For DOD, one in 1,048,000 is not unique enough

PM J-AIT Notice on Use of 22-bit Savi RFID Tags

A simple math problem related to serial numbers assigned to active radio frequency identification tags required the Defense Department to update 20 major logistics management information systems and more than 1,500 RFID workstations worldwide in the past year.

Since 1994, the Defense Department has used RFID tags and readers manufactured by Savi Technology to track and locate the flow of military supplies. Lee Weaver, assistant product manager for the Army’s Office of the Product Manager for Joint-Automatic Identification Technology (PM J-AIT), said a huge increase in the movement of tagged shipments in the past two years as a result of the wars in Afghanistan and Iraq means DOD will soon run out of serial numbers for the tags.

Savi used a 20-bit datastore for the serial numbers, Weaver said, which meant that a total of 1,048,575 serial numbers were available. Weaver said that to continue providing unique serial numbers for active RFID tags, Savi had to move to a 22-bit datastore, which will generate roughly 3 million more serial numbers.

The Savi tags have a 128 kilobits/sec datastore -- or roughly 80 pages of text -- to identify shipments. Readers at depots, ports and air hubs scan the tags, allowing DOD users to locate shipments and automatically inventory the contents of containers or pallets.

Reginald Bagby, PM J-AIT deputy product manager, said DOD officials never envisioned using more than 1 million tags so quickly when the RFID program kicked off a decade ago, and the move to 22-bit tags has had a ripple effect on major DOD logistics information management systems.

Weaver said that to correctly process information from the 22-bit Savi tags, officials had to develop a small piece of dynamic link library code that was installed on major logistics systems and 1,517 RFID client workstations worldwide in a joint effort with the Defense Logistics Agency and the U.S. Transportation Command.

Weaver said officials started working on a software patch to accommodate the 22-bit tags last April, with a beta patch tested in June and a final production patch available last October. He added that they expect to have all systems and workstations upgraded by next month.

Weaver said only 55 workstations have not been upgraded yet. Col. Tom Hogan, the Army’s deputy program executive officer for enterprise information systems, said those workstations are at sites with low usage.

A message on the PM J-AIT Web site instructed all RFID users to upgrade middleware used on handheld RFID readers manufactured by Intermec Technologies and Symbol Technologies.

Weaver said only one major logistics system, the Air Force’s Cargo Movement Operation System, still lacks the upgrade, and he expects that to be completed next month. Army Lt. Col. Scott Ross, a spokesman for the Transportation Command, concurred and said he expects that all logistics systems will be able to handle the 22-bit tags next month.

Although the tag upgrade was literally a two-bit problem, the PM J-AIT Web site states that not updating the RFID software in logistics systems and on readers could have serious consequences, including loss of in-transit visibility.