Sigfox is not publishing its detailed specifications. For this reason different people (like me) are doing reverse engineering. Thank to this activity we are now getting more and more information on how the IoT network communication works. I’ve been the first one to publish the uplink frame in details more than a year ago.

Today, during the 35th edition of CCC Congress, Florian Euchner has published, on Github, the first Open-Source Sigfox stack : LibRenard.

This library allows to transform a Sigfox radio signal into a decoded frame (uplink demodulation). It allows to create a Sigfox radio signal from a decoded frame (downlink modulation).

The LibRenard implementation follows the Open Sigfox Protocol specification also host on Github from Florian. It details the uplink as the downlink communication frames. Making this open specification as the real first Sigfox global protocol specification published.

I really want to congratulate Florian for this excellent work. I hope the stack will be soon enriched with the native Sigfox encryption I’ve just finished to detail, with the associated OOB frames.