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authorRefik Hadzialic2012-08-16 14:59:44 +0200
committerRefik Hadzialic2012-08-16 14:59:44 +0200
commit428e14dd77d2cc732f26cf9c6fb2b2f8bb850d6b (patch)
tree38ce1280ff719c10df09efbd738010e7880ce81b
parentGSM (diff)
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GSM
-rw-r--r--vorlagen/thesis/maindoc.pdfbin6904567 -> 6908839 bytes
-rw-r--r--vorlagen/thesis/src/bib/literatur.bib8
-rw-r--r--vorlagen/thesis/src/kapitel_x.tex56
-rw-r--r--vorlagen/thesis/src/maindoc.lof20
-rw-r--r--vorlagen/thesis/src/maindoc.lot16
5 files changed, 63 insertions, 37 deletions
diff --git a/vorlagen/thesis/maindoc.pdf b/vorlagen/thesis/maindoc.pdf
index 791303c..2a77b46 100644
--- a/vorlagen/thesis/maindoc.pdf
+++ b/vorlagen/thesis/maindoc.pdf
Binary files differ
diff --git a/vorlagen/thesis/src/bib/literatur.bib b/vorlagen/thesis/src/bib/literatur.bib
index 6569beb..174eaf4 100644
--- a/vorlagen/thesis/src/bib/literatur.bib
+++ b/vorlagen/thesis/src/bib/literatur.bib
@@ -688,4 +688,12 @@ ISSN={0018-9251},}
Publisher = {Wiley},
Year = {2010},
ISBN = {0470742984}
+}
+
+@book{0470030704,
+ Author = {Jörg Eberspächer and Hans-Joerg Vögel and Christian Bettstetter and Christian Hartmann},
+ Title = {GSM - Architecture, Protocols and Services},
+ Publisher = {Wiley},
+ Year = {2009},
+ ISBN = {0470030704}
} \ No newline at end of file
diff --git a/vorlagen/thesis/src/kapitel_x.tex b/vorlagen/thesis/src/kapitel_x.tex
index 28a5af9..2f59e75 100644
--- a/vorlagen/thesis/src/kapitel_x.tex
+++ b/vorlagen/thesis/src/kapitel_x.tex
@@ -134,6 +134,7 @@ in the cell phone. However, this method can be applied on any cell phone and doe
require a smart phone. It is a network based estimation technique.
\subsection{E-OTD and UL-TDOA}
+\label{LMUSync}
E-OTD and UL-TDOA are two similarly working positioning techniques, both use the time difference of
signal arrival and for this reason have been grouped as one.
E-OTD stands for Enhanced Observed Time Difference. This technique requires the GSM network to be
@@ -1381,7 +1382,7 @@ this chapter more details shall be given on the second generation GSM network wh
delivering GPS assistance data to cell phones. More information shall be provided on the general working principles of GSM
and how a Standalone Dedicated Control Channel (SDCCH) is initialized to deliver data to cell phones.
\newpage
-\section{Overview}
+\section{Overview of the Air interface}
In this section the reader shall be provided with principles how the GSM network operates.
The main task of GSM networks was to enable wireless voice transmission between GSM and other GSM/telephone users
inside of switched networks. It was not designed to be used with data services which are a necessity in today's standards.
@@ -1448,7 +1449,7 @@ TDMA applied on the FDMA technique constrains the GSM air interface to be of
2D structure. The idea of employing TDMA on FDMA in the GSM900 band can be seen in figure \ref{img:GSMFreqTime}.
Each time slot duration is $\approx$577 $\mu s$, all 8 time slots have a period of $\approx$ 4.615 $ms$
\citep{dennis} \citep{0890064717}. By applying this technique each GSM user can send data inside of the assigned time slot
-without disturbing users on different time slots.
+without disturbing users on different time slots.
\begin{figure}[ht!]
\centering
\includegraphics[scale=0.50]{img/GSMFreqTime.pdf}
@@ -1457,42 +1458,56 @@ without disturbing users on different time slots.
