Abstract:
A Digital Subscriber Line (DSL) network for improving the transmission of DSL signals includes a plurality of local loops for transmission of upstream and downstream DSL signals, control signals, and Direct Current (DC) power, a plurality of loop extenders with communications, control, and diagnostic functionality for amplifying the DSL signals, a loop extender communications/power supply for receiving the DC power and control signals, providing DC power to the plurality of loop extenders, and broadcasting the received control signals to the plurality of loop extenders, and a central office controller/power supply for controlling access to the plurality of local loops and controlling the plurality of loop extenders.
Abstract:
A DSL network for improving the transmission of DSL signals includes a plurality of local loops for transmission of upstream and downstream DSL signals, control signals, and DC power, a plurality of loop extenders with communications, control, and diagnostic functionality for amplifying the DSL signals, a loop extender communications/power supply for receiving the DC power and control signals, providing DC power to the plurality of loop extenders, and broadcasting the received control signals to the plurality of loop extenders, and a central office controller/power supply for controlling access to the plurality of local loops and controlling the plurality of loop extenders.
Abstract:
This disclosure depicts an active network for providing a virtual impedance to a voice frequency loaded pair having tip and ring terminals. The network comprises means for providing a predetermined capacitance between the tip terminal and ground and between the ring terminal and ground and has a variable resistive means. The means has a first input operatively connected to the tip terminal and a second input operatively connected to the ring terminal and also has first and second outputs. First and second fixed resistive means are operatively connected between the first output and the tip terminal and the second output and the ring terminal, respectively. The value of the predetermined capacitance is determined by the first and second fixed resistive means and the variable resistive means in the means for providing a predetermined capacitance.
Abstract:
Transmission and signaling range of a telephone transmission line is extended by controllably inserting boost potentials into the line to series aid an applied central office battery. Insertion of the potentials is realized by sensing the direction of current flow in the line and switching a corresponding potential into the line. Optical couplers, each including a light emitting diode and an associated phototransistor, are employed as the line current sensing elements and switching elements.
Abstract:
A telephone loop extending circuit for aiding central office battery. There are first and second pairs of input/output terminals and first and second voltage insertion circuits corresponding to the first and second pairs of terminals. Each insertion circuit has a path for current flow coupled between the corresponding pair of terminals. Each insertion circuit has a voltage source, a controllable switch operative when enabled for switching the voltage source between terminals of the corresponding terminal pair in first and second directions of polarity and a sensing circuit for sensing an applied current flow through the corresponding path in first and second directions and responsive to such sensing for enabling the controllable switches to switch the voltage source, respectively, in the first direction or in the second direction of polarity. Additionally included is a circuit operative in response to a rapid reversal in polarity of an applied voltage between two terminals, one from each of the terminal pairs, while the voltage source is coupled in one direction of polarity for enabling the controllable switch in either of the insertion circuits to reverse the polarity in which the corresponding voltage source is coupled in between terminals of the corresponding terminal pair.
Abstract:
Circuit apparatus is provided for extending the allowable distance between the subscriber''s loop and the central office. To provide this feature, the circuits sense a subscriber loop line closure to add an increased voltage for the conversation path and improved supervisory signalling. With the increased voltage, the current to the subscriber''s conversation path is maintained at a constant level. Further additional circuits such as a bidirectional voice frequency repeater, pulse correction circuits, and supervisory control circuits operative at the increased voltage may be connected into the conversation path. With reverse battery signalling, the polarity is sensed to activate the current regulation. On a call to the subscriber loop, the ringing signals are bypassed until the call is answered.
Abstract:
A circuit for automatically disconnecting circuitry such as voltage booster circuitry from a subscriber line to prevent such circuitry from interfering with the measurement of voltage and current on that line. The circuit includes booster disconnect switches which, in a first operative state, connect the voltage booster circuitry in aiding relationship to current flow through the subscriber line and which, in a second operative state, disconnect the voltage booster circuitry from the line and substitute therefore one or more current bypass conductors. A control circuit responsive to both the voltage across and current through the line controls the disconnect switches, as required, to establish the first operative state thereof when the subscriber line is being used by a subscriber and to establish the second operative state thereof when the subscriber line is being tested in either a high voltage-low current mode or a low voltage-high current mode.
Abstract:
This disclosure relates to a range extender having a through transmission path, a voice transmission path including a repeater, a relay for transferring back and forth between paths and a dual mode, loop current detector. In the idle state, the current detector is in a ''''slow'''' mode for the purpose of preventing (spurious) operation of the detector, except in response to an off-hook current flow. The transfer relay connects the repeater to the loop immediately after an off-hook is detected and the current detector is switched to its ''''fast'''' mode in preparation for dialing pulsing. The repeater normally remains connected to the loop for the duration of the call, even over dial pulsing. Dial pulsing is therefore repeated via the repeater, and not shunt aided. The dial pulses are detected by the fast current detector and the office loop is opened and closed through the repeater, which, from the office side, looks like a low resistance (1K) to low frequencies.