EPC Bag Tagging Takes Wing

Since its inception in 1997, the RF Interest Group of the International Air Transport Association (IATA) has been looking at how RFID tags might best be introduced to the aviation industry as an accurate and speedy method of identifying and tracking and cargo. Over the years, 13.56 MHz and 2.45 GHz systems were tested in a number of IATA-sponsored trials, but each posed readability problems within certain regulatory environments.

In the United States, the power level needed to get an adequate read range using 13.56 MHz tags is out of the permissible range. Users in Europe had the same problem with 2.45 GHz, according to Andrew Price, RFID project manager at IATA (see Helping Bags Make Their Flights). In late November, the IATA, which works with , authorities and other air transportation organizations to make the industry safer, more profitable and efficient, endorsed the use of ultra-high frequency tags and readers compliant with the ISO 18000-6C candidate protocol as a global standard for RFID baggage tags. The ISO 18000-6C protocol incorporates EPCglobal‘s Gen 2 standard.

RFID tags might be just the solution the aviation industry needs to make identifying and tracking baggage and cargo a speedier, more accurate process.

Until it completed field trials of an RFID-enabled bag tracking system last summer, however, the U.S. Transportation Security Administration (TSA) had a couple questions it wanted answered. Will a UHF system work all over the world? And if it does, how will the various entities using the system share their data?

In the United States, the Federal Communications Commission (FCC) mandates that ultra-high frequency (UHF) tags and interrogators use the 902-928 MHz frequency range to transit signals. In the European Union,the European Telecommunications Standards Institute (ETSI) stipulates the 865.6-867.6 MHz band. In Asia, some nations are still solidifying these regulations, but in Japan it’s 950 MHz to 956 MHz, and in Singapore it’s 866 MHz to 869 MHz. Other nations have their own specific ranges, as well. So could a UHF tag attached to a piece of luggage work equally well in all of the various countries through which it might ?

In summer 2004, the TSA conducted two tag-readability trials to see if tags could move between two contrasting regulatory environments. UHF tags were encoded and attached to bags moving between Honolulu Airport and Japan’s Narita Airport in Tokyo. The tagged bags were also encoded in Rome and sent to Philadelphia. At the Honolulu and Rome , using the frequency range allowed in each airport’s respective country, the tags were encoded with a random 10-digit number designed to simulate the 10-digit passenger name record airlines currently use on bar code labels to track bags. The tests were successful, revealing that tags could be encoded in the middle (902 MHz to 928 MHz) of the band and read at the high end (950 MHz to 956 MHz), or encoded in the middle band and read in the low end (865.6 MHz to 867.6 MHz). No tags, however, were read at all three bands. “A lot of airlines asked, ‘This looks good, but shouldn’t we go from low to high on the same tag?'” says Anthony (Buzz) Cerino, who worked for the TSA as leader of the baggage test in 2004. Semi-retired since Sept. 30, 2004, Cerino currently consults for the TSA and other clients through his own firm, BPS LLC.

In mid-June 2005, in response to the airlines’ request, Cerino set out to determine if passive UHF tags could, in fact, perform equally well when used in all three frequency bands. United Airlines agreed to work with TSA on this tag readability trial to encode and read tags in all three regulatory zones, as did Tokyo’s Narita, Chicago’s O’Hare and Amsterdam’s Schipohl airports.

Soon before the test was scheduled to begin, TSA brought in EPCglobal, the arm of GS1 (formerly EAN/UCC) charged with the commercialization of EPC technology. Its goal: to assess whether the industry’s 10-digit passenger name record could be translated into an EPC format, and if these bag tag EPCs could be shared and communicated between parties following the model EPCglobal has established for the retail supply chain. Air China was selected as the airline partner for this EPC data test and would send bags from Beijing’s Capital to Tokyo’s Narita airports.

For both the tag multifrequency readability and data-sharing tests, TSA selected RFID tag and reader manufacturer Symbol Technologies to outfit the airlines with tags and readers. Symbol had previously provided the hardware infrastructure for TSA’s 2004 trial.

“We sent people to all four airports to do site surveys and come back with recommendations on how the readers and antennas would be put in place,” says Mike Saunders, Symbol’s director of aviation. In total, the company installed 22 UHF AR400 readers and approximately 55 antennas, as well as 100,000 EPC Gen 1, Class 0+ 96-bit inlays for both trials. The inlays were converted into the baggage tags by Mid South Graphics, based in Nashville, Tenn.

At each site, Symbol installed antennas at the entrance zones of conveyor systems. In most cases, antennas were placed on each side and above the conveyor. Wherever the conveyor design allowed, Symbol also placed an interrogator antenna beneath the conveyor, to help ensure tag reads from the bags’ undersides. It was also important that Symbol install the antennas and readers unobtrusively. “We had to work with airlines and airports to ensure the tests did not impact normal operations,” says Saunders. “That was part of our mandate from the TSA.” The 2005 Tag Readability Test

The multifrequency tag readability test was conducted from June 16 to July 28. During that time, United Airlines’ ticket counter workers in Tokyo used AR400 readers, operating in the 950-956 MHz band, to encode a daily average of 15 baggage tags with randomly generated numbers that simulated the 10-digit passenger name record. The workers attached the tags to dummy bags being flown to Chicago, where they were read and moved to another flight headed to Amsterdam, then read a final time. In Amsterdam, the same process was repeated as the bags were sent back to Tokyo.

At each airport, readers installed on conveyors were used to read the tags attached to bags on their way to the planes and as they were received from the planes. At Narita, 100 percent of the tags were successfully read on bags headed for departing flights, while 99.2 percent were read on bags unloaded from returning planes. In Amsterdam, 99.2 percent of tags were read on inbound bags, with 99.4 percent read outbound. The tag read rates for bags arriving at and departing O’Hare ranged between 100 percent and 99.2 percent, according to Cerino. It was assumed the failed reads were the result of a misread. However, it is possible some of the tags were not read because of a handling error—for example, they could have been placed on an incorrect conveyor or could have been manually processed for some reason.

“These are excellent read rates and much better than anyone has ever gotten with other methods of tracking. It clearly showed that the tags can be read at all three frequency [ranges]. That’s what TSA and the participants concluded. And it is what TSA put in the final report to IATA, suggesting that UHF be used for bag tracking,” says Cerino. He presented this report to the RF Interest Group at an August meeting in Geneva.

By way of comparison, Cerrino says the average read rates of the bar codes ost airlines use to identify bags range from 75 to 80 percent. (However, according tothe IATA Web site, bar codes currently provide an 85 percent read rate.)

“We often say that the real value of EPC RFID is not in the hardware, but in the added visibility it provides,” says Mike Meranda, president of EPCglobal US. “But in this case, the value was in the hardware because the bar code read rates, at best, are 80 percent, and with RFID they’re in the high 90s.”

The Data-Modeling Test

To initiate the data-modeling test, EPCglobal brought RFID systems integrator and software developer Avicon into the project. Based in Westborough, Mass., Avicon contacted one firm to work with Air China at each airport and provide middleware and systems integration services. At Narita airport, this was handled by Mightycard, while Hummingbird Defense Systems accommodated Capital airport. This data modeling testing only involved Air China and took place exclusively at the Capital and Narita airports—United Airlines, O’Hare and Schipohl did not participate.

Before work on the data test could begin, Vijay Sundhar, Avicon’s chief technology officer and cochair of EPCglobal’s tag data translation working group, and Bernie Hogan, EPCglobal’s CTO, developed an EPCglobal Serialized Bag Tag Number, which would be encoded to the tags. They took the 10- digit passenger name record—which includes a one-digit prefix to indicate a general classification of tag (denoting, for instance, a bulky item such as skis), a three-digit airline code and a six-digit serial number identifying bags uniquely—and translated it into the EPC numbering scheme. The one-digit prefix was placed in the EPC scheme’s 4-bit item reference section, while the three-digit airline code was used place in the 12-bit company prefix field and the six-digit serial number was assigned to the 40-bit serial number field. This left 16 bits of that field unutilized for the trial; in the future, those 16 bits will be used to denote the date of the tag’s issuance. The 32 remaining bits of the EPC scheme are being reserved for a use as yet undecided.

To commission and manage these codes, and to demonstrate that data could be passed between locations (in this case, Air China at Capital and Narita airports), Avicon wrote an application called BagTagNet, which uses rules to process events, or RFID reads. Mightycard and Hummingbird Defense Systems developed middleware consisting of edgeware to control the Symbol readers, an application-level events (ALE) layer (now an EPCglobal data standard, but then a yet-to-be-ratified specification) to filter extraneous data from the tag reads, and an EPC Information System (EPC-IS), which Air China would use to send the tag data to the BagTagNet application. Avicon then worked with Mightycard and Hummingbird to establish a common format they would use to send the tag reads to BagTagNet. This format included the EPC, a time stamp, the location of the interrogator that read the tag, the airline and flight number and the business step (i.e., loading or unloading).

Between June 20 and July 27, a total of 3,422 bag tags embedded with Symbol EPC Gen 1 Class 0+ inlays were attached to bags at Capital Airport. There, workers used AR400 readers operating between 950 MHz and 956 MHz to encode the inlays with EPCglobal Serialized Bag Tag Numbers. The bags where then flown by Air China from Capital Airport to Narita Airport. At Capital, 98.6 percent of those tags were read before leaving the airport. At Narita, 99.3 percent were read upon receipt.

“The genius of the EPC model is that it allows the same tags, the same readers, the same software to be deployed around the world to track IATA bags or shipments to Wal-Mart,” says Marc Linster, Avicon’s CEO. “What we learned from this trial is that some of the most value-laden processes translate from one industry to another,” says Meranda. An advance shipment notice (ASN) mechanism was not part of this baggage-handling trial, he explains. Still, ASNs (which are generally used by trading partners in an open supply chain) could also be used by airlines and airports. For this, an airline might send the destination airport a list of the EPCs encoded to all of the baggage in the cargo hold of an outbound plane. The airline or third-party baggage handling company that would receive and process those bags could then use the ASN to certify that all bags have been received.

“The TSA was extremely pleased with the results of the EPC trial from a couple of perspectives,” says Meranda. “It proved the applicability of the EPCglobal Network in a closed-loop system, and it added to its knowledge of the inter-airport processes that bags go through.” Next Steps

As with so many RFID applications, price is one of the main hurdles to deployment. However, now that IATA has endorsed the use of UHF tags and readers compliant with the ISO 18000-6C protocol as a global standard for RFID baggage tags, perhaps makers of UHF products and their potential end users in the aviation industry—airlines, third-party baggage handlers, airport authorities and other potential users, such as the TSA—can move forward with more confidence that demand will drive production and cost competition.

“It’s always been a cart-before-the-horse problem,” says Cerino, “with the airlines saying, ‘We don’t want to go with RFID because it’s too expensive, and we haven’t agreed on a frequency,’ and the vendors saying, ‘We can’t drive cost down until we know what frequency it is.'” The results of the EPC trial proved the applicability of the EPCglobal Network in a closed-loop system, while increasing the understanding of inter-airport baggage-handling processes.

Still, IATA’s endorsement of ISO 18000-6C UHF does not a mandate make. The decision of whether to deploy RFID systems is ultimately up to each end user. Cerino says some airlines want the added data fields the EPC provides, while others would prefer to stick to the data constructs they have now and the bar code equipment in which they’ve already invested heavily. Many of the very small carriers run such low-volume operations that they’re not even using bar codes to track bags.

According to Cerino, a number of airports have been on the fence in recent years about building RFID infrastructures. The IATA decision could influence these organizations to move forward with their RFID plans. Saunders noted that his firm left the RFID interrogators and antennas installed at the Amsterdam airport after the trial because airport authorities are considering deploying an RFID system. A number of other airports and airlines have also tested—and, in some cases, are already using—RFID for bag-tracking purposes. SeeMcCarran Airport RFID System Takes Off, Asiana Deploying RFID at Six Airports and Delta Plans U.S.-Wide RFID System.

The TSA and EPCglobal are now working with American Airlines and freight forwarder Eagle Logistics on a field trial using RFID to track and trace airplane cargo. The trial began November 28 and is expected to be completed by mid-December. In July, Emirates, a Dubai-based airline, announced its plan to incorporate RFID in a new cargo-handling system at Dubai (seeEmirates Will Use RFID to Track Air Cargo).