continuing {HEAD ~ the synchronous scanning} of {TAIL ~ frequency channels} according to a synchronous scan list when no response to the scanning is received 
of
continuing { HEAD ~ the synchronous scanning } of { TAIL ~ frequency channels } according to a synchronous scan list when no response to the scanning is received
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH