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-rw-r--r--vorlagen/thesis/src/kapitel_x.tex59
1 files changed, 56 insertions, 3 deletions
diff --git a/vorlagen/thesis/src/kapitel_x.tex b/vorlagen/thesis/src/kapitel_x.tex
index c1755ab..baebf75 100644
--- a/vorlagen/thesis/src/kapitel_x.tex
+++ b/vorlagen/thesis/src/kapitel_x.tex
@@ -1490,12 +1490,12 @@ was defined due to internal synchronization of the GSM network and cyphering bet
\caption{Basic GSM network block diagram.}
\label{img:GSMBig}
\end{figure}
-
+\label{sec:GSMNetStruct}
BTS is the first hardware unit the cell phone is communicating with over the air interface
and provides a ``physical'' connection with the cell phone \citep[Chapter 3]{0890064717}. This physical connection between the
BTS and the cell phone is the \textit{$U_m$ interface}, as shown in figure \ref{img:GSMBig}. A BTS can serve up
-to seven users on one frequency since one out of eight time slot is used for broadcasting of signalling and system information,
-known as the broadcast control channel (BCCH). By sectorizing BTSs with different frequencies the number of seven mobile users
+to seven users on one frequency in full duplex mode since one out of eight time slot is used for broadcasting of signalling and system information,
+transmitted in the broadcast control channel (BCCH). By sectorizing BTSs with different frequencies the number of seven mobile users
can be increased. BTS consists of a RF tranceiver, internal clock and modulator/demodulator. The function of the RF transceiver is
to enable the reception and transmission on the uplink and downlink channel for the cell frequency where the
BTS is located\footnote{Cell is the area covered with GSM signal and from which a cell phone can communicate with a BTS.}.
@@ -1546,6 +1546,59 @@ ought to be tracked if they register \citep[Chapter 4]{0890064717}.
\newpage
\section{Logical channels and the SDCCH channel}
+In this section more details will be given on logical channels and the procedure to initialize (open) an SDCCH channel (Standalone
+Dedicated Control Channel). As mentioned in section \ref{sec:GSMNetStruct}, logical channels can be divided in two groups,
+traffic channels (TCH) and signalling channels (SCH). The former are employed for transfering payload data like speech and message data
+and the latter for managing and synchronizing the GSM network \citep[Chapter 4]{0470030704}.
+Traffic and signalling channels can be split up by their usage, as given in tables \ref{tbl:tchChannels} and \ref{tbl:cchChannels}.
+
+\begin {table}[hb]
+\caption{Traffic channels on the Air interface}
+\label{tbl:tchChannels}\centering
+%\rowcolor{2}{light-gray}{}
+\scriptsize\fontfamily{iwona}\selectfont
+\begin{tabular}{clccc}
+\toprule
+%$D$&&$P_u$&$\sigma_N$\\
+Channel name & Abbreviation & Function & Direction\\\toprule
+Traffic channel full rate &TCH/F & Full rate traffic transmission & MS$\leftrightarrow$BSS\\\midrule
+Traffic channel half rate&TCH/H& Half rate traffic transmission & MS$\leftrightarrow$BSS
+\\\bottomrule
+\end {tabular}
+\end {table}
+
+\begin {table}[hb]
+\caption{Control channels on the Air interface}
+\label{tbl:cchChannels}\centering
+%\rowcolor{2}{light-gray}{}
+\scriptsize\fontfamily{iwona}\selectfont
+\begin{tabular}{clccc}
+\toprule
+%$D$&&$P_u$&$\sigma_N$\\
+Channel name & Abbreviation & Function & Direction\\\toprule
+Frequency correction channel&FCCH &Frequency correction for oscillator on MS & MS$\leftarrow$BSS\\\midrule
+Synchronization channel&SCH&Synchronization information (TDMA frame& MS$\leftarrow$BSS\\
+ &&number to know current location in hyperframe)\\\midrule
+Broadcast common control channel&BCCH&Broadcast information about & MS$\leftarrow$BSS\\
+ &&current BTS and its neighbouring cells\\\midrule
+Access grant channel&AGCH&Required to assign the MS an SDCCH& MS$\leftarrow$BSS\\
+&&or TCH channels\\\midrule
+Paging channel&PCH &Paging request is sent out when MS has& MS$\leftarrow$BSS\\
+ &&incoming traffic (phone call, SMS, etc.)\\\midrule
+Cell broadcast channel&CBCH&Required to broadcast a message to all& MS$\leftarrow$BSS\\
+ &&MS inside of a MSC (e.q. weather forecast)\\\midrule
+Standalone dedicated control channel&SDCCH&Exchange of signalling information between&MS$\leftrightarrow$BSS\\
+ &&MS and BTS when no TCH is active\\\midrule
+Slow associated control channel&SACCH&Transmission of signalling data during an active&MS$\leftrightarrow$BSS\\
+ &&TCH connection (signal strength and sync. data)\\\midrule
+Fast associated control channel&FACCH&Transmission of signalling data during an active&MS$\leftrightarrow$BSS\\
+ &&connection but used only if necessary \\
+ &&(e.q. handover)\\\midrule
+Random access channel&RACH&Request from MS to BTS for a communication& MS$\rightarrow$BSS\\
+ &&channel (e.g. a phone call from MS)
+\\\bottomrule
+\end {tabular}
+\end {table}