Globespan, Inc.

Globespan Semiconductor, Inc.

Danny Amrany

Arnold Muralt

Laszlo Arato

An line interface circuit at a central office of a telecommunication system provides improved noise immunity to a ring signal. In accordance with one aspect of the invention, the line interface circuit includes a signal line having a first end for connection to a ring signal generating source and a second end for communication with a customer premises via a local loop. A POTS filter is electrically connected to the signal line. Preferably, the POTS filter is a relatively simple and thus inexpensive low-order filter, which may be implemented as a simple L-C circuit. The preferred embodiment of the present invention further includes a POTS communication device electrically connected to the signal line at a point between the POTS filter and the first end. In this regard, the POTS communications device broadly denotes any device designed to communicate information within the POTS frequency band, such as a telephone (e.g., voice information), a facsimile machine, a PSTN modem, etc. The circuit further includes a ring signal noise elimination filter integrally connected to the signal line and interposed between the POTS filter and the ring signal generating source. The ring signal noise elimination filter is a low-pass filter configured to substantially block the passage of signals above the frequency of the ring signal (e.g., 20 hertz).

Ring filter for pots communication system

A system and method for a communication to communicate both POTS and XDSL are provided. In accordance with one aspect of the invention, in improved central office line card circuit is provided, wherein the line card circuit includes a two-wire signal line for electrical connection with a two-wire local loop. A line interface card interfaces with the local loop and includes a bi-directional line for bi-directional communication with the signal line. In addition, the line interface circuit further has an input line and an output line. A first channel has an output electrically connected to the input line of the line interface circuit, and the first channel has inputs for both a pulse code modulation (PCM) input and a xDSL input. Similarly, a second channel has an input that is electrically connected to the output line of the line interface circuit. In addition, the second channel has outputs for both a PCM output and a xDSL output. An analog to digital converter is electrically interposed between the second channel input and the second channel PCM and xDSL outputs, and is operative to process (i.e., convert from analog to digital) shared PCM and xDSL signals. Finally, a digital to analog converter is electrically interposed between the first channel output and the first channel PCM and xDSL inputs. The digital to analog converter is similarly operative to process shared PCM and xDSL signals.

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Wayside, NJ, United States of America

Danny Amrany