A buffer information report can be sent to a system station from a node for relaying {HEAD ~ communications} between {TAIL ~ at least one user station} and the system station 
between
A buffer information report can be sent to a system station from a node for relaying { HEAD ~ communications } between { TAIL ~ at least one user station } and the system station
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH