The Truth About RFID Read Rates

By Stephane Pique

Providers of passive UHF RFID solutions need to be clearer regarding the read rates, or read reliability, that end users can expect to achieve.

Providers of passive ultrahigh-frequency (UHF) radio frequency identification systems often boast read rates of 99.8 percent, or a similar statistic just below 100 percent. But this simple number can be highly misleading, leading to distrust among potential customers hoping to employ the technology to improve the way they do business.

Let's assume that we push 10,000 pallets containing tagged products through an RFID portal. Every time that a pallet is moved through the portal, multiple read events are created. Sometimes, depending on the particular product, the read rate—or performance—will not reach 100 percent, meaning that not all products have been identified.

Now, let's say that we reach an overall average reading performance of 99.8 percent for the 10,000 pallets—due to the material of the product being tagged, the portal's setup or simply the nature of radio waves. The problem is that RFID systems vendors are publicizing only the overall average read rates, thereby leading some potential end users to wrongly believe either that passive UHF RFID technology is not sufficiently reliable and cannot be used to automate many tasks, or that it is reliable enough to automate certain tasks.

So let's assume that a company wished to utilize passive UHF RFID technology to automate processes and reduce labor costs. The firm would need to achieve 100 percent reading performance in order to be able to deploy such a solution. The problem is that when 10,000 pallets are being read in this hypothetical example, a 100 percent read rate might have been achieved for 9,900 of those pallets, while only 80 percent was achieved for the other 100. The overall read rate would be 99.8 percent, but the end user would need to manually read tags on only 100 pallets in order to interrogate every tag.

That might be acceptable to the end-user company, but what if the read rate were 100 percent for 5,000 pallets, and only 99.6 percent for the remaining 5,000? The overall read rate would still be 99.8 percent, but the end user would need to manually read tags using a handheld interrogator on 50 percent of all pallets moving through the portal, in order to achieve a 100 percent read rate. Clearly, this would be unacceptable.

In both examples described above, the average reading performance is 99.8 percent. What is more important, however, is the fact that in one scenario, 100 percent of the tags are being read 99 percent of the time, while in the other, a 100 percent read rate is being achieved in only half of the cases. The RFID industry is making a big mistake in communicating an average read accuracy of 99.8 percent to the market and/or customers.

An end-user company might determine that it cannot use RFID since the average read rate is only 99.8 percent, and the firm needs to achieve a 100 percent read rate in order to automate a process. But if the end user knew that the system was 100 percent accurate 99 percent of the time, and only required manual intervention 1 percent of the time, then it might decide that automating the solution would save a lot of money on labor, and that the 1 percent manual intervention was thus insignificant.

Passive UHF technology is not perfect. Radio waves are affected by the presence of water or metal, interference from other RF devices and so forth. But by better communicating the performance of RFID systems, the industry can help end users to better understand how and where the technology can benefit their business. Improved communication regarding read performance can also create greater confidence in the technology, and lead to broader adoption.

Stephane Pique is an independent RFID business consultant. Since 1993, he has worked for several leading RFID companies, such as Philips Semiconductors, Kudelski Group's NagraID division, Sokymat's Global ID Technologies division , Seeburger and GS1 EPCglobal. He is also the International RFID Business Association's cofounder, COO and VP for Europe, the Middle East and Africa (EMEA).