LPWAN standards such as LoRa or Sigfox allow you to transmit data over long distance, at ultra low power (up to 10 years on a AA battery), and for free if your use your own network (P2P or gateway), or a few dollars per years if you go through a network provider. The low cost is possible since those standards rely on 900 MHz ISM bands, meaning nobody has to pay millions of dollars to the government to obtain a license fee. Matt Knight looked at LoRa, and while Level 2 and 3 of the protocol (LoRaWan) has public documentation, Level 1 (LoRa PHY) is proprietary and the standard is proprietary.



So he decided to reverse-engineer LoRa PHY using Microchip RN2903 based LoRa Technology Mote and Ettus B210 USB software defined radio, and software packages and tools such as Python and GNU Radio to successfully deliver GR-LoRa open source “GNU Radio OOT module implementing the LoRa PHY”. He presented his work at GNU Radio Conference 2016 on September 15, and the video is worth a watch. He first explains why LPWAN IoT standards are awesome, the motivation about reverse-engineering work (mostly security), the hurdle (e.g. lies in documentation), the results, and work to be done.

You’ll find the presentation and the research paper on Github.

Thanks to Emanuele for the tip.