After large-scale testing, the U.S. Department of Defense (DoD) is considering the use of mesh-network location-tracking RFID tags to track high-value or mission-critical items. The relatively inexpensive tags are battery-powered and allow for the tracking of boxes and refrigerated containers through terminals, seaports, and/or airports even in remote locations via secure local mesh networks spanning up to half a mile in length.
According to the RFID Journal (http://www.rfidjournal.com/article/view/5087/1), each tag on transported goods serves as a network node, transmitting its own and other tags’ unique ID number and GPS coordinates. Using a proprietary 2.4 GHz mesh communication protocol, the tags form a network with each other and with mobile radio frequency (RF) gateways that transmit each tag’s ID number and GPS location over secure long-range communications channels such as satellite, cellular, Wi-Fi, or other available networks. Because the tags communicate with one another, the need for a great deal of infrastructure is reduced. This allows for fixed locations, such as shipping ports, to need only one or two gateways. Additionally, unlike most RFID technology, the system does not require fixed interrogators at every gateway because the mesh network provides visibility from almost any location.
To date, the largest test of the asset-tracking system occurred in March 2009 at Moffett Field (operated by NASA’s Ames Research Center in California) for the U.S. Army Logistics Innovation Agency (LIA). While the DoD has not yet decided whether to permanently deploy this system, there is conjecture that the testing could result in other its use by U.S. governmental branches, such as the Department of Homeland Security.