Coppergate Communications Ltd.

Tioga Technologies, Inc.

Coppergate Communication Ltd.

Orckitt Communications Ltd.

Roman Vitenberg

Liron Frenkel

Victor Koren

A digital subscriber line communication system (DCLCS) provides voice and data services to a subscriber premises within a building and to high speed data communication devices in the subscriber premises using in-building wiring and to-building wiring without having high speed communication equipment inside the subscriber premises.

Digital subscriber line communication system

A method for conveying over telephone lines digitized voice signals simultaneously with digital data signals by means of a communication system, having a transmitter having a discrete multi-tone unit yielding a plurality of carriers of different frequency, several of which are assigned to the voice signals and others to the data signals. The carriers for transmitting voice are selected on the basis of their signal-to-noise ratio characteristics, which carriers can be reallocated dynamically to data transmission. A first tone ordering circuit assigns data streams to data carriers, and a second tone ordering circuit assigns voice streams to voice carriers. Each carrier is modulated by QAM modulation, the data carriers by a sequence of QAM symbols representing data and the voice carriers by a sequence of QAM symbols representing voice. QAM modulation is carried out by a first constellation encoder that modulates the data carriers and a second constellation encoder that modulates the voice carriers.

Communication systems conveying voice and data signals over standard telephone lines

A communication system is provided. It comprises a central office (CO) of a communication service provider and at least one subscriber premise (SP), each SP being linked to a CO by a subscriber-associated communication line comprising a twisted pair of telephone lines, and at least one xDSL modem in the CO coupled to said subscriber-associated communication line. Each SP has a plurality of communication devices, which comprises one or more telephone devices connected to the communication line and at least one network DSL (NDSL) modem associated with a computerized device, the NDSL modem being connected to said communication line; each of said modems having an upstream transmitter and a downstream receiver for communication with the CO and an upstream transmitter and an upstream receiver for communication with other NDSL modems within the SP. Provided is also a novel NDSL modem for use in the above system.

Multipoint digital subscriber lines with home data network ability

A method and apparatus for selectively filtering signals on a digital subscriber line (DSL) so as to prevent interference resulting from a telephone instrument switching between its on-hook and off-hook states. One embodiment of the invention utilizes an off-hook detector controlling a variable attenuator element. Another embodiment of the invention uses a switch in parallel with a resistive element to implement the variable attenuator element. Yet another embodiment has an inductive element with a saturable core for providing attenuation to compensate for inconsistencies that result from the changing hookswitch status of a telephone instrument.

Method and apparatus for filtering asymmetric digital subscriber line (ADSL) signals

A communication system includes a plurality of subscribers having a telephone set and different types of home modems coupled using twisted pairs to a local server that includes a plurality of downstream repeaters, a central office coupled to a local server using twisted pair subscriber lines. The central office includes a telephone switch that provides telephone service to the subscribers and a concentrator that connects a plurality of upstream repeaters with a number of office modems that provide data service to the subscriber. A communication system uses CAP or DMT line signals with time division. The line signal transmits with different time framing. Every subscriber line can work in one of three operation modes Asymmetrical mode, Half-Asymmetrical mode, and Symmetrical mode. An office modem changes the operation mode of subscribers line and downstream/upstream bit rate depending on the type of an information source and the type of the subscriber home modem that is connected to the office modem in the current transmit cycle.

Source adaptive digital subscriber line and method

A receiver for high-speed data communications, which receives a differential signal through a pair of signal lines. The receiver includes a common-mode choke, which has first and second signal windings, which are respectively coupled in series to the pair of signal lines so as to attenuate common-mode interference in the differential signal. The choke also has a sampling winding, which is inductively coupled to the signal windings so as to generate a sampled signal responsive to current flowing in the signal windings. Signal processing circuitry is coupled to receive the sampled signal from the sampling winding and to receive the differential signal from the signal windings and to process the differential signal responsive to the sampled signal.

Method and apparatus for RF common-mode noise rejection in a DSL receiver

A system and method is presented for reducing the power consumed by a line driver driving a signal to be transmitted through a communications media. The preferred method includes the steps of: (1) delaying the signal; (2) determining whether the signal has reached a predetermined threshold value; (3) increasing power supplied to the line driver in response to an indication from the determining step that the threshold has been reached; and (4) delivering the delayed signal to the line driver. The preferred system includes: (1) a digital signal processor; (2) a line driver; (3) a digital delay line disposed between the digital signal processor and the line driver; and (4) a power regulator disposed between the threshold detector and the line driver. The system and method, while applicable to many communications formats, is particularly applicable to communications methods transmitting signals having a relatively large dynamic range, such as xDSL communications techniques.

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Holon, Israel

Roman Vitenberg