Patent ID: 7487538

Claim:
A security system for facilitating transponder carrier identification and tracking within a secure area, said secure area including regions requiring different access authority, said system comprising: an RF transponder having a memory in which is stored a unique identifier; the transponder including a transmitter to transmit the unique identifier; a transponder reader to receive from the transponder at least the unique identifier of the transponder; such that the transponder reader interrogates the transponder and, in response to the interrogation, receives from the transponder at least the unique identifier of the transponder and consequently, the location of the transponder is determined from the location of the transponder reader; and a security processor having an access database setting out access parameters for the regions and a carrier of the transponder, the security processor being operable to receive information from the transponder reader comprising at least the unique identifier of an interrogated transponder and the location of the transponder reader; the security processor capable of determining, from consultation of the access database, whether the carrier is authorized to be in the region corresponding to the interrogating transponder reader; wherein the security processor is configured to send a replacement unique identifier to the transponder from a transponder writer, the transponder replacing the identifier in the transponder memory with the replacement identifier, following a positive authorization.