Abstract: A network interface system is provided with an addressable application device and a processor. The addressable application device is adapted to interface with a transport medium internal to a customer premises. The processor is adapted to selectively process telecommunication information originating from a transport medium external to the customer premises. The processor is further adapted to transmit the processed telecommunication information to the addressable application device for implementation of an application over the transport medium internal to the customer premises in accordance with a state of the addressable application device. The addressable application device and the processor are disposed external to the customer premises.

Abstract: An improved modem architecture and associated method are disclosed that integrate modem and line-isolation circuitry so as to achieve modem functionality and system-side isolation functionality on a single integrated circuit. The combined modem and line isolation system has both on-hook and off-hook intrusion detection for use with parallel connected phone line connection devices. During on-hook intrusion detection, when the combined modem and line isolation system is on-hook the system can detect if other parallel connected phone line connection devices are already off-hook. During off-hook intrusion detection, when the combined modem and line isolation system is off-hook the system can detect if other parallel connected phone line connection devices are attempting to go off-hook. On-hook intrusion detection may be accomplished by monitoring the phone line voltage through a pin utilized for setting DC termination characteristics.

Abstract: A PC (10) connected to a low-voltage electricity supply system (9) via a mains plug (11) and a mains socket outlet (12), into which the said plug is plugged, exchanges messages with other apparatuses via the said electricity supply system by means of signals whose frequency is between 1 MHz and 40 MHz. In order to suppress high-frequency interference signals which are generated by further apparatuses which are connected to the low-voltage electricity supply system (9) via mains plugs (11′) and further mains socket outlets (12′), arranged in local proximity to the said mains socket outlet (12), or which are produced by reflections of signals at open line ends, an adapter (1) is in each case interposed there, which adapter is plugged into the mains socket outlet (12′) and into which adapter the mains plug (11′) of the respective apparatus is plugged.

Abstract: A method and apparatus for a telephone line interface or data access arrangement (DAA) which includes a shunt regulator in series with a line modulator. A sense resistor is placed in series between the shunt regulator and the line modulator to provide a measurement of the amount of current distortion in the DAA. The line modulator contains a Darlington pair which reduces the amount of current drawn by the line modulator, allowing the sense resistor to sense a majority of the system current. The voltage across the sense resistor is fed back to the line modulator. The line modulator is capable of adjusting the AC modulation and the DC termination presented to the telephone line. The method includes drawing power from the telephone line using a shunt regulator, modulating the telephone line in series with the shunt regulator, sensing a level of distortion in the DAA, and feeding the sensed level of distortion to the line modulator.

Abstract: Design techniques are describes in which a telephone interface circuit or DAA can be realized using two silicon integrated circuits which include integrated opto couplers. The LED is formed on the chips using technologies which can be easily integrated onto a silicon integrated circuit such as porous silicon, avalanching PN junction, forward biased PN junction, deposited silicon carbide PN junction, deposited organic LED material such as conjugated polymers, or deposited GaAs LEDs. The light detector is realized using either a PN junction based detector or a Schottky diode detector depending on the wavelength of the light transmitted by the LED. The two integrated circuits can be placed in a single package with suitable optical links within the package. This technology thus eliminates the need for discrete opto couplers and transformers.

Abstract: A voice over DSL telephone system for a customer premises. The system includes a network interface device having a DSL filter coupling DSL service from a central office to the customer premises wiring and a switch for automatically connecting POTS service from the central office to the customer premises wiring whenever there is no active integrated access device, IAD, connected to the wiring. A detection circuit detects the presence or absence of the IAD and opens and closes the switch accordingly. Both DSL and POTS ports of an IAD may then be connected to the same customer premises wiring. Telephone sets are coupled to the customer premises wiring through low pass filters which block DSL frequencies.

Abstract: A local area network using the telephone wiring within a residence or other building simultaneously with telephony signals, with network outlets having telephone and data connectors allowing connection of Data Terminal Equipment to the network. The network outlets use high pass filters to access the high-frequency band across the media, whereas the standard telephone service uses low pass filters to access the low-frequency voice/analog telephony band across the same media. The high pass filters of the network outlets at each segment end are connected to modems or other Data Communication Equipment, thus supporting data communication networks of various topologies, including point-to-point topologies. The invention also contemplates a network outlet having a data interface connector for allowing connection of Data Terminal Equipment thereto and having a telephone connector for connecting a standard telephone thereto.

Abstract: A communication apparatus including a network control unit for interfacing with a telephone line. The network control unit comprises a direct current circuit in which a loop state direct current can flow, and a direct current limiting device for limiting the loop state direct current to a prescribed value when communication with a foreign country that has adopted a different communication standard is performed.

Abstract: Methods and systems for providing operating system support of computer telephone sets are described. Services are provided to standardize the interactions between computer telephony applications and telephone sets, to unify those interactions into a coherent whole, and to simplify the interactions by automatically performing common tasks. A default Telephone Manager provides all the functionality needed to support basic telephony. With all call processing performed on the host computer, telephone sets attached to the host need have no native intelligence. Support for transporting voice to distant locations is provided entirely by the host computer rendering the telephone set independent of any transport technology.

Abstract: A bidirectional equalizer arrangement for cancelling the effect of residual capacitance and/or residual resistive loss in a separation filter having a low-pass filter and a high-pass filter. The equalizer comprises a differential amplifier whose input forms the equalizer's connection terminals, and whose output is coupled, via a transformer, to a positive feedback circuit that includes the transformer's secondary winding, a capacitor and a resistor of predetermined values. When the equalizer is operatively coupled to the low-pass filter, the positive feedback circuit produces a feedback current of opposite polarity and equal magnitude to that produced by the residual capacitance and/or the residual resistive loss, thereby substantially cancelling their effect. The equalizer may be advantageously used with an ADSL/POTS separation filter.

Abstract: A high bandwidth telephone line transceiver for connecting telecommunications equipment to a telephone line provides a pair of isolation capacitors connected to the telephone line to transmit the telephone signals across the requisite electrical isolation barrier. The capacitors are connected to a user-side hybrid circuit that provides a line impedance match for the telephone circuit, and converts the two wire connection to the capacitors to a 4 wire circuit for separate transmit and receive signal paths. The receive signal path extends through a signal op amp to a high pass filter that transmits the DSL download bandwidth and rejects the upload bandwidth and voice spectrum. The received signal is then fed to an analog/digital converter, and the digitized signal is connected to a DSP. The DSP is connected to a data handling device via a USB port, a PCI interface, or the like. The transmit signal path extends from the DSP circuit to a transmit path digital/analog converter.

Abstract: A system and method that provides a user multiple, simultaneous uses of a single analog line.

Abstract: A relay is described to facilitate communication through the telephone system between deaf people and hearing people. To overcome the speed limitations inherent in typing, the call assistant at the relay does not type most words but, instead, re-voices the words spoken by the hearing person into a computer operating a voice recognition software package trained to the voice of that call assistant. The conversation-type flow of communications achieved by this type of relay enables the design of a new class of interpreters for the deaf.

Abstract: A telephone handset that can be remotely activated. The audio data can be operating instructions of the handset and/or telephone numbers stored in the phone. The handset contains a line interface circuit that can detect a plurality of ring signals on a telephone line. The phone line is also coupled to a secondary phone device that has a line voltage detection circuit which detects a voltage drop within a predetermined time interval. The handset further contains a controller that can generate a tone signal to be transmitted onto the telephone line. The caller can then provide a responsive activation signal to activate the handset. The handset connects onto the telephone line for a time interval to detect the activation signal. The line connect time interval is less than the predetermined time interval of the line voltage detection circuit of the secondary phone device so that the line connect does not cause the secondary phone device to hang up the call.

Abstract: The invention relates to the separation of narrowband and broadband services in a telecommunications network. Signals belonging to a narrowband service are transferred in a first frequency range below a given threshold frequency and signals belonging to a broadband service are transferred in a second frequency range above said threshold frequency in the transmission link. The transmission link utilizes a splitter element comprising a low-pass filter unit and a high-pass filter unit, signals relating to narrowband service being separated to their dedicated interface by the low-pass filter unit and signals relating to broadband service being separated to their dedicated interface by the high-pass filter unit. In order that high-quality service may be offered to subscribers by means of a splitter element as simple and cost-effective as possible, filtering is implemented in the low-pass filter unit by means of a bidirectional active filter (LPF′).

Abstract: An telecommunications access device is disclosed which allows an administrator to set an amount of time per day that a user can access the Internet or use a telephone. The telecommunications access device may be permanently electrically connected to first and second telecommunications lines each of which may include a telephone cord and a plug. The first telecommunications line may be electrically connected to a port of a computer processor. The second telecommunications line may be electrically connected to a port of a telephone jack. The telecommunications access device may include a keypad, which allows the user to enter a user code, which permits the user to access, the Internet or use a telephone, if the amount of time has not expired. The telecommunications access device may include a display, which dynamically displays the amount of time that the user has remaining to access the Internet for a particular day.

Abstract: A filter system (and associated filtering method) is disclosed, the filter system being connected between a large-amplitude, high-frequency noise source and a frequency-division multiplexed communications channel. The large-amplitude, high-frequency noise commonly being a POTS (plain old telephone service) ring signal generated by a CO (central office) telephone switch. The frequency-division multiplexed communications channel generally used to carry digital signals at frequencies above the POTS baseband in order to implement a digital subscriber line (DSL). Large-amplitude, high-frequency signal components from the POTS ring signal impair the performance of frequency-division multiplexed channels on a transmission line such as a subscriber loop. The filter system of the present invention utilizes amplitude and also may utilize frequency to selectively suppress the transients and harmonics on the transmission line caused by a telephone ring signal.

Abstract: A communications system includes a telephone, a data network, a device coupled to the data network and telephone, and a communications routine in the device. The communications routine controls communication of voice data between the telephone and the data network.

Abstract: One embodiment of the present invention includes a telephony interface, a network interface and a local area network (LAN). The telephony interface provides connectivity between one or more netphones and an external telephone network such as a PSTN telephone system. The network interface provides connectivity between one or more computers and an external computer network such as the Internet. The local area network provides interconnectivity between the netphone(s), the computer(s), the telephony interface and the network interface. In some embodiments, there may be two or more netphones which can communicate with each other internally via the LAN, in addition to communicating with the external telephone network. Similarly, there may be two or more computers that can also communicate with each other internally via the same LAN, in addition to the external computer network.

Abstract: An improved modem architecture and associated method are disclosed that integrate modem functionality and line-side isolation functionality while also providing flow control of internal data between an isolation interface, digital-signal-processor (DSP) circuitry, and an analog input. The integrated modem and line-isolation circuit may also have an analog output for which data flow control is also provided.

Abstract: A telephone line interface or data access arrangement (DAA) is provided which draws power for the customer premises equipment from the telephone line. The DAA includes a shunt regulator as the power source drawing power from the telephone line, and a line modulator in series with the shunt regulator. A sense resistor is placed in series between the line modulator and shunt regulator to sense the line current. Accordingly, DC termination and AC modulation characteristics as presented by the DM to the telephone line can be adjusted by variation of an AC signal with DC offset input to the amplifier driving the line modulator without requiring a different DAA for use in regions or countries having various DC termination and AC modulation requirements. The differential feedback from a sense resistor reduces the noise induced in the circuit from the shunt regulator.

Abstract: The emergency call such as Enhanced 911 call or the like is also originated through an exchange such as PBX (Private Branch Exchange). In this case, the identification information such as the extension number of the extension telephone terminal connected to the PBX should be transmitted to a network corresponding to the emergency call. For the extension telephone terminal, it is necessary to unhook or to capture an arbitrary line by the line key, before inputting the dial data “911”. Independent of the capture of arbitrary line, the PBX searches a vacant line connected to the network corresponding to the emergency call, captures the vacant line, transmits the identification information such as the extension number, and switches over and connects the extension telephone terminal from the line captured by the terminal to the vacant line.

Abstract: An interface apparatus interposed between a cordless telephone base unit and a personal computer sound card. Such interface emulates a Central Office connection with respect to the telephone and a mic and speaker connection with respect to the computer sound card. The apparatus is suitable for all cordless telephones regardless of frequency allocation standards because the interface occurs at the RJ-11 modular jack of the cordless phone base, normally intended for connection to a CO line. Differences in telephone line regulations that exist among countries are accounted for with no burden of complexity to the user of the present invention. The interface comprises active and passive circuits perform two-wire-to-four-wire conversion and signal conditioning. Local loop current may be obtained from batteries or a suitable AC power adapter.

Abstract: A multifunction, communication device including a user recognition device for obtaining user identifying data from a user, an interface for receiving the user identifying data from the user recognition device, a memory for containing personal user contact data associated with the user, and a controller having a user interface for controlling the operation of the communication device by using the personal user contact data associated with the user in performing at least one function of the communication device. Control of the operation of the multifunction communication device includes obtaining user identifying data from the user, associating the user identifying data with the user's personal user contact data located in a memory, and performing a function of the communication device using the personal user contact data of the user.

Abstract: The invention relates to a network station (1) comprising a selector switch (4) for coupling a switching center (2) to a POTS or ISDN telephone, and a detection circuit (3). After the detection circuit (3) has been made operative or after the mode change from the POTS mode to the ISDN mode, the detection circuit (3) controls the selector switch (4) such that this switch goes to the ISDN mode and thus couples the switching center (2) to an ISDN network terminator (11). When the ISDN mode is changed into the POTS mode, the selector switch (4) is actuated by the detection circuit (3) so that the switch couples the switching center (2) to the POTS telephone.

Abstract: An apparatus and method provide for filtering of voiceband and specified tone frequencies of a mixed voice/data signal, such as an Asymmetric Digital Subscriber Line (ADSL) signal. A lowpass filter section passes voiceband content of the mixed signal and suppresses mixed signal content having frequencies falling within a databand of the mixed signal. A bandpass filter section is coupled to or integral with the lowpass filter section and passes the specified tone frequency, such as a metering or billing tone frequency. The lowpass and bandpass filter sections exhibit a combined frequency response that provides for a stopband between the voiceband and the metering tone frequency. The bandpass filter section effectively detunes a frequency response of the lowpass filter section to provide for the stopband.

Abstract: A telephony services distribution system includes a voice/data server that receives and transmits telephony data in accordance with a suitable digital communication protocol. The voice/data server is associated with a customer premise that supports a number of enhanced telephony devices, which may include wired and/or wireless telephone devices, videophone devices, facsimile devices, or the like. The customer premise may also support any number of conventional POTS telephony instruments. The voice/data server and the enhanced telephony devices communicate signaling data therebetween via a signaling technique such as the V.21 modem protocol. The signaling information conveys data associated with the status of the enhanced telephony devices, calling party and called party identification, characteristics of the incoming and outgoing calls, and/or data related to any number of operating parameters and characteristics of the system.

Abstract: The current invention provides a method and apparatus for wireline characterization is disclosed. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The apparatus may be incorporated into physical or logical modems. In an embodiment of the invention an apparatus for wireline characterization in a modem with a transmit path and a receive path each configured to couple with a remote modem via a wireline in which available communication bandwidth is split into a number of independent sub-channels is disclosed. The apparatus comprises: a tone selector, a cumulative loss estimator and a shift register. The tone selector selects a subset of the number of sub-channels within the bandwidth of a received wireline communication for which subset the sum of the square roots of the corresponding sub-channel indices may be expressed as an integer power “n” of 2.

Abstract: A telephone terminal capable of keeping a line to the other party's telephone terminal connected through a telephone line network in a connected state even after an output destination and an input source of audio signals are switched to an audio input/output unit. In a multifunction machine serving as the telephone terminal, a transmission path to be used for input/output of audio signals from/to an outside source is switched to an audio cable when a switch key is pressed during a voice call through the telephone line network. If an Internet call function is used at a PC, a voice call by the Internet call function may be performed indirectly by using a transmitter/receiver. The multifunction machine may automatically disconnect the line through the telephone line network when receiving a BT from the telephone line network after the transmission path is switched to the audio cable.

Abstract: A method and apparatus for coupling a voiceband modem circuit to a common phoneline connector, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line. The voiceband modem interface ring line is coupled to the ring line and the voiceband modem interface tip line is coupled to the tip line connection by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency.

Abstract: An IC card terminal device reads functions stored in an IC card inserted therein, and displays them on its screen. The card user selects that one of the functions, which they intend to execute. The IC card terminal device determines whether or not it has an application corresponding to the selected function. If the terminal device does not have the application, it reads information stored in the IC card and related to the function. On the basis of the information, the terminal device is connected to a host apparatus as a service provider, thereby downloading a necessary application therefrom. After that, the downloaded application corresponding to the selected function is executed.

Abstract: The telephone system of the invention combines at least one telephone terminal (40 to 43) and one microcomputer (38 to 40) using a set of software modules, especially a module for functions normally carried out by top range telephone stations: free hand functions, recorder telephone answering sets, fax/modems, storage of numbers, automatic dialling, display on the screen of a microcomputer, and/or a module for services normally centralised for a large number of users, and/or a module concerning new functionalities: Internet/Intranet access, vocal recognition, automatic reading, small capacity unit automatic exchanges.

Abstract: Digital answering machine that can receive not only voice but also fax information via a telephone line. In order to receive and send faxes with a computer, it is inventively provided to expand a digital answering machine such that incoming faxes are intermediately stored in a memory and can be transmitted to the computer via an interface after the computer is switched on.

Abstract: An apparatus and method for providing a ringing voltage to a communication device such as a telephone or a modem. Typically, communication devices are coupled to a ringing voltage providing telephone network, such as a Plain Old Telephone Service (POTS) network. The POTS network generally provides the necessary ringing voltages to the communication device. However, in other telephone networks, such as a PBX system, ringing voltages are not provided by the telephone network. The apparatus provides ringing voltages to the communication devices coupled to the non-ringing voltage providing telephone networks. The apparatus includes a switching regulator that provides the necessary ringing voltages to an indicator such as a bell or other output indicator.

Abstract: Apparatus and methods are provided for selectively providing telephone service that is either PSTN-based or Internet-based using a standard analog telephone circuit. In a first embodiment, the apparatus comprises a hardware module and associated software for coupling a personal computer or Internet appliance and a standard analog telephone. The apparatus includes a DTMF interface circuit, a subscriber line interface circuit, a ring detection circuit, and an interface circuit for interfacing with the PC or Internet appliance. The apparatus permits the analog telephone to be toggled between an Internet-based telephone mode and a PSTN-network mode by inputting a predetermined sequence of DTMF digits. In alternative embodiments, the apparatus comprises a processor, modem and optionally, analog telephone circuit, to provide a stand-alone or partially-integrated device capable of selectively switching between PSTN-based and Internet-based telephony services.

Abstract: The present invention is directed to a novel system and method for connecting and interfacing a communications device, such as a modem, to a two-wire telephone line via a telephone base set (e.g., PBX or PBX-like), thereby allowing for data communications on the telephone line. The modem and the telephone base are interconnected by way of an interface adapter. Interface circuitry present within the interface adapter converts the digital interface (e.g., a wireless or cellular interface) into a PBX-compatible interface for interaction with a PBX phone base set. The interface adapter allows a modem that has a digital peripheral interface such as a cellular interface to communicate with a PBX base using the existing cellular interface. In a preferred embodiment, the system also includes a cable detector circuit that allows the modem to automatically detect when it is connected to a telephone base by way of the interface adapter.

Abstract: Method and apparatus for transmitting encoded data and/or voice signals with increased data speed in a communications system using high resolution analog to digital and digital to analog conversions to attain transmission rates higher than 33.6 Kb/s rate limit of V.90 modem is provided.

Abstract: The present invention relates to a filter arrangement (8C) and a method for frequency filtering and impedance conversion. The invention makes it possible to perform frequency filtering and impedance conversion using fewer inductors than what is required using previously known technique for obtaining the corresponding effect. According to an alternative aspect the invention provides more effective frequency filtering and equivalent impedance conversion compared to the prior art when the same number of inductors are used. According to the invention an electromotive force (e′) is generated in at least one filter coil (L1, L4). The electromotive force is adjusted so that the filter arrangement (8C) receives a desired impedance converting effect. A filter arrangement according to the invention, compared to the prior art, in this manner provides a filter integrated with an impedance converter. Compared to the prior art the invention can make a saving of one transformer per impedance converter possible.

Abstract: An odd-order low-pass microfilter is disclosed for being interposed between a home telephone wiring network and a POTS, or voice band, device to separate voice-band signals from higher frequency signals, such as ADSL signals and home networking signals. The filter topology is substantially symmetric so that the filter is reversible in that either end of the filter may be directly coupled to the home telephone wiring network without impairing high frequency signal performance or the filter characteristic of the filter. In one embodiment, the filter is a three-pole filter with a single capacitor disposed between a pair of coupled inductors. Each of the coupled inductors advantageously has an interwinding capacitance over about 100 pF to improve the filter frequency response without increasing the cost of the filter. In another embodiment, the filter is a reversible three-pole filter with a single capacitor disposed between first and second pairs of uncoupled, or discrete, inductors.

Abstract: A conventional computer is coupled to an analog telephone transmission link by means of an analog/digital conversion interface adapter. Modem transmission is accomplished by performing the modulation and demodulation functions digitally in the computer's existing processor which executes programs which transfer data between the computer's memory and the interface adapter. Using the same interface adapter and existing processor, the arrangement may be used to send and receive images in the form of standard V.29 format facsimile data, to send and receive data operating as a synchronous IBM 3270 compatible terminal device, or to record and play back conventional voice transmissions rather than data to implement a telephone answering, voice message handling, and telemarketing systems.

Abstract: A call system for performing a voice call by an Internet call function using a known telephone terminal. In a multifunction machine serving as the telephone terminal, the output destination and the input source of audio signals input/output from/to a transmitter/receiver may be switched to an audio I/F. In the switched state, audio based on audio signals input/output from/to an outside source through the audio I/F is output/input from the transmitter/receiver. Therefore, when the multifunction machine is connected to a PC having the Internet call function such that audio signals can be input/output through an audio cable, an indirect audio call by the Internet call function with the transmitter/receiver is available. When an incoming call from a telephone line network is received, reception of the incoming call is notified so that a user can confirm the reception of the incoming call during the voice call by the Internet call function.

Abstract: If any of the communication terminals has incoming calls, calling signals are repeatedly output to the communication terminal at predetermined intervals until the communication terminal answers. When one communication terminal is called before another communication terminal answers its preceding call, calling signals to each communication terminal are repeatedly output alternately. Thus, a simple structure that is capable of changing output destinations for very calling signal output is provided. Upon receiving multiple incoming calls at about the same time, the apparatus can repeatedly output calling signals to corresponding communication terminals, without having multiple calling signal output apparatuses.

Abstract: A TAPI method according to an implementation of the present invention includes installing a TAPI service provider and associating a first PID with the TAPI service provider; re-installing the TAPI service provider and associating a second PID with the TAPI service provider; and automatically associating TAPI devices that had been associated with the first PID with the second PID.

Abstract: A communications terminal operates in multiple modes including a wired phone mode, an Internet phone mode, and a combined mode. The terminal includes a wired phone unit and an IP phone unit which separately processes calls to/from PSTN- and Internet-communications networks. The terminal also includes a processor which processes a call through a voice path which connects the wired phone unit and the IP phone unit in a third mode of operation which is referred to as an external connection mode. By processing a call along this path, the cost of performing long-distance and/or international calling may be substantially reduced and transmission efficiency may simultaneously be improved.

Abstract: Computer integrated telecommunication systems are disclosed that provide a message exchange interface that transfers data and control requests generated by applications running on a computer system directly to a telecommunications unit that is adapted to respond to the data and control requests generated by these application programs. In particular, PBX systems are disclosed that include message exchange interfaces that provide fault tolerant operation and that directly map application programs running on a computer system into the controller element of the PBX system. Further systems are disclosed that provide message exchange interfaces that allow the efficient transfer of audio signals between a computer system and a telecommunication unit.

Abstract: In an apparatus for supplying a tip and ring telephone line with voice band and broadband signals, a first pair of drivers supply at least DC signals to the respective tip and ring line components, and a second pair of drivers supply broadband signals to the tip and ring line components. Feed components combine the outputs of said respective drivers for the respective tip and ring components of the telephone line.

Abstract: The present invention provides a digital pre-distortion filter in arrangement with a data access arrangement (DAA) on the component side (e.g., in a modem chipset). This arrangement of the pre-distortion filter outside of the DAA allows digital processes such as digital emulation of the central office impedance to remain unaffected by the pre-distortion in the transmitted signal, allowing the dynamic range of the transmitted signal to be flattened to minimize return loss without complicating the transfer function of the digital emulation of the central office complex load. In the case of a digital emulation filter, placement of a digital pre-distortion filter outside of an analog-to-digital (A/D) digital-to-analog (D/A) loop also minimizes the noise otherwise associated with the use of a pre-distortion filter. Thus, benefits of a pre-distortion filter can be gained without interfering with emulation of impedance, and without causing a significant amount of noise in the transmitted signal.

Abstract: A telephone set of a telephone system is provided with an infrared interface. This infrared interface is able to communicate with an infrared port on a local computer. The computer is configured to send data to the infrared port, and receive data from the infrared port, in the same manner as if the computer was sending and receiving data over a telephone system. The telephone circuitry in the telephone system receives the infrared data and converts the infrared data into a format for transmitting across the telephone system.

Abstract: An apparatus for interrupting data transmissions along a communications link between an input terminal and an output terminal of the apparatus. According to one embodiment, the apparatus includes a switch connected in series along the communications link, a bandpass filter and a processor. The bandpass filter includes an input terminal connected to the communications link and an output terminal connected to an input terminal of the processor. The processor includes an output terminal connected to a control terminal of the switch. The processor is programmed to detect participation in a handshake operation by a modem connected to the communications link and open the switch when participation in a handshake operation is detected.

Abstract: A telephone loop monitoring and isolation device which can be connected to a wireless telephone subscriber unit providing an interface between an analog or digital central station network and the internal telephone wiring of a subscribers premises. The device is also operable with a cable telephone subscriber unit. The device provides passive real time loop status information as well as loop isolation if the voltage across the loop falls below a predetermined level. When normal loop impedance conditions are restored, the subscriber loop is automatically reconnected to the subscriber telephone unit. The device is effective for examining open circuit and abnormal impedance conditions and provides loop status information to the telephone subscriber.