Abstract: A system for transmitting data to a first and a second user device within a user's premises, the system including a distribution point having an aggregation device comprising a plurality of access network modems and having a plurality of lines connected thereto, a splitter device connected to the aggregation point 10 via one of the lines connected thereto and being located within the user's premises, a first connection between the splitter device and a first customer premises equipment modem, the first customer premises equipment modem being connected to the first user device, and a second connection between the splitter device and a second customer premises equipment modem, the second customer premises equipment modem being connected to the second user device, wherein the aggregation device is operable to transmit data for the first device via a first one of the plurality of modems in the aggregation device, the splitter device and the first customer premises equipment modem using a Digital Subscriber Line p

Abstract: A microphone unit has a transducer, for generating an electrical audio signal from a received acoustic signal; a speech coder, for obtaining compressed speech data from the audio signal; and a digital output, for supplying digital signals representing said compressed speech data. The speech coder may be a lossy speech coder, and may contain a bank of filters with center frequencies that are non-uniformly spaced, for example mel frequencies.

Abstract: One exemplary problem addressed by the techniques disclosed herein is that the A-to-D converter of the broad-band audio codec that is being used more frequently in IP telephony, G.722, samples the analog audio source 16,000 times per second, rather than 8,000. Since all G.722-capable telephones must continue to be G.711-capable, one problem is that a microphone that provides appropriate bandpass filtering for G.722 encoding fails to provide adequate filtering for G.711. One exemplary aspect is therefore directed to telephones that must be able to switch back and forth between narrow-band digital audio encoding in which the A-to-D converter samples the audio stream 8,000 times per second, and a wide-band audio encoding in which the A-to-D converter samples the audio stream 16,000 times per second. This is accomplished using one or more of a plurality of switched microphones, a filter and a modification of the resonant frequencies of a handset.

Abstract: A CODEC circuit for POTS system comprises a digital circuit for outputting a digital control signal having a first bit width, the digital control signal being indicative of a voltage to be applied to a POTS subscriber line pair. Further, the CODEC comprises a noise shaper coupled to an output of the digital circuit for generating a noise-shaped control signal and a digital-to-analog converter coupled to an output of the noise shaper, the input of the digital-to-analog converter having a second bit width being larger than 1 and smaller than the first bit width.

Abstract: Systems, methods, and equipment for use in the management of network topology and bandwidth for computing networks are provided. In an illustrative implementation of a device acting as a patch panel is provided. The patch panel works on both the physical wire and on the frequencies of the wire to route data to appropriate destination points. For example, both ADSL and telephony could be bridged among copper wires, using several independent busses. Home Phone Network Alliance Association (HPNA) standardized data could either be bridged among wires, or connected to an internal switching device, that would store and forward the native Ethernet packets used by HomePNA in a way similar to that done by Ethernet switches today. Additionally, an Ethernet uplink could attach the HPNA ports to a larger network or to a DSL Modem, and HPNA/ADSL could be removed from wires that might have privacy concerns or otherwise need filters to perform properly.

Abstract: An outlet for a Local Area Network (LAN), containing an integrated adapter that converts VoIP to and from analog telephony, and a standard telephone jack (e.g. RJ-11 in North America) for connecting an ordinary analog (POTS) telephone set. Such an outlet allows using analog telephone sets in a VoIP environment, eliminating the need for an IP telephone set or external adapter. The outlet may also include a hub that allows connecting both an analog telephone set via an adapter, as well as retaining the data network connection, which may be accessed by a network jack. The invention may also be applied to a telephone line-based data networking system. In such an environment, the data networking circuitry as well as the VoIP/POTS adapters are integrated into a telephone outlet, providing for regular analog service, VoIP telephony service using an analog telephone set, and data networking as well. In such a configuration, the outlet requires two standard telephone jacks and a data-networking jack.

Abstract: A system for bandwidth management and codec negotiation, according to one embodiment of the present invention comprises: a configuration storage module having supported codecs storage, codec lists and preferred site settings storage, and a call manager having an extension module, a trunk module, a location service engine, a codec manager, a bandwidth manager, and a media manager. The codec manager and the bandwidth manager used for negotiating a codec for a call between two endpoints. The present invention also includes a number of methods including a method for negotiating a codec for a call, a method for managing bandwidth for a call, a method for adding a description of a new codec supported by an endpoint, a method for adding an identifier of a supported codec to a codec list and a method for editing code site codec settings.

Abstract: Seamless wideband support is afforded by utilizing split-band data streams. For wideband signals, the 8 kHz bandwidth is divided into a low band, with approximately 0-4 kHz bandwidth, and a high band, with approximately 4-8 kHz bandwidth. Narrowband functions and services operate on the low band, while wideband functions and services operate on both low and high bands.

Abstract: Methods, systems, and products are disclosed that describe a network interface to a data network. A modulator-demodulator receives a modulated carrier signal from an input connection. A power circuit connected to the input connection receives electrical power from a loop plant and provides the electrical power to the modulator-demodulator.

Abstract: A method for scheduling ringing signals for a plurality of subscriber lines includes maintaining a schedule of ringing signals for the plurality of subscriber lines. A plurality of ringing counts is determined. Each ringing count specifies a number of subscriber lines ringing at a selected point in the schedule. A ringing request for a particular subscriber line is received. A position in the schedule for the ringing request is identified based on the ringing counts that does not exceed a maximum ringing limit. The ringing request is scheduled in the schedule responsive to identifying the position. A ringing signal is generated for the particular subscriber line in accordance with the schedule.

Abstract: A subscriber line interface circuit apparatus includes a linefeed circuit and a subscriber line control circuit (SLCC). In an embodiment, the linefeed circuit includes a signal conversion circuit having cross-coupled first and second MOSFETs for providing a differential mode signal and a common mode signal in response to at least a tip signal and a ring signal from the subscriber loop. The linefeed circuit includes a tip control circuit and a ring control circuit, each having two or more MOSFETs. In an embodiment, the SLCC is provided in a single integrated circuit chip and is coupled to the linefeed circuit which isolates the SLCC from the tip or ring signals. The SLCC includes a first and a second differential mode inputs for receiving the differential mode signal, and a common-mode input for receiving the common-mode signal.

Abstract: Systems and methods of Voice over Internet Protocol (VOIP) communication are provided. A particular system includes a VoIP endpoint. The VoIP endpoint is adapted to monitor a packet loss measure between the VoIP endpoint and a second VoIP endpoint during a VoIP communication using a first CODEC. The VoIP endpoint is also adapted to negotiate with the second VoIP endpoint to select a substitute CODEC having a nominal data rate that is lower than an in-use nominal data rate of the first CODEC.

Abstract: A CODEC circuit for POTS system comprises a digital circuit for outputting a digital control signal having a first bit width, the digital control signal being indicative of a voltage to be applied to a POTS subscriber line pair. Further, the CODEC circuit comprises a noise shaper coupled to an output of the digital circuit for generating a noise-shaped control signal and a digital-to-analog converter coupled to an output of the noise shaper, the input of the digital-to-analog converter having a second bit width being larger than 1 and smaller than the first bit width.

Abstract: A subscriber line interface circuit apparatus includes a linefeed circuit and a subscriber line control circuit (SLCC). In an embodiment, the linefeed circuit includes a signal conversion circuit which provides a differential mode signal and a common mode signal in response to at least a tip signal and a ring signal from the subscriber loop. The linefeed circuit includes a tip control circuit and a ring control circuit. In an embodiment, the SLCC is provided in a single integrated circuit chip and is coupled to the linefeed circuit which isolates the SLCC from the tip or ring signals. The SLCC includes a first and a second differential mode inputs for receiving the differential mode signal, and a common-mode input for receiving the common-mode signal. In an embodiment, the SLCC also provides various tip control signals and ring control signals to the tip control circuit and the ring control circuit, respectively.

