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<?xml version="1.0" encoding="UTF-8"?>
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<chapter id="chapter_introduction">
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<title>Introduction</title>
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<section id="intro_overview">
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<title>History</title>
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<para>SIMtrace was created out of necessity. Harald Welte wanted
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to see the communication between a GSM Mobile Station (or
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what we call a cellphone) and the SIM. He was not able to
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find an existing solution, or the existing ones had mayor
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drawbacks that made using them very time consuming and slow.
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The Atmel AT91SAM7 came to the rescue. This microcontroller
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has hardware support for the ISO7816 T0/T1 Smart Card
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specification. We can connect the external clock to the UART
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and are able to read bytes coming and going to the SIM.
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The next step in the project was taken by Kevin Redon
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that started to modify an existing AT91SAM7 design, started
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to use the Free Software KiCAD CAD Software. In 2011 the project
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went from having Schematics to having routed circuits, prototypes
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and the final product. The first production run was in August.</para>
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</section>
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<section id="intro_picture">
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<title>Overview</title>
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<para>The setup of SIMtrace consists out of a Hardware and a
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Software part. The SIM card needs to be put into the SIMtrace
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Hardware, the flex cable needs to be connected to the SIMtrace
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Hardware and the SIM end needs to be placed in the SIM socket
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of the phone. The SIMtrace hardware can be seen as a USB device
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from the host, the SIMtrace software will try to find this device
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and claim it. The SIMtrace software will receive packets from the
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SIMtrace hardware and can forward them using the GSMTAP protocol
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to the IANA assigned GSMTAP port (4729). A modified version of Wireshark
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can be used to analyze the data.</para>
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<figure><title>Schematic Overview</title>
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/setup_overview.png" width="6cm"/>
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</imageobject>
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<textobject><phrase>SIMtrace being connected</phrase></textobject>
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</mediaobject>
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</figure>
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</section>
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</chapter>
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