U.S. Customs' Bonded Warehouse Deploys Virtual Perimeter

At the same time, if an individual wearing a Dot Wireless badge breaches such a perimeter, his or her badge is awoken by the activator, which transmits a 132 kHz signal encoded with an ID number. The badge's tag then sends its own unique ID number, along with that of the activator, to the RFID readers, either at 315 MHz or 433 MHz, using a proprietary air-interface protocol. AxcessView software compares the quantity of personnel who have breached the perimeter, based on the detection hardware data, against the number of ID badges read. In the event of a mismatch—in other words, if the total number of people crossing the line is greater than the quantity of badges read—an alarm can be sounded, and a text message or e-mail can also be sent to management. In addition, if video surveillance is being used, the images taken at the location and time of the breach can be forwarded to interested parties.

Depending on building codes, Griebenow says, readers and activators could be installed on ceilings or walls. The read field could be adjusted to make it more sensitive, he adds (for example, to reduce stray reads of those near but not crossing the perimeter) by adjusting the strength of the activators' signals or the sensitivity of the readers. But typically, he notes, the read field would be four to six feet wide.

Since each activation point has its own unique ID number, the system can also detect the approximate spot at which an individual with a badge crossed the perimeter. Granularity would depend on the number of activators installed.

This latest functionality to Axcess Wireless' existing system, Griebenow explains, is part of a strategy of providing a total solution for access control that goes beyond permitting access at doorways. "We believe this is significant, because we can augment what our wireless credential offering provides," he states. "There is no product on the market that can do this kind of intrusion detection during hours of operation." Most perimeter security, he notes, is managed at night, outside of a company's regular business hours, when any movement detection would trigger an alert.

In addition, the system can be utilized to ensure assets are not taken outside of a facility's permitted sections. If, for instance, a tagged projector was carried toward a stairway or an exit, an alert could be sent, along with information regarding where that breach was occurring. If the individual with the asset was wearing a badge, the system could also link him or her with the event.