Adding index, adding complete script

1 files changed, 4 insertions, 4 deletions

diff --git a/chapter00/preface.tex b/chapter00/preface.tex
index e56b1d9..83e8ae1 100644
--- a/chapter00/preface.tex
+++ b/chapter00/preface.tex
@@ -1,6 +1,6 @@
 \phantomsection
-\addcontentsline{toc}{chapter}{Digital Communication -- A Future Technology}
-\chapter*{Digital Communication -- A Future Technology}
+\addcontentsline{toc}{chapter}{Preface: Digital Communication -- A Future Technology}
+\chapter*{Preface: Digital Communication -- A Future Technology}
 
 The current time during the Corona lockdown shows the great significance of telecommunication. It is self-evident to have access to online media and communication platforms. The internet helps to keep in touch with our loved ones. A huge amount of entertainment relies on internet access. The internet is highly integrated in our every-day life. Furthermore, it is a growing economy. There are not only the online services like social media or online warehouses which are going to expand their business in the future. The communication technologies, which the internet is built upon, are a growing and innovative market, too. Besides consumers, the \ac{B2B} market is a huge driver of innovation. It must be expected, that more devices get interconnected. This is a challenge because physical resources are limited. Nevertheless, it is a great possibility for the communication technology to advance. The technologies, which are able to cope with the new requirementes, are digital. This where the course on \emph{Digital Communication Systems} starts. You are warmly welcomed!
 
@@ -16,7 +16,7 @@ Transferring information became more important as societies advanced.
 	\item People all over the world used drums or other devices to generate sounds.
 	\item Some Native Americans tribes used smoke signs to communicate over large distances.
 	\item The invention of paper simplified communication. Large amount of information could be stored and transferred.
-	\item An example of more sophisticated communication technology is the Caesar cipher used in the Roman Empire in ancient times. It is one of the first devices developed for cryptography.
+	\item An example of more sophisticated communication technology is the \index{Caesar cipher} Caesar cipher used in the Roman Empire in ancient times. It is one of the first devices developed for cryptography.
 	\item Homing pigeons delivered letters over long distances.
 	\item In the Middle Ages, beacons were used in defensive communication to relay a signal.
 	\item In the 18th century, semaphore lines had been built. They used visual telegraphy. Semaphores on fixed towers could display a set of symbols, which were relayed along the line.
@@ -26,7 +26,7 @@ Transferring information became more important as societies advanced.
 
 \todo{Semaphores, beacons, lighthouses}
 
-The research of electricity created the foundations for modern communication systems. Electrical telegraphy speeded up telecommunication. At the end of the 19th century, electromagnetic waves have been discovered. James Clerk Maxwell postulated them in 1865. Heinrich Hertz produced the first electromagnetic waves in 1887. The potential had soon been acknowledged by inventors, who developed first radios. The era of analogue radio communication began. The vacuum tube became an important component in radio electronics.
+The research of electricity created the foundations for modern communication systems. Electrical telegraphy speeded up telecommunication. At the end of the 19th century, electromagnetic waves have been discovered. James Clerk Maxwell postulated them in 1865. Heinrich Hertz produced the first electromagnetic waves in 1887. The potential had soon been acknowledged by inventors, who developed first radios. The era of analogue radio communication began. The \index{vacuum tube} vacuum tube became an important component in radio electronics.
 
 In 1947, the bipolar transistor had been invented. This marked the beginning of the semiconductor era, which still endures. Over the decades, semiconductors became more integrated. In 1958, the first \ac{IC} had been demonstrated by Jack Kilby, engineer at Texas Instruments. At this time, wireless communication was mostly restricted to broadcasting and professional users.