Abstract: The invention relates to a line terminating device for a subscriber line which transmits and receives broadband signals via a single subscriber line, a broadband signal being composed of a broadband or narrowband audio-frequency data signal and a broadband higher-frequency data signal and the frequency bands of the voice signal and of the data signal essentially not overlapping. The line terminating device according to the invention has a digital frequency separating filter in the digital section of the line terminating device, which is arranged in the digital section of the line terminating device so that the audio-frequency voice signal is separated from the higher-frequency data signal. In particular, the line terminating device is suitable for separating an ISDN or POTS voice signal from an ADSL data signal.

Abstract: A method for testing subscriber access lines wherein the test is carried out locally, online and virtually all the time with the assistance of the digital signal processor for the subscriber line. The test results are gathered at a central point and are signaled from there; when required, to specific locations in the subscriber access network, for example, to a distribution node where maintenance work is currently being carried out.

Abstract: A method of handling telephone signals supplied by an analog telephone set and data supplied by a data terminal in a subscriber line circuit of a digital telephone switching system used at least in subregions for data transmission includes directly connecting a telephone set and a data terminal with a modem to the digital telephone switching system through a common analog subscriber line, at least one of subjecting data supplied by the data terminal to a sampling operation at a sampling rate above a sampling rate required for telephone information during analog/digital conversion and coding sampling values representing data supplied by the data terminal according to a linear characteristic during analog/digital conversion, and feeding data originating from and handled by the data terminal directly to a data transmission network. A subscriber line circuit for handling telephone signals supplied by an analog telephone set and data supplied by a data terminal is also provided.

Abstract: The invention relates to an xDSL modem that can be operated in the remote diagnosis mode and to a corresponding maintanance system according to which the xDSL modem (2) comprises, in addition to a transceiver device (3) for transmitting/receiving data in a predetermined transmission format a failure profile detection device (4) for detection a failure profile and a failure profile transmission device (5, 3) for transmitting the detected failure profile to a maintenance installation. The invention provides an inexpensive means for carrying out the initial start-up as well as an error diagnosis of failure with a subscriber.

Abstract: The invention relates to a method for determining the transmission parameters of a transmission link for high bit rate data transmission, wherein the transmission link consists of a line module (1) in a switching centre, a subscriber modem (2) and a subscriber connection line (3) for connecting the line module (1) and the modem (2). The invention also relates to a line module (1) for high bit rate data transmission for a switching centre and a modem (2) for high bit rate data transmission for a subscriber in order to carry out said method.

Abstract: For modem connections via telephone lines, modems that respectively correspond to the modems of the terminal equipment side are arranged in the subscriber line circuits of the telephone switching centers as close as possible to the entry point of the subscriber line circuits. Modem communication only respectively between these pairs.

Abstract: A circuit arrangement for a subscriber-remote termination of a subscriber line, high-bit rate data signals and analog telephone signals. The arrangement integrates exchange-side devices, a splitter and a modem into a subscriber line circuit for the subscriber line. Additionally, the exchange-side devices, splitter and modem may be protected from overvoltages by an overvoltage protection circuit contained within the subscriber line circuit.

Abstract: Given the prerequisite of a division of a subscriber line circuit into a high-voltage portion and a signal processor that defines the transmission-oriented properties, voltages arising at significant locations of the receiving branch and of the transmitting branch of the signal processor as a result of supplied and reflected sine signals are taken via a digital interface and specific transmission properties such as reflection attenuation and hybrid transfer attenuation are calculated therefrom on the basis of a correlation.

Abstract: A harmonic tone having an amplitude which is significantly lower than a fundamental audible tone is superimprosed on the audible tone to drown out quantization noises for audible tones transmitted in digital telecommunications exchange systems.

Abstract: A digital interface between at least two subscriber line interface circuits and a processing unit is described. The interface is configured in the form of a parallel interface. The level of an input/output register and of a control register is allocated, as needed, to the connections of the processing unit. These connections can be operated selectively as inputs or outputs. They can also be operated in two modes, depending upon which type of subscriber line interface circuit (SLIC) is connected. The connections of the last-mentioned units are partially operable as inputs or outputs and partially operable only as inputs but in the input case, selectively for various types of input signals.

Abstract: A digital interface of an integrated subscriber line interface circuit is provided. The interface serves for the connection of a signal processor unit. Individual connections are used as signal inputs in signal entry operation of the interface, and as signal outputs in signal transmission operation. Other connections are used as signal inputs in both operating mode, but receive different signals in each operating mode. One group of connections includes two registers with respective associated decoders to enable switching from one to the other, so that the number of operating instructions that can be represented by means of binary signal value combinations applied to the connections is doubled.

Abstract: In a subscriber termination module for coupling a plurality of subscriber termination lines of a digital time multiplex telecommunications network, lines coupling a central portion and local portions individually allocated to at least one subscriber termination line are selectably utilized for the transmission of status setting information to the local portions for setting different operating conditions and for serial transmission, that is, successive transmission of information to be supplied to the individual local portions as well as for simultaneous information transmission from the local portions to the central portion, that is, parallel information transmission.

Abstract: The invention describes a protective circuit for the protection of the electronic interconnect circuit (SLIC) and the electronic switches for test access, by means of a threshold setting element which is provided for each conductor (a,b) of a core pair for the shunting of overvoltages to ground, as well as a current path of higher breakover voltage for each conductor of the core pair, which permits checking the subscriber line circuit for line interruption during a malfunction of the threshold setting element.

Abstract: A protective circuit for the electronic interface circuit (SLIC) as well as the electronic switches for test access is described, in which a first threshold setting element for each conductor of the core pair is connected between the line side and a test access and/or isolation switch and the test access switch for the related first conductor of the core pair, for conducting overvoltages to ground, as well as a second threshold setting element bridging access switch which is connected to ground via a third threshold setting element.