewed by a technician performing a patch cord tracing procedure. The graphics overlay serves three primary functions. The first function is to provide is a visual indication that can inform a technician as to the location of a patch cord in a telecommunications patch system. The second function is to provide a trace button so that a technician can initiate a trace from any patch cord connect port in the patching system. Lastly, the third function is to identify the patch cord at each connector port in the telecommunications patching system. The present invention provides different embodiments of a graphics overlay that all embody the necessary functions yet are uniquely adapted for use in a telecommunications patch cord tracing system.

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: A long-distance transmission system includes a network terminal that accommodates terminal equipment, and a line terminal connected to the network terminal via a two-wire metallic subscriber line. The network terminal includes an amplifier, which amplifies a transmission level of a transmission signal to be transmitted to the line terminal via the two-wire metallic subscriber line on the basis of a characteristic of the two-wire transmission line.

Abstract: A method and apparatus for qualifying a telephone transmission line for XDSL communication services is disclosed. The system includes a modem, located at the customer premises to be connected. The modem analyzes actual signals to determine the electrical characteristics of the communication channel associated with the customer premises. The modem includes a transmitter, receiver and controller to generate test signals and receive responses. The modem then analyzes the data to generate an output value indicative of the electrical characteristics of the communication channel being tested. This output value is then displayed to a user or transmitted over the communication channel to a network. The system thereby eliminates the necessity of dispatching a technician to test the telephone line, and provides more accurate test results than those achievable at the network-side of the connection alone.

Abstract: A conditioner unit is wired in parallel with a pair gain test controller used to test a digital loop carrier telephone network. The conditioner unit senses a signal intended to request test results from the pair gain test controller and provides a response signal which indicates that the pair gain test controller performed a successful test, even though the pair gain test controller was not activated. This allows testing of the network without use of a bypass pair or the need to interface the digital loop carrier network with the pair gain test controller.

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 network termination device which will operate correctly even if its connection to a central office has reverse polarity. A network termination device at customer premises is connected to a line termination device located at a central office via a two-wire subscriber loop. If this connection was made with reverse polarity, the supply voltage provided by the line termination device would oscillate at specific intervals, alternating between normal polarity and reverse polarity. In such a case, a polarity switch controller in the network termination device directs its local polarity reversing switch to alternate the polarity at predetermined intervals longer than the cycle time of the above oscillation. This produces such a situation where a reverse supply voltage is present and the polarity reversing switch is in reverse mode, resulting in correct polarity as a whole.

Abstract: A line circuit for serving a digital telephone set over a link of indeterminate length and attenuation characteristics includes a processor for issuing test messages over the link to the telephone set and which responds to the receipt of an acknowledgment message from the telephone set by inserting increasing amounts of finite attenuation into the link until the acknowledgment message fails to be received, at which point the value of inserted attenuation is a measure of the excess link margin.

Abstract: The present invention is generally directed to a telephone handset for testing the transmission quality of a local loop. In accordance with one aspect of the invention, the telephone handset includes a connector configured to connect to the local loop at, for example, a junction box. The invention also includes a low-pass filter circuit electrically interposed between the connector and operational circuitry of the telephone handset. In operation, the low-pass filter is designed to pass (substantially undisturbed) electrical signals within the POTS frequency band from the connector to the operational circuitry. In the same way, the low-pass filter is designed to substantially block the passage of electrical signals above the POTS frequency range. In this way, the low-pass filter blocks the introduction of high frequency signals, which may otherwise generate intermodulation products within the audible range, from reaching the operational circuitry of the testing handset.

Abstract: A method of testing telecommunication facilities first records a real communication between at least two telecommunication facilities. The recorded real communication is then analyzed, and from the results of the analysis a test case is generated. The test case is then used to test one of the telecommunication facilities and the test results are evaluated. The method may be incorporated as part of a test generator.

Abstract: A system and methodology for qualifying a twisted pair copper loop for digital subscriber loop services are described. The system automatically queries telecommunications provider database records and/or requests measurements from network switching equipment or testing systems to obtain data regarding the twisted pair copper loop, such as loop length, electrical characteristics, and other loop topology characteristics such as wire gauge, the presence of load coils, and the presence of bridge taps. The system determines which digital subscriber loop services are available for the copper loop based on the combination of all data obtained. The system may be implemented in part as an expert system with a knowledge base of qualification rules used in the decision-making process.

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.

Abstract: A network interface device intended to be placed approximate to the customers equipment and remote from a central office of a telephone company (“TELCO”). The purpose of the network interface device is to allow the twisted pair transmission line between the central office and the customer's port to be selectively switched from a normal monitoring mode into a test mode. The test mode has two phases. In the first phase, the NIU transmits a signal back to the central office. This allows the central office to determine whether there are any problems with the transmission line, the potential bandwidth for the transmission line and related parameters concerning the efficacy and suitability of the transmission line for a variety of communication services. In the second phase, which is entered into upon completion of the first phase, the customer-end ADSL low pass filter is bypassed so that the central office can test the customer's POTS equipment.

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 if 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.