Showing papers on "High-bit-rate digital subscriber line published in 2007"

Method and apparatus for providing electrical power to a broadband digital subscriber line access

Abstract: Power is supplied to telecom equipment in DSLAM outdoor/remote cabinets with relatively short distances between the subscriber and the cabinet. All of the subscriber Customer Premises Equipment connected to the DSLAM each provide a portion of the required power to the remote cabinet via the telephone line connecting the DSLAM and the subscriber CPE. The CPE at the subscriber premises is already connected to power mains in the subscriber premises so, providing power, via the telephone line to the outdoor cabinet is relatively simple. The remote cabinet includes a circuit for receiving the power input from each subscriber and then distributing the power, required by the DSLAM load, equally among the subscribers.

Methods and apparatus to manage a bonded digital subscriber line (dsl) service

Abstract: Methods and apparatus to manage a bonded digital subscriber line (DSL) service are disclosed. A disclosed example method comprises collecting data representative of bandwidth usage for two or more applications serviced by a bonded set of subscriber lines; analyzing historical activity of the two or more applications based on the collected bandwidth usage data; and selecting a first digital subscriber line (DSL) line profile for a first wire pair in the set of subscriber lines, the set of subscriber lines forming a single DSL communication link.

Splitter wall plates for digital subscriber line (DSL) communication systems and methods to use the same

Abstract: Splitter wall plates for digital subscriber line (DSL) communication systems and methods to use the same are disclosed An example apparatus comprises a splitter to separate a digital subscriber line (DSL) signal from a plain old telephone signal (POTS) signal, and a switch to selectively couple a VoIP signal received via a first jack or the POTS signal to a second jack

Impact of non-stationary noise on xDSL systems: an experimental analysis

Abstract: Broadband services require data rates that can only be achieved by using relatively high spectrum frequencies. At such high frequencies, the DSL (Digital Subscriber Line) signal is more susceptible to external noise sources, such as radio frequency interference and impulsive noise. This paper aims to characterize how the impulsive noise impacts on services and applications for a broadband system using an ADSL2+ loop. The first approach was to use the impulsive noise defined in the standards G.996.1 (Test Procedures for DSL Transceivers) from ITU-T and TR-048 (ADSL Interoperability Test Plan) from DSL Forum. In this approach we have also used a HDSL (High Bit Rate DSL) and white noise disturbers on the line. The impulsive noises c1 and c2 (defined in G.996.1) are injected into the circuit at the CO (Central Office) end and CPE (Customer Premises Equipment) end of the loop simulator. Additionally, it was analyzed the spikes of noise's impact on the ADSL2+ line. In this case, pre-defined models of NEXT (Near-end crosstalk) and white noise are injected on CO and CPE side, simultaneously. Metrics like packet rate, lost packet count, bandwidth, short-term average transfer delay, and errored seconds are used to characterize the DSL loop under the noise impairments. (Less)

Transmit spectrum for a digital subscriber line signal

Abstract: A technique to shape the transmit spectrum for a digital subscriber line modem includes utilizing information indicative of crosstalk into the line of another modem. The transmit spectrum is divided by an adjustable transition frequency into a lower frequency region and a mask region. Crosstalk information about the line of the other modem is obtained and the transition frequency and the low frequency region power spectral density are adjusted to account for the data rates of both modems.

Employment of Voice Band Modems in Subscriber Loop Qualification

Abstract: This letter presents the method useful in subscriber line qualification for asymmetric digital subscriber line service. It is based on the results of the line frequency response measurement in the voice band by V.34 modems. The response is related to the line attenuation at 300 kHz. The measurement results are also presented.

Very High Bit Rate Digital Subscriber Line (VDSL2) technology for triple play services

Abstract: In an Customer demand for triple-play services is on the rise, and cable operators have responded by adding services such as Internet access, VoIP, Video on Demand (VoD), and High Definition TV (HDTV) to their standard television service. Unfortunately for carriers and service providers looking to compete with cable and even satellite operators, triple-play services require a great deal more bandwidth than what is currently available over last-mile copper loops. To compete effectively for customer business and to create a future-proof network, carriers and service providers have a critical need for a fiber-fast broadband capability of 50 Mbps to 100 Mbps. While extending fiber to every home seems a logical solution, it is not feasible economically or competitively. Very-High-Bit-Rate Digital Subscriber Line 2 (VDSL2), a standard by the ITU-T. The proposed VDSL2 standard increases the spectrum allocation to 30 MHz for higher performance. VDSL2 enables fiber-fast broadband at speeds of up to 100 Mbps symmetrical—fast enough to deliver broadband applications such as the triple play of voice, data, and video.

A long reach digital subscriber loop transceiver

Abstract: An echo-cancelling duplex transmission system is described for the digital subscriber loop which uses a 4-level zero redundancy line code (2B1Q) to give very long reach in the presence of crosstalk. Novel digital signal processing algorithms are used to simplify the analogue line interface circuitry. All the digital signal processing, along with sophisticated maintenance and interfacing circuitry, can be contained on a single LSI circuit. Measured performance results are presented.

Model for estimate ADSL service area in presence of channel losses and electromagnetic coupling due HDSL services

Abstract: A model for ADSL service area evaluation, considering the losses of channel and the electromagnetic induction from HDSL signals is proposed. The evaluation is made with the maximum distance from central office that the ADSL signal can reach with a specific bit rate. The models parameters are gotten from real measures on the principal types of cables. Some simulations are made with the presented model to analyze the service area for ADSL signals.

Simulation of DSL systems

Abstract: This report contains simulations of performance for different versions of ADSL, VDSL and SHDSL in 0.4 mm twisted pair cables. An important part of the work has been to investigate the compatibility between different DSL systems. The range of SHDSL system compliant with ITU G.991.2 Annex G has been analysed. These systems allow for bitrates up to 3.848 Mbit/s and 5.696 Mbit/ for 16-PAM and 32-PAM systems respectively. The overall conclusion is that downstream ADSL and ADSL2+ is compatible with both SHDSL Annex G and HDSL systems. The degradation in bitrate of downstream ADSL due to these systems is moderate, less than 13% compared to a cable containing only ADSL systems. ADSL subloop means that an ADSL DSLAM is installed between the local exchange and the subscriber. The purpose is to reduce the loop length between the DSLAM and the subscriber in order to increase the bitrate. This subloop signal will represent a strong interference in the downstream direction of the ADSL systems from the local exchange. As is shown in Section 7 in this report there is a severe degradation in the downstream direction of the ADSL system from the local exchange. The remedy to reduce this degradation is to use power backoff in the subloop systems. Use of power backoff regimes is not analysed in this report. The potential bitrates for VDSL2 systems have been analysed for bandplans 997 and 998. The simulations show that bandplan 997 will give almost symmetrical up- and downstream bitrates for the cables less than 800 meters, whereas for bandplan 998 the downstream/upstream ratio is close to 2:1. Three different bandwidths have been analysed, 12 MHz, 17 MHz and 30 MHz. The frequency bands above 12 MHz are used only for loop lengths less than 800 meters. The frequency bands above 17 MHz are used only for loop lengths less than 650 meters. Bandplans that makes use of the lowest upstream band U0 can still provide adequate upstream capacity (1 Mbit/s) even for loop lengths in excess of 2 km. The downstream bitrate is significant (17-18 Mbit/s) for both 997 and 998 at these lengths.

Multimedia Across Asymmetrical Digital Subscriber Line

Abstract: This paper seeks to provide the concept of multimedia transmission across asymmetrical digital subscriber line (ADSL) . After a brief overview of ADSL characteristics, we deal with multimedia service delivery including broadband Internet access. An example concerning Bosnia and Hercegovina is given, too.