Digital Subscriber Lines - PowerPoint PPT Presentation

Loading...

PPT – Digital Subscriber Lines PowerPoint presentation | free to view - id: 3efe8-OWY2M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Digital Subscriber Lines

Description:

ISDN - requires upgrade of local loop to four wire lines and digital switches ... Leaders: Microsoft, Intel, BellSouth, & SBC Communications ... – PowerPoint PPT presentation

Number of Views:230
Avg rating:3.0/5.0
Slides: 20
Provided by: edti
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Digital Subscriber Lines


1
Digital Subscriber Lines
  • Tisha McDermott
  • Ed Tignor

2
Agenda
  • Technology Overview
  • So What?
  • Questions

3
Plain Old Telephone Service
  • Voice
  • Analog
  • Baseband - 300 to 4,000 Hz
  • 24 - 26 Gauge Wire
  • Data
  • Digital
  • Baseband - 300 to 4,000 Hz
  • 56 kbs max

4
High(er) Data Rate Alternatives
  • ISDN - requires upgrade of local loop to four
    wire lines and digital switches
  • T1\E1 leased line - requires specially
    conditioned circuits
  • Relatively expensive and not universally
    available.

Frankly, not very fast.
5
Alphabet Soup
  • DSL Digital Subscriber Line
  • HDSL High bit rate DSL
  • SDSL Symmetric DSL
  • ADSL Asymmetric DSL
  • Universal ADSL
  • RADSL Rate Adaptive DSL
  • IDSL ISDN DSL

6
Distinguishing Features of DSL
  • Can use existing two-wire copper infrastructure
  • Does not go through switched network
  • Frankly, Fast

7
Data Rates
  • Modem 56 Kbs
  • ISDN 128 Kbs
  • T1 1.5 Mbs
  • ADSL up to 8 Mbs downstream
    up to 640 Kbs upstream
  • Universal ADSL 1.5 Mbs downstream
    384 Kbs upstream

8
Higher Data Density Signaling Protocols
  • More data per cycle
  • Lower frequencies Longer loops
  • Higher bit rates
  • Protocols
  • Discrete MultiTone (DMT)
  • Carrierless Amplitude Phase (CAP) Modulation

9
Why doesnt ADSL interfere with phone calls?
POTS
Upstream
Downstream
F(kHz)
4
30
10
Reference Diagram
11
Universal ADSL
  • Less Complex
  • Lower Frequencies equal Longer Loops
  • Lower bit rate - 1.5 Mbs / 384 Kbs
  • Less equipment - no POTS splitter
  • Less expensive
  • Can run on 70 to 90 of existing infrastructure

12
So What?
  • Data communications fastest growing segment of
    communications
  • Growth 7x faster than voice communications
  • By end of 2000, 77 of network traffic
  • Possibilities ? Realities
  • Real-time Video Conferencing Web Hosting
  • Video Streaming Video
    on Demand

13
Forces Driving ADSL
  • Businesses - Small, Medium and Large
  • By 2002 ? 66 million teleworkers
  • Currently, 88 of businesses use dial-up
    connections for site-to-site connectivity

14
Primary Uses of ADSL
  • Branch Office Connectivity
  • Telecommuting Services
  • Virtual office experience
  • Reduction in facility expenses
  • Business to Business Services
  • Internet Connectivity Services
  • Content Delivery Services
  • Shopping catalogs, real estate listing, yellow
    pages

15
Universal ADSL Working Group
  • Leaders Microsoft, Intel, BellSouth, SBC
    Communications
  • Goal Provide consumers with assurance that
    products and services will work together
  • Universal, single standard
  • Simple plug and play
  • Performance ? 25x faster than standard modem
  • Always On

16
Who Supplies ADSL?
  • Hardware
  • Alcatel
  • 30 of market
  • 3Com
  • Texas Instuments
  • Lucent Technologies
  • Service
  • PairGain
  • SBC Communications
  • Rhythms NetConnections
  • Bell Atlantic-AOL

17
ADSL Now
  • SBC Communications
  • ADSL Service in Texas, Missouri, Oklahoma,
    Arkansas, Kansas and possible New England
  • Package price
  • Hardware - 198 Connection - 39-49/mon
  • Goal by the end of 1999
  • 8.2 million residential customers
  • 1.3 million business customers

18
ADSL Now Locally
  • Bell Atlantic - AOL Partnership
  • AOL Premium Service - DSL Connection
  • When? Available by the end of 1999
  • Where? Bell Atlantic region
  • Who? 7.5 million AOL customers
  • How much? Additional 20/month on top of
    regular service

19
Questions?
About PowerShow.com