Abstract: A system and method for testing a transmission line to a protected system includes measuring voltages between a tip-side node of an overcurrent protection device and the protected system, between a ring-side node of the overcurrent protection device and the protected system, between the tip of the transmission line and the protected system, and between the ring of the transmission line and the protected system. Using the measured voltages, the status of the overcurrent protection device and the overvoltage device may be recognized, and the magnitude of a voltage surge on either of the tip and ring wires may be determined.

Abstract: A system and method for managing battery slump in a battery-powered communications device including: an input configured for receiving battery voltage level information; an output configured for sending a signal for terminating a transmission; and a controller connected to the input and the output and configured to receive the battery voltage level information from the input; monitor the battery voltage level information; and send a signal via the output to terminate a transmission if the battery voltage level information crosses a predetermined threshold during the transmission. In particular, the system and method may further include an input connected to the controller and configured for receiving a signal indicating when a transmission is beginning or occurring and the controller is further configured to receive and monitor the battery voltage level information only when the transmission is occurring.

Abstract: An improper connection determination method includes a closed circuit forming step, a current detection step and a determination step. In the closed circuit forming step, a closed circuit from one of at least two contacts in a telephone connection terminal of a communication apparatus to another one of the at least two contacts in the telephone connection terminal is formed. In the current detection step, a current flowing in the closed circuit, when the closed circuit is formed in the closed circuit forming step, is detected. In the determination step, it is determined that the telephone line is improperly connected to the telephone connection terminal when the current is detected in the current detection step.

Abstract: The present invention discloses circuits for isolating and attenuating signals generated by a telephone network. In disclosed embodiments, a metering pulse signal is isolated from the terminals of the connecting device, and then attenuated with an impedance that is synthesized with a programmable digital signal processor. Embodiments also utilize the digital signal processor to synthesize a termination impedance for the connecting device. The termination impedance matches closely the characteristic impedance of the network, so as to minimize wave reflections and the like.

Abstract: Test systems and methods are disclosed for determining the cause of an extended off-hook condition on a subscriber line. A test system as described herein measures a first resistance of the subscriber line based on a first current, and also measures a second resistance of the subscriber line based on a second current. The test system then determines the difference between the first and second resistance measurements. If the difference between the first and second resistance measurements is greater than a threshold value, such as 20 Ohms or more, then the test system determines that the extended off-hook condition is the result of an off-hook telephone on the subscriber line. If the difference is less than the threshold value, then the test system determines that the extended off-hook condition is the result of a short circuit on the subscriber line.

Abstract: A telephone switchboard provides various operating voltages to a telephone in different operation modes. The telephone switchboard includes a control unit, an output control circuit and a voltage converter. The control unit detects the operation mode of a telephone and generates control signals to the output control unit. The output control unit controls direction of current flowing through the telephone according to the control signal, and generates a feedback signal according to any change in the operation mode of the telephone. The voltage converter receives the feedback signal and converts the received power to a suitable output operation voltage according to the feedback signal. The telephone switchboard is capable of providing various operation voltages to the telephone in the different operation modes.

Abstract: The present invention provides for a system, method and apparatus for monitoring telecommunication components. The invention provides a switch placed at a remote location, wherein the switch includes a converter that converts power from a first voltage to a second voltage, a plurality of communication lines for a connection to a plurality of end users; and an interface that establishes a communication link with a central office. A transmitter is associated with the converter or other switch component; the transmitter transmits a wireless signal relating to a converter or other switch component operating condition. A receiving device receives wireless signals from the transmitter and provides the signals to a serving area interface for processing and/or transmission of the signals to a Central Office for monitoring. A transmitter may initiate transmission upon the occurrence of a change in operating condition.

Abstract: A method for reducing noise is in a subscriber line interface circuit of a phone includes detecting a work state of the phone, and reading a voltage on hook on the tip wire when the phone is in the on hook state. Voltages of an off hook state on the tip wire and a voltage off hook state on the ring wire are read when the phone is in the off hook state, and calculation of a public voltage based on the voltages in the register, and loading the public voltage on the ring wire are done. The public voltage on the ring wire are converted into oscillatory voltages on the ring wire in symmetric wave forms having phases opposite to those on the tip wire, when the phone is in the pulse dialing state.

Abstract: A managed port circuit includes a detection circuit that is disposed in a communication channel between a first local port and a second local port and a controller that is coupled to the detection circuit and is operable to configure the detection circuit in a detection configuration in which the first and second local ports are connected to the controller and a second pass through configuration in which the first and second local ports are connected to each other via the communication channel, the controller being further operable to determine when an end device is connected to one of the first and second local ports when the detection circuit is in the detection configuration.

Abstract: A method and system are presented for sensing a physical position of a cordless handset with respect to a base unit. A dataset of measured line currents may be initialized. A line extension may receive a number for use in determining the position of an associated cordless handset. Stored on-base-unit and off-base-unit line currents may be accessed. A determination may be if the cordless handset is positioned on the base unit, and in response to a determination that the handset is in contact with the base unit, a desired task may proceed.

Abstract: A loop polarity auto-reversing system 100 of a U interface is disposed in a line terminal 10 connected to a digital service unit 20 via the U interface. The loop polarity auto-reversing system includes a current detection module 101, a loop polarity determining module 103, and a loop polarity reversing module 105. The current detection module is for detecting whether there is loop current at the U interface. The loop polarity determining module is for determining whether a loop polarity of the U interface is correct if there is loop current. The loop polarity reversing module is for reversing the loop polarity of the U interface if the loop polarity is incorrect. An auto-reversing method for reversing the loop polarity of the U interface is also provided.

Abstract: Embodiments related to line testing are described and depicted.

Abstract: A sealing current system for a subscriber line that comprises a power source coupled to a first end of the subscriber line configured to apply a voltage to the subscriber line. The sealing current termination circuit coupled to a second end of the subscriber line configured to limit a current in the subscriber line, the current produced by the applied voltage.

Abstract: The present invention discloses circuits for isolating and attenuating signals generated by a telephone network. In disclosed embodiments, a metering pulse signal is isolated from the terminals of the connecting device, and then attenuated with an impedance that is synthesized with a programmable digital signal processor. Embodiments also utilize the digital signal processor to synthesize a termination impedance for the connecting device. The termination impedance matches closely the characteristic impedance of the network, so as to minimize wave reflections and the like.

Abstract: A test unit for an aircraft cabin telephony system includes a pair of connectors for inserting the test unit in-line within the system; an AC voltage module that is operative to indicate the presence of an AC voltage when the test unit is connected to the Cabin Delivery System connector of the cabin telephony system; a signal module that is operative to detect the presence of data signals when the test unit is connected to the Cabin Delivery System connector; a DC power module that is operative to indicate the presence of DC voltage when the test unit is connected to a seat telephony box within the cabin telephony system; and an AC current module that is operative to detect an over-current condition when the test unit is connected to the Cabin Delivery System connector of the cabin telephony system.

Abstract: A method uses circuitry in a data interface that provides telephony service over a high-speed network to detect the presence of a secondary source of VBH battery voltage on a tip-ring system. If a detected source other than the data interface is impressing battery voltage on the tip-ring system, the circuitry disconnects the data interface's battery source and produces a message that another source is VBH. The determination that another source is present may be based on a threshold value to account for noise. The message is used to produce an alarm at a user interface device. The alarm may be a light indication mounted on the data interface. The alarm may also be a web page that is retrieved from a memory device and displayed on a PC, a PDA or the data interface. The alarm may be provided locally and remotely to a provider's server.

Abstract: A method and apparatus for internally testing portions of a subscriber loop interface circuit. Testing may be conducted on a semiconductor circuit including the subscriber loop interface circuit. The portion of the subscriber loop interface circuit being tested may be the ring trip detector and/or the off-hook detect circuit. Testing may be conducted without disabling the capability of the subscriber loop interface circuit to monitor the hook status of a subscriber.

Abstract: The present invention provides for an apparatus and a method for testing and evaluating a transmission line. A set of command and data signals is received through an input/output interface. The command and data signals from the input/output interface are processed for controlling at least one relay. At least one switch is activated for testing a transmission signal line using the relay. The transmission signal line is tested based upon the activated switch.

