The
kind of cable that NetDay volunteers install is called Category 5.
It's made up of eight color-coded, twisted copper phone wires encased
in a sheath, and it costs about 10 cents a foot at computer supply
stores. State-of-the-art, it's the same cable on which high-speed
networks in most businesses run. If Category 5 cable is installed
according to specifications, computer data can travel over it at
high speeds. It's also said to have high bandwidth. (Bandwidth refers
to the rate at which information that can travel through telecommunications
cable or wiring; sending data over a network with higher or lower
bandwidth is like letting water flow through a bigger or smaller
pipe.)
Fiber-optic cable,
which transmits electronic data as light waves, has even greater
bandwidth than Category 5 cable, but it's more expensive and requires
more expertise to install. However, Category 5 cable cannot be
used for runs longer than 328 feet (100 meters), whereas fiber-optic
cable can.
What difference does
bandwidth make? First, within a school's local network, lots of
data will be able to travel very quickly. Students in different
schoolrooms will be able to send one another e-mail and text files
without hitting a bottleneck that makes them wait for things to
come up on screen. They'll also be able to call up one another's
pictures and movies. Second, schools won't be a bottleneck in the
future, as bigger and bigger chunks of data become available over
the Internet. Many phone companies are now replacing old phone
networks with high-bandwidth cable.
Category 5 cable will
accommodate advances in computer technology for a long while to
come. Right now, only 10 percent of all computers in schools are
fast enough to make full use of Category 5's data transmission
capacity.
"Grange
was built in 1973, and the builders left us an empty 1-inch
conduit that we used to pull Category 5 cable to the classrooms."
A
NetDay technical volunteer from Grange Middle School,
Fairfield, California, on Grange's March 9, 1996, wiring effort
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