High-bit-rate digital subscriber line

About: High-bit-rate digital subscriber line is a research topic. Over the lifetime, 516 publications have been published within this topic receiving 8537 citations. The topic is also known as: HDSL & high-bit-rate DSL.

Connection setup method, service control point, and communications network

Abstract: A method for setting up a telecommunications connection from a calling subscriber (A) to a called subscriber (B) who is assigned to a numbering-plan area (AREA 2 ) shared by two or several subscriber line networks (KN 2 , KN 3 , KN 4 ) of different network operators (OP 2 , OP 3 , OP 4 ) as well as a communications network (KN 6 ) and a service control point (SCP) for implementing the method. A call request (CR) from subscriber line network (OP 2 ) of the calling subscriber is routed to the communications network (KN 6 ), which is assigned to a long distance carrier (OP 6 ), and the connection between the calling subscriber (A) and the called subscriber (B) is set up via this communications network (KN 6 ). The arrival of the call request (CR) at the communications network (KN 6 ) of the long distance carrier (OP 6 ) triggers an IN service. The IN service executes for the call request both an access monitoring function that monitors access to the communications network (KN 6 ) of the long distance carrier (OP 6 ) and a number portability function that determines the subscriber line network (KN 3 ) of the called subscriber (B).

Performance evaluation study of signal design and equalization options for high-bit-rate digital subscriber line transceivers

Abstract: This paper analyses different equalization, coding and signal constellation alternatives for the proposed high-bit-rate (800 kb/s) digital subscriber loop transmission interface. The simulation results presented in the paper demonstrate that bit rates above 1000 kb/s at acceptably low bit-error rates (≤ 10−7) are feasible, if baseband transceivers with appropriate equalization and simple trellis coding are used. It is also shown that baseband transmission and Tomlinson precoding provide a significant performance advantage over bandpass transmission and decision-feedback equalization, respectively.

Hardware design and performance analysis of VDSL transceivers

Abstract: With a hybrid fiber/twisted-pair architecture, data rates up to about 50 Mbit/s can be transmitted over installed twisted-pair cables in the distribution part of twisted-pair access networks. Based on a channel model for twisted-pair cables for frequencies up to 40 MHz derived from measurements, different transmission formats are compared. It is concluded that frequency division multiplexed VDSL (Very high bit rate Digital Subscriber Line) systems based on QAM (Quadrature Amplitude Modulation) or CAP (Carrierless AM/PM) are a good choice. In this paper, two scalable system proposals are presented. Both systems can transmit 12.5 Mbit/s symmetrically over a distance of about 800 m. System 1 enables as well the asymmetrical transmission of 50/2 Mbit/s over 280 m, whereas system 2 enables the symmetrical transmission of 25 Mbit/s over 300 m. Based on the required filter lengths of the equalizer and the wordlengths of the signals within the adaptive filters, the hardware complexity of the proposed VDSL transceivers is determined.

A novel tunable-complexity turbo-soft detector for high-throughput HDSL applications over ISI channels with crosstalk

Abstract: We present a novel iterative (turbo) receiver with tunable complexity for reliable detection of (uncoded) payload data transmitted over long intersymbol interference (ISI) channels affected by crosstalk, as those typically encountered in emerging HDSL2 services standardized by ANSI T1.418 recommendation. The proposed receiver combines in an original way "minimum mean square error (MMSE) estimation principle," "turbo-processing principle" and "crosstalk-prediction principle" for achieving both suboptimal maximum a posteriori probability channel equalization and reliable soft-mitigation of ISI tail plus crosstalk. More in detail, according to the turbo-processing principle, at each iteration suitable extrinsic information is extracted from the equalizing and interference-canceling modules and used as "a priori information" for the next iteration. Several simulation results on typical HDSL-like test-loops confirm the superiority of the proposed turbo-detector (TD) over current solutions based on conventional MMSE decision-feedback equalizers and precoders (such as the Tomlinson-Harashima precoder). The numerical tests also point out that performance of the presented TD on typical high bit-rate digital subscriber lines (HDSL) is not limited by error-floor phenomena, even at error-probabilities below 10/sup -7/.