dectmon how to ?

Hi again, Since I got the pcap to work with dect I'm trying to capture traffic between a handset and its base. I've been able to find my FP with dect-llme-scan (as specified here http://dect.osmocom.org/trac/dect/wiki/Configuration), but now I'd like to lock to this FP and capture the traffic with wireshark. I've used the dectmon utility but it's locking to other FP. Is there a way to lock to a specific FP ? Is there a how to somewhere for capturing traffic ? Thanks again, Romain