Abstract: Systems and methods for reducing the peak-to-average power ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal in the oversampled regime, using tones reserved for PAR reduction. A set of vectors corresponding to PAR tones is generated by processing out-of-phase symbols for each PAR tone to form a span matrix. The span matrix is used to find a best fit of a desired target signal to a time-domain compensation signal comprising only PAR tones.

Abstract: An apparatus and method are provided for bypassing a load coil in a Digital Subscriber Line (DSL) circuit. An interface is provided for making a connection with the DSL circuit and receiving a combined multichannel signal. The combined multichannel signal includes a high frequency or DSL signal and a low frequency signal or voice signal. A high pass filter is utilized to block the voice signal and route the DSL signal over a communications path to bypass the load coil in the DSL circuit. The voice signal is then routed by a low pass filter to the load coil in the DSL circuit.

Abstract: A correlation canceller modulates a communication signal over a plurality of channels and an epoch aperture by a plurality of interference response signals corresponding to linear response by one or more filtering effects to generate an inversely correlated communication signal.

Abstract: A method and apparatus is disclosed for processing two or more encoded signals received over a multi-channel communication system to cancel or mitigate coupling and the effects of the channel on the two or more encoded signals. In one embodiment a multi-channel communication system utilizes DMT processing and some form of encoding, such as block coding or convolutional coding. To recover the transmitted signal, processing in the receiver may comprise MIMO processing in conjunction with decoding. The MIMO processing may be configured with decision directed processing to thereby generate one or more cancellation signals based on isolated error terms. Decoding occurs on encoded signals after MIMO processing. Memory may be interspersed or available throughout the system to store incoming symbols that have not yet undergone decoding and MIMO processing. Decoding and MIMO processing may occur sequentially through the channels.

Abstract: A frequency interpolation apparatus is provided which reproduces a signal similar to an original signal by approximately recovering suppressed frequency components, from an input signal having the suppressed frequency components in a specific frequency band of the original signal. The input signal is divided into a plurality of signal component sets each having frequency components in a frequency band among a plurality of frequency bands, and a signal component set in the band with the suppressed signal components is synthesized from the plurality of divided signal component sets and added to the input signal. Each of the plurality of divided signal component sets is frequency-converted to a signal component set in the same frequency band, and the signal component set in the band with the suppressed signal components is synthesized through linear combination of the frequency-converted signal component sets.

Abstract: Discovering routing policies in information networks. Large networks such as Autonomous Systems are abstracted as a single network element. A plurality of taps on the borders of the abstracted element filter ingress/egress data which is forwarded for collection and correlation. By correlating information from different taps, routing policies are discovered. These discovered policies may be compared with published policies. Access control makes discovered policies and the comparisons with published policies selectively available depending on predefined access classes.

Abstract: An improved OFDM receiver is realized by employing a simplified delay function for the transmissions channel. The simplified delay function yields a simplified frequency-domain correlation that is applied to develop an Eigen matrix U that is used in developing estimates of the channels. Those channel estimates are used in the receiver to develop the output signals.

Abstract: A method and apparatus provide a receiver with an architecture to regulate a bit error rate of the receiver using an offset based on detecting false transitions in received data. In an embodiment, such false transitions in data may be determined in a bang-bang detector.

Abstract: A signal receiver is arranged to process a portion of a received signal in each of a plurality of filter branches and to determine a quality metric for each branch. The configuration of a second filter for processing the entirety of the received signal is subsequently performed according to the determined quality metrics.

Abstract: A system, method and computer program product are provided for filtering various voice protocols. A plurality of voice protocols is initially displayed. Next, an indication is received from a user as to the selection of the voice protocols. It is further determined as to a particular filtering mode that is currently operating. Next, the selected voice protocols are filtered in the determined filtering mode.

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 multiplexer includes: a first band-pass filter for a first channel, which is formed in a microstrip line on a dielectric substrate and has a first branching characteristic having a center frequency of f1 and an attenuation pole at a frequency of fa1; and a second band-pass filter for a second channel, which is formed in a microstrip line on a dielectric substrate and has a second branching characteristic having a center frequency of f2 and an attenuation pole at a frequency of fa2. The following relationships (1) to (5) are satisfied: (1) f1<f2; (2) f1<fa1; (3) fa2<f2; (4) f2?fa1<(f2?f1)/2; and (5) fa2?f1<(f2?f1)/2. The second branching characteristic exhibits ?20 dB or less at the frequency of fa1 and the first branching characteristic exhibits ?20 dB or less at the frequency of fa2.

Abstract: A clock reconstruction mechanism for synchronous TDM communications traffic transported over asynchronous networks such as Ethernet networks. The invention is applicable to edge switches in Metropolitan Area Networks (MANs) that transport legacy TDM traffic using a Circuit Emulation Services (CES) module whereby TDM traffic is encapsulated and transported across the Ethernet network where it is de-encapsulated and clocked out to the destination. The mechanism encapsulates the input TDM data stream into Ethernet packets and inserts a network timestamp within the packet. At the destination CES, a local timestamp is generated for each received packet as it is received. The network timestamp is extracted and input along with the local timestamp to a Digital Time Locked Loop (DTLL) which is operative to accurately reconstruct the original transmit TDM clock.

Abstract: A system and method of implementing a Fast Fourier Transform (FFT) function in a high data rate communication network. The communication network, employing technology such as VDSL and DMT or FDM, frequently implements a FFT at a transmitter to transfer frequency domain modulated signals into time domain signals. An IFFT is implemented at the receiver to obtain the original signal. The present system divides the channel bandwidth into sub-bands and performs the FFT function with multiple FFTs in order to reduce chip size and computation time.

Abstract: A wireless device is provided with a first wireless transceiver and a second wireless transceiver operative in a coordinated manner and coupled to at least one controller manager. The first wireless transceiver transmits and receives signals in accordance with a first protocol to and from a first network device of a first wireless network communicatively coupled to the apparatus, and the second wireless transceiver transmits and receives signals in accordance with a second protocol to and from a second network device of a second wireless network communicatively coupled to the apparatus. The wireless device is further provided with a network manager to coordinate the transmit and receive operations of the first wireless transceiver and said the second wireless transceiver in order to enable the wireless device to communicate contemporaneously with the first and second wireless networks.

Abstract: A packet converting apparatus and method is disclosed, in which audio packet data of various types used in cable/radio networks can effectively be converted. The packet converting apparatus includes a bit unpacking unit for bit unpacking first type packet data, a parameter inverse quantization unit for inverse quantizing the unpacked data to obtain a main parameter of the first type packet data, a parameter converter for converting the obtained main parameter to a parameter of second type packet data through inter-frame interpolation, a quantization unit for quantizing the second type parameter converted by the parameter converter, and a bit packing unit for bit packing the quantized data to reassemble the bit packed data to second type packet data and output the second type packet data to a destination.

Abstract: In an environment where the transmission medium leading to the receiver is time-variant within a block of received signals, and where transmission medium has an finite impulse response extending over a number of symbols intervals, a receiver that includes a filter that, based on an estimate of the transmission channel, is controlled to have filter coefficients that minimize inter-carrier interference due to the intra-block time variations in the transmission medium. The estimate channel coefficients are determined from pilot signals and an interpolation process. When the receiver is an OFDM receiver, the pilot signals are advantageously selected to be in clusters that are equally spaced from each other in the time or the frequency domains. This approach applies to multiple antenna, as well as to single antenna arrangements, and to arrangements that do, or do not use space-time coding.

Abstract: A WLAN (Wireless Local Area Network) receiver having a synchronization unit is provided. The synchronization unit comprises a first functional unit for performing a first signal processing function, a second functional unit for performing a second signal processing function different from the first signal processing function, and at least one signal processing circuit. In the synchronization unit the first functional unit is operating at least one of the signal processing circuits for performing the first signal processing function, and the second functional unit is arranged for operating the at least one signal processing circuit operated by the first functional unit for performing the second signal processing function. Since the above-described signal processing circuits or modules can be re-used for the antenna diversity unit and the preamble detection unit this results in a smaller number of gates and an improved density of the circuitry.

Abstract: A telecommunications rack has one or more shelves connected to a narrowband network and to a broadband network for serving a plurality of subscribers. Line termination and network termination equipment are interconnected by a bus internal to the shelf for providing subscriber access. One half of a redundant equipment pair can be placed in one shelf and the other half in another shelf in a same rack for sharing network termination equipment between such shelves. The rack or shelf in the rack can be used as a hub for connecting to a remote shelf or housing that includes the line termination equipment for connection to subscribers.

Abstract: A method and apparatus for performing packet processing is described. A signal having a preamble sequence is received. A detection parameter estimate is derived from the preamble sequence. The detection parameter estimate is evaluated to process at least one packet in the signal.

Abstract: In a distributed control system in which a plurality of nodes are connected to a transmission line, each node controlling components connected to this node and transmitting a message to other nodes, a message sent by each node includes at least two message-sending condition-identifying portions, one of the condition-identifying portions including data indicating a message-receiving node or non-designation of a message-receiving node; and a comparison-selection circuit provided in each node includes registration parts for registering data of message-receiving conditions, at least two registration parts for comparing contents of the condition-identifying portion in the taken-in message with the data of message-receiving conditions registered in the registration parts, a received-message storing part for storing a message to be received in this node, a control part for determining whether or not the taken-in message is to be received in this node based on a result of comparison-processing performed in the compar

Abstract: A system and method for demultiplexing an RF signal including nested frequency division multiplexed (FDM) channels is disclosed. The system can demultiplex an RF signal including at least two nested sets of FDM channels extending over a bandwidth B.

Abstract: A number of features for enhancing the performance of a cable transmission system in which data is transmitted between a cable modem termination system at a headend and a plurality of cable modems located different distances from the headend. The power transmission level, slot timing, and equalization of the cable modems are set by a ranging process. Data is transmitted by the modems in fragmented form. Various measures are taken to make transmission from the cable modems robust. The upstream data transmission is controlled to permit multiple access from the cable modems.

Abstract: Apparatus, and an associated method, for communicating data pursuant to a frequency division multiplexing scheme that takes into account channel conditions on the communication channel upon which the data is communicated. Sub-bands are defined in which adjacent ones of the sub-bands overlap upon one another. When data parts of data communicated upon separate ones of the sub-bands are received at a receiving station, each sub-band is filtered by a first filter to pass signal parts within frequencies within each of the first sub-bands. Over sampling is performed upon each of the past signal parts at the separate sub-bands to frequency-shift interfering component parts thereof. Then, additional band pass filtering is performed to reject the interfering signal component portions. Subsequent processing is thereafter performed upon the data components.

Abstract: A method for recording and storing independent and/or simultaneous transport streams of data is suggested. The inventive method comprises at least a recording mode in which at least a first transport stream of data to be recorded/stored is received. The transport streams are divided into series of packets with respect to a predefined clock or with respect to their temporal relationships. To each transport stream and to the series of packets respectively a packet identifier is assigned. A series of partial transport streams is generated from at least said series of packet identifiers and said series of packets. A time series of said partial transport streams based on said clock is recorded and stored as a combined transport stream.

Abstract: A method of training and operating a dual-duplex, four-wire communications system to provide for time alignment in the receivers of data that is time aligned in the transmitters, even in the presence of a differential transmission delay in the wire pairs. In a training mode, a known sequence of training data is concurrently sent across each wire pair such that equalizers in the receivers are forced to train together. After the equalizers have been trained to eliminate the differential delay, the system is switched to a data mode.

Abstract: In one embodiment, a system is provided for processing an input signal communicated on a telephone line, the input signal including a first component associated with a first frequency band, a second component associated with a second frequency band higher than the first frequency band, and a third component associated with a third frequency band higher than the second frequency band. The system includes a first filter to receive the input signal and to pass a first signal substantially comprising the second component, a second filter to receive the input signal and to pass a second signal substantially comprising the first and third components, and a third filter to receive the second signal and to pass a third signal substantially comprising the first component according to an input capacitance of a fourth filter that limits the ability of the third filter to pass the second component.

