Showing papers on "High-bit-rate digital subscriber line published in 2001"

Method for providing high-speed data service and voice service

Abstract: Disclosed is a method for providing a high-speed data service and a voice service in a transmission system employing two binary, one quarternary (2B1Q) modulation/demodulation, the transmission system including a remote terminal providing a high-speed data service, a plurality of user terminals including data service terminals and voice service terminals, and a multi-rate digital subscriber line (MDSL) terminal connected to the remote terminal through a twisted pair line, the multi-rate digital subscriber line terminal being also connected to the user terminals. During a downstream voice service, the remote terminal assembles an high bit rate digital subscriber line (HDSL) frame by including signaling signals for the voice service and signal processing mode information in a user-defined interval of the high bit rate digital subscriber line frame, and transmits the assembled high bit rate digital subscriber line frame to the multi-rate digital subscriber line terminal through the twisted pair line. During an upstream voice service, the remote terminal receives the high bit rate digital subscriber line frame and transmits the signaling signals in the received high bit rate digital subscriber line frame to an exchange.

POTS/xDSL services line sharing for multiple subscribers

Abstract: A method and system for providing POTS/xDSL services line sharing for multiple subscribers over the same twisted wire pair is disclosed herein. The lower end of a twisted wire pair's spectrum is used to deliver narrowband services such as POTS to a first subscriber while the higher end of the spectrum is used for high-speed services such as video or data destined to a second subscriber. A POTS splitter remotely located from the central office (CO) separates the POTS signals from the XDSL signals and forwards each signal to its destined subscriber.

Method and apparatus for interference cancellation in shared communication mediums

Abstract: An apparatus and method for reducing interference over a common communication medium, wired or wireless is provided. The apparatus reduces interference from a number of sources using a common architecture which may be used to service a modem pool or discrete modems which share the common communication medium. Interference due to near end cross-talk (NEXT), self-NEXT or echo, and far end cross-talk (FEXT) may all be substantially reduced or cancelled by the apparatus. Additionally, channel characteristics for individual data channels across the common communication medium may be determined. The apparatus provides support for multiple modem protocols including X-DSL protocols such as G.Lite, ADSL, VDSL, SDSL, MDSL, RADSL, and HDSL. The apparatus supports multiple line codes such as the discrete multi-tone (DMT) and carrier less AM/PM (CAP) line codes associated with X-DSL communications. The apparatus may be implemented in hardware, firmware or software. The apparatus has a compact form factor due to pooling of the interference canceling elements.

Apparatus, method and system for correlated noise reduction in a trellis coded environment

Abstract: An apparatus, method and system are provided for correlated noise reduction, in a trellis decoding environment, such as second generation HDSL, in which crosstalk impairments may be significant. The preferred embodiments provide equalization and correlated noise reduction, utilizing a training period to generate corresponding coefficients, and utilizing two different training error signals. In addition, the apparatus method and system also provide continued and adaptive correlated noise reduction during data transmission, utilizing two additional error signals, a trellis error signal and a tentative error signal. The trellis error signal is a decision error of a selected previous state of a selected trellis path, in which the selected trellis path has a smallest cumulative error of a plurality of trellis paths, and the selected previous state is preferably the immediately previous state. The tentative error signal is formed as a difference between a delayed, tentative symbol decision and a delayed received data signal subsequent to equalization, in which the delay is preferably one symbol time. The various embodiments may be utilized with trellis encoding, with or without data precoding.

High-frequency characterization of twisted-pair cables

Abstract: A wave propagation method model is proposed for the extraction of propagation parameters of high-bit rate digital subscriber twisted-pair cables. The model is derived from the scattering parameters of a transmission line. The frequency dependence and the skin effect are studied. Experimental simulations are performed to evaluate the accuracy of the extracted parameters. Good agreement is found in the cases studied.

