\select@language {english} \contentsline {chapter}{\numberline {1}Introduciton}{1} \contentsline {section}{\numberline {1.1}Structure}{1} \contentsline {chapter}{\numberline {2}GSM}{3} \contentsline {section}{\numberline {2.1}A Historical Perspective}{3} \contentsline {section}{\numberline {2.2}The GSM Network}{5} \contentsline {subsection}{\numberline {2.2.1}Mobile Station}{6} \contentsline {subsection}{\numberline {2.2.2}Network Subsystem}{8} \contentsline {subsubsection}{Mobile Switching Center}{9} \contentsline {subsubsection}{Home Location Register}{10} \contentsline {subsubsection}{Visitor Location Register}{11} \contentsline {subsubsection}{Equipment Identification Register}{11} \contentsline {subsubsection}{Authentication Center}{12} \contentsline {subsection}{\numberline {2.2.3}Intelligent Network}{13} \contentsline {subsection}{\numberline {2.2.4}Base Station Subsystem}{13} \contentsline {subsubsection}{Frequencies and the Cellular Principle}{14} \contentsline {subsubsection}{Base Transceiver Station}{15} \contentsline {subsubsection}{Baste Station Controller}{16} \contentsline {subsubsection}{Transcoding rate and Adaption Unit}{17} \contentsline {section}{\numberline {2.3}The $U_m$ Interface}{18} \contentsline {subsection}{\numberline {2.3.1}Radio Transmission}{19} \contentsline {subsubsection}{Frame Numbering}{19} \contentsline {subsubsection}{Burst Types}{20} \contentsline {subsection}{\numberline {2.3.2}Logical Channels}{21} \contentsline {subsubsection}{Dedicated Channels}{22} \contentsline {subsubsection}{Common Channels}{22} \contentsline {subsubsection}{Combinations}{23} \contentsline {subsection}{\numberline {2.3.3}Layers}{24} \contentsline {paragraph}{Physical Layer (Layer 1):}{24} \contentsline {paragraph}{Data Link (Layer 2):}{24} \contentsline {paragraph}{Network (Layer 3):}{25} \contentsline {section}{\numberline {2.4}IMSI-Catcher}{25} \contentsline {subsection}{\numberline {2.4.1}Mode of Operation}{26} \contentsline {subsection}{\numberline {2.4.2}Law Situation in Germany}{26} \contentsline {chapter}{Bibliography}{I} \contentsline {chapter}{Acronyms}{III}