Nov. 7/00High Speed Internet Technologies The Need For Speed Terry Foley Rhonda Hoskins Jerry Gilroy Jill Morgan High Speed Internet Technology

Outline What is DSL? Where did DSL originate? How does DSL work? What types of DSL are available? Myths and Truths about DSL Its closest competitor width/howfast.asp

What is DSL? DSL – Digital Subscriber Line Uses ordinary telephone wire Speed varies depending on type An “always on” service – No dial-up One line carries both data and voice

Where Did DSL Originate Created by Bellcore in 1989 To deliver video on-demand to compete with cable TV Never really used for this People noticed the potential for internet applications

How Does DSL Work Implemented over the “last mile” Uses digital technology Utilizes line-coding scheme Divides line into 3 bands Lower for voice, Higher 2 for data

How Does DSL Work cont’d Phone company must install special router – DSL access multiplexer This transfers data from copper line to larger backbone CO must be approx ft from the end user for top performance End user must have special router or modem

Types Of DSL HDSL – High-Data-Rate DSL ADSL – Asymmetric DSL RADSL – Rate Adaptive DSL SDSL – Symmetric DSL VDSL – Very-High-Rate DSL

Speeds Of Different Types

Myths And Truths Myth – DSL is easy to install Truth – Technician needed to install modem and wiring Myth – Speed of DSL Truth – Performance is effected by electromagnetic noise and distance

Its Closest Competitor Cable – It provides similar speeds, service and technology Uses local TV line to give continuous connection

The Need For Speed