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Traditional phone service (sometimes called POTS for "plain old
telephone service") connects your home or small business to a
telephone company office over copper wires that are wound around
each other and called twisted pair. Traditional phone service was
created to let you exchange voice information with other phone users
and the type of signal used for this kind of transmission is called
an analog signal. An input device such as a phone set takes an
acoustic signal (which is a natural analog signal) and converts it
into an electrical equivalent in terms of volume (signal amplitude)
and pitch (frequency of wave change).
Since the telephone company's
signaling is already set up for this analog wave transmission, it's
easier for it to use that as the way to get information back and
forth between your telephone and the telephone company. That's why
your computer has to have a modem - so that it can demodulate the
analog signal and turn its values into the string of 0 and 1 values
that is called digital information.
Because analog transmission only
uses a small portion of the available amount of information that
could be transmitted over copper wires, the maximum amount of data
that you can receive using ordinary modems is about 56 Kbps
(thousands of bits per second). (With ISDN, which one might think of
as a limited precursor to DSL, you can receive up to 128 Kbps.) The
ability of your computer to receive information is constrained by
the fact that the telephone company filters information that arrives
as digital data, puts it into analog form for your telephone line,
and requires your modem to change it back into digital. In other
words, the analog transmission between your home or business and the
phone company is a bandwidth bottleneck.
Digital Subscriber Line is a technology that assumes digital data
does not require change into analog form and back. Digital data is
transmitted to your computer directly as digital data and this
allows the phone company to use a much wider bandwidth for
transmitting it to you. Meanwhile, if you choose, the signal can be
separated so that some of the bandwidth is used to transmit an
analog signal so that you can use your telephone and computer on the
same line and at the same time.
Win.Net uses a variation of DSL called ADSL (Asymmetric Digital
Subscriber Line). ADSL is called "asymmetric" because most of its
two-way or duplex bandwidth is devoted to the downstream direction,
sending data to the user. Only a small portion of bandwidth is
available for upstream or user-interaction messages. However, most
Internet and especially graphics - or multi-media intensive Web data
need lots of downstream bandwidth, but user requests and responses
are small and require little upstream bandwidth. Using ADSL, up to
1.5 megabits per second of data can be sent downstream and up to 256
Kbps upstream. (Win.Net’s Corporate Power DSL service has greater
bandwidth capacities.) The high downstream bandwidth means that your
telephone line will be able to bring motion video, audio, and 3-D
images to your computer. In addition, a small portion of the
downstream bandwidth can be devoted to voice rather data, and you
can hold phone conversations without requiring a separate line.
Unlike cable modems, by using DSL you won't be competing for
bandwidth with neighbors in your area. In many cases, your existing
telephone lines will work with DSL. Please contact us to see if your
phone line qualifies. |
