CONNECTING TO THE INTERNET

CONNECTING TO THE INTERNET:
Narrowband, Broadband, & Access Providers

What are the means of connecting to the internet, and
how fast are they? What are the three kinds of internet
access provider?

In general terms, bandwidth, or channel capacity, is an expression of how
much data—text, voice, video, and so on—can be sent through a communications
channel in a given amount of time. The type of data transmission
that allows only one signal at a time is called baseband transmission.
When several signals can be transmitted at once, it’s called broadband transmission.
Broadband —very high speed—connections include various kinds
of high-speed wired connections (such as coaxial and fiber-optic, described in
Chapter 6), as well as DSL, cable, and satellite and other wireless connections,
discussed shortly. Today more than half (55%) of all adult Americans have
broadband internet connections at home.4
THE PHYSICAL CONNECTION: WIRED OR WIRELESS? What are your choices
of a physical connection —the wired or wireless means of connecting to the
internet? A lot depends on where you live. As you might expect, urban and
many suburban areas offer more broadband connections than rural areas do.
Among the principal means of connection are (1) telephone (dial-up) modem;
(2) several high-speed phone lines—ISDN, DSL, and T1; (3) cable modem; and
(4) wireless—satellite and other through-the-air links.
DATA TRANSMISSION SPEEDS Data is transmitted in characters or collections
of bits. A bit, as we will discuss later, is the smallest unit of information used
by computers. Today’s data transmission speeds are measured in bits, kilobits,
megabits, and gigabits per second:
• bps: A computer with an older modem might have a speed of 28,800
bps, which is considered the minimum speed for visiting websites with
graphics. The bps stands for bits per second. (Eight bits equals one
character, such as A, 3, or #.)
• Kbps: This is the most frequently used measure; kilobits per second, or
Kbps, are 1 thousand bits per second. The speed of a modem that is
28,800 bps might be expressed as 28.8 Kbps.
• Mbps: Faster means of connection are measured in megabits per second,
or Mbps —1 million bits per second.
• Gbps: At the extreme are gigabits per second, Gbps —1 billion bits per
second.