Centillium Communications, Inc.

Fujitsu Corporation

Fujitsu Network Communications, Inc.

Serdar Kiykioglu

Catherine Yuan

Hessam Mohajeri

Vikas Mittal

Peter Vaclavik

Mark A Bolla

Heron Babaei

Mark Bolla

Tsuyoshi Ueshima

A network element is disclosed. In accordance with some embodiments of the present disclosure, a network element may comprise a network interface configured to communicatively couple to a network, and a controller communicatively coupled to the network interface. The controller may be configured to determine a delay-measurement interval, and to perform a plurality of delay measurements at a respective plurality of randomly determined times within the delay-measurement interval. Performing a delay measurement may comprise sending an outgoing signal, receiving an incoming signal, and determining a delay time based on the outgoing signal and the incoming signal.

Proactive delay measurement for optical transport network

A splitterless interface between a digital subscriber line (DSL) and the central office equipment that can receive and isolate the low frequency voice data and high frequency digital data from a telephone line. This interface can also mix and transmit low frequency voice data and high frequency digital data onto a telephone line. For POTS band frequencies, a reactive impedance coupled across the two-wire interface of the POTS line card, and serially coupled to the line side of the DSL coupling transformer, has an open state magnitude. The magnitude of the line side windings of the DSL coupling transformer is low at POTS band frequencies. POTS band signal power is therefore delivered to the POTS line card. For DSL band frequencies, the reactive impedance across the two-wire interface of the POTS line card has a closed state magnitude. The POTS line card is therefore essentially short-circuited at DSL band frequencies, and DSL band signal power is delivered to the DSL modem. The frequency band in which the reactive impedance transitions from an open state magnitude to a closed state magnitude corresponds to the frequency band between the POTS frequency band and the DSL frequency band.

Central office interface techniques for digital subscriber lines

A digital subscriber line and POTS voice interface between a telephone line and central office equipment is provided. For POTS band frequencies, a reactive impedance coupled across the two wire interface of the POTS line card, and serially coupled to the line side of the DSL coupling transformer, has an open state magnitude. The magnitude of the line side windings of the DSL coupling transformer is low at POTS band frequencies. POTS band signal power is therefore delivered to the POTS line card. For DSL band frequencies, the reactive impedance across the POTS line card has a closed state magnitude. The POTS line card is therefore essentially short-circuited at DSL band frequencies, and DSL band signal power is delivered to the DSL modem. The frequency band in which the reactive impedance transitions from an open state magnitude to a closed state magnitude corresponds to the frequency band between the POTS frequency band and the DSL frequency band. Negative impedance synthesis techniques provide compensation for the reactive impedance across the POTS line card.

Techniques for interfacing a telephone line and central office equipment of a network operator providing and digital subscriber line data services are disclosed. The interface is splitterless in that no conventional bulky splitter is required. A SLIC independent, impedance synthesis network provide compensation for impedance imbalance caused by capacitor coupled across two-wire interface of voice circuit.

One embodiment of the present invention provides a method for conditioning a signal for transmission in a DMT-based communication system, the method comprising: converting the signal in a digital environment of the DMT-based communication system into a pre-clipped signal to avoid subsequent analog clipping in an analog environment of the DMT-based communication system. Another embodiment of the present invention provides a signal conditioner for conditioning a signal for transmission in a DMT-based transmission system, the signal conditioner comprising: a digital environment configured to convert the signal into a pre-clipped signal to avoid subsequent analog clipping in an analog environment of the DMT-based communication system.

Signal conditioning techniques in DMT-based transmissions

A ring trip detector has a voltage difference detector with first and second inputs, for supplying an off-hook signal upon detection of a voltage difference. The ring trip detector also has a switch extending between the first and second inputs of the voltage difference detector. The ring trip detector detects when a telephone current starts to flow through a sensing resistor having first and second ends and to a telephone set. The switch closes upon an initial current flow through the sensing resistor and then opens. The ring trip detector has a pulse generating mechanism having two inputs respectively connected to the first and second ends of the sensing resistor. The pulse generating mechanism has an output and generates a pulse at the output when current starts to flow through the sensing resistor. The switch has a trigger connected to the output of the pulse generating mechanism for closing the switch when the pulse is generated. A differentiator mechanism may be used as the pulse generating mechanism. Such a differentiator mechanism may have a resistor and a capacitor connected in series between the first end of the sensing resistor and the trigger of the switch, and a resistor connected between the second input of the voltage difference detector and the trigger of the switch. Alternatively, a differentiator/integrator mechanism may be used as the pulse generating mechanism.

Growing community of inventors

Plano, TX, United States of America

Serdar Kiykioglu