The radio port then transmits, over a pre established unidirectional virtual circuit, {HEAD ~ the OA&M cell} to {TAIL ~ a radio port manager} 
to
The radio port then transmits , over a pre established unidirectional virtual circuit , { HEAD ~ the OA&M cell } to { TAIL ~ a radio port manager }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL