US Patent 9513364 Personnel authentication and tracking system

Disclosed are techniques to authenticate tags passing through detection regions against an access control list, receive data that identifies a number of people passing through or within the detection regions, compare the number people identified by the received data with the number of tags identified by the system, and cause an alarm to be asserted when a discrepancy is detected in the number people identified with the number of tags in a detection region with personnel within the detection region.