free5GRAN is an open-source 5G RAN stack. The current version includes a receiver which decodes MIB & SIB1 data. It also acts as a cell scanner. free5GRAN works in SA mode.

free5GRAN includes a library which can be reused for further developments. Documentation is available https://free5g.github.io/free5GRAN-documentation/.

free5GRAN is under active developments. A full 5G SA PHY layer should be released in Q1 2022.

Before compiling, make sure that the following libraries are installed:

• cmake
• libfftw3
• libconfig++
• boost
• cpufrequtils

On ubuntu, those libraries can be installed via:

sudo apt-get install cmake libfftw3-dev libconfig++-dev libboost-program-options-dev libboost-log-dev cpufrequtils

We currently support USRP B210, N210 and X310 natively. libuhd-dev is required. It can be installed on Ubuntu via:

sudo apt-get install libuhd-dev

USRP N210 is partially supported (it can be unstable) and free5GRAN requires Liquid SDR library for sampling rate resampling : https://liquidsdr.org/doc/installation/. To build free5GRAN with USRP N210 support, just run the cmake command with option -DINCLUDE_N210=ON.

free5GRAN executable can be compiled from sources with the following commands:

git clone https://github.com/free5G/free5GRAN.git
cd free5GRAN
mkdir build
cd build
cmake ..
make
sudo make install

Two functions are supported by free5GRAN.

Searching a cell with pre-defined parameters. Example config file is provided (free5GRAN/config/search_cell.cfg).

Scanning one or more 5G NR bands. Example config file is provided (free5GRAN/config/scan_band.cfg).

If you want to use a pre-defined RF device, USRP device has to be configured:

• Run uhd_find_devices
• Find the device you want to use
• Copy the serial field of the device and paste it in the config file.

To run free5GRAN with USRP X310, set mtu size to 8000: ifconfig ETHERNET_INTERFACE mtu 8000.

To run free5GRAN with USRP N210, set mtu size to 1500: ifconfig ETHERNET_INTERFACE mtu 1500.

free5GRAN should be available globally after installation. Configuration files are located in /root/.config/free5GRAN/config. There is two possible options for running free5GRAN:

• Run sudo free5GRAN to run free5GRAN with default config file /root/.config/free5GRAN/config/free5GRAN.cfg.
• Run sudo free5GRAN RELATIVE_CONFIG_FILE_PATH to run free5GRAN with a specific configuration file.

free5GRAN writes logs in /var/log/free5GRAN/free5GRAN.log. It can be used for debugging. Foremost, free5RGAN writes some data files in /root/.files/free5GRAN/execution_raw_files/ directory (if it exists). For plotting those files, run python analyse.py in /root/.files/free5GRAN/. This python script generates files that are stored in /root/.files/visualization_files/ directory.

free5GRAN has been successfully tested on Ubuntu 18.04 with USRP B210. It is currently under active development, which means that it might not be fully stable.

All the issues have to be reported in the issues page of this repository. Some known issues about the current version are already detailed in issues section.

As 5G NSA uses 4G cell for attachment, SIB are transmitted on a 4G cell and this receiver won't be able to decode SIB1 data from 5G NSA mode. However, this receiver should be able to detect 5G NSA cell and decode MIB data.

A number of bands are already supported by free5GRAN. New bands can be added in free5GRAN/lib/variables/common_structures