From the base station , {HEAD ~ the data} may be further relayed to {TAIL ~ a central control and recording system}  
relayed to
From the base station , { HEAD ~ the data } may be further relayed to { TAIL ~ a central control and recording system }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH