The first receiving unit streams {HEAD ~ the content} to {TAIL ~ the second receiving unit} through the network 
The first receiving unit streams { HEAD ~ the content } to { TAIL ~ the second receiving unit } through the network
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH