Tuesday, April 22, 2014

DECT 6.0 collection with HackRF

After seeing an interest in DECT on reddit  thought it would be easy enough to grab a recording of this and share.

I have a vTech DECT 6.0 cordless phone system.  I may ciricle back and update this post with more details on DECT and the phone itself, but for now wanted to quickly share the results

Some initial observations: 
  • Frequency usage isn't as high as I thought it would be (number of frequencies), I searched around abit and it seemed 80% of the traffic (as least was isolated to two frequencies)
  • The density of transmissions seemed highest at initial call setup, and on hang up. (But this may be due to the display on my phone receiving information from the base station.
  • Both the handset and base station are visible in the file.  I believe the stronger signal is the handset.
Below is a 8MHz collection via hackrf_transfer as follows:

hackrf_transfer -a 0 -r 1924MHz_DECT_hackrf_8MHz_8MS_8bit.iq -f 1924000000 -s 8000000

Collection was focused around this frequency since this seemed to be where my phone was primarily active. 

And DECT waveform zoomed (in time):

Finally, here is the sample  of the DECT 6.0 from my vTech cordless if you want to take a look yourself:

(To view in Baudline, decompression off, Initial byte 2, sample rate 8000000, channel 2 quadrature, 8 bit linear, unsigned)  NOTE: these collects from older HackRF firmware, latest firmware creates signed 


  1. Intriguing! Do you have time to write a tutorial for simpletons? Do you have time to add this to the SDR metapackage available from Kali Linux?

    1. Thanks! What is the content your thinking about for the tutorial?

      Looks like Kali Linux may be covered for SDR tools via the kali-linux-sdr metapackage. Also noticed the following post about a wide number of tools as of release 1.0.5 (to include HackRF): http://www.kali.org/news/kali-linux-software-defined-radio-support/ ....I didn't dig too deep into the Kali documentation to determine what is default install, and what comes with the kali-linux-sdr metapackage