An FDMA method allows {HEAD ~ a number} of frequency channels to be used within {TAIL ~ the various frequency bands} 
An FDMA method allows { HEAD ~ a number } of frequency channels to be used within { TAIL ~ the various frequency bands }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL