\chapter{Introduction}

In our lives we use many communication technologies that work over a short
range: for connecting our mice and keyboards to our computers, listening to
music wirelessly and to pay contactlessly. Those technologies include, but are
not limited to: Bluetooth, \gls{rfid}, \gls{nfc} and many others.

What many of those technologies have in common is that they work on top of
radio waves that utilize electromagnetic induction. Some problems of radio
waves are the difficulty of passing through conductive materials such as water
or metals \cite{RadioWaves} and they are susceptible to interference
\cite{RadioInterference} and jamming \cite{RadioJamming}. An alternative to
those technologies would be communication over magnetic induction.

Other research projects in this area already exist and some have covered the
use of the magnetic fields emitted from CPUs as a communication channel
\cite{MagneComm} and other cover the general use of magnetic induction
communication in body area networks \cite{magneticInductionBAN}. 

This thesis researched the concept of communication using magnetic induction
and created a prototype implementation of a protocol that works through
attempted manipulation of magnetic fields using a CPU in a laptop called
MagSend. A simple user interface in the form of a website is created that
allows a user to send messages over the protocol and an Android application
is used to receive messages using the protocol.