Wired for speed – DSL technology

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We all want more speed from every service we choose to use. The theory goes that the greater the speed of service delivery we obtain, the more leisure time we have to enjoy. The fact is that in an accelerating world, our expectations and demands keep outstripping the art of the possible. The result is frustration and stress.

Traffic jams create road rage; supermarket queues generate trolley rage; and the Internet delivers the worldwide wait to most of the globe’s 200 million on-line individuals. With data volume on the Internet doubling every three or four months and the number of users doubling every 12 months or so, there will be over 400 million of us potentially suffering access anxieties in the first year of the millennium.

So, what’s the answer? What we need is some acceleration of the technologies to deliver that world to us - and those speedier access routes are just around the corner in the form of DSL (digital subscriber line).

Put simply, DSL gives the humble and ubiquitous copper wires that run throughout the world to provide POTS (plain old telephone service), the capacity to send enormous volumes of data at very high speeds.

Some DSLs do that in parallel with the standard voice service, all on the same line and at the same time. Some deliver higher speeds or wider bandwidth - the more dense the data you are sending, the wider the bandwidth you need for quality and speedy transmission. Still others deliver higher capacity for downloading than for uploading data. There is a whole portfolio of DSL technologies coming on stream to match user needs at home and at work. The new millennium is putting a completely new dimension into those telephone lines we have all come to take for granted.

Already there are towns and cities around the globe which really are wired for speed with DSL. There are even whole countries which are DSL-ed - like Singapore where ADSL on the phone lines have been given the capacity to deliver video on demand at the quality you would expect on television or in the cinema.

ADSL is the asymmetric version of DSL - offering differing upload and download speeds. This is usually configured to deliver 6 megabits of data per second from the network to the customer and up to 1 megabit from the customer back to the network, all while providing voice communication on the same copper line at the same time. Compare that with the standard 26 or 56k modem and you start to appreciate the difference DSL will make. Since few of us use Internet access to send seriously large documents but all of us use it to access data-intense information such as websites with heavy graphic content, this asymmetric service will more than meet most needs.

ADSL can also be added to the ISDN lines that are already delivering some extra speed to businesses and homes but are still considerably slower than ADSL. With this technology over ISDN lines in Germany, for example, business users are being offered speeds of up to six megabits per second - 100 times faster than ISDN.

ADSL services over standard telephone lines have been extensively trialled throughout Europe, the USA and beyond. Those trials have proven the technology and ironed out most of the hiccups that are a natural consequence of getting long-established infrastructures to achieve the next big step in their potential.

G.lite is another new term to look out for in the DSL portfolio. It is the general name being used for an ITU (International Telecommunications Union) standard ADSL service for the delivery of speeds of up to 1.5 megabits downstream and up to 384 kilobits upstream. In most cases it will operate over existing home telephone wiring and be installed by the familiar ‘plug and play’ process on a compatible home computer. DSL ready computers are already being shipped in the USA ready for use when telephone companies have the necessary service on line so European deployment is expected to be not far behind.

SDSL is an umbrella term for symmetric DSL services- delivering the same speed up and down stream. There are a number of supplier-specific implementations over a single copper pair providing variable rates of symmetric service, with or without ordinary telephone services.

You may also hear of HDSL, HDSL-2, VDSL and many more DSL-based acronyms. Whatever the prefix, the message is fundamentally the same: DSL equals point to point connection over your existing telephone line for high-speed data and/or voice. With DSL you are wired for speed.

This point to point connection is a key to speed and to security of data. It means that your data connection over a DSL service, like your telephone call, is a direct link between you and the other party. There is no line sharing, as there is on cable telephony, to reduce the speed of transmission nor to place security of your information at risk.

If your only use of the Internet is to research best buys, shop or check out public domain information for school or work, the security issue is hardly important. Similarly, if your Internet access is in relatively short bursts and is usually based on simple text information, the sorts of speeds available from DSL services will amaze you and be a bonus, but not a necessity.

But if you are dealing with sensitive information, even for e-mail, plugging in to your office network from home or while travelling, commercial security is a fundamental requirement. And if you are routinely sending, viewing or downloading dense data - from graphics and photographs to music and video clips or even PowerPoint presentations and databases - you will probably never be happy until you have hooked up to the speed and security of DSL technologies.

Like everything else, it is all a matter of choice to meet the needs of your lifestyle. What is surprising is how little we recognise the lifestyle changes we have all made because of developments in technology. Think about it and you can pinpoint anybody’s age simply by checking if they remember life without some of today’s products and services at home and at work.
• Remember life without a telephone at home? You are over 50
• Remember life without a television at home? You are over 50
• Remember office life without a photocopier? You are over 45
• Remember life without pocket calculators? You are over 45
• Remember office life without a computer? You are over 35
• Remember office life without a fax machine? You are over 35
• Remember life before voicemail? You are over 25
• Remember school without computers? You are over 15
• Remember life without email? You are over 10
• Remember life without the Internet? You are over five years old and probably already tired of the worldwide wait.

Today’s children will soon be taking the speed and security of electronic communication using DSL technologies for granted just as the rest of us have come to accept all those other technological advances as an integral part of our lifestyle, without noticing the impact they have had on the way we live. They simply will not understand the access anxieties of the worldwide wait that we have suffered at the turn of the century, in the days before DSL arrived on a telephone line near us. It won’t be long now before we can stop waiting and move into real time for all our electronic transactions.

DSL Forum is a non-profit international organization of more than 300 companies representing the world’s computer, networking and telecommunications industries. Established in 1994, it is dedicated to the development and mass market deployment of broadband communications technologies based on DSL over existing copper telephone cable infrastructures.

Its technical committee and working groups focus on the resolution of telecommunications architecture and operational management issues to facilitate interoperability of equipment and system development worldwide. It provides recommendations to and liaison with international telecommunications standards bodies (ITU, ETSI, ANSI and so on).

Its marketing committee and working groups develop and implement programs to:
• engage the stakeholder markets in the Forum and its work (telephone companies, phone service providers, phone and computer equipment providers, internet service providers, other application service providers)
• and to educate end user markets (service providers, corporate businesses - IT and facilities managers and policy makers, professional firms, small and medium sized businesses, telecommuters and residential consumers).

DSL Forum

DSL Life



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