DSL enables today's users to gain continuous access to the Internet
or corporate Local Area Networks (LANs) at an astonishing 25 times to
100 times faster than the 56.6 Kilobits per second (Kbps) modems now
in vogue. And in the next several years, top transmission speeds will
accelerate from roughly 6 Megabits per second (Mbps) to 53Mbps or
higher. This will transform the existing telephone network used for
transmitting voice, text and low-resolution graphics into a high-speed
connection capable of bringing multimedia, including full-motion video,
into homes and businesses worldwide.
DSL modems use sophisticated digital coding techniques to squeeze up
to 99% more capacity out of an ordinary copper phone line, making
super-fast network access possible.
DSL was originally developed to support video-on-demand services
that telephone companies planned to offer to compete with cable
television companies and satellite direct-to-home entertainment
providers. Recently, however, most phone companies have backed
away from those services.
Instead, DSL's high-speed, high capacity and solid reliability have made it the
technology of choice for the majority of the T-1 lines leased by large corporations for private voice and data networks. Using one DSL-based technique, the 1.544Mbps T-1 service is split into two pairs (four wires), each running at 784Kbps. Splitting the service and increasing the bits per baud reduces the per-line speed and resulting frequency spectrum. This results in
longer loop reaches of up to 18,000 feet, without the need for repeaters.
Another advanced line coding technique also uses DSL technology to transmit
multiple bits of information ranging from 2 to 9 bits per baud. This
results in even less signal attenuation and still longer loop reaches
to accommodate users located farther from a carrier's Central Office
(CO). So even though low-cost connection services such as Oasys
DSL have only been on the market since late 1997, DSL technology
actually has a proven track record in the telecommunications industry.
Different Flavors of DSL
DSL services come in a variety of types, or "flavors," each designed to suit different functions.
Asymmetric or Asynchronous Digital Subscriber Line service transmits
data faster one direction (1.544Mbps downstream to the house) than the other
(384Kbps upstream to the telephone company's CO). ADSL-based network
services offer this blazing speed to power Internet users who want to
download large files and other resources from the Web in a fraction of
the time required for conventional methods.
Symmetric Digital Subscriber Line (also known as single line) service provides 144Kbps of bandwidth in both directions. SDSL's affordable cost (less than half that of ADSL services) and its ability to support high-speed transfers of information in both directions makes SDSL ideal for most business applications, including Internet access, telecommuting or connecting remote offices of larger corporations.
ISDN Digital Subscriber Line service is designed to accommodate users that have already invested in ISDN. This business-oriented service provides ISDN signaling at 144Kbps over a DSL circuit, and plugs into existing ISDN equipment at the local carrier's CO.
High-Speed Digital Subscriber Line service runs at approximately 6Mbps. This flavor is the one used to provide T-1 digital service (1.544Mbps) over standard copper telephone lines.
Very High-Speed Digital Subscriber Line is the next generation of DSL that will take advantage of sophisticated new modems to blast video and data over existing telephone company network infrastructures at speeds of 8Mbps to 53Mbps. When VDSL arrives, the age of multimedia in our homes and businesses will have arrived.
This generic acronym is used to refer to any of the above flavors of DSL. Prices range from $124/month for our business-oriented SDSL service to $359/month for the lightning fast ADSL. There are also up-front costs for necessary hardware and installation.
Rapid Rise of DSL
DSL services are exploding around the world as customers discover the benefits of this technology.
The Ovum Research Group predicts that worldwide, DSL lines will grow from 7
million in 1997 (most of these used for T-1 service) to 49 million by 2003.
The Yankee Group pinpoints the growing use of DSL to access the Internet,
projecting that 2.65 million homes and businesses will rely on DSL for
this purpose by 2002.
What is behind this broad acceptance of DSL?
For example, ISDN services run at 128 Kbps. That's 13% slower than
Oasys's slowest DSL speed of 160Kbps (for SDSL service). With
ISDN, users pay based on usage, (as opposed to OasysDSL's flat
monthly rate), and typical bills for ISDN run from several hundred
dollars monthly to much higher. So, OasysDSL business customers
get faster service for less money than ISDN users.
High-speed T-1 services cost approximately $2,000 a month. This
is more than five times as much as Oasys's high-speed ADSL
service. The high cost of T-1 lines puts them within the reach of
only the largest corporations. OasysDSL makes this speed
affordable for a wide spectrum of small to medium-sized business
In addition to superior price and performance, OasysDSL
offers other important benefits. The flat-rate service provides
around-the-clock connectivity, so the user is always online, which
means no more busy signals or worrying about usage charges.
This continuous connection makes it possible to use OasysDSL to
support Web or e-mail servers. OasysDSL also provides
connectivity for a single PC or an entire LAN, so it fits the
needs of everyone from power Internet users to growing businesses.
Oasys also offers solutions for cable modem users. We know cable
modems offer a dedicated service over a shared medium. While cable
modems do have greater downstream bandwidth (up to 30Mbps), that
bandwidth is shared among all the users on a line, so when more homes
in a neighborhood sign up for the service, speed and capacity will
quickly degrade. In addition, specialized cable modem-based services
are available to only a fraction (less than 2%) of the homes connected
to the regular telephone network, and few businesses will have access
to cable-based services.
For Internet access and other network connectivity uses, Oasys
offers complete solutions, including circuit and equipment ordering,
installation, customer support, and billing. Customers don't have to
deal separately with telephone companies and hardware vendors. As
one of the nation's leading DSL providers, Oasys does it all.
Availability of OasysDSL
Because it is a new application, DSL services are not available everywhere. Generally, customers must work or reside within 18,000 feet of a telephone company's CO that is equipped to support DSL connections. (IDSL services can sometimes reach as far as 40,000 feet.) The only way to know for sure if OasysDSL is available in a given area is to call a service provider like Oasys.