The quantity and nature of {HEAD ~ actual message transmissions} involved in {TAIL ~ the primary communications test} varies in accordance with embodiments of the invention 
involved in
The quantity and nature of { HEAD ~ actual message transmissions } involved in { TAIL ~ the primary communications test } varies in accordance with embodiments of the invention
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH