A first wireless communications device for generating and transmitting {HEAD ~ data} to enable {TAIL ~ tracking} of the first wireless communications device by a second wireless communications device, the first wireless communications device comprising: 
to enable
A first wireless communications device for generating and transmitting { HEAD ~ data } to enable { TAIL ~ tracking } of the first wireless communications device by a second wireless communications device , the first wireless communications device comprising :
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH