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.

Bandwidth selection for the very high-rate digital subscriber line (VDSL) system

Abstract: Work is under way to develop a very high-rate digital subscriber line (VDSL) system capable of operating over twisted-pair media at data rates in excess of 10 Mbps. The twisted-pair channel is characterized by both an attenuation and crosstalk susceptibility which increase with frequency and length. The signaling bandwidth for such a channel can be selected to maximize the bit rate. This optimization is carried out for loop lengths in the 1-5 kft range. It is shown that the optimal signal bandwidth is quite sensitive to the loop length. For example, the optimal bandwidth for a 1 kft loop is more than twice that of the 3 kft loop.

Device for the multiple use of subscriber lines

Abstract: Analog telephone sets (TA) are connected as shared connection via a connecting device (RWD) and a common subscriber line (TL) to an ISDN exchange. The connecting device (RWD) contains an echo cancellation module (IEC), a communication controller (ICC) with a microcomputer ( mu C) for signalling evaluation, a digital/analog converter group (SICOFI) and one subscriber line module (SLIC) for each telephone set (TA). Due to the digital/analog conversion at the subscriber end, utilisation of the ISDN standard saves subscriber lines (TL) and a later conversion to digital subscriber connections can take place without problems. In operation, the connecting device (RWD) and the telephone sets (TA) are supplied with power by remote power feeding.

A 160-kb/s digital subscriber loop transceiver with memory compensation echo canceller

Abstract: A full-duplex transceiver chip incorporating an adaptive echo canceling modem and a 2.048-Mb/s serial interface is described. The device provides a full-duplex communication link at 160 or 80 kb/s on up to 4 or 5 km, respectively, of 0.5-mm twisted-pair cable. Full integration is achieved through the use of RAM-based sign-algorithm echo-cancellation, biphase line code, a fixed switched-capacitor equalizer, and a digital phase locked loop. The authors emphasize system design considerations and a chip architecture minimizing power dissipation, silicon area, and off-chip components. A double poly 3-/spl mu/m CMOS technology is used to implement the 5-V 22-pin device which dissipates less than 50 mW and occupies 27.7 mm/SUP 2/.

DSL line testing with a sealing current

Abstract: A system, method, and computer readable medium for a metallic test method in a digital subscriber line system in which a subscriber's voice service has been switched from plain old telephony service to an inband digital subscriber line data stream characterized in that a direct current loop current used for plain old telephony service is replicated for testing, comprising, providing a sealing line current to a transmission line via a digital subscriber line device serving the subscriber and supervising the provided sealing line current between the digital subscriber line device and a subscriber's premises for determining a connectivity therebetween

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.