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7450715 Transceiver for bidirectional frequency division multiplexed transmission  
The present invention relates to a transceiver for bidirectional frequency division multiplexed transmission, a communication system including one or more transceivers. Optionally, the...
7408993 Digital communication extender system and method  
An extender circuit for handling a communication signal transmitted over a transmission line includes a voltage clamp and a current booster circuit. The voltage clamp is connected to a receive end...
7386117 Efficient handling of ISDN connections by a packet-oriented exchange  
The invention relates to the representation, independent of access type, of ISDN accesses (PRA, BRA) in the central core (cVst) of a packet-oriented exchange (P-Vst). By adapting the signaling...
7269254 Integrated driver circuitry  
A linear amplifier architecture includes first, second, and third stages. The first stage is a transconductance stage. The third stage is a current amplification stage. The second stage is an...
7155008 Power offloading for a subscriber line interface circuit  
A power offload network has a first node for receiving a first supply V 1 and a second node for receiving a second supply V 2 . The power offload network includes a plurality of switches and a...
7149246 Method and apparatus for reducing oscillator pull in a CMOS wireless transceiver integrated circuit  
A monolithic transceiver integrated circuit that includes a substrate, a transmitter subsystem of one or more subcircuits on the substrate, and a receiver subsystem of one or more subcircuits on...
6940970 Ring boost circuit to extend ringing range of telephone SLICs  
A ring boost circuit has a first switching device coupled to a ring node. The first switching device is responsive to a ring operation. A charge pump is connected to the ring node, and the charge...
6920218 Combination clock and charge pump for line powered DAA  
Disclosed is a method and apparatus which facilitates the use of existing power that is ordinarily unused or discarded to provide power to a telephone interface circuit when the circuit is in the...
6912282 Enabling Cisco legacy power to support IEEE 802.3 AF standard power  
An apparatus and method for enabling Cisco legacy power to support IEEE 802.3 AF standard power. A network power system capable of delivering data terminal equipment power via a media dependent...
6873702 Telephone subscriber system  
A subscriber's telephone system is presented that includes at least one driver circuit connected to Tip and Ring terminals. An additional network is connected between an output of the driver...
6823066 Digital access arrangement circuitry and method having current ramping control of the hookswitch  
A digital direct access arrangement (DAA) circuitry may be used to terminate the telephone connections at the user's end to provide a communication path for signals to and from the phone lines....
6782096 Subscriber line driver and termination  
A subscriber line driver (SLD) is provided for the continuous and automatic transformation of the characteristics of a communication system signal so that the signal conforms to a power spectral...
6665339 Method and apparatus for reducing oscillator pull in a CMOS wireless transceiver integrated circuit  
A monolithic transceiver integrated circuit that includes a substrate, a transmitter subsystem of one or more subcircuits on the substrate, and a receiver subsystem of one or more, subcircuits on...
6654462 Line terminal circuit for controlling the common mode voltage level on a transmission line  
A line terminal circuit comprises a buffer section (A, D) for connection to a transmission line (TL) and for performing at least one of the functions receiving signals from said transmission line...
6519339 Method of regulating power transfer across an isolation barrier  
An efficient method and circuitry for transferring various levels of power across a high voltage isolation barrier. In one embodiment of the invention, a data access arrangement (DAA) is provided...
6144647 Communication system, mobile services switching center and method for establishing a multi-dialogue communication between subscriber stations  
A communication system, a mobile services switching center and a method is described, for allowing a multi-dialogue communication to take place between a first subscriber station (MS1, MS2, . . ....
5960075 Switchmode power converters for telephone subscriber line interface circuits  
A power converter forming part of a telephone subscriber line interface circuit selectively generates a ringing signal waveform, for supply to the line, or a supply voltage for a driver circuit for...
5889854 Technique for compensating for signal attenuation on a telephone line  
An apparatus compensates for an attenuation of a signal on a telephone line in a communication system connected to the telephone line via a transformer. A photo coupler detects a loop current at a...
5862213 Circuit arrangement for generating charge pulses  
A circuit arrangement for generating charge pulses during digital telecommunications is indicated, whereby subscribers (Tln) of a telephone network are connected by cables with an exchange. The...
5721766 Communication apparatus able to call plural designated destinations  
A communication apparatus capable of designating plural destinations in a simple manner. The communication is automatically initiated after the lapse of a predetermined time from the designation of...
5553132 Method and an arrangement for generating a ringing signal  
To generate a ringing signal by means of a subscriber line interface circuit having two final stages, each for supplying an individual subscriber line wire, one of the subscriber line wires is...
5396553 Automatic loss control circuit  
Disclosed is a circuit for providing an appropriate amount of on-hook loss in a digital loop carder transmission system serving telephone customers. The resistance of the customer loop is measured...
5359655 Supply circuit for a telecommunication line, providing highly symmetrical and rapid response to line voltage disturbances  
A supply circuit for a two-wire telecommunication line includes a voltage adjusting circuit section coupled between one of the wires and a first reference potential point and further includes a...
5349640 Option bus adapter  
A method and apparatus for connecting a programmable computing device to a digital telephone via an adapter. The digital telephone includes an option bay connection, having a hierarchical control...
5315653 Current limited subscriber interface circuit  
An electronic interface circuit between a telephone subscriber line and a telephone main exchange is disclosed which forms, with the main exchange battery, a supply bridge for the telephone line,...
5280525 Adaptive frequency dependent compensation for telecommunications channels  
The quality of speech being transmitted in a telecommunication channel is enhanced by adaptively compensating for frequency dependent attenuation in the telecommunication channel. The frequency...
5274702 Wideband telephone line interface circuit  
An active impedance line interface circuit for connection to a two-wire telephone line comprises tip and ring unity gain d.c. amplifiers having outputs d.c. coupled via feed resistors to tip and...
5051980 Data communication interface device  
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...
4931988 Communication apparatus with a remotely adjustable signal level function  
A communication control system of a communication apparatus, such as a facsimile machine, which uses an analog communication network, such as the public telephone network, includes setting means...
4431869 Telephone line feed  
In a telephone line feeding arrangement, the line current is monitored by a multi-resistor network (R p R s ) and the output of the network applied to the inputs of an operational amplifier (A3)....
4205204 Telephone loop extending apparatus  
A subscriber loop extender for a telephone system in which a variable shunt conductance (41) is placed across the loop in response to a loop current indicating an off hook condition (32). An...
4130735 Loop extender  
A loop extender for adding a series-aiding boost voltage to a subscriber loop of a telephone system and having a d.c. boost voltage supply, an amplifier circiit having an active device connecting...
4127747 Voltage boost circuit for telephone systems  
In a voltage boost circuit, for telephone systems where reverse battery supervision is employed, optically coupled semiconductor devices are used to control both the polarity and the charge on a...
4122312 Loop extender  
A loop extender is used in conjunction with a pair of telephone lines extending from a telephone central office to a subscriber location in order to insert a booster DC potential on the telephone...
4061883 Repeater for transmission lines of differing lengths  
A circuit for varying the amplification afforded to a-c signals transmitted through a transmission line in accordance with the a-c losses of that transmission line. Gain control circuitry is...
3992591 Telephone line battery boost circuit  
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...
3955052 Subscriber unit particularly useful for time-division-multiplex system  
A line circuit for connecting telephone subscriber terminals to a signal transmission network which includes constant current sources for driving the subscriber terminals and an isolated line...
3906162 Loop extender with bypass capacitor discharge  
A telephone loop extending circuit for aiding central office battery. Each voltage insertion circuit includes the following: First and second pairs of terminals, first and second voltage sources,...
3898389 Voltage and/or current-sensitive loop extender  
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...
3872258 Voltage booster circuit for telephone systems  
A voltage booster circuit for additively increasing the d-c operating current and voltage of the subscriber lines of telephone systems. Current gating circuitry senses the current through each...
3852536 TEST-THROUGH VOLTAGE BOOSTER CIRCUIT FOR TELEPHONE SYSTEMS  
A telephone system voltage booster circuit adapted to provide a d-c boost voltage in series-aiding relationship to the current in a subscriber line when ordinary telephone system operating current...
3843844 SUBSCRIBER LOOP CIRCUIT APPARATUS  
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...
3828139 DISCONNECT CIRCUIT FOR TELEPHONE SYSTEMS  
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...
3825698 TEST-THROUGH CIRCUIT FOR TELEPHONE SYSTEM VOLTAGE BOOSTERS  
A circuit for automatically disconnecting a voltage booster circuit which is in service in a subscriber line to prevent the booster circuit from interfering with the taking of voltage and current...
3781480 LOOP EXTENDER  
To increase the effective signaling and supervisory range of a central office, a loop extender has tip side and ring side booster circuits, each of which comprise a pair of oppositely polarized...
3763320 VOLTAGE BOOSTER CIRCUIT HAVING TEST-THROUGH CHARACTERISTICS  
A circuit for increasing the magnitude of subscriber line current flow in a variety of types of telephone systems. A voltage booster network is connected in series with at least one conductor of a...
3763319 IMPEDANCE RESPONSIVE VOLTAGE BOOSTER CIRCUIT FOR TELEPHONE SYSTEMS  
The invention includes a circuit for additively increasing the d-c operating voltage of long subscriber lines in telephone systems utilizing reverse battery supervision. A plurality of switching...
3757052 TELEPHONE LINE EXTENDER WITH TEST-THRU CAPABILITY  
A line, or loop, extender for a telephone system which is intended for connection in the tip and ring lines of a remotely located telephone set thereby to increase the line current to a level...
3689704 CONSTANT CURRENT OUTPUT CONTROLLED REPEATER INSERTION  
Individual voice frequency repeaters may be associated with any telephone connection, as required. More particularly, the lines involved in the connection are supplied by a constant current output...
3639696 MULTISTATE VOLTAGE BOOSTER CIRCUIT FOR TELEPHONE SYSTEMS  
A circuit for increasing the flow of telephone line current in telephone systems which utilize reverse battery supervision and the grounding of the telephone line at the subscriber station for...
Matches 1 - 50 out of 56 1 2 >