A selection device monitors {HEAD ~ all} of the incoming channels, registers and queues all new transmissions on the channels, and, when the star coupler is free, selects one incoming channel for {TAIL ~ broadcast} of its message through the star coupler 
A selection device monitors { HEAD ~ all } of the incoming channels , registers and queues all new transmissions on the channels , and , when the star coupler is free , selects one incoming channel for { TAIL ~ broadcast } of its message through the star coupler
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH