LoRaJam GNU Radio implementation

Overview

This a GNU Radio implementation of a LoRaWAN Reactive Jammer. It was designed in the scope of an experiment aiming at finding the number of jamming symbols required to spoil the network throughput to a certain level, considering different network parameters. It provides an interface for setting in advance the number of symbols transmitted by the jammer, for each possible coding rate (CR) value detected in the frame header.

It is composed of three blocks []:

• frameDetect: in charge of detecting a LoRa frame start (looking for a preamble) given the physical layer parameters such as the channel, the bandwidth, the spreading factor. Upon a frame detection, it decodes the header and forwards the CR with the SF to the trigger block.
• trigger: configured with the number of symbol for each value of CR, it randomly generate the corresponding number of symbols and according to the SF when it receives a detection message from a frameDetect block. The generated number(s) is/are transmitted to the jammer block for modulation.
• jammer: modulates any number received according to the physical layer parameters it is configured with (bandwith, sample rate, sf) and transmits it to the next block that could be a hardware sink (a SDR for example).

Installation

Assuming you already have GNU Radio installed on your system,

• Clone this repo:

    git clone [text](https://github.com/ssuDoS/gr-loraJam.git)

• Go to the newly cloned repo:

    cd gr-loraJam

• Create a build directory, and move into it:

    mkdir build
    cd build

• Generate build files (if using conda):

    cmake .. -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX

Make sure the right conda environment is currently active.
If using installing default system location instead, simply use:

    cmake ..

• Compile the jammer (if using conda):

    make install -j$(nproc)

If installing to the default system location instead (probably /usr/local), sudo right is required:

    sudo make install -j$(nproc)

• If the default system location option is used (with sudo), then let the dynamic linker know about the new binaries with:

    sudo ldconfig

That's it ! You are now all set. You can view the new blocks by opening GNU Radio Companion if installed:

    gnuradio-companion &

Enjoy your time with the reactive jammer.

Credit

The implementation of the frame detection is inspired from and based on the GNU Radio implementation of a LoRa transceiver at https://github.com/tapparelj/gr-lora_sdr