Abstract: The present invention provides a system and method for using a standard private branch exchange (PBX), such as e.g., the Lucent Technologies, Inc. DEFINITY® PBX, for interfacing with a wireless (e.g., cellular, etc.) communication network and the public switched telephone network (PSTN). The system employs an adjunct controller and uses computer telephony integration (CTI) associated with a standard PBX to communicate directly with an audio switch and the PSTN. Through the use of CTI, the standard PBX also provides feedback to the caller. For example, when an inbound call arrives (i.e., from the PSTN to a radio transceiver), the adjunct controller determines whether the wireless system has available resources (i.e., an available link) to grant calls and instructs the PBX to provide an audio connection between dynamically assigned wireless links (e.g., RF channels). If no link is available, a busy signal is referred back to the PSTN, and eventually back to the originating switch.

Abstract: An apparatus which produces a ringing signal for a telephone system, effectively suppressing impulse noises. A ringing voltage generator produces a ringing voltage. A ringing signal sending unit sends a ringing signal to the called telephone terminal over the subscriber line by outputting the ringing voltage intermittently. This ringing signal consists of ringing periods and silent periods which will appear alternately with a prescribed duty cycle. One of those silent periods is used by a data transfer unit used to transport data to the called terminal. A feed impedance setting unit provides a feed voltage with higher source impedance. A feed impedance selection unit selects a low-impedance feed voltage in the one of the silent periods during which a data transfer is performed, and selects a high-impedance feed voltage in the other silent periods during which no data transfer is scheduled.

Abstract: A circuit where the same amplifiers and the same volume adjustment circuitry are used for the ringer mode as well as for the audio mode of a mobile phone is achieved. The volume adjustment in the audio and ringer mode is provided by a precise amplitude setting via the gain control stages of an inverting voltage amplifier used in a bridge circuit through a current-voltage conversion. This volume adjustment circuit avoids the high power dissipation of a volume control through pulse width modulation (PWM) and avoids the risk of over-and undershooting of the amplifier's output signal due to a high slew rate in combination with the inductance of the loudspeaker. The current-voltage conversion is performed by a series of resistors activated by a series of correspondent switches. High impedance current less sense paths are eliminating the parasitic effect of the resistance of low cost standard switches to adjust the volume of the loudspeaker in the audio and the ringer mode.

Abstract: A telephone receiver circuit with sidetone signal generation controlled by voice activity detection in accordance with the present invention uses the voice activity detector (VAD) to detect the presence of voice activity within the microphone signal and dynamically adjust the sidetone signal generation to compensate for noisy environments by eliminating or reducing the sidetone signal in the absence of voice activity. Hence, a sidetone signal is generated in the presence of voice activity, when feedback is required, while the sidetone signal is not generated in the absence of voice activity, since audio feedback for the user is not required then.

Abstract: A redundant ringing signal generator subdivides a ringing signal bus into multiple ringing bus segments. A plurality of redundant ringing voltage generators sourcing internally and/or externally ringing voltages are individually and selectively connectable to the multiple ringing bus segments. In the event of a prescribed anomaly in the ringing signal sourced by a ringing generator, the faulty ringing signal is automatically disconnected from its associated ringing bus segment, and that ringing bus segment is connected to a redundant ringing signal source, provided by either the same or another ringing generator.

Abstract: A remote telephone call notification system for notifying a user at a remote location that a communication device is receiving a call. The remote telephone call notification system includes a base unit and a remote unit, with the base unit being adapted for interfacing with the communication device and the remote unit being adapted for being toted by a user. The base unit includes a transmitter for wirelessly transmitting to the remote unit, and detection circuitry for detecting reception by the communication device of an incoming ring signal. The detection circuitry causes the transmitter to transmit an activation signal upon the detection of the incoming ring signal. The remote unit comprises a receiver for receiving wireless transmissions of the activation signal from the transmitter of the base unit. The remote unit includes an audible sound device for generating an audible sound upon reception of the activation signal.

Abstract: A system and method is provided for collecting and transporting DTMF digits between two network end points in a packet network in order to preserve the integrity of the DTMF digits. The system and method use a Session Initiation Protocol (SIP), which is currently defined by the standard body of Internet Engineering Task Force. SIP applications utilize certain predetermined messages, such as an INFO message, and templates. DTMF digits can be collected and transported by using the SIP INFO messages. This works especially well for telephony applications which may require mid session signaling.

Abstract: An electroacoustic transducer (1) includes a ringing signal generation means (20) for generating a ringing signal (CS) and an electroacoustic transducer (9) for the acoustic reproduction of the ringing signal (CS), in which the ringing signal generation means (20) includes at least two fundamental tone signal generation stages (GT1, GT2, . . . GTn), which are each adapted to generate a fundamental tone signal (GS1, GS2, . . . GSn) of a given frequency (f1, f2, . . . fn), which frequencies (f1, f2 . . . fn) are in a rational ratio to each other, and in which the ringing signal generation means (20) has a control means (21) with the aid of which each of the fundamental tone signal generation stages (GT1, GT2, . . . GTn) can be activated for a given time interval, namely in such a manner that at least two fundamental tone signal generation stages (GT1, GT2, . . . GTn) are activated simultaneously.

Abstract: A telephone reads out caller information between rings even if a caller is unregistered. The telephone includes a caller information receiver for receiving a call ring and caller information coming in from a caller identification service, a caller information memory for storing the received caller information, a voice generator for generating voice data from the caller information, a speaker for outputting the voice data, and an output-time monitor for monitoring appropriate and inappropriate time for announcing the caller information in voice form.

Abstract: The size and power consumption of a ring trip monitor circuit, which performs one of the BORSHT functions of a telephone line card, is reduced by utilizing an operational amplifier with feedback resistors, a resistor network, and a ring signal generator that is only connected to the line when a ring condition is present.

Abstract: A computer having a modem outputs a telephone bell signals regardless of an active state of the computer as well as the modem. The modem provides a voltage signal responsive to the active state thereof. The computer system includes a bell signal generator for producing a bell signal in response to a ring signal received over a telephone line connected to the modem. Further, a relay switch is provided across the telephone line directed to the bell signal generator, the relay switch comprising normal-on switches allowing the telephone line to be connected to the bell signal generator when the modem is inactive state, and being activated to cut off the switch in response to the voltage signal fed from the modem. A speaker is connected to the output of the bell signal generator. If a telephone set is not connected to the modem, the computer of this invention may detect the telephone ring signal and sound a bell signal even if the computer as well as the modem is not in the active state.

Abstract: An apparatus and method for supporting enhanced ring scheduling for devices on platforms with limited power supply while seeking to preserve caller ID information and normal ringing cadence is disclosed. The ring scheduling apparatus includes a “Line Manager” coupled to a “Ring Scheduler”. The Line manager monitors the signaling events and determines whether the signaling commands associated with the signaling events should be modified to indicate ringing, no ringing, or pass the signaling commands unmodified. The “Ring Scheduler” manages the available resources according to a ring cadence schedule so that the power supply of the device is not exceeded.

Abstract: A telephone line management system in communication with a telephone line is provided. In one aspect, the system includes a caller ID module operatively coupled to the telephone line for receiving and displaying a name and a telephone number of a calling party associated with a received telephone call and a false special information tone (SIT) generator module operatively coupled to the telephone line for sending a false signal on a telephone line substantially similar to at least a first part of a SIT in response to an incoming telephone call. In another aspect, the system includes a caller ID module, a false SIT generator module, and a controller for determining when the name and telephone number of a calling party is displayed and when the false signal is operationally coupled to the telephone line. In other embodiments, the system may include an answering machine module or a telephone module.

Abstract: A fast-converging, computationally simple, method for recognizing a single frequency tone or a sinusoid in a signal without prior knowledge of the tone frequency. The method employs a second order or higher auto-regressive model and includes: (a) sampling the signal at a constant sampling rate, and, for each sample, recursively determining a finite number of correlation coefficients using a time-reversed, exponentially weighted, future sliding equivalent of the signal, wherein the correlation coefficients are determined using pre-existing values of the correlation coefficients determined in a previous iteration, a current sample of the signal and at least two consecutively previous samples of the signal; (b) periodically determining at least the second auto-regressive coefficient modeling the signal using the correlation coefficients; and (c) recognizing the presence of the tone based on the value of the second auto-regressive coefficient.

Abstract: A ringing voltage power management circuit is configured to extract an isolated high-value intermediate voltage from a central office powered digital subscriber line through a current limiting circuit, and to charge a storage capacitor that serves as an energy reservoir for the ring generator of a subscriber line circuit. The storage capacitor and the current limiting circuit isolate the peak power drawn by the ringing load from the telephone line and translate the ringing signal's (20 Hz) ripple to the sub-Hz oscillations of the ringing cadence.

Abstract: A telephone signal discriminator to be used with one pair of telephone wires and a telephone company with coded ring services. The invention detects the interruptions of the ring signals, shapes them into square waveforms and initially sets off two timer circuits for enabling a shift register or counter for a first predetermined time period. A subsequent second time period is renewed with each set of coded ring signals. The result in the shift register or counter is advance a state in the outputs for each ring. The negated output ending with a low state is presented to the corresponding AND gate, that passes the low state through a corresponding OR gate. The OR gates have one of two inputs commonly connected so that they are disabled during the first period of time. In this manner, only one switch will permit the connection to a telephone outlet connection where one or more telephone devices are connected while the other telephone outlet connections are disabled.

Abstract: Activating a switch by a handset where the switch is manually activated when the user wishes to answer an incoming call. While the switch is in the deactivated state, the handset transmits to a sound card within a personal computer a multi-frequency tone which is detectable by the sound card. When the manual switch is activated, the handset ceases to transmit the multi-frequency tone to the sound card. The sound card detects the absence of the multi-frequency tone to determine if the handset is answering a call. In traditional telephony terms, when the manual switch is activated, this is the offhook condition. When the manual switch is deactivated, this is the onhook condition . When the user is done with the call and deactivates the manual switch, the handset again generates the multi-frequency tone that is subsequently detected by the software via the sound card. Then, the software knows to signal the other party on the call that the call has been terminated.

Abstract: A subscriber loop interface circuit and method for externally programming the on-hook, off-hook, and transition states of the subscriber loop interface circuit. The circuit having an off-hook overhead sufficient for long loop applications and having a continuous loop current to loop voltage relationship. The circuit may have plural means for generating reference currents for comparison with loop currents.

Abstract: A line card for interfacing with a plurality of subscriber lines includes a plurality of data processors and a tone detector. Each of the data processors is associated with one of the subscriber lines. The tone detector is adapted to detect one of a plurality of activation tones on a selected subscriber line. The plurality of activation tones include a first activation tone having an active portion and a silent portion. The active and silent portions repeat periodically at a first frequency having a first period. A second activation tone has a phase reversal portion repeating at a second frequency and having a second period. The tone detector is further adapted to sequence between the subscriber lines at a predetermined interval. The predetermined interval is based on the first and second periods. The tone detector is adapted to signal the data processor associated with the selected subscriber line in response to detecting one of the activation tones.

Abstract: Deactivating a switch in a handset when a user wishes to answer an incoming call or terminate a call. A sound card within a personal computer transmits a hook tone that is above the human hearing range to a transmitter section of the handset. When the switch is in the activated state, the handset re-transmits the hook tone back to the sound card which converts the hook tone to digital information so that the hook tone can be detected by software running in the personal computer. When the manual switch is deactivated, the handset ceases to re-transmit the hook tone back to the sound card. The software detects the absence of the hook tone to determine if the handset is answering the incoming call. In traditional telephony terms, when the manual switch is deactivated, this is the offhook condition. When the manual switch is activated, this is the onhook condition.

Abstract: The instant invention discloses a method and system for providing a novel wireless centrex service that untethers subscribers from the immobility associated with traditional desktop telephones. Essentially, the present invention extends the benefits of wireless voice and data services to subscribers having a need to move within a plurality of localities such as business and hospital campuses. In accordance with the invention, a wireless telephone subscriber can use a standard cellular/PCS telephone as a wireless extension of their desktop phone, while in the proximity of a miniature radio base station capable of communicating with the PCS/cellular telephone. The advantage of such a system is that a subscriber can use the same cellular/PCS telephone that provides service in the public network in the wireless centrex environment. Additionally, the wireless centrex system provides services and features which are similar to those offered to regular centrex telephone subscribers.

Abstract: A method and apparatus are described for using a series of signals that create an illusion of a continuous ascending or descending series of pitches as call waiting or call progress or process progress signals. In a preferred embodiment, a condition appropriate for representation by a call waiting or call progress or process progress signal is detected and, in response thereto, a series of signals is generated that creates an illusion of a continuous ascending or descending series of pitches. Preferably, the series of signals is Shepard's tones and the tones are generated by generating a plurality of tones, or partials, at octave intervals, amplitude filtering the partials to produce an amplitude envelope that peaks near the centermost partial or partials, and shifting the partials upwards (or downwards) through the octave in steps that are a fraction of an octave and preferably are a semitone.

Abstract: In order to be able to measure the transmission properties of transmission links mutually influencing one another with crosstalk in electrical message systems, particularly of handsfree equipment (FSE) such that the measurement is not falsified by occurring crosstalk influences, measuring signals that are essentially orthogonal are generated in the time or frequency domain in the measuring system (MS) from respectively at least two voice or test signals.

Abstract: A system for generating number tones for dialing a telephone device. The system comprises a socket assembly, at least one button assembly, and a converter. The socket assembly defines at least one socket. Each button assembly comprises a memory device for storing a sequence of numbers and a switch device. The converter generates a DTMF signal comprising a sequence of DTMF tones. Operation of the switch device causes the converter to generate the DTMF signal based on the sequence of numbers stored by the memory device. The socket assembly electrically connects the converter to the telephone device.

Abstract: A line card for coupling to customer premises equipment at a termination for detecting hook condition in a telephone system, the line card comprising an interface for transmitting and receiving an analog signal with the telephone line, an AC ring signal generator for generating a ring signal at the customer equipment, a DC signal generator for generating a DC signal when said customer equipment is off hook, and a circuit for determining the duty cycle of a loop current in the customer equipment (telephone) for determining the hook status of the customer equipmen.

Abstract: A ring back signal for a call between a calling party and a called party can be simulated. A ring back message associated with the call is received. The calling party is associated with a first network. The called party is associated with a second network. A prestored ring back signal is selected from a set of prestored ring back signals based on the ring back message and/or a called number for the call. The selected prestored ring back signal is associated with the second network and is different from a second prestored ring back signal associated with the first network. The prestored ring back signal is sent to the calling party.

Abstract: The present invention is directed to a voice tone discriminator for distinguishing between call progress tones and voice. The voice tone discriminator is useful in various applications involving the ability to automatically charge a telephone user based on the exact time the user starts speaking. According to another aspect of the present invention, a prediction algorithm may be implemented for distinguishing voice and tone based on the fact that tones are more accurately modeled with a linear filter than voice signals. Thus, a low order filter or predictor may accurately model redundancies in tones but not in voice. A normalized error between an original and a predicted signal may be used to distinguish voice from tones. Voice may be detected when the error is above a preset threshold for a time greater than a preset fixed duration.

Abstract: A telephone ring signal detector is coupled to a telecommunication line for detecting a first telephone ring signal, and for discriminating the first telephone ring signal from other line signals on the line. This detector comprises an event generator, coupled to the line, for receiving an incoming signal and for generating an initial event signal and an ending event signal, and a signal characteristic generator, coupled to the line and to the event generator, for generating a signal characteristic of the incoming signal after the initial event signal. This detector further comprises a signal characteristic limit device, for generating a predetermined signal characteristic range limit of the first telephone ring signal, and a signal characteristic comparator coupled to the signal characteristic generator, to the signal characteristic limit device and to the event generator, for comparing the signal characteristic with the predetermined signal characteristic range limit.

Abstract: A system and method are provided for special signaling with customer premises equipment. The system includes loop termination equipment coupled to a local loop and comprising a signal generator. The system also includes customer premises equipment coupled to the local loop. The customer premises equipment and loop termination equipment are operable to communicate across a communication link established on the local loop. The loop termination equipment is further operable to control characteristics of a signal generated by the signal generator and to provide the signal to the customer premises equipment as special signaling where the signal has a frequency that does not substantially interfere with voice traffic on the local loop. The special signaling can be used to implement enhanced service to the customer premises including busy signal, queued data request processing, push data and telephony services.

Abstract: A ring voltage generator uses values stored in random access memory to generate a train of pulses used to drive a voltage waveform to ring a telephone ringer. The values are stored in RAM, and are programmable by a user without requiring a change in the ring voltage generator design.

Abstract: A method and structure for cutting a ring current when a telephone enters an off-hook state. The method includes: (1) activating an off-hook detected signal when the telephone enters an off-hook state, (2) applying the off-hook detected signal to a selected input terminal of a coder/decoder (CODEC), (3) storing configuration information in the CODEC identifying the selected input terminal and a selected output terminal of the CODEC, (4) activating a ring cut control signal on the selected output terminal in response to the activated off-hook detected signal and the configuration information, and (5) cutting the ring current in response to the activated ring cut control signal. The CODEC includes a control register for storing the configuration information, and a hardware cut ring current (HCRC) circuit, which activates the ring cut control signal on the selected output terminal in response to the activated off-hook detected signal and the configuration information.

Abstract: A sound volume-controllable communication apparatus capable of outputting signals as monitoring sounds simultaneously with the transmission and reception of the signals is disclosed. At the time of transmission of a signal from, for example, a facsimile machine, a sound volume control unit performs control such that the volume of a sound output from a sound outputting unit is set to a volume lower than the volume normally set. More specifically, when a number key or an automatic dial key is operated, the facsimile machine stores into a memory the present volume of monitoring sounds from a speaker, and then sets the speaker volume to zero, thereby establishing a state where no sound will be produced from the speaker. If the key operated is a number key, the facsimile machine continually transmits a selection signal until the operation on the number key ends.

Abstract: Signaling tone detection systems are presented that may allow for reductions in talk-off, cut-through, or both. In one general aspect, a detection system includes an outgoing signaling tone detector responsive to an output from a first station to a communication channel. An incoming signaling tone detector is responsive to an input to the first station from the communication channel. A sensitivity control input of the incoming signaling tone detector is responsive to a detection output of the outgoing signaling tone detector. This and other configurations may allow a system to detect tones more reliably, or they may allow a system with particular computational capabilities to detect more tones with a similar level of accuracy.

Abstract: A system within a PC server cabinet for receiving an externally supplied loop feed voltage (−48 VDC) and generating a ringing voltage (75 VAC) from the loop feed voltage. For universal applicability, the ringing voltage generator is preferably located in a 5.25 inch standard disk-drive housing of the cabinet, allowing it to fit into any PC. All required telecommunications signaling and power is thereby provided in the PC while limiting accidental user exposure to hazardous ringing signal voltage levels.

Abstract: DTMF tones used to enter a password reflected by an answering machine or voice mail system can be masked using a jamming signal generator. When an answering machine or voice mail system is accessed with a cellular phone, the DTMF tones used for the password can be reflected back over the cellular network, which compromises security. A method and apparatus are disclosed which detects tones on an input line and outputs a jamming signal on the output line to mask the reflected tones.

Abstract: An electroacoustic transducer (1) includes a ringing signal generation means (20) for generating a ringing signal (CS) and an electroacoustic transducer (9) for the acoustic reproduction of the ringing signal (CS), in which the ringing signal generation means (20) includes at least two fundamental tone signal generation stages (GT1, GT2, . . . GTn), which are each adapted to generate a fundamental tone signal (GS1, GS2, . . . GSn) of a given frequency (f1, f2, . . . fn), which frequencies (f1, f2 . . . fn) are in a rational ratio to each other, and in which the ringing signal generation means (20) has a control means (21) with the aid of which each of the fundamental tone signal generation stages (GT1, GT2, . . . GTn) can be activated for a given time interval, namely in such a manner that at least two fundamental tone signal generation stages (GT1, GT2, . . . GTn) are activated simultaneously.

Abstract: A tone supplying device generates various tone signals which an exchange can provide for public subscribers. Address signals generated by a counting operation of a first counter are inputted to a plurality of tone tables, which in turn successively output a tone signal corresponding to each of the address signals and provide same to a corresponding buffer through a corresponding latch. The first counter allows the tone selecting signals and the address signals to be generated in the tone tables so as to successively output corresponding tone signals therefrom and, at the same time, supply the tone selecting signals to the cadence selecting circuit so as to allow the cadence selecting circuit to select any one of cadence data inputted thereto from the cadence table and to output it.

Abstract: A high efficiency ringer circuit having low distortion of the ringer output signal, which is simple in design and inexpensive to manufacture is disclosed. This may be accomplished with a ringer circuit comprising an input signal source, a signal amplifier for receiving and amplifying an input signal from the input signal source, a direct current source for providing power to the signal amplifier, a comparator circuit for receiving an input signal from the signal amplifier, and a switching circuit for receiving an input signal from the comparator circuit for providing an output signal to the direct current source, where, when said input signal to the comparator circuit exceeds a set value, the output signal from the switching circuit de-energizes the direct current source. The amplifier may be a Push-Pull amplifier. The direct current power supply may be a DC/DC SMPS.

Abstract: In a ringing-tone control device for a telephone set, an audio signal which is sent from a communication opposite party is converted into a corresponding bi-level signal. The bi-level signal is stored into the memory. The bi-level signal is read out from the memory. A ringing tone is generated in response to the bi-level signal read out from the memory.

Abstract: A system and method for enabling a subscriber to receive incoming telephone calls on a telephone line and ring all of the telephones connected to a first conductor pair inside the subscriber's premises, wherein the first conductor pair would have normally been connected to the line. The telephones may be rung even when the subscriber is performing data communications with a remote data site on the telephone line. This obviates the necessity of the subscriber having to purchase a second telephone line for incoming calls while data communications are being performed, thus reducing access costs. The system and method shown advantageously employs a wiring device to reroute the telephone line from the first conductor pair connected to the phones to a second conductor pair normally not used. The system and method further employs a modem which receives telephone signals from the telephone line via the second conductor pair.

Abstract: An apparatus, system, method, and computer program product for providing a flexible ringer for multiple deskset phones. A controller detects a flag message that precedes an incoming telephone call, and selects one or more frequencies based on a local expectation of a ringing telephone at the geographic location, or according to a user preference. A digital signal processor (DSP) generates a digital ringer signal based the selected frequencies. An audio code converts the digital ringer signal to an analog ringer signal and sends the analog ringer signal to multiple deskset phones using a receive cable. The analog ringer signal is amplified to drive a speaker that converts the analog ringer signal into an audible ringer sound at each deskset phone. The audible ringer sound can be customized for multiple geographic locations by modifying the selected frequencies used in the digital ringer signal.

Abstract: A method and system in a network telephony system for transporting audio signals with lower delay when DTMF is not present. The method of transporting audio signals determines whether DTMF signals are included in the audio signal, or are likely to be transported according to the called or calling parties. A delay is imposed in the audio when DTMF signals are sensed or determined to be present as indicated by the calling party, the destination telephone number, the called party, and various other indicators. A timer may be used to trigger a reduction and elimination in the audio delay after an initial period in the call for calls in which DTMF signaling is used for an initial period of the call. The timer may also trigger the reduction and elimination in the audio delay when no DTMF signals have been received after a period of time. The system uses a DTMF detector to sense DTMF signals in the audio signal and to signal the delay generator to impose a delay in the audio stream.

Abstract: A telephone is provided with a means for automatically generating ringing tones to be heard by a user over ambient noise and in spite of any muffling environment in which the telephone may be located. The ambient noise is measured to determine its amplitude and frequency characteristics and appropriate amplitude and frequency characteristics of ringing tones to be heard by a user over the ambient noise are calculated and generated. The degree to which the ringing tones are muffled by the muffling environment is calculated and suitable amplitude and frequency characteristics of further ringing tones necessary to be heard by a user in spite of the muffling environment are calculated and further ringing tones having the suitable amplitude and frequency characteristics are generated.

Abstract: A vibrating device for alerting a phone user of an incoming call includes a receiver of an electric signal representing the incoming call, and a converter which renders the electric signal into a mechanical movement that is felt by the skin of the user as a sensational touching. The converter contains a magnetostrictive generator controlled by an electric signal representing incoming signals. A telephone set incorporates the vibrating device into its ringer.

Abstract: This invention provides a dial tone for use in analog, TDMA, and CDMA wireless environments and includes the capability to collect additional digits during certain calling feature activation. The dial tone supports call forwarding, cancel call forwarding, call waiting, cancel call waiting, calling number identification presentation, calling number identification restriction, three way calling (including IS-53 version of three way calling, three way calling with cancel call waiting and calling number identification presentation/restriction, and three way calling interactions with call forwarding), and limited call transfer. After the mobile user requests the desired feature, a tone generator typically located at the mobile switching station or the mobile station will provide dial tones or confirmation dial tones to aid the mobile users when initiating a calling feature.

Abstract: Remote supply circuitry for remotely supplying a subscriber connections in a communications system wherein subscribers can be connected to a central point via subscriber lines. Subscriber supply voltage or power supply is provided for each subscriber via a supply voltage source assigned to the subscriber and at least one supply isolating element wich is connected in series with the subscriber and associated subscriber line. The supply voltage source assigned to the subscriber supplies an output voltage which is controllable as a function of a measurable variable.

Abstract: A telephone apparatus connects to a telecommunications network via an exchange line. It has signal recognition for detecting and recognizing calling line identity (CLI) and called number identity (CNI) signalling transmitted over the exchange line. The apparatus causes an incoming call to be transferred to a second exchange line in response to specified CLIs and/or CNIs.

Abstract: In generating a ringing signal of predetermined frequency and shape between the A- and B-wires to a subscriber's station in a telephone network, the ringing signal is directly injected in or superposed on the DC-levels of the wires. A voltage difference converting device converts any voltage difference between the A- and B-wires into a first current. A signal generating device generates a first voltage of the frequency and shape of the ringing signal to be generated, and a signal converting device then converts the first voltage into a second current. In a summation node the first current is subtracted from the second current to obtain a third current and this current is converted by passing it through a resistor to a second voltage. The second voltage is buffered and is again converted to a fourth current by applying the voltage to resistor. This fourth current is amplified by current amplifiers circuits comprising operational amplifiers, and is then supplied to the A-wire and drawn from the B-wire.

Abstract: Annunciator apparatus, and an associated method, for a mobile station, such as a radio telephone operable in a cellular communication system. When a call is to be terminated at the mobile station, a determination is made of the ambient noise levels proximate to the mobile station. Responsive to the determinations of the ambient noise level, selection is made of the loudness level of the ringing tone to be generated by an annunciator, used to annunciate the terminating call. Thereby, the loudness level of the ringing tone generated by the annunciator is of a loudness level appropriate for the conditions at which the mobile station is positioned.

Abstract: A method of communicating an incoming call through a telephone receiver having an incoming call circuit and an audible signal system operatively connected to the circuit. The incoming call is communicated to a person remotely located from the receiver. The method comprises disconnecting the audible signal system, and placing on the person a pager having a receiver circuit capable of sensing the existence of an incoming call destined for the incoming call circuit of the telephone receiver. The pager having a silent announcer thereon operatively connected to the receiver circuit of the pager. Thus, the presence of an incoming call can be transmitted to the receiver circuit of the pager to actuate the vibrator without actuating the audible signal system of the telephone receiver.