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.

Digital loop carrier system

Abstract: There is provided a remote digital terminal (RDT) which connects digital lines extended from integrated digital terminals(IDTs) with subscriber lines extended from subscribers accommodated in the integrated digital terminals comprising: first means for cross-connecting the digital lines and logic digital lines which are for identifying the digital lines on each of the integrated digital terminals; second means for cross-connecting the subscriber lines and logic subscriber lines which are for identifying the subscriber lines on each of the integrated digital terminals; and third means for cross-connecting the logic digital lines and the logic subscriber lines on each of the integrated digital terminals. Accordingly, the digital lines connected to each of the IDTs can be identified by the first means, and an arbitrary subscriber line can be allocated for an arbitrary logical subscriber by the second means. Furthermore, the first and the second means can be linked together by the third means, so that the IDT digital lines can be linked with the subscriber lines on the subscriber side, and the subscribers can be accommodated by an arbitrary IDT. Therefore, a plurality of IDTs can be connected to one RDT.

Design of filters for SHDSL over POTS

Abstract: One of the substandard variants of speech signal transmission (POTS - Plain Old Telephone Service) is coexistence with the single-pair high-speed digital subscriber line (SHDSL). It refers to a principle similar to speech signal transmission with the asymmetric digital subscriber line (ADSL over POTS). However, asymmetric digital subscriber line is conceived as original analogue telephone line extended by high-speed data transmission in the ADSL pass band. But in the standard case of SHDSL it is necessary to terminate primary services. Research objectives and results of coexistence of POTS and SHDSL services are described in the following report.

A high-speed, high-resolution analog front end for digital subscriber line applications

Abstract: A 5 V CMOS chip providing the D/A, A/D, filter, and a programmable gain amplifier (PGA) for HDSL and ADSL is described. The chip includes 12-bit, 10 Msample/sec converters, filters, and a PGA having 48 dB gain with 1.7 MHz bandwidth. This chip is used in an E1-rate (2.048 Mbps) ADSL transceiver achieving a bit error rate of less than 10/sup -9/ over 5.4 km of 0.4 mm twisted copper wire.

Computationally efficient joint partial crosstalk cancellation and multi-user power control algorithm in xDSL networks

Abstract: Far-end crosstalk (FEXT) is the major limitation to achieve high data rates in very high bit rate digital subscriber line (VDSL) systems. Full crosstalk cancellation (FCC) techniques have been proposed to mitigate the effect of crosstalk. However, these are too complex for application in typical VDSL binders. Considering the fact that there are only a few strongest cross-talkers that contribute to main part of crosstalk, the crosstalk cancellation can be simplified to line selection (LS), tone selection (TS) and joint line-tone selection (JLTS) partial crosstalk cancellation (PCC). These all result in much less online complexity. In this paper, first, we propose a new modified JLTS algorithm with significantly lower initialisation complexity than the optimal JLTS (OJLTS) algorithm and approximately with similar performance. Then a novel joint algorithm is presented that combines the multi-user power control technique with the PCC scheme to achieve near the capacity rates. We also consider dynamic online complexity constraint for each user. This joint algorithm leads to a much larger online complexity reduction (around 60% for long lines) and higher data rates at the expense of slightly higher initialisation complexity. The performance of the proposed algorithm is verified by some simulation results and compared with current algorithms that use flat power spectral densities (PSDs) and other existing joint algorithms. Copyright © 2009 John Wiley & Sons, Ltd.

Method for prequalification of subscriber lines for high speed data services

Abstract: A method and system for determining the high speed data service capability of a subscriber line includes sending an embedded test signal to a subscriber line. A reflected signal received in response to the test signal is analyzed for determining transmission characteristics of the subscriber line. Based on the reflected signal, a determination about the high speed data service capabilities of the subscriber line is made and stored for future reference.