Abstract: A telephone communication system having a cordless telephone operating in conjunction with a cellular transceiver. A subscriber line interface circuit (SLIC) is controlled by a microprocessor in the cellular transcriber. The SLIC can be controlled to provide standard telephone service to other telephone sets, and includes circuits for testing for foreign voltages on the telephone lines prior to providing SLIC service. Standard RJ-11 jacks are utilized for coupling the telephone sets to the communication system to provide standard telephone service by way of the cellular network.

Abstract: The invention presented herein is directed to a battery injection and loop supervision (BILS) system and method that can be used in the DSL environment. The BILS of the present invention provides battery injection, loop supervision, and butt set operation mode detection in the DSL environment. A voltage source, detector and comparator in the BILS unit can be used to supervise the copper loop status from the central office. In addition, using the present invention, a field technician using a conventional butt set can detect battery voltage and receive an audible tone from the cooper loops in the DSL environment. Furthermore, the BILS can be implemented in accordance with two preferred embodiments, voltage sensing and current sensing. The BILS includes circuitry, working in conjunction with a shared common resource card and a conventional butt set, for testing, maintaining, and installing copper loops in the DSL environment.

Abstract: Method for measuring a load impedance (ZL) of a load circuit which is connected to an SLIC circuit (6) of an analog terminal connection of a terminal device, having the following steps: specifically a digital toll signal (x1) is generated by means of a Codec circuit (13) connected to the SLIC circuit (6), said toll signal (x1) being converted into an analog toll signal; the analog toll signal is output by the SLIC circuit (6) to the load circuit; an analog voltage which is brought about at the terminal connection (4,5) of the terminal device of the SLIC circuit (6) via the analog toll signal is sensed; the digital toll signal (x1) is filtered by means of an adaptive filter (39) which is provided in the Codec circuit (13) and has adjustable filter coefficients (g1, g2) for generating a filtered digital comparison signal (yv) which is converted into an analog comparison voltage (Uv); the filter coefficients (g1, g2) of the adaptive filter (39) are adjusted until the analog comparison voltage (Uv) and the analog

Abstract: In a telecommunications system, a switching device selectively applies one of two different voltage supplies to a common node. A first of the voltage supplies is coupled to the common node by a first switch and a second of the voltage supplies is coupled to the common node by a second switch. The switching device includes the following elements. A difference detector detects a difference between the first and second voltage supplies. A control circuit selectively enables one of the first and second switches and disables the other of the first and second switches, for switching between the first and second voltage supplies in response to the difference detector. The control circuit performs the switching between the first and second voltage supplies when the detected difference falls below a predetermined threshold.

Abstract: A method for transferring alarms, in which method a pre-determined area (1) is monitored by a monitoring device (24) connected to a subscriber line (10, 12, 14); the condition of the subscriber line (10, 12, 14) is monitored by line testing; when the ISDN subscriber line (10, 12, 14) lacks functionality an alarm is identified in a switching center (20); and from the switching center (20) the alarm is directed to an alarm monitoring system.

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: A telephonic apparatus comprises terminals for connecting it to respective electric cables, telephonic circuitry, and a switch between the terminals and the circuitry. It also includes a sensor for detecting a DC voltage above a first level between said terminals. It the sensor detects a DC voltage between said terminals above the first level, it prevents the switch from connecting the circuitry between the terminals.

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 network interface circuit employing differentially driven capacitive couplings across a high voltage isolation boundary and in which a &Sgr;/&Dgr; CODEC is positioned on the line side of the high voltage interface. In this manner, only four wires cross the high voltage boundary, namely differential pairs for transmit data and receive data. The transfer functions for setting AC and DC parameters, such as impedance matching, are provided by digital filters. Further, with the CODEC on the line side of the high voltage isolation interface, the data which crosses the interface is modulated at the &Sgr;/&Dgr; data rate and, thus, capacitive coupling can be used across the high voltage isolation boundary without the loss of DC data.