Looking to stem failure rates &emdash; sometimes as high as 50% &emdash; due to mismatched or out of synch RFID tags and readers, a Reston, VA company has developed a benchmark report that can assist end users in determining the right kind of tag and reader for their particular environment.
“One of the things we realized was that there are a lot of marketing claims out there and users had no way to differentiate one from the other,” said Bret Kinsella, vice president of operations and marketing for ODIN Technologies. “Every tag manufacturer said they had the best product, but there was no way to test this. It was a lot of trial and error with nothing based on RF science.”
The EPC Tag Benchmark analyzes 14 EPC-compliant RFID tags. The company claims the benchmark “is the most comprehensive and scientific analysis available of EPC tags used to support the Wal-Mart, Target and DoD RFID programs.”
The expanded EPC Tag Benchmark was developed “at the request of some of our clients,” said Mr. Kinsella. It is designed to provide end users with an objective insight into how well tags actually work in real world use and what criteria should be considered when making tag selection decisions. The Benchmark also provides a scientific and objective comparison of how leading RFID tags work with various standard materials such as paper, plastic, water and metal.
The EPC Tag Benchmark research is available as a single user license for $425 or as an enterprise use license for $995.
“RFID infrastructure is new. It’s a wireless communications network that works well when tuned properly, but not otherwise. It can create all sorts of problems when people don’t understand the physics of RF,” said Mr. Kinsella.
Christopher Fennig, director of Professional Services and ODIN Labs, who has a background in experimental physics, oversaw the testing. “A year ago, there were only four tags you could get your hands on. Now, there are a lot of tag choices.”
He said the company, in developing the benchmark, looked at four main areas. “The first was the quality of the tag. We’ve seen as much as a 50% failure in the field. That appears to be the result of a poor conversion process, but no end user can afford to have 50% of his tags fail.”
Second, he said, “We really focused on orientation and sensitivity of the applied tags. Some tags require that they be parallel and others need to be turned 45 or 90 degrees to the antenna, so if it’s going down a conveyor belt, it may or may not have to be turned a specific way. That’s orientation sensitivity.”
The next areas examined have to do with performance, “as a function of distance and as a function of speed,” said Mr. Fennig. “We tested tag performance at multiple distances and we tested (reading) speed,” he added. “Those are the four main areas as well, but there was also performance as a function of material type.”
Material types need to be considered
Four types of material, metal, plastic, corrugate, and fluid were tested. “We saw dramatically different performances for each tag as applied to these materials. Tags are impacted significantly depending on the type of materials that tag was applied to,” said Mr. Fennig.
“One of the important things we looked at was that the testing had to be practical,” said Mr. Kinsella. “From an end user perspective, their product either has plastic, water, or other common materials and they need to understand, when looking at tags, whether it’s appropriate depending on the material type, if it’s RF-friendly material.”
“Some of these tags work wonderfully with water, or other materials that are more RF-friendly, but some tend to be over-engineered,” added Mr. Fennig.
ODIN helps identify the optimal tag. “It’s a service we’ve been providing for a couple of years,” said Mr. Kinsella.
“We’ve developed properties to make it very quick to conduct a test. We presented this methodology just last week to an EPC Global meeting,” he added.
What areas are in need of most improvement? “Quality is a big issue,” said Mr. Fennig. “You have a tag with a specific product type, the biggest issue is tag selection and placement on a case. Fluids, for example, will absorb RF energy, while metals will reflect it.”
Companies that shine
Are there any companies that stand out? “Large traditional firms compete very effectively with the very agile high tech startups out there,” said Mr. Fennig. Added Mr. Kinsella: “We saw some very strong performance from one of Avery Dennison’s tags. We also saw good performance from Alien Technology tags.”
Some of the benchmark guidelines, said Mr. Fennig, simply involved taking “a scientific approach to tag placement and testing. Rather than allow a reader to tell you which tag is better, you really need to get that from the physics of RFID. Repeatability is the key. You don’t want to rely on a single test or data point. We executed tests many times, then reported the average data point.”
Setting up a proper RFID system involves three critical elements, he said, “performance, tag/reader configurations, and site and environmental factors. You need to optimize all three areas. Improper tag selection, is one of the most common causes of failure in an RFID system. If a tag and reader can’t communicate, then the whole system doesn’t work.”
Added ODIN’s president and CEO, Patrick Sweeney: “Selecting an RFID tag is a tough task, but it can make or break your RFID program. If the tags don’t work with your products in the field, your RFID system simply will not work.”
The bottom line
According to ODIN, the EPC Tag Benchmark evaluated RFID tags from Alien, Avery, Impinj, Matrics (now owned by Symbol) and Rafsec. Each of the tags underwent the same testing accumulating over 6,000 individual data sets with different cases of common product materials. The report presents a side-by-side comparison of the tags based on the materials and performance criteria required by end users. ODIN purchased all of the tags tested in the benchmark and has no financial or other interest in any of the companies whose tags were tested.
The EPC Tag Benchmark includes:
- Communication Link Margin analysis — this analysis measures how well each tag extracts, consumes and reflects RF power and assesses the quality variance in a random lot of 100 tags – the analysis reveals manufacturing consistency data as well as implied tag performance in the field
- Distance performance analysis — provides a ranking based on tag performance at several distances with different common product materials
- Speed performance analysis — provides insight into how well tags performed when moving rapidly through a reader interrogation field similar to a conveyor application
- Orientation sensitivity analysis — ranks each tag based on orientation sensitivity with different common materials