Abstract: An apparatus is described. The apparatus includes a semiconductor chip having cross-talk noise cancellation circuitry disposed between a disturber trace and a trace to be protected from cross-talk noise emanating from the disturber trace. The trace is to be coupled to a receiver disposed on a different semiconductor chip.

Abstract: A hybrid circuit without inductors is provided. Embodiments can be used in high-speed communication devices, including Cable modem and Digital Subscriber Line (DSL) devices. In particular, embodiments can be used in Very High Speed DSL (VDSL) devices. Embodiments provide a cheap and compact solution to the echo rejection problem in high-speed communication devices. Furthermore, embodiments perform at least comparably to conventional solutions with respect to key performance measures.

Abstract: A reliability authorizing device determines whether to authorize a service transfer based on reliability of a partner device or a partner user when one user of one device authenticates other user of other device to exchange the service between devices connected to a network. A partner-reliability collecting unit collects reliability of the partner device or the partner user. A partner-reliability providing unit provides the reliability of the partner device or the partner user collected by the partner-reliability collecting unit.

Abstract: A method, system and device are disclosed for compensating or tuning one or more communication pathways between an external network and an information handling system. In one aspect, one or more inductive devices may be coupled to one or more transmission lines coupling a physical layer transceiver (PHY) to one of a plurality of external network communication ports via a board-mounted communication switch. Selection and placement, such as serial placement, of the one or more inductive devices depends, at least in part, upon one or more electrical characteristics of the transmission lines, the PHY, the communication switch and requirements of the external network.

Abstract: A DSL line conditioner achieves high performance sufficient to simultaneously support video, voice and data signals on standard telephone twisted pair lines over substantially greater distances than are currently available. The line conditioner automatically adjusts and sets the upstream and downstream preamplifier gains and attenuations according to the actual degradation imposed upon the upstream and downstream signals by the twisted pair line in which the line conditioner is used. The line conditioner achieves high performance by optimizing the signal-to-noise ratio and signal quality of DSL signals, and has a low power budget that enables it to operate by deriving power from the twisted pair lines over which it is used.

Abstract: A bidirectional long distance driver for Ethernet, named Ethernet Booster, is disclosed that comprises a forward transmission circuit and a backward transmission circuit, wherein each of the circuits includes Ethernet interface socket RJ45, an impedance matching circuit, power amplifying circuit and frequency compensation circuit. The booster is characterized in that the differential signals received from the Ethernet interface socket RJ45 in the forward/backward transmission circuits are sent to twisted-pair lines through the first impedance matching circuit, power amplifying circuit, the frequency compensation circuit and the second impedance matching circuit in turn. The advantage of the driver is that the booster can greatly enhance the transmission power of 10BASE-T by lengthening network segment distance to 350–500 m, and can decrease the cost greatly by dispensing with in-building switches and making full use of the resources of switches without any or with very few switch ports being wasted.

Abstract: Systems and methods are disclosed for improving DSL performance, including ADSL and VDSL performance, over a local loop between a telephone company central office and a customer premises. In particular, a loop extender is coupled to the local loop and differentially amplifies downstream and upstream DSL signals to at least partially compensate for DSL signal attenuation that occurs as DSL signals pass over the local loop. Pursuant to one embodiment, the loop extender includes an upstream filter/amplifying equalizer, a downstream filter/amplifying equalizer, a differential amplifier pair, an inverting amplifier, and a pair of electromagnetic hybrids, which couple the loop extender to the loop and provide upstream and downstream signal amplification. In another embodiment, the loop extender includes POTS loading coils to improve the POTS or voice band transmission over the local loop. According to this embodiment, the loop extender provides both improved POTS band signal transmission and DSL service.

Abstract: A circuit for exchanging communications via a transmission line, including a detector for detecting a predetermined start-of-communication signal, a means for coupling the transmission line on the one hand to a transmit line to provide outgoing communications to the transmission line, and on the other hand to a receive line, to receive incoming communications from the transmission line. The detector is connected to the transmit line.

Abstract: In at least one embodiment, a current mode differential active hybrid circuit having an H-bridge output driver with a first output resistor coupled across a transmission medium output. Drive circuitry is coupled to the output H-bridge and constructed to supply data modulated signals to the output H-bridge. A second H-bridge is coupled to the drive circuitry in parallel with the output H-bridge to allow a second output across a second output resistor.

Abstract: An HPNA bridge comprises a bi-directional filter for blocking non-HPNA signals and splitter for distributing the filtered signal to at least one additional telephone wire pair. The filter may be a high pass filter allowing signals with a frequency above a threshold value, including HPNA signals, to pass. Alternatively, the filter may be a band pass filter allowing only signals within the HPNA frequency range to pass.

Abstract: This invention relates to a method for data transmission in two-way communication via low-voltage systems that are linked to a higher order telecommunication network. Data transmission takes place within the low-voltage system at a high-frequency range of up to 30 MHz using band spreading of data signals and a transmit level below the specified radio interference or noise voltage limit, in that said band-spread data is given a direction coding to specify a logical direction within the low-voltage system using different sequences of a family of pseudo-random numbers to enable multiple-user operation, and in that the binary sequences of data with their user-specific spreading and direction-specific coding are identified by correlation using specified sequences at attenuation-dependent intervals within the low-voltage system, then said data sequences are regenerated and assigned new direction codes for forwarding.

Abstract: Systems and methods are described for asymmetric digital subscriber loops.

Abstract: An apparatus for improving signal quality in a communications link includes apparatus for regenerating only the speech-like characteristics of signals received over the communications link so that an estimate of the original speech signal can be retransmitted. The apparatus may include a vocal tract model coupled to a synthesizer.

Abstract: A broadcasting system discriminating television receiver including a circuit for evaluating the output of an FM demodulator, a circuit for evaluating the output of an I/Q wave detector, and a controller for controlling a switch based on the results of each evaluation. The switch is used primarily to determine whether the output of the receiver is analog or digital.

Abstract: A channel unit network having a two-wire port for interconnecting a two-wire, bidirectional signal transmitting means with a four-wire digital transmitting means in a communication system to create a precision bidirectional simulated two-wire cable pair with an extended operation range over a transmission medium includes a signal processing circuit, tip and ring switch mode driver, a negative inductor circuit, a negative capacitor circuit, and a 200 Hz impedance circuit. The negative conductor circuit and the negative capacitor circuit are used to generate respective negative inductance and negative capacitance at 24 Hz in order to maintain loop stability. The 200 Hz impedance circuit is used to generate a positive impedance at a frequency of approximately 200 Hz so as to prevent overloading of external telephone communication testing circuitry.

Abstract: A computer system employs a repeater unit which repowers a serial channel link. The repeater unit also monitors and records non-idle usage and errors for both directions of the repeated serial link. Non-idle usage of the serial link is recorded as a number of seconds that non-idle traffic flowed in the link over a given period of time. Link serial code violations and loss-of-light transitions are also counted. Link code violations are counted with an accuracy that permits targeted serial link bit-error rates, of no more than one bit error in approximately two months, to be accurately verified for the first time in a normal customer environment. The repeater unit permits an attached monitoring computer to read and reset all its usage and error counters as often as required by the customer, and without losing any counts of any counted event.

Abstract: A channel interface unit for interconnecting a two-wire transmission path which transmits analog signals and a digital signal transmission path. The channel interface unit includes a digital interface unit coupled with the digital signal transmission path and producing digital signals based on digital signals received from the digital signal transmission path, a converter for converting the digital signals to analog signals, a filter for removing noise, produced by the converter, from the analog signals, a driver, coupled with the two-wire transmission path, for amplifying the filtered analog signals, and a power supply for providing regulated voltage to the driver.

Abstract: A computer system employs a repeater unit which repowers a serial channel link. The repeater unit also monitors and records non-idle usage and errors for both directions of the repeated serial link. Non-idle usage of the serial link is recorded as a number of seconds that non-idle traffic flowed in the link over a given period of time. Link serial code violations and loss-of-light transitions are also counted. Link code violations are counted with an accuracy that permits targeted serial link bit-error rates, of no more than one bit error in approximately two months, to be accurately verified for the first time in a normal customer environment. The repeater unit permits an attached monitoring computer to read and reset all its usage and error counters as often as required by the customer, and without losing any counts of any counted event.

Abstract: A channel unit network for interconnecting a two-wire, bidirectional signal transmitting means with a four-wire digital transmitting means in a communication system to create a precision bidirectional simulated two-wire cable pair over a transmission medium includes tip and ring switch mode drivers, a signal processing circuit, a decoupling circuit, and tip and ring balance amplifiers. The decoupling circuit is used for splitting off "voice band" frequency signals from incoming tip and ring "DC band" signals from the two-wire means. The signal processing circuit performs both analog-to-digital conversions and digital-to-analog conversions.

Abstract: A telephone line repeater (28) includes a pattern decoder/recognizer (100) which recognizes, inter alia, an input interrogating signal transmitted on a telephone network (20). The interrogating signal includes an address field (302) having at least one subfield (304) therein. The pattern decoder (100) determines that its repeater (28) is to be tested, if a predetermined subfield (304) of the interrogating signal is configured according to a predetermined select convention. When the repeater (28) recognizes that it is being addressed, a controller (110) causes the addressed repeater to "loop back", returning, in alternating sequence, test-indicative no-operation signals and diagnostic information ("DSM") signals generated by the repeater. Methods for testing a repeater and methods for testing telephone networks are also disclosed.

Abstract: A transmission input/output device for signal transmission through a telephone line, with reduced power consumption, size, and cost. The device includes: a resistor, connected to the telephone line, for setting a signal input and output impedance; and a transmission control circuit for amplifying the transmission signals to be outputted to the telephone line, including: a variable resistor, connected in series with the resistor, for supplying voltages corresponding to the transmission signals to be outputted to the telephone line into the resistor according to changes of an impedance of the variable resistor; and an operational amplifier for controlling the changes of the impedance of the variable resistor by supplying an output according to the transmission signals to be outputted to the variable resistor.

Abstract: A telephone includes a speech network for transmitting an outgoing voice signal and receiving an incoming voice signal from a remote telephone. The speech network is not supplied with power from a telephone exchange through a telephone line but supplied with a separate power supply. To interrupt the power supply from the telephone exchange, a transformer is interposed between the speech network and the telephone line. A ringer circuit and a dialer circuit are connected to the primary side of the transformer. Because the power supplied to the speech network does not fluctuate, the circuit design of the speech network can be readily performed using inexpensive circuit components.

Abstract: An improved transformer-less electronic isolating transformer is obtained with an output subcircuit that outputs a controlled current rather than voltage. Specifically, the improved hybrid comprises an output drive subcircuit that receives an ac signal and creates a corresponding current that is passed to the line that supports two way communication. The subcircuit not only converts the applied voltage to current but includes means for effecting gain. Signals arriving to the hybrid from the line are applied directly to a near-end echo circuit that is also responsive to the signal applied to the output drive subcircuit. Both the input of the output drive subcircuit and the output of the near-end echo subcircuit are isolated with opto-isolators that employ photodiodes in their photo-voltaic mode.

Abstract: In a TDM communication system (100), full duplex communication is provided for two communication units(104) and (105) which communicated communication messages through a repeater (102). Communication messages transmitted from the communication units (104) and (105) are combined in the repeater (102) to produce a combined communication message. The repeater (102) transmits the combined communication message to the communication units (104) and (105). The communication units (104) and (105) remove from the combined communication message the communication the previously transmitted communication message so as to recover the communication message from the other communication unit.

Abstract: A metallic channel unit network for interconnecting a two-wire, bidirectional signal transmitting means and a four-wire signal transmitting means in a communication system includes a voice hybrid driver, A/D signal processing circuit, D/A signal processing circuit, tip and ring switching drivers, and tip and ring sensing amplifiers. The metallic channel unit network is suitable for use with substantially all of the different alarm-signalling techniques utilized by the various alarm companies for connecting their equipment to a channel bank multiplexer coupled to the four-wire means. The metallic channel unit network provides an apparent metallic cable pair over the digital carrier in the frequency range of DC to 3.5 KHz with an amplitude variation between +200 to -200 VDC.

Abstract: A telephone line card circuit includes an operational amplifier circuit having first and second inputs and an output. A field-effect transistor circuit has first, second and control electrodes, the control electrode is coupled to the output of the operational amplifier circuit, the first electrode is coupled to the TIP/RING terminal, and the second electrode is coupled to the second input of the operational amplifier circuit. A first resistor is coupled between the TIP/RING terminal and the first input of the operational amplifier circuit. A second resistor is coupled between the first input of the operational amplifier circuit and a terminal of the circuit whereby the terminal of the circuit is typically coupled to a supply voltage terminal.