Abstract: Apparatus, and an associated method, for communicating data pursuant to a frequency division multiplexing scheme that takes into account channel conditions on the communication channel upon which the data is communicated. Sub-bands are defined in which adjacent ones of the sub-bands overlap upon one another. When data parts of data communicated upon separate ones of the sub-bands are received at a receiving station, each sub-band is filtered by a first filter to pass signal parts within frequencies within each of the first sub-bands. Over sampling is performed upon each of the past signal parts at the separate sub-bands to frequency-shift interfering component parts thereof. Then, additional band pass filtering is performed to reject the interfering signal component portions. Subsequent processing is thereafter performed upon the data components.

Abstract: An improved OFDM receiver is realized by employing a simplified delay function for the transmissions channel. The simplified delay function yields a simplified frequency-domain correlation that is applied to develop an Eigen matrix U that is used in developing estimates of the channels. Those channel estimates are used in the receiver to develop the output signals.

Abstract: A multicarrier transmission apparatus that achieves both power efficiency in a high-frequency amplifier and quality of transmission signal in a radio transmission system in next-generation mobile communications that supports high speed data packet transmission. In the apparatus, adaptive peak limiter 400 performs adaptive hard limit processing on baseband signals of frequency channels passed through multiplexing sections 200a to 200d for users, multicarrier signal generating circuit 500 with peak suppressing function performs peak limit processing on a synthesized multicarrier signal, hybrid distortion compensating circuit 700 corrects non-linear distortion due to high-frequency amplifier 32, and the multicarrier signal is transmitted from an antenna (ANT).

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: Virtual Private Networking (VPN) is an emerging technology area enabling e-business on the Internet. A key underlying VPN technology is IP Security (IPsec), for providing private (encrypted and authenticated) secure data transmission over public (Internet) networks. The definition of what data to protect ultimately results in IP filter rules, loaded to the operating system kernel. These are used to select the correct IP datagrams and cause each to be processed by the correct IPsec Security Associations. Connection filters which are used to implement VPN connections are dynamic, and must be inserted and deleted within the currently installed set of IP filters (non-VPN related). IP filter order is crucial to proper functioning. Micro filter placement employees filter collision detection and eliminates order Aependeney collisions among a set of connection filters.

Abstract: A method for removing MPEG-2 chroma upconversion artifacts in a video stream includes detecting a presence of artifacts in an incorrectly upsampled MPEG-2 video stream and removing the presence of artifacts resulting in an artifact free video stream.

Abstract: In a distributed control system in which a plurality of nodes are connected to a transmission line, each node controlling components connected to this node and transmitting a message to other nodes, a message sent by each node includes at least two message-sending condition-identifying portions, one of the condition-identifying portions including data indicating a message-receiving node or non-designation of a message-receiving node; and a comparison-selection circuit provided in each node includes registration parts for registering data of message-receiving conditions, at least two registration parts for comparing contents of the condition-identifying portion in the taken-in message with the data of message-receiving conditions registered in the registration parts, a received-message storing part for storing a message to be received in this node, a control part for determining whether or not the taken-in message is to be received in this node based on a result of comparison-processing performed in the compar

Abstract: A signal multiplexer for N channel signals of different frequency bands that utilizes only N+1 hybrid couplers and presents a constant impedance to the transmitters that supply the N channel signals. The channel signals are coupled by separate ones of N of the N+1 hybrid couplers to N pairs of matched band pass filters. The outputs of the filters are combined in a signal combiner to form a pair of quadrature phase multiplexed channel signals that are converted to a single multiplexed output signal by the remaining hybrid coupler. A selector mechanism operates to select one of the N inputs for connection to a load for test purposes.

Abstract: In a distributed control system with a plurality of nodes connected to a transmission line, each node controlling components and transmitting a message to other nodes, a message includes at least two message-sending condition-identifying portions, one of the portions including data indicating a message-receiving node or non-designation of a message-receiving node.

Abstract: A controller for residential telephone wiring. Apparatus associated with the controller provides multiple communication channels on ordinary residential telephone wiring. The controller (1) routes incoming calls to a selected telephonic device within the residence, (2) routes outgoing calls to a free external line servicing the residence, and (3) routes calls within the residence from one telephonic device to another.

Abstract: An apparatus and method for reordering traffic flow templates (TFTs) in a mobile communication system. The apparatus and method include a primary GPRS tunneling protocol (GTP) tunnel for transmitting and receiving packet data to and from a mobile station and one or more secondary GTP tunnels having the same mobile station address as the primary GTP tunnel and each being divided into different TFTs. The TFTs each include different packet filter contents so that the secondary GTP tunnels are separated through TFT packet filtering. A controller is adapted to sequentially perform TFT packet filtering on input packet data for the TFTs, manage statistical data of packet data successfully TFT packet filtered according to the TFTs, and reorder an order of the TFTs by comparing the statistical data of the packet data successfully TFT packet filtered for the TFTs if a preset period expires.

Abstract: A wireless device is provided with at least one wireless transceiver and at least one controller manager to transmit and receive signals wirelessly to and from network devices of a first and second wireless network, in a coordinated manner, in accordance with a first and a second protocol respectively. The wireless device is further provided with a network manager to coordinate the network devices of the first and second wireless networks to reduce interference between the network devices of the two wireless networks. In various embodiments, the reduction is effectuated through proactive avoidance of interference with dominant devices by dominated devices, whenever an interference is predicted to occur. In other embodiments, the reduction is effectuated through corresponding application of appropriate filtering to correspondingly cancel the respective interfering signals, whenever an interference is predicted to occur.

Abstract: A signal multiplexer for N channel signals of different frequency bands that utilizes only N+1 hybrid couplers and presents a constant impedance to the transmitters that supply the N channel signals. The channel signals are coupled by separate ones of N of the N+1 hybrid couplers to N pairs of matched band pass filters. The outputs of the filters are combined in a signal combiner to form a pair of quadrature phase multiplexed channel signals that are converted to a single multiplexed output signal by the remaining hybrid coupler.

Abstract: A system for processing an input signal communicated on a telephone line includes an input node to receive the input signal. The input signal comprises a first component associated with a first frequency band, a second component associated with a second frequency band higher than the first frequency band, and a third component associated with a third frequency band higher than the second frequency band. A first filter coupled to the input node receives the input signal, attenuates the first and third components, and communicates a first signal substantially comprising the second component. A second filter coupled to the input node receives the input signal, attenuates the second component, and communicates a second signal substantially comprising the first and third components. A third filter coupled to the second filter receives the second signal, attenuates the third component, and communicates a third signal substantially comprising the first component.

Abstract: The invention relates to apparatus for filtering, decimating and transposing into baseband, the apparatus being of the entirely digital type, and serving both to extract and transpose into baseband one of the channels, referred to as the “channel of interest”, of a frequency multiplex of channels, and also to reduce the oversampling factor of said channel of interest, each channel being associated with a distinct carrier. The said apparatus comprising at least two stages in cascade (401 to 40L), each stage comprising filter means (42) and decimation means (43), said filter means being placed upstream from said decimation means and enabling a portion of the spectrum to be purged at locations where the decimation means produce aliasing.

Abstract: A communications device (100) with an extended filter (74) provides more bandwidth for V.34, V.90 and other data communications protocols. The device (100) permits voice and data communications over the same twisted pair connection (22) to a central office facility (35) and allows an increased data rate between a subscriber (15) and the central office linecard (50). A variable frequency filter (74) capable of switching between “voice” mode and “data” mode is used. In “data” mode, the bandwidth of filter (74) is extend to provide more bandwidth which can be utilized to transfer data. A line monitoring mechanism (102) is provided which monitors the PCM data flowing over a digital backplane (60) as well as requests from a subscriber for an increased data rate connection. A micro-controller (104) can be provided to adjust the bandwidth of the filter (74) and cause it to enter “data” mode.

Abstract: A method for use by a terminal (or a set of terminals all communicating via for example time division multiple access) of a communication access network seeking to communicate with the head end of the network, the head end for communicating with many terminals in a signal comprising many different frequencies, one frequency for each of many corresponding transceivers of the network, where the communication between the terminal and the head end is via communication between the terminal and a particular transceiver, and the method is used to establish a correspondence between the terminal and the particular transceiver. The method involves exchanging initialization packets between the head end and the terminal seeking to communicate with the head end, initialization packets that convey to the terminal the frequency to use to communicate with the particular transceiver, and that communicate to the particular transceiver the identity of the terminal.

Abstract: Auxiliary data is transported in subbands of a primary data signal by hiding the data in the form of colored noise. The colored noise has a spectrum that simulates the spectrum of the primary data signal in each subband. The data to be transported is first converted to a spread spectrum signal. The primary data signal is analyzed to determine its spectral shape. The same spectral shape is imparted to the spread spectrum signal in each subband, which is then combined with the primary data signal for transmission. The spectral shaping can be performed using time domain modeling and synthesis such as linear predictive coding. A plurality of different auxiliary information streams can be transported on the primary data signal. By adjusting the gain of individual spread spectrum signal carrier(s) and the power of the colored noise, the auxiliary information stream(s) can be rendered at any desired level below or above an interference threshold in the primary data signal.

Abstract: Digital signal processing apparatus for frequency demultiplexing a wide band channel which converts the data stream into parallel branches by means of serial-to-parallel conversion, and demultiplexing which consists of low pass and high pass fine filtering stages and a coarse filtering stage split among processors across parallel branches. Wideband signals arc processed without expensive processors because of the slower rate in the parallel channels. This may also be used for the inverse function of multiplexing.

Abstract: The present invention includes a system and method for ensuring reception of a communications signal. A modulating baseband signal with desired information is accepted, and a plurality of redundant spectrums is generated. Each redundant spectrum comprises the necessary amplitude, phase, and frequency information to substantially reconstruct the modulating baseband signal. It is expected but not required that the redundant spectrums will be generated at a first location and sent to a second location over a communications medium. At the second location, the redundant spectrums are independently processed to recover a demodulating baseband signal for each of the redundant spectrums. In one embodiment, an error detection process is employed at the second location to detect and eliminate those demodulated baseband signals that have been corrupted during transmission. An error-free demodulated baseband signal is selected from the remaining demodulated baseband signals.

Abstract: A device for the selection of address words each having n bit locations and serving for addressing m different receiving locations of a digital communication module, in at least one of the receiving locations, including a digital acceptance module through which address words can be selected. The device has an address word segmenting module through which each address word received by the receiving location can be subdivided into s address word segments with b segment bit locations each, wherein b=n/s and n is an integral multiple of s. The device further has z digital segment filters whose inputs can each be fed with an address word segment, with each segment filter having the function of examining one address word segment each with respect to conformity with a predetermined segment bit pattern, and a filter output signal being available at the output of the respective segment filter, which in accordance with the examination result is either a conformity signal or a non-conformity signal.

Abstract: A variable-bandwidth frequency-division multiplex communication system which needs no interpolation circuits, but uses switch element of simple structure. The system includes a signal combining circuit which has N A/D converters associated respectively with independent information signals to be transmitted, a complex local oscillator for generating complex signals each having a frequency k.DELTA.f (1.ltoreq.k.ltoreq.N-1), .DELTA.f being the channel frequency interval, N complex multipliers for multiplying the outputs of the A/D converters by the respective complex signals, and producing N output signals, a circuit for effecting an inverse Fourier transform of N points, an N.times.

Abstract: The range of digital data communication services, such as a basic rate 2B1Q ISDN channel, to customer premises located beyond the industry standard achievable range of a two-wire loop can be extended by increasing the capacity of the ISDN line code from two information bits per symbol to three information bits per symbol, so as to reduce the effective symbol rate, which is error correction encoded to an effective 4B1H line code for defining a sixteen level PAM signal waveform, and employing enhanced low signal-to-noise ratio signal processing techniques in both the transmitter and receiver to accommodate the increased insertion loss of the two-wire line resulting from its extended length. Such enhanced low signal-to-noise ratio signal processing techniques include a Tomlinson precoder in the transmitter, and an adaptive linear equalizer and a module unit in the receiver.