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TELECOMMUNICATIONS
- April 2001 by John F. Clark Solving the DSL
Mystery An annually-featured activity of the National Communication Forum (NCF) is the group’s Infovision Award ceremony. During the event, companies are honored for the best new technologies, applications, products and services in the telecommunications field. One NCF award given last October went to a product that promises to have a huge effect on a service that is now highly sought by both corporations and individuals. The product is the Celerity system, made by the Teradyne Corporation (www.teradyne.com). Fundamentally, Celerity is a testing and evaluation system for assessing the capability of phone lines to support Digital Subscriber Line (DSL) services. A significant advantage of DSL service is that it makes use of the twisted pair (2X) telephone lines that already enter everyone’s homes and businesses. Using DSL, you can use your computer to access the web and send your e-mail while leaving your phone open to make and receive calls. There are a variety of service plans and payment schedules, but the bottom line is transmission speeds that range from 768 Kbps to 1.5 Mbps. Compare that to your 56 Kbps modem (which in reality will never exceed about 49.3 Kbps) and you have a significant improvement.
The explanation for this phenomenon lies in the history of the evolution of the local loop, or the main infrastructure that provides local phone service. Without going into a lot of detail, the relevant factors include the distance of your home or business from a telephone central office (CO), the method by which the various parts of the local loop were connected to each other, and the overall condition of the lines, in a physical context. The thing is, you can’t rely on your local service provider to tell you if your line is capable of supporting DSL service. Recent visits to websites maintained by Verizon, BellSouth, and several DSL manufacturers revealed that each has a online service that allows you to input your address and zip code for the purpose of discovering whether or not you can obtain DSL service. However, none of these websites could provide me with the information for my address, even though I live right off East Main Street in the heart of Lexington, the second biggest city in Kentucky. If you were to call your service provider to arrange for DSL service, there’s a good chance they would sign you up and then tell you weeks or months later that they really can’t provide the service. The reason? They just don’t know. Part of the process of finding out if DSL service can be provided requires actual physical inspection of the lines. Therein
lies the beauty of Teradyne’s new Celerity product,
a technology that enables service providers to accurately
qualify millions of lines for DSL in a matter of hours,
rather than the months that it can, and usually does
take. Celerity works independently of installed testing
systems. It inputs results to a data warehouse that is
used to tell you if your line will support DSL, requires
conditioning, or is simply disqualified until major
improvements are made. John
F. Clark is an assistant professor of telecommunications
in the University of Kentucky School of Journalism and
Telecommunications.
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Copyright 1996-2001, by Kentucky Business Online. All rights reserved. Editorial
content is copyright 2001, Lane Communications Group The Lane Report is a trademark of Lane Communications Group. All other trademarks are the property of their respective owners. |
You may be
aware by now, especially as the public’s frustration
mounts day by day, that it is not possible to obtain DSL
services in significant areas of large metropolitan
areas, despite the perception that sophisticated
telephone infrastructures underlie these areas. And once
you leave the city and head for rural areas and small
towns, all bets are off. (Editor’s Note: See a
late-breaking story about more widespread DSL service
coming to Kentucky in Fast Lane, page 13.)