Tag Archives: srs

Viewing the SIB – The LTE System Information Block with SDRs

EUTRAN, LTE, Mobile Networks, , , , , ,

I’ve been experimenting with Inter-RAT & Inter-Frequency handovers recetly, and had an issue where what I thought was configured on the eNB I wasn’t seeing reflected on the UEs.

I understood the Neighbouring Cell reelection parameters are broadcast in the System Information Blocks, but how could I view them?

The answer – srsUE!

I can’t get over how cool the stuff coming out of Software Radio Systems is, but being able to simulate a UE and eNB on SDR hardware is pretty awesome, and also allows you to view low layer traces the vast majority of commercial UEs will never expose to a user.

After running srsUE with the PCAP option I let it scan for networks and find mine. I didn’t actually need to authenticate with the network, just lock to the cell.

Deocoding it using the steps I laid out here for decoding LTE MAC traces in Wireshark, there it all was!

I’ve attached a copy of the pcap here for your reference.

iPhone connecting to SRS LTE eNodeB SDR

srsLTE Install for BladeRF & LimeSDR on Debian / Ubuntu

EUTRAN, LTE, Mobile Networks, , , , , , ,

Note: I’m running version 19.12.0 which I installed from the repos due to issues with 20.4.0 (latest when I wrote this) and stability on LimeSDR.

I wrote the other day about installing SRS LTE stack,

But installing it is one thing, meeting all the requirements to use it with your SDR hardware turns out to be another whole thing all together.

srsENB is a software defined eNodeB, allowing you to use a Software Defined Radio to serve as an eNodeB, UE and a few other utilities.

SRS’ implementation of the eNB is supposed to be 3GPP R10 compliant and supports eMBMS to boot.

Meeting Dependencies

Installing prerequisites

I’m using a LimeSDR, but these instructions also for for the BladeRF. I found the frequency stability of my BladeRF X40 wasn’t great, meaning when running SRS’s eNodeB the cell wasn’t visible to my UE. 

sudo apt install tree vim git g++ make cmake pkg-config python-numpy swig libi2c-dev libusb-1.0-0-dev libfftw3-dev libmbedtls-dev libboost-program-options-dev libconfig++-dev libsctp-dev gnuradio

Install SoapySDR from Source

git clone https://github.com/pothosware/SoapySDR.git 
pushd SoapySDR
git checkout tags/soapy-sdr-0.7.2 -b soapy-sdr-0.7.2
mkdir build
cd build
cmake ..
make
sudo make install
sudo ldconfig
popd

Install LimeSuite

You can skip this if you’re using a BladeRF

git clone https://github.com/myriadrf/LimeSuite.git 
pushd LimeSuite
#git checkout tags/v19.04.0 -b v19.04.0
mkdir builddir
cd builddir
cmake ..
make
sudo make install
sudo ldconfig
cd ../udev-rules
sudo sh ./install.sh
popd

Install BladeRF

You can skip this if using a LimeSDR

git clone https://github.com/Nuand/bladeRF.git
pushd bladeRF/host/
mkdir build
cd build/
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr/local -DINSTALL_UDEV_RULES=ON -DBLADERF_GROUP=plugdev ..
make
sudo make install
sudo ldconfig
sudo mkdir -p /etc/Nuand/bladeRF/
sudo wget https://www.nuand.com/fpga/hostedx40-latest.rbf --output-document /etc/Nuand/bladeRF/hostedx40.rbf
popd


git clone https://github.com/pothosware/SoapyBladeRF.git
pushd SoapyBladeRF
mkdir build
cd build
cmake ..
make
sudo make install
popd

Install SRS GUI

(Optional but makes life easier and has to be done prior to installing SRSLTE) 

sudo apt-get install libboost-system-dev libboost-test-dev libboost-thread-dev libqwt-qt5-dev qtbase5-dev
git clone https://github.com/srsLTE/srsGUI.git
pushd srsGUI
mkdir build
cd build
cmake ..
make
sudo make install
popd

Install SRSLTE (SRSenb & SRSue)

pushd srsLTE
mkdir build 
cd build 
cmake ../ 
make 
make test 
sudo make install 
sudo ldconfig 
sudo ./srslte_install_configs.sh service 
popd