Digital Subscriber Line (DSL) Technologies
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The Twisted-Pair Telephone Transmission Line
High Frequency Design From November 2002 High Frequency Electronics Copyright © 2002, Summit Technical Media, LLC TRANSMISSION LINES The Twisted-Pair Telephone Transmission Line By Richard LAO Sumida America Technologies elephone line is a This article reviews the prin- balanced twisted- ciples of operation and Tpair transmission measurement methods for line, and like any electro- twisted pair (balanced) magnetic transmission transmission lines common- line, its characteristic ly used for xDSL and ether- impedance Z0 can be cal- net computer networking culated from manufactur- ers’ data and measured on an instrument such as the Agilent 4395A (formerly Hewlett-Packard HP4395A) net- Figure 1. Lumped element model of a trans- work analyzer. For lowest bit-error-rate mission line. (BER), central office and customer premise equipment should have analog front-end cir- cuitry that matches the telephone line • Category 3: BWMAX <16 MHz. Intended for impedance. This article contains a brief math- older networks and telephone systems in ematical derivation and and a computer pro- which performance over frequency is not gram to generate a graph of characteristic especially important. Used for voice, digital impedance as a function of frequency. voice, older ethernet 10Base-T and commer- Twisted-pair line for telephone and LAN cial customer premise wiring. The market applications is typically fashioned from #24 currently favors CAT5 installations instead. AWG or #26 AWG stranded copper wire and • Category 4: BWMAX <20 MHz. Not much will be in one of several “categories.” The used. Similar to CAT5 with only one-fifth Electronic Industries Association (EIA) and the bandwidth. the Telecommunications Industry Association • Category 5: BWMAX <100 MHz. -
A Technology Comparison Adopting Ultra-Wideband for Memsen’S File Sharing and Wireless Marketing Platform
A Technology Comparison Adopting Ultra-Wideband for Memsen’s file sharing and wireless marketing platform What is Ultra-Wideband Technology? Memsen Corporation 1 of 8 • Ultra-Wideband is a proposed standard for short-range wireless communications that aims to replace Bluetooth technology in near future. • It is an ideal solution for wireless connectivity in the range of 10 to 20 meters between consumer electronics (CE), mobile devices, and PC peripheral devices which provides very high data-rate while consuming very little battery power. It offers the best solution for bandwidth, cost, power consumption, and physical size requirements for next generation consumer electronic devices. • UWB radios can use frequencies from 3.1 GHz to 10.6 GHz, a band more than 7 GHz wide. Each radio channel can have a bandwidth of more than 500 MHz depending upon its center frequency. Due to such a large signal bandwidth, FCC has put severe broadcast power restrictions. By doing so UWB devices can make use of extremely wide frequency band while emitting very less amount of energy to get detected by other narrower band devices. Hence, a UWB device signal can not interfere with other narrower band device signals and because of this reason a UWB device can co-exist with other wireless devices. • UWB is considered as Wireless USB – replacement of standard USB and fire wire (IEEE 1394) solutions due to its higher data-rate compared to USB and fire wire. • UWB signals can co-exists with other short/large range wireless communications signals due to its own nature of being detected as noise to other signals. -
Lecture 8: Overview of Computer Networking Roadmap
Lecture 8: Overview of Computer Networking Slides adapted from those of Computer Networking: A Top Down Approach, 5th edition. Jim Kurose, Keith Ross, Addison-Wesley, April 2009. Roadmap ! what’s the Internet? ! network edge: hosts, access net ! network core: packet/circuit switching, Internet structure ! performance: loss, delay, throughput ! media distribution: UDP, TCP/IP 1 What’s the Internet: “nuts and bolts” view PC ! millions of connected Mobile network computing devices: server Global ISP hosts = end systems wireless laptop " running network apps cellular handheld Home network ! communication links Regional ISP " fiber, copper, radio, satellite access " points transmission rate = bandwidth Institutional network wired links ! routers: forward packets (chunks of router data) What’s the Internet: “nuts and bolts” view ! protocols control sending, receiving Mobile network of msgs Global ISP " e.g., TCP, IP, HTTP, Skype, Ethernet ! Internet: “network of networks” Home network " loosely hierarchical Regional ISP " public Internet versus private intranet Institutional network ! Internet standards " RFC: Request for comments " IETF: Internet Engineering Task Force 2 A closer look at network structure: ! network edge: applications and hosts ! access networks, physical media: wired, wireless communication links ! network core: " interconnected routers " network of networks The network edge: ! end systems (hosts): " run application programs " e.g. Web, email " at “edge of network” peer-peer ! client/server model " client host requests, receives -
Introduction to Digital Subscriber's Line (DSL) Chapter 2 Telephone
Introduction to Digital Subscriber’s Line (DSL) Professor Fu Li, Ph.D., P.E. © Chapter 2 Telephone Infrastructure · Telephone line dates back to Bell in 1875 · Digital Transmission technology using complex algorithm based on DSP and VLSI to compensate impairments common to phone lines. · Phone line carries the single voice signal with 3.4 KHz bandwidth, DSL conveys 100 Compressed voice signals or a video signals. 1 · 15% phones require upgrade activities. · Phone company spent approximately 1 trillion US dollars to construct lines; · 700 millions are in service in 1997, 900 millions by 2001. · Most lines will support 1 Mb/s for DSL and many will support well above 1Mb/s data rate. Typical Voice Network 2 THE ACCESS NETWORK • DSL is really an access technology, and the associated DSL equipment is deployed in the local access network. • The access network consists of the local loops and associated equipment that connects the service user location to the central office. • This network typically consists of cable bundles carrying thousands of twisted-wire pairs to feeder distribution interfaces (FDIs). Two primary ways traditionally to deal with long loops: • 1.Use loading coils to modify the electrical characteristics of the local loop, allowing better quality voice-frequency transmission over extended distances (typically greater than 18,000 feet). • Loading coils are not compatible with the higher frequency attributes of DSL transmissions and they must be removed before DSL-based services can be provisioned. 3 Two primary ways traditionally to deal with long loops • 2. Set up remote terminals where the signals could be terminated at an intermediate point, aggregated and backhauled to the central office. -
Glossary of Terminology
Glossary of Broadband Terminology This glossary was compiled by Ray Elseth of Broadband Development 3 (http://www.bbd3.com) and Thomas Asp of Virchow Krause (http://virchowkrause.com), and is a supplement to “Broadband Access: The Local Government Role” by Thomas Asp, Harvey L. Reiter, Jerry Schulz, and Ronald L. Vaden (IQ Report 36, no. 2 [Washington, D.C.: ICMA, 2004]). 802.11 A family of specifications covering wireless connectivity between devices normally located within 100’ to 300’ of each other. Often referred to as Wireless Local Area Network (WLAN). Most common implementation is 802.11b (see Wi- Fi), but 802.11a and 802.11g are also in active use. 802.15 A family of specifications covering wireless connectivity between devices normally located within 10’ to 30’ of each other. Often referred to as Wireless Personal Area Network (WPAN). Implemented as “Bluetooth.” 802.16 A family of specifications covering wireless connectivity between devices normally located within 1 to 30 miles of each other. Often referred to as Wireless Metropolitan Area Network (WMAN). Access Point (AP) A hardware device that acts as a connectivity hub to permit users of a wireless device to connect to a wired local area network. Provides a bridge between Ethernet wired LANs (local area networks) and the wireless network. Access points are the connectivity point between Ethernet wired networks and devices equipped with a wireless LAN adapter card. Antenna The equipment that allows the transmission or reception of radio frequency energy. Asynchronous Digital A technology that allows high-speed data to be sent over a Subscriber Line single pair of existing copper telephone lines, with data rates (ADSL) for receiving data differing from data rates for sending data. -
QUESTION 20-1/2 Examination of Access Technologies for Broadband Communications
International Telecommunication Union QUESTION 20-1/2 Examination of access technologies for broadband communications ITU-D STUDY GROUP 2 3rd STUDY PERIOD (2002-2006) Report on broadband access technologies eport on broadband access technologies QUESTION 20-1/2 R International Telecommunication Union ITU-D THE STUDY GROUPS OF ITU-D The ITU-D Study Groups were set up in accordance with Resolutions 2 of the World Tele- communication Development Conference (WTDC) held in Buenos Aires, Argentina, in 1994. For the period 2002-2006, Study Group 1 is entrusted with the study of seven Questions in the field of telecommunication development strategies and policies. Study Group 2 is entrusted with the study of eleven Questions in the field of development and management of telecommunication services and networks. For this period, in order to respond as quickly as possible to the concerns of developing countries, instead of being approved during the WTDC, the output of each Question is published as and when it is ready. For further information: Please contact Ms Alessandra PILERI Telecommunication Development Bureau (BDT) ITU Place des Nations CH-1211 GENEVA 20 Switzerland Telephone: +41 22 730 6698 Fax: +41 22 730 5484 E-mail: [email protected] Free download: www.itu.int/ITU-D/study_groups/index.html Electronic Bookshop of ITU: www.itu.int/publications © ITU 2006 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. International Telecommunication Union QUESTION 20-1/2 Examination of access technologies for broadband communications ITU-D STUDY GROUP 2 3rd STUDY PERIOD (2002-2006) Report on broadband access technologies DISCLAIMER This report has been prepared by many volunteers from different Administrations and companies. -
Cable Versus Dsl
53-10-60 DATA COMMUNICATIONS MANAGEMENT CABLE VERSUS DSL John R. Vacca INSIDE DSL; Cable Modems; ADSL; CDSL; G.Lite; HDSL; IDSL; RADSL; SDSL; VDSL; POTS; DSL and Cable Modem Rollouts; High-Speed Data Entry; Buying DSL Service; Installing DSL; Security Problems, Residential Users, Telecommuters, DSL System Components; DSL Network; DSL Hubs INTRODUCTION Internet access via cable modem has become available in many residen- tial areas over the past few years. Cable has the capacity to transmit data at speeds as fast as Digital Subscriber Line (DSL) when configured prop- erly and under optimal conditions. Due to the fact that cable lines are not available in the vast majority of commercial districts, cable does not com- pete with DSL in the enterprise market at all, in most cases. Cable was designed for residential use, and in some cases may be a cost-effective solution for residential high-bandwidth Internet access. Therefore, the challenge of cable versus DSL is primarily in the residential and telecom- muter markets. With that in mind, and before continuing with the theme of this article (cable vs. DSL), one can take a look at the technology issues first, and then some basic terminology. TECHNOLOGY ISSUES What is DSL? How does it work? What are the types of DSL? These are some of the questions this article will surely answer; as well as some of the pros and cons of the use of cable modems versus DSL. PAYOFF IDEA The article discusses the current state of cable DSL: What Is It? modem access versus DSL. It also examines how In essence, by using the existing tele- prevalent cable modem and DSL services are in major U.S. -
Digital Subscriber Lines and Cable Modems Digital Subscriber Lines and Cable Modems
Digital Subscriber Lines and Cable Modems Digital Subscriber Lines and Cable Modems Paul Sabatino, [email protected] This paper details the impact of new advances in residential broadband networking, including ADSL, HDSL, VDSL, RADSL, cable modems. History as well as future trends of these technologies are also addressed. OtherReports on Recent Advances in Networking Back to Raj Jain's Home Page Table of Contents ● 1. Introduction ● 2. DSL Technologies ❍ 2.1 ADSL ■ 2.1.1 Competing Standards ■ 2.1.2 Trends ❍ 2.2 HDSL ❍ 2.3 SDSL ❍ 2.4 VDSL ❍ 2.5 RADSL ❍ 2.6 DSL Comparison Chart ● 3. Cable Modems ❍ 3.1 IEEE 802.14 ❍ 3.2 Model of Operation ● 4. Future Trends ❍ 4.1 Current Trials ● 5. Summary ● 6. Glossary ● 7. References http://www.cis.ohio-state.edu/~jain/cis788-97/rbb/index.htm (1 of 14) [2/7/2000 10:59:54 AM] Digital Subscriber Lines and Cable Modems 1. Introduction The widespread use of the Internet and especially the World Wide Web have opened up a need for high bandwidth network services that can be brought directly to subscriber's homes. These services would provide the needed bandwidth to surf the web at lightning fast speeds and allow new technologies such as video conferencing and video on demand. Currently, Digital Subscriber Line (DSL) and Cable modem technologies look to be the most cost effective and practical methods of delivering broadband network services to the masses. <-- Back to Table of Contents 2. DSL Technologies Digital Subscriber Line A Digital Subscriber Line makes use of the current copper infrastructure to supply broadband services. -
Digital Multi–Programme TV/HDTV by Satellite
Digital multi–programme TV/HDTV by satellite M. Cominetti (RAI) A. Morello (RAI) M. Visintin (RAI) The progress of digital technology 1. Introduction since the WARC’77 is considered and the perspectives of future The significant progress of digital techniques in applications via satellite channels production, transmission and emission of radio are identified. Among these, digital and television programmes is rapidly changing the established concepts of broadcasting. multi–programme television systems, with different quality levels (EDTV, SDTV) and possible The latest developments in VLSI (very–large scale evolution to HDTV, are evaluated in integration) technology have significantly contrib- uted to the rapid emergence of digital image/video terms of picture quality and service compression techniques in broadcast and informa- availability on the satellite channels tion–oriented applications; optical fibre technolo- of the BSS bands (12 GHz and gy allows broadband end–to–end connectivity at 22 GHz) and of the FSS band (11 very high bit–rates including digital video capabil- GHz) in Europe. A usable channel ities; even the narrow–band terrestrial broadcast capacity of 45 Mbit/s is assumed, as channels in the VHF/UHF bands (6–7 MHz and 8 well as the adoption of advanced MHz) are under investigation, in the USA [1] and channel coding techniques with in Europe [2], for the future introduction of digital QPSK and 8PSK modulations. For television services. high and medium–power satellites, in operation or planned, the The interest for digital television in broadcasting receiving antenna diameters and multimedia communications is a clear exam- required for correct reception are ple of the current evolution from the analogue to reported. -
Understanding Bluetooth® 5
Volume 1 Issue 1 Understanding Bluetooth® 5 Primary Logo Secondary Stacked Logo 1 Contents 3 Foreword 4 A Look Back and Ahead 5 Case Study: Bluetooth 5 Automatic Parking Meter 6 Bluetooth 5 Mesh Networking 11 Industry Experts Roundtable 14 Bluetooth 5: Your Questions Answered Weclome From the Editor For design engineers, “methods” can mean many things: The Scientific Method, for example, provides the basis for testing hypotheses. The Engineering Method allows us Editor to solve problems using a systematic approach. Method Engineering allows us to create Deborah S. Ray new methods from existing ones. And, I think we’ve all said, “There’s a method to my madness,” when creating new designs or applying existing ones in new ways. Contributing Writers Barry Manz Publishing high-quality technical content is just one method we use to enable our customers Steven Keeping and subscribers to apply technologies and electronic components in new ways and to help drive Steve Hegenderfer revolution and solutions in their various industries. Methods was conceived to provide a new format Technical Contributors to meet our readers’ evolving information needs. And with the resounding success of our Bluetooth 5 Paul Golata webinar on April 11—and the huge thirst for more information around the concepts and applica- Rudy Ramos tion of the new standard—we knew we had the topic for the first edition of our new ezine. So, like Design and Layout Method Engineering, new methods of content delivery came from a project that was underway. Ryan Snieder This first issue of Methods includes a variety of Bluetooth 5 related content that supports and extends the webinar. -
BANDWIDTH UTILIZATION on CABLE-BASED HIGH SPEED DATA NETWORKS Terry D
BANDWIDTH UTILIZATION ON CABLE-BASED HIGH SPEED DATA NETWORKS Terry D. Shaw, Ph. D.1 CableLabs Abstract These observations indicate the The CableLabs Bandwidth Modeling and importance of deploying DOCSIS 1.1 in Management project addresses the use, order to meet this increasing demand for management, performance simulation, and upstream capacity. Preliminary simulation network economics of cable high-speed data results indicate DOCSIS 1.1 will enable a systems. On this project, we have analyzed significant increase in upstream system consumer usage patterns based upon data carrying capacity over the already collected on live cable-based high-speed substantial capacity of DOCSIS 1.0. These data systems as well as network simulations. simulations indicate that DOCSIS 1.1 will allow almost 20% more upstream capacity Usage data on live cable networks than DOCSIS 1.0. indicate that traffic flows are fairly predictable over DOCSIS™ networks. Simulations have also been used to study Some of the primary patterns emerging the characteristics of specific types of traffic include: found on cable networks. For example, simulations of peer-to-peer applications • Skewed distribution of bandwidth indicate that one user without rate limits can consumption. As a general rule in consume up to 25% of upstream capacity many systems, 30% of the with a usage pattern resembling a very high- subscribers consume about 60% of speed constant bit-rate application. These the data. simulation results highlight the potential • Students drive seasonal benefits for cable operators to manage their characteristics. System usage is bandwidth using tools such as rate limits, appreciably higher during local service tiers, and byte caps on usage. -
CALRAD 70 Series - Telephone Accessories
CALRAD 70 series - telephone accessories CALRAD’S NEW TELEPHONE HEADSETS HANDS FREE TELEPHONE HEADSETS Calrad’s telephone headsets help reduce phone fatigue and provides hands-free convenience for working on computer data entry, taking notes, and in fact do the work you need to do and talk on the phone at the same time. Adjustable volume control, telephone/headset selection switch, voice mute button. All units come with base unit, headset, and cables. 70-600 TELEPHONE LINE POWERED This unit works directly when connected to your telephone. Requires two AA batteries, not included. 70-601 BATTERY POWERED This unit works with most home type instruments. A selectable configuration switch is provided on the side of the unit for easy interfacing to your telephone equipment. This unit connects to your handset jack on the telephone. Two AA batteries not included. 70-602 BATTERY / DC POWERED This unit works with most business type instruments. A selectable configuration switch is provided on the side of the unit for easy interfacing to your telephone equipment. This unit easily connects to your handset jack on the telephone. A small opening on the front of the unit is provided so that a small phillips screwdriver can be used to adjust the microphone gain. Two AA batteries/AC adapter not included. AC adapter is 45-756-S. FLUSH MOUNT, SINGLE-JACK FLUSH MOUNT, MODULAR WALL PLATES DECORA STYLE For new construction or conversion to modular instruments. Screw terminals. MODULAR WALL PLATES 70-403 ..................................................4-Wire, Ivory Wall plates designed to accept 70-403-W ..........................................4-Wire, White modular plugs.