\end{figure}
Eight time slots in GSM are called a TDMA frame. Each time slot
-in GSM is known as a burst. Every TDMA frame is assigned a unique integer number which is then repeated and reassigned
+in GSM is known as a physical channel, on the physical channels are built up the logical
+channels. Logical channels have a predefined pattern of time slot they are assigned. Logical channels
+can be divided in two groups, traffic channels (TCH) and signalling channels (SCH).
+User payload data like speech and message data are transmitted in the TCH channels whereas control data
+for control, synchronization and management of the GSM network are transmitted through the
+SCH channels \citep[Chapter 4]{0470030704}.
+
+\begin{figure}[ht!]
+ \centering
+ \includegraphics[scale=0.70]{img/GSMHierarchy.pdf}
+ \caption{Hierarchy of the GSM frames.}
+\label{img:GSMHierarchy}
+\end{figure}
+
+Every TDMA frame is assigned a unique integer number which is then repeated and reassigned
every 3h:28m:53s:760ms, also known as \textit{hyperframe} \citep[Chapter 7]{0890064717}. In the hierarchy pyramid,
a layer lower of the hyperframe is the \textit{superframe}. There are two types of superframes, consisting of two types
of \textit{multiframes}, differing in their length \citep[Chapter 7]{0890064717}. The relations can be seen in figure
\ref{img:GSMHierarchy} with their duration periods. The multiframe with 26 TDMA frames carries only traffic channels (TCH) and associated
-control channels (CCH). The other multiframe type, with 51 TDMA frames carries solely signaling data. This hierarchy constrain
+control channels (CCH). The other multiframe type, with 51 TDMA frames carries solely signalling data. This hierarchy constrain
was defined due to internal synchronization and cyphering between the MS and the Base Transceiver Station (BTS)
\citep[Chapter 7]{0890064717}.
+
+\newpage
+\section{GSM Network structure}
\begin{figure}[ht!]
\centering
- \includegraphics[scale=0.70]{img/GSMHierarchy.pdf}
- \caption{Hierarchy of the GSM frames.}
-\label{img:GSMHierarchy}
+ \includegraphics[scale=0.50]{img/GSMBig.pdf}
+ \caption{Basic GSM network block diagram.}
+\label{img:GSMBig}
\end{figure}
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 signaling and system information,
+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
-can be increas. BTS consists of a RF tranceiver, internal clock and modulator/demodulator. The function of the RF transceiver is
+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.}.
The main function of the internal clock is to supply the BTS with a frequency such that the internal
-circuits can produce the TDMA frames, with an accuracy of at least $\pm$5 ppm \citep{dennis}.
+circuits can produce the TDMA frames. The internal clock has to be sufficiently accure for the GSM network to work,
+an accuracy of at least $\pm$5 ppm (parts per million) \citep{dennis}. If the GSM network is synchronized,
+this internal clock is not employed but an external clock generator signal from an atomic clock,
+this is required for some of the position localization techniques, as described in section \ref{LMUSync}.
Modulator/demodulator main function is the modulation and demodulation of the received and transmitted signals.
The transmission from the cell phone to the BTS is shifted for 3 time slots compared to the reception
of the signal from the BTS\footnote{Timing advance factor is added to the three time slots.}
-\citep[Chapter 7]{0890064717} \citep{konrad} \citep{}.
-\begin{figure}[ht!]
- \centering
- \includegraphics[scale=0.50]{img/GSMBig.pdf}
- \caption{Basic GSM network block diagram.}
-\label{img:GSMBig}
-\end{figure}
+\citep[Chapter 7]{0890064717} \citep{konrad} \citep[Chapter 4]{0470742984}.
One or more BTSs are connected to the Base Station Controller (BSC). The main task of the BSC is to control the radio
resources of the connected BTSs such as assigning radio channels to different BTS, frequency hopping in case of an handover
@@ -1503,9 +1518,12 @@ is responsibe for compressing and decompressing speech between the cell phone an
from 64 kbps to 16 or 8 kbps depending if it is a full or half rate channel.
The next subsystem block is the Network Switching Subsystem (NSS), as it can be seen on figure \ref{img:GSMBig}, on right
-side inside of the gray dashed line rectangle.
+side inside of the gray dashed line rectangle. The main task of NSS is to connect the GSM with other telephony networks
+(GSM networks from other providers or the Public Switched Telephone Network) \citep[Chapter 4]{0470742984}. It consists of
+Mobile Switching Center
-\section{SDCCH Channel}
+\newpage
+\section{Logical channels and the SDCCH channel}
diff --git a/vorlagen/thesis/src/maindoc.lof b/vorlagen/thesis/src/maindoc.lof
index bcdb2fe..9641f5e 100644
--- a/vorlagen/thesis/src/maindoc.lof
+++ b/vorlagen/thesis/src/maindoc.lof
@@ -27,18 +27,18 @@
\contentsline {figure}{\numberline {3.1}{\ignorespaces Frequency ranges of uplink and downlink channels in the GSM900 band. Each box represents a frequency band (channel).\relax }}{39}{figure.caption.29}
\contentsline {figure}{\numberline {3.2}{\ignorespaces Each frequency channel is split into 8 time slots. More GSM users can be served at the ``same'' time.\relax }}{40}{figure.caption.30}
\contentsline {figure}{\numberline {3.3}{\ignorespaces Hierarchy of the GSM frames.\relax }}{40}{figure.caption.31}
-\contentsline {figure}{\numberline {3.4}{\ignorespaces Basic GSM network block diagram.\relax }}{41}{figure.caption.32}
+\contentsline {figure}{\numberline {3.4}{\ignorespaces Basic GSM network block diagram.\relax }}{42}{figure.caption.32}
\addvspace {10\p@ }
-\contentsline {figure}{\numberline {4.1}{\ignorespaces RRLP Request protocol. Assistance data can be sent before the request is made. If the assistance data are sent, their reception acknowledgement is sent as a response from the MS.\relax }}{44}{figure.caption.33}
-\contentsline {figure}{\numberline {4.2}{\ignorespaces An example RRLP request. Constructing a binary RRLP request in PER from ASN.1. Yellow zero bits are extension markers or spare bits. \relax }}{50}{figure.caption.34}
-\contentsline {figure}{\numberline {4.3}{\ignorespaces Reference location is a 14 octet stream built according to the given rule as specified in the standard \citep {3gppequations} under section \textit {7.3.6}.\relax }}{54}{figure.caption.35}
-\contentsline {figure}{\numberline {4.4}{\ignorespaces World Geodetic System 1984\relax }}{54}{figure.caption.36}
-\contentsline {figure}{\numberline {4.5}{\ignorespaces Requested AGPS assistance data to be delivered\relax }}{60}{figure.caption.41}
+\contentsline {figure}{\numberline {4.1}{\ignorespaces RRLP Request protocol. Assistance data can be sent before the request is made. If the assistance data are sent, their reception acknowledgement is sent as a response from the MS.\relax }}{46}{figure.caption.33}
+\contentsline {figure}{\numberline {4.2}{\ignorespaces An example RRLP request. Constructing a binary RRLP request in PER from ASN.1. Yellow zero bits are extension markers or spare bits. \relax }}{52}{figure.caption.34}
+\contentsline {figure}{\numberline {4.3}{\ignorespaces Reference location is a 14 octet stream built according to the given rule as specified in the standard \citep {3gppequations} under section \textit {7.3.6}.\relax }}{56}{figure.caption.35}
+\contentsline {figure}{\numberline {4.4}{\ignorespaces World Geodetic System 1984\relax }}{56}{figure.caption.36}
+\contentsline {figure}{\numberline {4.5}{\ignorespaces Requested AGPS assistance data to be delivered\relax }}{62}{figure.caption.41}
\addvspace {10\p@ }
\addvspace {10\p@ }
-\contentsline {figure}{\numberline {6.1}{\ignorespaces nanoBTS with its plastic cover. Image courtesy of ip.access ltd\relax }}{66}{figure.caption.45}
-\contentsline {figure}{\numberline {6.2}{\ignorespaces nanoBTS with two external antennas and five connection ports\relax }}{67}{figure.caption.47}
-\contentsline {figure}{\numberline {6.3}{\ignorespaces Navilock NL-402U, opened up with the antenna and USB cable\relax }}{68}{figure.caption.49}
-\contentsline {figure}{\numberline {6.4}{\ignorespaces Cable connections, showing interconnection diagram\relax }}{69}{figure.caption.50}
+\contentsline {figure}{\numberline {6.1}{\ignorespaces nanoBTS with its plastic cover. Image courtesy of ip.access ltd\relax }}{68}{figure.caption.45}
+\contentsline {figure}{\numberline {6.2}{\ignorespaces nanoBTS with two external antennas and five connection ports\relax }}{69}{figure.caption.47}
+\contentsline {figure}{\numberline {6.3}{\ignorespaces Navilock NL-402U, opened up with the antenna and USB cable\relax }}{70}{figure.caption.49}
+\contentsline {figure}{\numberline {6.4}{\ignorespaces Cable connections, showing interconnection diagram\relax }}{71}{figure.caption.50}
\addvspace {10\p@ }
\addvspace {10\p@ }
diff --git a/vorlagen/thesis/src/maindoc.lot b/vorlagen/thesis/src/maindoc.lot
index 7ff6d6f..88b7c5c 100644
--- a/vorlagen/thesis/src/maindoc.lot
+++ b/vorlagen/thesis/src/maindoc.lot
@@ -5,15 +5,15 @@
\addvspace {10\p@ }
\contentsline {table}{\numberline {3.1}{\ignorespaces GSM operating frequencies in Germany\relax }}{38}{table.caption.28}
\addvspace {10\p@ }
-\contentsline {table}{\numberline {4.1}{\ignorespaces GPS UTC Model content\relax }}{55}{table.caption.37}
-\contentsline {table}{\numberline {4.2}{\ignorespaces Navigation message (ephemeris) content\relax }}{56}{table.caption.38}
-\contentsline {table}{\numberline {4.3}{\ignorespaces Almanac message content\relax }}{57}{table.caption.39}
-\contentsline {table}{\numberline {4.4}{\ignorespaces GPS Ionosphere Model content\relax }}{57}{table.caption.40}
-\contentsline {table}{\numberline {4.5}{\ignorespaces Requested AGPS assistance data bit meaning\relax }}{61}{table.caption.42}
+\contentsline {table}{\numberline {4.1}{\ignorespaces GPS UTC Model content\relax }}{57}{table.caption.37}
+\contentsline {table}{\numberline {4.2}{\ignorespaces Navigation message (ephemeris) content\relax }}{58}{table.caption.38}
+\contentsline {table}{\numberline {4.3}{\ignorespaces Almanac message content\relax }}{59}{table.caption.39}
+\contentsline {table}{\numberline {4.4}{\ignorespaces GPS Ionosphere Model content\relax }}{59}{table.caption.40}
+\contentsline {table}{\numberline {4.5}{\ignorespaces Requested AGPS assistance data bit meaning\relax }}{63}{table.caption.42}
\addvspace {10\p@ }
\addvspace {10\p@ }
-\contentsline {table}{\numberline {6.1}{\ignorespaces Indicator LED status on the nanoBTS\relax }}{70}{table.caption.48}
+\contentsline {table}{\numberline {6.1}{\ignorespaces Indicator LED status on the nanoBTS\relax }}{72}{table.caption.48}
\addvspace {10\p@ }
\addvspace {10\p@ }
-\contentsline {table}{\numberline {A.3.1}{\ignorespaces Example uncertainties (latitude and longitude) for various integer values of $K$\relax }}{83}{table.caption.56}
-\contentsline {table}{\numberline {A.3.2}{\ignorespaces Example uncertainties (altitude) for various integer values of $K$\relax }}{84}{table.caption.57}
+\contentsline {table}{\numberline {A.3.1}{\ignorespaces Example uncertainties (latitude and longitude) for various integer values of $K$\relax }}{85}{table.caption.56}
+\contentsline {table}{\numberline {A.3.2}{\ignorespaces Example uncertainties (altitude) for various integer values of $K$\relax }}{86}{table.caption.57}