Another algorithm is a time based algorithm which employs {TAIL ~ a real time clock} to establish {HEAD ~ preset time intervals} during which each of the access codes are used 
Another algorithm is a time based algorithm which employs { TAIL ~ a real time clock } to establish { HEAD ~ preset time intervals } during which each of the access codes are used
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH