Sigfox just released publicly its Radio Signal Analyzer tool. This is a tool for the device & module maker to prepare the P1 certification : basically it checks the radio signal shape, power… and tell you if you are following the requirements.

The tool have to be used with the SIGFOX SDR dongle provided with the SNEK tool.

The software solution can be downloaded here : https://support.sigfox.com/downloads/sigfoxradiosignalanalyzer.iso

Installation

Personally I’m using the RSA tool in a Virtual Box VM. The RSA is an ubuntu Linux bootable CD so it is really easy to set it up. Create a new VM, 2GB of memory is good to me. Load the ISO file in the virtual cd drive and boot it up.

On the ubuntu desktop you will find all the needed documentations to get started. In a short word :

• First : you plug the SDR dongle and attached it to the VM.
• Second : you wait for SIGFOX NED device appearing and you attached it again (this is a marvelous shit …)
• Third : you click on Tester >> Open then on Start

At this point you should see a moving FFT. You can fire some sigfox messages and check the result on the application.

Some of the results

The tool contains a lot of information around the radio signal like some of the following

Sigfox Signal Shape Verification

In this view, as an example you can see the Sigfox signal shape compared to the emitter signal.

You can also see the frequency drift during message transmission :

Sigfox frequency drift measurement

You can also have an idea of the message itself with the phase view (as a reminder bit 0/1 are encoded with the signal phase – bit value is switching when phase is changing)

Sigfox phase decoding

At end, the tool gives you a global analysis of your transceiver once you executed all the test expected for the certification.

Sigfox certification checklist

The maker point of view

The tool is really great for what it has been made for. In a hacker (or device maker) point of view this tool can be a great help for some radio debugging (as an example I have an FCC device not working correctly in terms of provided power – this tool can help me to investigate this and report it to the module provider).

It is also a good tool to learn about the technology because it capture the transmission and see them in details.

What is missing :

• A raw frame decoding for learning purpose with a protocol analysis (see the frame headers…) working out of the box (not only for the authenticated frames … this is just a software limitation)
• The snek software suite could be part of the iso

Stability is not really good, the software hangs and in this case you have to unplug the SDR key (virtual machine disconnection is good enough, no need for a physical one)

What is really good :

• The software suite is ready for use in less than 5 minutes
• You can deeply investigate your sigfox radio signal
• You have a lot of things to learn with that tool

😉

Tips

• The password for the default user is RSA, this is useful for lock screen. Be careful : the keyboard is qwerty so you have to type the good ‘A’ key 😉