GSM-Basestation
Setting Up a GSM Base Station
Quickly create a GSM network that can support calls and SMS. Previously covered on this RTL-SDR Post.
Requirements
Software
- DragonOS
- UHD
- OpenBTS
Hardware
- Computer or Raspberry Pi running DragonOS
- Software Defined Radio (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
- Plug in the SDR.
- Connect SDR to the computer.
- Perform Radio Checks.
lsusb ifconfig
- Configure the network connection for IPv4.
- Create a new interface netmask graphically or via CLI:
Interface# IPV4 192.168.1.20/24
- Confirm the setup using:
uhd_find_devices
Ensure the device is listed.
- Update the configuration:
cd /usr/src/osmo-nitb-scripts sudo nano config.json sudo main_uhd.py -u --sip
- `-u` enables interactive mode.
- `--sip` enables Asterisk support.
- Run the following in another terminal:
/usr/bin/osmo-trx-uhd -C /etc/osmocom/osmo-trx-uhd.cfg
Set Up Base Station OpenBTS
- Plug in the SDR.
- Confirm the interface name:
lsusb ifconfig
- Configure the network connection for IPv4.
- Create a new interface netmask:
Interface# IPV4 192.168.1.20/24
- Navigate to the OpenBTS directory:
cd /usr/src/OpenBTS/
- Register the SIM:
sudo /usr/src/OpenBTS/OpenBTS
Connection should be quick.
Details
Compatible Phones
For this to work, the mobile device needs to have a Calypso baseband chip.
- Motorola:**
- C115 $40 or 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 table.
- Requirements:**
- Full-duplex SDR
- Covers frequency ranges: **850 MHz and 1900 MHz**
- Compatible with the software