GSM-Basestation

Previously covered on this RTL-SDR Post. Quickly create a GSM network that can support calls and sms.

Requirements

Software

DragonOS UHD OpenBTS ### Hardware Computer or RaspberryPi running DragonOS Software Defined Radio (one required) Compatible Phone compatible SDR

Cemaxecuter Guide <iframe width="560" height="315" src="https://www.youtube.com/embed/6EnASi9MvSI?si=Oh7POmnmVHGAewSs" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

Watch on Youtube

Set Up Base Station Calling

0. Plug in SDR
   1. Connect SDR to Computer
   2. Perform Radio Checks

<syntaxhighlight lang="bash">lsusb ifconfig</syntaxhighlight>

1. Configure Network Connection IPV4
   1. Create a new interface netmask for the interface graphically or via CLI example:

   <syntaxhighlight lang="text">Interface# IPV4

   192.168.1.20/24</syntaxhighlight>
2. confirm using uhd_find_devices. It should have an additional search for the installed device

<syntaxhighlight lang="bash">uhd_find_devices</syntaxhighlight>

3. Update Config. Set Call to True

<syntaxhighlight lang="bash">cd /usr/src/osmo-nitb-scripts sudo nano config.json # sudo main_uhd.py -u --sip

--sip for astric support</syntaxhighlight>

4. In another terminal

<syntaxhighlight lang="bash">/usr/bin/osmo-trx-uhd -C /etc/osmocom/osmo-trx-uhd.cfg</syntaxhighlight>

Set Up Base Station OpenBTS

0. Plug in SDR
   1. Plugin
   2. Confirm the Interface name

   <syntaxhighlight lang="bash">lsusb

   ifconfig</syntaxhighlight>
1. Configure Network Connection IPV4
   1. Create a new interface netmask for the interface graphically or via CLI example:

   <syntaxhighlight lang="text">Interface# IPV4

   192.168.1.20/24</syntaxhighlight>
2. Move the Directory to OpenBTS

<syntaxhighlight lang="bash">cd /usr/src/OpenBTS/</syntaxhighlight>

3. Register SIM

<syntaxhighlight lang="bash">sudo /usr/src/OpenBTS/OpenBTS

Connection should be very quick</syntaxhighlight>

Details

Compatible Phones

For this to work, the mobile device needs to have a Calypso baseband chip Motorola: - C115 $40or C117 (E87) - C123/C121/C118 (E88)
- C140 $27 or C139 $15 (E86)
- C155 (E99)
- V171 (E68/E69)
SonyEricsson - J100i $8.99 #### Compatible SDR See the software-defined-radio comparison cross table. For this to work, the SDR must be Full duplex, cover the correct frequency range (850 MHz and 1900 MHz), and work with the software:

YateBTS works with:

BladeRF $540+ ##### srsRan supports: BladeRF $540+ LimeSDR ##### Osmo-nitb works with: LimeSDR AntSDR E200 ##### OpenBTS works with: LimeSDR maybe BladeRF $540+