A global time signal from {TAIL ~ a global time reference} or {HEAD ~ common time source} can be used to calculate a common view based clock offset between the two clocks 
A global time signal from { TAIL ~ a global time reference } or { HEAD ~ common time source } can be used to calculate a common view based clock offset between the two clocks
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH