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.

A transceiver system for dual‐simplex high‐bit‐rate digital subscriber lines

Abstract: High bit‐rate digital subscriber lines (HDSL) technology is a new technology that may provide bi‐directional transmission at a rate of 1.544 Mb/s in conventional copper wires. A transceiver system for dual‐simplex (DSX)‐HDSL is presented. Simulation results show that the DSX‐HDSL system combined with simple pair‐selection can provide 18Kft/24AWG service distance without line repeaters. In the presented DSX‐HDSL transceiver, 2B1Q code with (1‐D) precoding is used to reduce the inter‐symbol interference (ISI) and the dynamic range of signal. Hence, a 12‐bit or less A/D converter can satisfy the performance requirement. In addition, another switchable (1‐D) filter is used in the receiver to shorten the duration of channel response, therefore a (5, 32) hybrid‐decision‐feedback‐equalizer (DFE) can obtain an adequate performance.

Optical network unit of demand-concentrated broadband subscribers

Abstract: PURPOSE: An optical network unit(ONU) of demand-concentrated broadband subscribers, is provided to connect and multiply voice of a general telephone/a public phone, an integrated services digital network(ISDN), N64k, DS1, DS1E and high speed service data services such as an asymmetric digital subscriber line/very high bit rate digital subscriber line(ADSL/VDSL), and to optically transmit STM-4c(STM-1) to an opposed station of a host digital terminal(HDT). So that receiving capacity per shelf can be maximized. CONSTITUTION: An optical network unit main control unit(OMCU) manages and controls information of an optical network unit(ONU) as a main controller, and performs a communication function with a host digital terminal(HDT). An optical network interface unit(ONIU) has a function generating clocks from signals inputted from an external, and an 622Mbps(155Mbps) optical interface function. An extension unit(EXTU) performs three STM-1 connections as a unit for extending a shelf, and relays an asynchronous transfer mode(ATM) cell. An E1T1 unit selectively supplies a 1.544Mbps or 2M dedicated line to each port. A channel test interface unit(CTIU) tests a line/speech path as a subscriber line test unit. Subscriber telephone coin phone/basic rate interface unit/data 64kbpsxN/primary rate interface unit(STCP/BRIU/D64N/PRIU), receive data and clocks from the ONIU and directly connect a subscriber. A subscriber channel unit applies an asymmetric digital subscriber line/very high bit rate digital subscriber line(VDSL/ADSL).

Performance evaluation of selected transmission schemes on digital subscriber loops

Abstract: The authors provide a quantitative performance comparison of selected digital transmission schemes proposed for providing reliable communication on two-wire twisted-pair digital subscriber loops in support of ISDN (integrated services digital network) services. More specifically, they consider the bit error probability (BEP) performance of both hybrid adaptive echo cancellation (HAEC) and time compression multiplexing (TCM) schemes employing either AMI or 2B1Q line codes. The modeling assumptions are carefully described and used to develop a quantitative relative-performance evaluation methodology. Numerical results illustrate the nature of the performance trade-offs as a function of channel and system design parameters. These results are useful in characterizing the parameter choices when there is a clear preference for one system over another. >

Telephone station carrier system

Abstract: A station carrier telephone system employing single sideband transmission permits optimal utilization of the available frequency spectrum without requiring individual stable subscriber carrier sources by utilizing a common source signal for all subscriber carriers. The common source signal is received via the common transmission line at each subscriber circuit where it is processed and mixed with the similarly received central office carrier to derive a difference frequency signal which serves as the subscriber carrier. In a preferred embodiment sixteen channels share the common transmission line and employ sixteen adjacent subscriber frequency bands and sixteen adjacent central office frequency bands.