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2 Chapter 1 • Introduction to Wireless Networking, Wardriving, and Kismet
Exploring Past
Discoveries That Led to Wireless
Wireless technology is the method of delivering data from one point to another without
using physical wires, and includes radio, cellular, infrared, and satellite. A historic
perspective will provide you with a general understanding of the substantial evolution
that has taken place in this area. The common wireless networks of today originated
from many evolutionary stages of wireless communications and telegraph and radio
applications. Although some discoveries occurred in the early 1800s, much of the
evolution of wireless communication began with the emergence of the electrical age
and was affected by modern economics as much as by discoveries in physics.
Because the current demand of wireless technology is a direct outgrowth of
traditional wired 10-Base-T Ethernet networks, we will also briefly cover the advent
of the computer and the evolution of computer networks. Physical networks, and
their limitations, significantly impacted wireless technology. This section presents
some of the aspects of traditional computer networks and how they relate to wireless
networks. Another significant impact to wireless is the invention of the cell phone.
This section will briefly explain significant strides in the area of cellular
communication.
Discovering Electromagnetism
Early writings show that people were aware of magnetism for several centuries before
the middle 1600s; however, people did not become aware of the correlation between
magnetism and electricity until the 1800s. In 1820, Hans Christian Oersted, a Danish
physicist and philosopher working at that time as a professor at the University of
Copenhagen, attached a wire to a battery during a lecture; coincidentally, he just
happened to do this near a compass and he noticed that the compass needle swung
around. This is how he discovered that there was a relationship between electricity
and magnetism. Oersted continued to explore this relationship, influencing the works
of contemporaries Michael Faraday and Joseph Henry.
Michael Faraday, an English scientific lecturer and scholar, was engrossed in
magnets and magnetic effects. In 1831, Michael Faraday theorized that a changing
magnetic field is necessary to induce a current in a nearby circuit. This theory is
actually the definition of induction. To test his theory, he made a coil by wrapping a
paper cylinder with wire. He connected the coil to a device called a galvanometer, and
then moved a magnet back and forth inside the cylinder. When the magnet was