Method and apparatus for channel estimation for X-DSL communications

Abstract: An apparatus and method is disclosed for channel estimation in an X-DSL communication device. The communication device may include physical or logical modems. The modems may implement one or more of a group of X-DSL protocols including: G.Lite, ADSL, VDSL, and HDSL. The apparatus may be used for determining the location and magnitude of discontinuities or faults within the communication medium to which the X-DSL communication device is coupled. The information provided by the device may be used for line qualification or repair. No additional equipment is required for channel estimation. Instead the apparatus may be located within a single modem or shared between a group of modems. An N bit pseudo random codeword injected into the transmit path is used to generate both a leakage signal and a plurality of reflected signals on the receive path. No timing information is needed from the transmit path. Instead a unique correlator is utilized on the receive path to extract timing information for the reflected signals relative to the leakage signal. The broad bandwidth of the codeword and its relatively long duration allow channel estimation at significantly higher signal-to-noise ratios and with greater degrees of accuracy than heretofore possible.

Crosstalk cancellation in ADSL systems

Abstract: Near-end crosstalk (NEXT) is one of the major impairments to current ADSL downstream transmission. This paper presents two methods for an ADSL receiver to cancel one (dominant) NEXT signal from other types of services (such as HDSL, SDSL, T1 etc). The methods exploit the fact that the crosstalk signal has a large excess bandwidth and its spectra in the main lobe and in the excess band are strongly correlated. The principal idea is then to estimate the crosstalk in some frequency bands (e.g., excess band) and cancel it in other frequency bands (e.g., main lobe). Simulation results show that one of the proposed methods, MMSE estimation and cancellation, is very effective to cancel one (dominant) NEXT and the improvement is significant in terms of the data rate and the line reach for the ADSL service. For example, using a real measured NEXT transfer function, the proposed method can increase the ADSL downstream data rate by 200% for some loops.

System and method for switching digital subscriber line

Abstract: A system and method for providing digital subscriber line service that uses a cross-connect switch to switch in new connections and switch out obsolete connections. The method comprises the steps of: providing digital subscriber line service for a first subscriber via a cross-connect switch connected to a digital subscriber line access multiplexer connected to a digital telecommunications network, the cross connect switch supplying a connection between data processing equipment of the first subscriber and the digital subscriber line access multiplexer; receiving, at a network management system connected to the cross connect switch, an indication that the first subscriber has terminated service; in response to receiving the message at the network management system, transmitting a command to the cross connect switch to switch out the connection of the data processing equipment of first subscriber to the digital access multiplexer; and in response to receiving the command at the cross-connect switch, switching out the connection of the data processing equipment of first subscriber to the digital access multiplexer.

Integrated adsl interface with tdm mapping

Abstract: An integrated asymmetric digital subscriber line interface card with time division multiplex mapping is provided. The asymmetric digital subscriber line interface card includes an asymmetric digital subscriber line interface device and a translation device coupled to the asymmetric digital subscriber line interface device. Additionally, the asymmetric digital subscriber line interface card includes an inverse multiplexer coupled to the asymmetric digital subscriber line interface device and a time division multiplex interface coupled to the inverse multiplexer.

Telecommunications system and subscriber equipment therefor

Abstract: An xDSL (x-Digital Subscriber Line) signal is multiplexed with POTS on a twisted pair between a subscriber modem and line termination equipment in a shelf that also includes network termination equipment for connection to a broadband network. The line termination and network termination equipment are interconnected by a bus internal to the shelf for providing subscriber access. Separate lowpass filters are provided at each end of a twisted wire pair between the shelf and each subscriber equipment. A shelf can be used as a hub for connecting to a remote shelf that includes the line termination equipment for connection to subscribers.

System and method for programmable spectrum management

Abstract: Line interface for coupling a twisted pair telephone line with a communications network. The line interface includes a broadband analog front end for coupling the twisted pair telephone line with the line interface, and a programmable filter for filtering frequency bands to separate transmission channels, the transmission channels located in the communications network, wherein the frequency bands are determined by the programmable filter. In this manner, various services can be provided over the twisted pair telephone line.

Method of measuring and improving xDSL transmission characteristic

Abstract: In accordance with the present invention, a system for measuring the transmission characteristic of an xDSL system that implements high-speed data communication over existing copper wires connecting an office and a subscriber includes a pulling device included in the outside line of an xDSL circuit, which is installed in an office, for pulling a subscriber line. A noise level measuring circuit measures the level of cross-talk noise on the subscriber line. A decision circuit determines, based on the level of cross-talk noise measured, whether or not the subscriber line is usable.

The wireless art and the wired force of subscriber access

Abstract: Different technologies for subscriber access are put side by side. Starting from the various transmission media characteristics of all systems, the well-known twisted pair lines with their corresponding digital subscriber line services are evaluated against wireless local loops, communications over ubiquitous power lines, high-bandwidth cable modems, and mobile radio. Each technology has its advantages and disadvantages. The different technologies will find their fields of applications. Most networks will have to provide a mixture of solutions for individual subscribers and customer segments to meet their boundary conditions. As a result, the future of subscriber access is a hybrid solution.

System and method for switching digital subscriber line service

Abstract: A system and method for providing digital subscriber line service that uses a cross-connect switch to switch in new connections and switch out obsolete connections. The method comprises the steps of: providing digital subscriber line service for a first subscriber via a cross-connect switch connected to a digital subscriber line access multiplexer connected to a digital telecommunications network, the cross connect switch supplying a connection between data processing equipment of the first subscriber and the digital subscriber line access multiplexer; receiving, at a network management system connected to the cross connect switch, an indication that the first subscriber has terminated service; in response to receiving the message at the network management system, transmitting a command to the cross connect switch to switch out the connection of the data processing equipment of first subscriber to the digital access multiplexer; and in response to receiving the command at the cross-connect switch, switching out the connection of the data processing equipment of first subscriber to the digital access multiplexer.

Communications channel performance determination for high-speed access

Abstract: A method and apparatus to determine performance of a subscriber loop includes using a database containing information pertaining to physical characteristics of a subscriber loop (or group of subscriber loops). Based on the information, a data communications speed of the subscriber loop is estimated. An actual data communications speed of the subscriber loop is determined and compared to the estimated data communications speed. The information in the database is updated based on the comparison.

Method and apparatus for digital subscriber line transfer

Abstract: VDSL (Very-high-data-rate Digital Subscriber Line) technology uses at least one downlink frequency band (D1, D2) for conveying information from a data network to a subscriber's transceiver unit. At some sites VDSL technology cannot be used because no standardized uplink frequency band (U1, U2) is usable. The invention solves this problem by using at least one non-VDSL uplink frequency band (N1) for conveying information from the subscriber's transceiver unit to the data network.

Connection requirement ascertainment method for telecommunications devices connected parallel to analog subscriber line esp. for data-over-voice applications

Abstract: A method for ascertaining the connection requirement of telecommunications devices connected parallel to an analog subscriber line (7), in which initially none of the hybrid circuit switches (5,6) of the telecommunications. devices is closed. The connection requirement of a first of the telecommunications. devices (1,2) is ascertained and through that the DC level in the subscriber line (7), as a result of closing the associated hybrid switch (5,6), exceeds a first limiting value. The connection requirement of a further telecommunications. device is then ascertained as soon as the DC level in the subscriber line exceeds a further limiting value, which is higher than the first limiting value.

3.3-V line drivers for digital subscriber line applications

Abstract: In this paper, we designed 3.3-V line drivers for DSL (digital subscriber line) applications. The line driver consists of pre-amplifier, error amplifiers, output transistors, and quiescent current (I/sub Q/) control circuits. A new method is proposed for the quiescent current control circuit in order to obtain high linearity performance. One driver is designed for ISDN U-interface and the other for HDSL applications. Both drivers are fabricated in a 0.35-/spl mu/m n-well CMOS technology and THD (total harmonic distortion) better than -64 dB is achieved.

Separate control line for maintenance of repeaters of a digital subscriber line

Abstract: Digital subscriber line (DSL) system comprising a digital subscriber line access multiplexer (DSLAM, 20) having a line trunk unit (LTU, 13), a repeater container (23) containing a repeater (16) and a customer premises equipment (CPE, 11) having a network terminating unit (NTU, 15) in which the repeater (16) connects a line trunk unit (13) to a network terminating unit (15) through respective lengths (18, 19) of a digital subscriber line and in which both the digital subscriber line access multiplexer (20) and the repeater container (23) comprise an operation and maintenance unit (OMU, 21, 24) which are connected to each other by a line (25) which is separate from the digital subscriber line for controlling the operation and maintenance of the repeater (16) or repeaters (16) of the repeater container (23) from the digital subscriber line access multiplexer (20).

High-Speed Modems

Abstract: High-speed modems and standards have been developed to meet the user demands for high-speed data information and faster communications with the Internet. DSL modems have been successful in reaching a large population because of the low cost structure, reliability, and high-speed data rates. ADSL and versions of ADSL, such as G.lite addressed a need in the market for many users. Hybrids using ISDN and ADSL have been produced, and high speed DSL such as HDSL and VDSL are reaching even greater modem speeds. Cable modems are rapidly becoming a solution for high-speed information to the home and office. Many new standards for bringing voice, data, and video to the home are being established as higher speeds and the number of users continue to grow.

Managed HDSL repeater

Abstract: A repeater for HDSL transmission is presented. The repeater replaces the regenerator commonly used in HDSL by utilizing the activation/deactivation process in the HDSL specification. The repeater is adjusted to detect an activation/deactivation sequence, whereby a flip-flop in the repeater is alternated. A first state of the flip-flop allows transmission passing through the repeater to the terminating point, e.g. a network terminal, and a second state loops transmission back to the originating point, e.g. a line terminal. The looping may then be utilized for maintenance and error detection and recovery. By use of one of the free bit in the overhead channel in the HDSL transmission as an origin bit, wherein “1” is set in the upstream direction, and “0” is set in the downstream direction, it is possible to detect at the line terminal whether there is a loop in the repeater.

System and method for testing subscriber line

Abstract: PROBLEM TO BE SOLVED: To provide a system and method for metallic-testing a subscriber line that provides both voice and digital subscriber line services. SOLUTION: The voice service is provided by a voice switch and the DSL service is provided by a digital subscriber line access multiplexer (DSLAM). Each of them includes a metallic line test unit. The voice line in the voice switch has a connection to a first metallic line test bus connected to the voice switch metallic line test unit via a first relay set. The DSL line in the DSLAM card has a connection to a second metallic line test bus, which is also connected between the DSLAM metallic line test unit and the subscriber line. A second set of relays control the connection of the metallic line test bus to the subscriber line. A signal is sent from either metallic test unit to cause the relays to change to provide a clear path for metallic testing. COPYRIGHT: (C)2002,JPO

Trunk interface unit between base station and base station controller using v.35 interface in cdma communication system

Abstract: PURPOSE: A trunk interface unit between a base station and a base station controller using a V35 interface in a CDMA communication system is provided to efficiently operate channel resources by embodying a fractional E1 as a trunk line between a base station and a base station controller using a V35 interface and executing data communication between the base station and the base station controller using a specific channel of the fractional E1 CONSTITUTION: A V35 interface board(10) is configured in a network access subsystem of a base station and supports a V35 interface A V35 interface board(20) is configured in a network access subsystem of a base station controller and supports the V35 interface An HSM(High Speed Modem) or HDSL(High bit rate Digital Subscriber Line) system(30) has a fractional E1 function and makes data, outputted from the V35 interface boards(10,20), transmitted and received between the base station and the base station controller through a specific channel of the fractional E1 A telephone office device(40) transmits the data transmitted through the specific channel to a PSTN(50) and transmits the data transmitted through the PSTN(50) to the HSM or HDSL system(30) according to the V35 interface

Private branch exchange for interconnecting data networks

Abstract: For interconnecting data networks which use cabling, which is actually provided for other purposes, as transmission medium for data packets, a private branch exchange is provided for connecting subscriber terminals via subscriber lines. The private branch exchange has an integrated interconnecting device via which data packets which are transmitted via the subscriber lines and which are coded into signals outside a frequency range used for communication with the subscriber terminals are extracted from a first subscriber line and extracted data packets are injected into a second subscriber line.

ISDN alarm notification system

Abstract: An ISDN alarm notification (fault locating) system in subscriber transmission equipment is connected to switching equipment conforming to TR-303 standard, in particular. The system includes a controller for setting switch options in subscriber transmission equipment externally, in addition to a digital switch and subscriber transmission equipment. The subscriber transmission equipment is provided with a switching equipment interface unit, a control path unit, and an ISDN subscriber interface unit. The controller sets the switch options provided in the switching equipment interface unit, the control path unit, and the ISDN subscriber interface unit. Thereby each switch option performs identical function, corresponding to each digital switch connected to the subscriber transmission equipment. Thus an ISDN alarm can be notified accurately to any TR-303 digital switch even network terminals NT1 of different types are connected to ISDN subscribers, and the compatibility with conventional services (TR-008 POTS/ISDN, TR-303 POTS/ISD N) is maintained.

Method for servicing subscribers by utilizing virtual LAN on ATU-R of ADSL

Abstract: The invention is a method for servicing subscriber ends by utilizing virtual LAN on ATU-R of ADSL, which utilizes VLAN to generate a plurality of virtual connections in an ADSL connection, couples equipment of each subscriber end to a plurality of subscriber input/output (I/O) ports in ATU-R, adds a switching hub in the ATU-R for identifying tagged data in the virtual connections, connects each subscriber end in the virtual connections with the switching hub via Ethernet, and assigns each subscriber I/O port in the switching hub to one of the virtual connections having a distinct tag. By utilizing this, each virtual circuit may service different subscriber ends, ensure no data packet of each subscriber end assigned to other subscriber line on the same ATU-R.

Telecommunication system for an ISDN network

Abstract: The system has an ISDN communications network (24) via which at least a first and a second subscriber (A,B) communicate with each other and a central recording device (20) connected to the ISDN network The central recording device, after recording a message left by a calling first subscriber, makes a connection to an ISDN network terminal (16) specified by the called second subscriber and passes the subscriber address of the specified terminal using a specified service characteristic for the ISDN network which transfers the calling subscriber's address The subscriber address passed from the central recording device to the terminal is stored in the terminal and notified to the second subscriber

Method for subscriber administration in a variety of telecommunications networks, and telecommunications systems for carrying out the method

Abstract: A method and telecommunications system for subscriber administration in a variety of telecommunications networks, wherein first setting information for a first subscriber of a line-switching communications network and second setting information for a second subscriber of a packet-switching communications network are generated using a controller. The first setting information is transmitted between the controller and at least a first control unit of the line-switching communications network, and the second setting information is transmitted between the controller and at least a second control unit of the packet-switching communications network. Using the transmitted setting information, the first control unit sets service features and other features at the first subscriber and the second control unit sets service features and other features at the second subscriber.

Method of establishing telecommunications connections in the connection area of a subscriber switch, subscriber interface system, subscriber switch, and subscriber access point

Abstract: The authorization of an end subscriber is checked by a local access (ER) to setup telecommunication connection, in response to accept a setting up request. A channel is individually setup for connection to the subscribers between local access and remote unit (MR), and a setup request is transmitted to the remote unit. When the request is accepted, a subscriber-specific path is connected from the remote unit to subscriber channel. Independent claims are also included for the following: (1) subscriber access system; (2) local access; (3) remote equipment; and (4) telecommunication connection setup program module.