Abstract: A method, apparatus and computer program product for providing rapid information dissemination using network coding is presented. A coded message including a payload and a code vector, is transmitted from a first node of the network to a second node of the network. The information thus stored can also be retrieved by collecting code vectors from at least one node and viewing the collected code vectors as a matrix. A determination is made regarding whether a dimension of the matrix is equal to a predefined number. When the dimension of the matrix equals the predefined number, the information is retrieved using the collection of code vectors in the matrix.

Abstract: A system for improving the attenuation of an undesired signal found in a differential signal path through the use of inductive coupling. The system includes a primary inductor, a secondary inductor, and a filter. The primary inductor and the secondary inductor operably couple an input differential signal pair to an output differential signal pair, and the filter attenuates an undesired signal in the output differential signal pair.

Abstract: Systems, methods, and equipment for use in the management of network topology and bandwidth for computing networks are provided. In an illustrative implementation of a device acting as a patch panel is provided. The patch panel works on both the physical wire and on the frequencies of the wire to route data to appropriate destination points. For example, both ADSL and telephony could be bridged among copper wires, using several independent busses. Home Phone Network Alliance Association (HPNA) standardized data could either be bridged among wires, or connected to an internal switching device, that would store and forward the native Ethernet packets used by HomePNA in a way similar to that done by Ethernet switches today. Additionally, an Ethernet uplink could attach the HPNA ports to a larger network or to a DSL Modem, and HPNA/ADSL could be removed from wires that might have privacy concerns or otherwise need filters to perform properly.

Abstract: Various technologies and techniques are disclosed that improve media communications. In one embodiment, a media server receives a media communication with a first quality from a personal computer with VoIP telephone capabilities. The media server translates the media (e.g., audio, visual, etc.) communication into a second quality, and forwards the media communication to a communication gateway. The translation to improve communications can also be done when receiving the media communication from the communication gateway for forwarding to the personal computer having VoIP telephone capability. In some embodiments, a media server sits in the communication channel between a personal computer with VoIP telephone capabilities and a communication gateway and is able to translate communications into codec protocols they each understand.

Abstract: In a communication apparatus has a line control unit that controls connection with a communication line network, a communication unit transmits/receives data through the communication line network. A detection circuit detects one of a line voltage value and a line current value when the communication apparatus is connected to the line network. A memory unit stores multiple voltage-current characteristic curves defining relationships of line voltage values with respect to line current values satisfying a predetermined standard. An adjusting unit adjusts the line voltage value and the line current value so as to satisfy the predetermined standard based on one of the voltage-current characteristic curves stored in the memory unit. A selecting unit selects another voltage-current characteristic curve different from the one of the voltage-current characteristic curves from among the multiple voltage-current characteristic curves stored in the memory unit.

Abstract: A main terminal and a method of operating the same. In this method of operating the main terminal, the main terminal is connected to a telephone network so as to communicate with the telephone network, and selectively connects an external terminal to the telephone network. To perform the method, first, if it is requested that the telephone network be disconnected from the external terminal and instead be connected to the main terminal, an internal current to flow into the main terminal is obtained from a loop voltage generated when the external terminal is in connection with the telephone network. Next, the internal current is applied to the main terminal. Thereafter, the telephone network is disconnected from the external terminal and instead connected to the main terminal. While the internal current is flowing in the main terminal, the main terminal maintains the loop voltage generated when the external terminal is in connection with the telephone network.

Abstract: A system and method for establishing a high speed, substantially constant circuit based data connection over a conventional telephone line is provided. The circuit based connection is non-switched, thereby eliminating the need to establish a connection through a dial-up process. The circuit based connection is established between a user's terminal device and a digitizer, such as a basic rate interface transmission exchange card. The user's terminal device may be a modified version of a conventional integrated services digital connection modem. A user's computer, telephone, or other device may be connected to the user's terminal device to access an external network. The connection established in accordance with the present invention can transmit data at a rate far exceeding that of traditional dial-up connections.

Abstract: As part of a system and method for transmitting a signaling tone over a packet switched data (or other communication) network, an audio encoder may have a speech encoding unit and a tone distorter. The tone distorter may distort one or more components of a signaling tone within an audio signal and the speech encoding unit may encode speech and the distorted signaling tone within the audio signal. A control signal may be sent to a tone generator to reproduce the distorted tone.

Abstract: Methods and communication systems are presented, in which impulse noise is monitored on a communication channel, and impulse noise protection parameters are adjusted according to the monitored impulse noise without interrupting communication service.

Abstract: An analog front end. The analog front end comprises a converter configured to convert a differential input signal to a single-ended input signal, and convert a single-ended output signal to a differential output signal. And a transformer configured to couple the differential input signal from a twisted pair telephone line to the converter, and couple the differential output signal from the converter to the twisted pair telephone line.

Abstract: The present invention provides a control method for an error detection & correction apparatus, comprising a plurality of data processing apparatuses which reside in a data communications path and partake in exchanging data by the unit of error correcting code, and a plurality of information exchange paths which are installed between the plurality of data processing apparatuses; and generating a true syndrome by exchanging a partial syndrome relating to a part of the data partaken by each of the data processing apparatuses by way of the information exchange paths, comprising the step of exchanging renewal information relating to a part of the data partaken by each of the data processing apparatuses with the other data processing apparatus by way of the information exchange path.

Abstract: An office-line trunk circuit is provided to selectively operate on ground-start and loop-start modes. In this circuit, a DC current detection circuit has (i) a first photo coupler detecting a DC loop current caused responsively to supply of the ground to a tip line and a negative power to a ring line from an office bilateral trunk and (ii) a resistor whose resistance is adjusted to prevent a loop start in the office bilateral trunk and allow DC current to be detected. The first photo coupler detects the loop current using the resistor. An incoming detection circuit has a second photo coupler detecting a ring signal coming from the office bilateral trunk. A DC sink circuit has a diode bridge placed between the tip and ring lines and configured to have a DC circuit provided with a transistor controlling the DC loop current so that the office bilateral trunk is allowed to selectively be loop-activated and loop-held.

Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.

Abstract: A flexible data outlet includes a housing configured for placement in an operating area of a user, such as on a wall adjacent to a user's work space. User interface circuitry in the housing provides an interface to user equipment located in the user operating area, including a user telephone device and a user data device such as a personal computer. The user interface circuitry includes a link-layer interface to the user data device. Both wired and wireless user connections are supported. Premises interface circuitry in the housing provides an interface to premises equipment located generally outside the user operating area. The premises equipment includes data processing equipment and telephone communications equipment providing access to a public telephone network. Bridge circuitry in the housing provides communications connections between the user interface circuitry and the premises interface circuitry in a flexible manner, enabling the provision of a variety of information services to the user.

Abstract: A CODEC circuit for POTS system comprises a digital circuit for outputting a digital control signal having a first bit width, the digital control signal being indicative of a voltage to be applied to a POTS subscriber line pair. Further, the CODEC circuit comprises a noise shaper coupled to an output of the digital circuit for generating a noise-shaped control signal and a digital-to-analog converter coupled to an output of the noise shaper, the input of the digital-to-analog converter having a second bit width being larger than 1 and smaller than the first bit width.

Abstract: A communication system in which a profile of codecs is loaded at the originating end. The originating end sends the profile of codecs to the terminating end and receives in return an indication of which codec to use. The originating end and the terminating end create a reduced profile that includes the codec identified by the terminating side and its peers. The peers are codecs that use the same amount of resources as the selected codec or that use less resources than the selected codec. Even though the reduced profile includes more than one codec, packets are coded and decoded using only the codec identified by a bit map that is available to the DSP channel at both the originating end and the terminating end. At a later time a change can be made to a different codec in the reduced profile by changing the bitmap and without closing and re-opening the channel.

Abstract: The invention relates to a distribution device (2) in a data signal processing installation (1), and a data signal processing installation (1). The distribution device comprises a distribution block (3) which has a receiving device containing elements to which data signal lines (4, 5, 6) can be connected, the functional elements having a circuit to distribute signals transmitted by the data signal lines (4, 5, 6). The distribution device also comprises a data signal editing unit with active and/or passive electronic components, in which the data signals transmitted from the data signal lines (3, 4, 5) are edited in a pre-determined manner. The data signal editing unit is integrated into the components of the distribution block (3).

Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.

Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.

Abstract: A method that measures a skew between a data signal and a clock signal at a receiving end of a serial link and then adjusts a phase relationship between the data signal and the clock signal to reduce the skew.

Abstract: An Infiniband device can have an input port operable to receive a packet and to forward the packet to an output port of the device for onward transmission toward an ultimate destination of the packet. The input port can also be operable to examine at least a header portion of the packet to determine a transmission validity status of the packet and in the event of a negative transmission validity status being determined, to truncate the packet to remove a data payload from the packet including regenerating a checksum field of the packet on the basis of a truncated size of the packet.

Abstract: A subscriber line interface circuit apparatus includes a signal processor having sense inputs for sensed tip and ring signals of a subscriber loop. The signal processor generates linefeed driver control signals in response to the sensed signals. A linefeed driver provides the sensed tip and ring signals. The linefeed driver drives the subscriber loop in accordance with the linefeed driver control signals.

Abstract: A system for determining the transmit power of a communication device operating on a twisted pair subscriber line includes a communication server coupled to a first subscriber line and a second subscriber line. The communication server comprises a communication device that communicates a signal using the first subscriber line. A memory coupled to the communication server stores noise information and cross-channel-coupling information for the first subscriber line and the second subscriber line. A processor coupled to the memory determines the transmit power of the communication device based upon the noise information and the cross-channel-coupling information.

Abstract: A passive echo cancellation circuit for reducing echoes on a subscriber line includes an output driver adapted to drive a downstream signal on the subscriber line. First sensing circuitry is coupled to the output driver and adapted to sense a current on the subscriber line to generate a first voltage. A balancing network is adapted to receive at least a portion of the downstream signal. Second sensing circuitry is adapted to sense a current in the portion of the downstream signal passing through the balancing network to generate a second voltage. An upstream driver is adapted to subtract the second voltage from the first voltage to generate an upstream signal.

Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.

Abstract: An approach is provided for a method of encoding structure Low Density Parity Check (LDPC) codes. Memory storing information representing a structured parity check matrix of Low Density Parity Check (LDPC) codes is accessed during the encoding process. The information is organized in tabular form, wherein each row represents occurrences of one values within a first column of a group of columns of the parity check matrix. The rows correspond to groups of columns of the parity check matrix, wherein subsequent columns within each of the groups are derived according to a predetermined operation. An LDPC coded signal is output based on the stored information representing the parity check matrix.

Abstract: The invention provides a method for controlling a subscriber line interface circuit, which is connected to at least one data line and to at least one subscriber line associated with a subscriber, in the on-hook state, having the following steps: on-hook data transmission signals are detected in the data line; if an on-hook data transmission signal intended for the subscriber (102) is detected in the data line (122), the detected on-hook data transmission signal is buffer-stored and the subscriber line interface circuit (106) is switched from a passive operating mode to an active operating mode; the buffer-stored detected on-hook data transmission signal is transmitted by the subscriber line interface circuit (106) in the subscriber line (104) to the subscriber (102); and the subscriber line interface circuit (106) is switched to the passive operating mode. The invention also provides a circuit arrangement for carrying out the method.

Abstract: A gain or input volume controller and method includes a modified R2R ladder network having a number of R2R branches, switches coupled respectively to the R2R branches, and a switch controller for respectively controlling the switches to control and provide an overall gain value for a signal. The switch controller further includes a mapper for mapping a gain control signal to the switches wherein the gain control signal respectively activates or deactivates the switches. A fine gain control stage provides a fine gain control of the overall gain value. A coarse gain control stage is coupled to the fine gain control stage. The coarse gain control stage includes the modified R2R ladder network and provides a coarse gain control of the overall gain value.

Abstract: An isolation system with analog communication across an isolation barrier includes an isolation barrier circuit having at least one isolation element; a digital to analog circuit having an analog output connected to the isolation barrier and an input for receiving an input digital signal to be communicated across the isolation barrier; and an analog to digital circuit having an input coupled to the analog output of the isolation barrier circuit for providing a digital output signal.

Abstract: A DC/DC converter capable of preventing abnormal temperature increase in a power transistor. The DC/DC converter comprises a loop circuit, a power transistor, an abnormal high temperature detection circuit, and an abnormality processing circuit. The power transistor supplies an electric current to the loop circuit according to a control pulse signal. The loop circuit accumulates electromagnetic energy in an inductor when the electric current is supplied and generates a negative DC voltage by causing a loop electric current to flow by using the electromagnetic energy accumulated in the inductor when no electric current is supplied. The abnormal high temperature detection circuit detects a normal/abnormal state of temperature of the power transistor. The abnormality processing circuit switches the power transistor off when the abnormal high temperature detection circuit has detected that the temperature of the power transistor is abnormal.

Abstract: Method and apparatus for transmitting a transmission signal via a two-core line, in particular a telephone line, in which case, with the aid of corresponding transmission devices (2, 3), two partial signals are generated and are transmitted via a respective core (A, B) of the line and the transmission signal is formed by the alternating-current difference between the two partial signals. In order to suppress common-mode components in the partial signals, a calibration is carried out in such a way that the transmission devices (2, 3) output essentially the same output level.

Abstract: In a digital cordless telephone system, a different speech coding scheme is used in the audio path from the base unit to its remote handset than that which is used in the audio path in the opposite direction from the remote handset to the base unit. It is found that this unbalanced coding scheme optimizes overall system cost and performance. In particular, two different types, quality and/or bit rates of speech encoders are implemented in opposite directions of the same full-duplex audio path, providing an unbalanced coding in a digital cordless telephone. Implementation of different types of speech encoders in a common full duplex path optimizes system cost and performance. It is recognized by the invention that the communications link in a first direction from a base unit to its remote handset in a digital cordless telephone system potentially requires better codec and audio performance than the communications link in the opposite direction from the remote handset to base unit.

Abstract: An isolation system is provided that is suitable for use in telephony, medical instrumentation, industrial process control and other applications. Preferred embodiments of the invention comprise a capacitive isolation barrier across which a digital signal is communicated. The system provides a means of communication across the isolation barrier that is highly immune to amplitude and phase noise interference. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier. Delta-sigma converters may be disposed on both sides of the isolation barrier to convert signals between analog and digital domains. An isolated power supply may also be provided on the isolated side of the barrier, whereby direct current is generated in response to the digital data received across the isolation barrier.

Abstract: The present invention provides a method to configure the hardware and software resources in a system to utilize two physical interface boards in pairs such that their aggregate units of voice processing DSP resources can be applied to either all of a T1 board's physical interfaces or all of an E1 board's physical interfaces. This allows a single telecommunications system to run as either T1 or E1 with no additional hardware required. The present invention also provides the ability to run protocols normally associated with T1 physical interfaces on a card with only E1 physical interfaces. A method for changing the configuration from T1 to E1 and from E1 to T1 is provided as well. Additionally, the method includes configuring the system to look like a single set of contiguous T1 or E1 channels.

Abstract: A technique for implementing impedance matching circuits 100 that use the transfer functions of each line impedance model. This technique allows implementation of an impedance match for a diverse number of line impedances reusing the same circuit 100 topology, by simply adjusting coefficients to accommodate different line impedances.

Abstract: 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. Briefly described, a means for providing a proper hookswitch transition for a variety of international phone standards is provided. The invention may also be utilized with means for transmitting and receiving a signal across a capacitive isolation barrier. More particularly, a DAA circuitry may be utilized which satisfies many or all hookswitch transition standards without the use of additional discrete devices. The hookswitch transition standards may be satisfied by ramping down the current flowing through the hookswitch prior to transitioning the hookswitch state. In this manner the hookswitch current change as a function of time (di/dt) may be decreased. Thus, the current through the hookswitch may be actively controlled prior to switching the hookswitch from an off-hook condition to an on-hook condition.