Rather, cable modems are designed to work with the “fat” pipe that delivers
dozens or hundreds of television signals into your home.Another advantage: Just as you can instantly tune into the Left-Handed Model
Dump Truck Shopping Network anytime you turn on your television set, the
Internet on a cable modem is constantly available to your computer. There is
no dialing up and no sign-on delays. Using the Internet doesn’t interfere with
your use of the same cable for television; the provider installs a properly
designed splitter to send one feed to your laptop or desktop computer and
the other to the television sets.And yet another advantage: It is very easy to add a router or gateway between
the cable modem and your computer; doing so permits you to attach several
laptops or desktops to the same Internet connection. (Chapter 13 takes you
through routers and gateways.) You can also add a WiFi router that spreads
your incoming signal through your house, allowing you to bring your laptop
from room to room. It also allows desktops in the house to share the same
incoming feed. Although you will be dividing a single connection, the truth is
that rarely will more than one of the machines be making a major demand on
the pipe at the same time. Because the incoming signal is so fast, split-second
differences in demand are inconsequential.Even better, many cable television providers have upgraded their systems to
use fiber optic cable that is faster, with even greater capacity, and more relia-
bility than even the cable television coaxial. Typically, fiber optic cableis used
for long distance runs from headquarters to a distribution box on the street
near a group of homes or offices; from there the pulses of light that travel on
the fiber optic cable are converted to an electrical signal that is carried on a
coaxial cable.(This type of cable uses a copper core surrounded by an insu-
lator and then a ground; if you’ve ever attached a TV to a cable television
outlet, you’ve probably handled a coax.)Chapter 15: Modems: The Essential Translators 229
Get it right to begin with
If the quality of your cable television service is
not very good before you add cable modem
Internet, you’re probably asking for a further
degraded TV signal and a less-than-optimal
Internet connection. Insist that your cable televi-
sion connection be brought up to specifications;
the company may have to add an amplifier at the
street or in your home to improve a weak signal.
My office is attached to my home, which has
(gulp) six and sometimes seven televisions. I
also use the cable feed to provide incoming FM
radio signals for my stereo system. And so when
the installer came to wire my office for a cable
modem, he determined that there were too
many splits in the incoming cable to allow my
computer to get full speed. And so I requested
and received a separate cable — without any
splitters — from the outside of the house
directly into the office.