I've uploaded a first release of dectmon, a DECT protocol decoder.
It can decode MAC, DLC and NWK-layer messages and show their
content in a human readable form.
See
http://dect.osmocom.org/trac/dect/wiki/Siemens#Traces for examples.
Details, including links to the git repository, can be found at
http://dect.osmocom.org/trac/dect/blog/kaber-2010/10/27/dectmon_released