Abstract: A reciprocal impedance conversion network is disclosed. Such conversion network preferably is used in a reciprocal negative impedance repeater for the nonloaded cable facilities of a telephone system. Two independent voltage sources for generating reciprocal negative impedance are connected between a first port and a second port. The first port is operably connected to the first voltage source such that a series negative impedance appears at that port. This port is specifically connected to the switching equipment of the telephone system. The second port is operably connected to the second voltage source such that a shunt negative impedance appears at that port. The second port is specifically connected to the nonloaded cable facilities of the telephone system. The invention further provides a frequency dependent gain circuit which is useful for equalizing the losses along the nonloaded cable facilities.

Abstract: A Data Communication Device permits extended range RS-232 communications between two devices by utilizing a current loop between the remote device and the Data Communication Device. The Data Communication Device may be used for any mix of signal or control lines specified for RS-232 and will support multiple remote devices in a broadcast mode or half duplex polled mode. Only a single Data Communication Device per remote communications circuit is required.

Abstract: Encoder/decoders are associated with conventional local and far-end communications equipment such as facsimile machines. Information to be faxed is encoded at one end, transmitted to the other end, and decoded, without affecting normal communications protocol or requiring other specialized equipment at either end. A secure information processing device is provided at each end, between the equipment and the communications line, and either encodes outgoing information or decodes incoming information, in accordance with a randomly generated key code, depending on whether the equipment at a particular end is transmitting or receiving a communication.

Abstract: A reciprocal impedance conversion network is disclosed. Such conversion network preferably is used in a reciprocal negative impedance repeater for the nonloaded cable facilities of a telephone system. Two independent voltage sources for generating reciprocal negative impedance are connected between a first port and a second port. The first port is operably connected to the first voltage source such that a series negative impedance appears at that port. This port is specifically connected to the switching equipment of the telephone system. The second port is operably connected to the second voltage source such that a shunt negative impedance appears at that port. The second port is specifically connected to the nonloaded cable facilities of the telephone system. The invention further provides a frequency dependent gain circuit which is useful for equalizing the losses along the nonloaded cable facilities.

Abstract: The invention relates to a telephone line interface circuit for use in switching a call connection between subscriber telephone sets via a switching matrix. The interface circuit is provided with two terminals for connection to a telephone line of a subscriber and two terminals for connection to one side of a switching matrix. The circuit comprises a cascade circuit of a first and a second bidirectional amplifier which are connected to each other via a common point, acting as a one-to-N transformer for speech signals. Also included is a third and fourth bidirectional amplifier for providing direct voltage decoupling and impedance to thereby provide the telephone set with the required line voltage.

Abstract: The invention relates to a method for the gain control of an intermediate amplifier used in two-wire connections of a dial telephone network. The invention is also concerned with an intermediate amplifier used in such connections, the direction of the gain of the amplifier being controlled in accordance with the signal strength. The method comprises measuring the amplitudes of signals coming from different transmission directions, comparing the measured amplitudes of signals coming from different directions with each other, and controlling the gain of controllable amplifiers (12, 22) on the basis of the difference value of the amplitudes by applying a control voltage to the controllable amplifiers (12, 22) through reversephase control adapters (13, 23).

Abstract: A signal repeater for regenerating digitally encoded signals transmitted in bursts over a single pair telephone line to enable simultaneous communication between a telephone central office and any one of up to four subscriber transmitter/receivers. The repeater decouples signals from the line for regeneration thereof and recouples the regenerated signals onto the line. Clock frequency and phase information characteristic of the decoupled signals is derived in order to facilitate accurate regeneration of the signals. The decoupled signals are decoded and then regenerated to replicate the signals originally produced by the telephone central office and subscriber transmitter/receivers respectively. The regenerated signals are then re-encoded and recoupled onto the telephone line.

Abstract: An in-line data communication system includes a bidirectional communication cable for connecting at least two terminal stations. A signal level compensation circuit is connected to the bidirectional communication cable for compensating for signal attenuation in the bidirectional communication cable. The signal level compensation circuit includes first and second amplifying circuits connected to each other in a parallel fashion. When a data signal is transmitted in one direction in the bidirectional communication cable, the first amplifying circuit is enabled and the second amplifying circuit is disabled. When the data signal is transmitted in the opposing direction, the first amplifying circuit is disabled and the second amplifying circuit is enabled.