Minimal Software Installation

The minimal software stack is comprised of:

srsEPC. Lightweight LTE Evolved Packet Core.
srsENB. LTE eNodeB basestation implemented entirely in software.
Lime Suite. Software-defined radio (SDR) driver.
Ubuntu Linux. Operating system.

This is the quickest way to get up and running and provides only a data service, with a simple EPC where subscribers are provisioned via a CSV file.

The minimal configuration may also prove useful where there is an existing EPC and only the eNodeB is required.

Ubuntu Server 22.04

Ubuntu Server version 22.04 LTS should be downloaded and installed. Default installation options should suffice, although for convenience the SSH server should probably be selected for installation.

Desktop Ubuntu could be used instead, but includes all sorts of redundant software which is not required. Other Ubuntu versions or Linux distros could also likely be used, but have not been tested.

Once rebooted install any updates, then configure the PPAs for Lime Suite and the LibreCellular fork of srsRAN:

sudo apt update && sudo apt dist-upgrade
sudo add-apt-repository ppa:myriadrf/drivers
sudo add-apt-repository ppa:myriadrf/librecellular
sudo apt update

If the command to add a PPA hangs, this may be due to IPv6 issues and to resolve edit the file /etc/gai.conf and uncomment the line precedence ::ffff:0:0/96 100, following which save and retry the command.

Next configure the CPU governor to use performance mode:

sudo apt install cpufrequtils
echo 'GOVERNOR="performance"' | sudo tee /etc/default/cpufrequtils
sudo systemctl disable ondemand
sudo reboot

This is to ensure that the SDR transceiver application does not suffer scheduling delays, which could result in reduced performance and/or instability.

Lime Suite and srsRAN

srsRAN version

A fork of the srsRAN 4G software is being maintainted which adds native support for LMS API, the API provided by Lime Suite and used by LimeSDR hardware. In testing this has been found to provide much better performance than use via SoapySDR. In addition to which, direct integration enables greater control of the SDR hardware, such as providing the ability to configure an external reference clock.

Warning

Issues in connection with this fork should be logged under the srsRAN 4G repo in the MyriadRF organisation and not the upstream srsRAN repo, since this is an experimental fork which is not supported by the srsRAN developers.

PPA packages

With the PPAs configured, install Lime Suite and the srsRAN fork:

sudo apt install limesuite srsran

Source build

Install Lime Suite build dependencies:

sudo apt install build-essential git g++ cmake libsqlite3-dev libi2c-dev libusb-1.0-0-dev libwxgtk3.0-gtk3-dev freeglut3-dev

Clone, build and install Lime Suite:

git clone https://github.com/myriadrf/LimeSuite.git
cd LimeSuite
git checkout v23.11.0
mkdir builddir
cd builddir
cmake ../
make -j 4
sudo make install
sudo ldconfig

Install srsRAN build dependencies:

sudo apt install build-essential cmake libfftw3-dev libmbedtls-dev libboost-program-options-dev libconfig++-dev libsctp-dev

Some of these will already be installed if Lime Suite was previously built from source, but are included here for completeness.

Note that if Lime Suite has not been installed from source, it will be neccessary to add liblimesuite-dev to the above dependencies installation.

git clone https://github.com/myriadrf/srsRAN_4G.git
cd srsRAN_4G
git checkout lc/main
mkdir build
cd build
cmake -DUSE_LTE_RATES=true ../
make -j 4
sudo make install

This will install the latest development build.

To install a LibreCellular release, instead of checking out lc/main, check out a release tag, e.g. release_23_11_LC01. The latest LibreCellular release will be the one with the highest upstream version and highest LC release suffix. Note that if a release if checked out which does not have an LCnn suffix, this will not have LMS API support and hence the eNodeB cannot be configured with the device_name parameter set to lime.