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Dec 06, 2018

Zwei Faktoren die verhindern, dass Anwender von RFID RAIN Systemen von den Verfgbarkeit der hheren ETSI-Frequenzen profitieren

Im Januar 2016 hatte ich einen Blog darüber geschrieben, wie RAIN RFID-Unternehmen ihre Interessen vor allem in Europa vertreten sollten. Die Regulierung der Frequenzzuteilung schreitet langsam voran und jetzt, zweieinhalb Jahre später, ist es mir eine große Freude festzustellen, dass die bisherigen Ergebnisse beeindruckend sind. Lassen Sie uns einen Blick darauf werfen, wie die Nutzung des höheren ETSI-Frequenzbandes möglicherweise die Art und Weise der Optimierung des Tagging (Markierung von Objekten mittels RFID RAIN UHF Transpondern) verändert. Sicherlich werden sich diese Änderungen nicht unmittelbar bemerkbar machen. Mein Beitrag hebt zwei Faktoren hervor die derzeit einen unmittelbaren Vorteil dieser neuen Verordnung für den Anwender behindern.

Wie Tags traditionell abgestimmt werden

Im Jahr 2005 wurde das RAIN-Tagging in Europa weitgehend für das Frequenzband 866-868 MHz weitgehend optimiert. Eine solche Kennzeichnung bot in den USA nur eine sehr begrenzte oder nicht vorhandene Lesbarkeit, dies führte schnell zur Entstehung globaler Tag-Designs.

Während die weltweite (globale) Lesbarkeit im Prinzip keine so große technische Herausforderung darstellt, hat dies die Entwickler von Transponder (Tag) Antennen gezwungen, Einbußen bei der Sensitivität der Transponder in Kauf zu nehmen. Bei der Entwicklung von RFID Transpondern für die Montage auf Metall verlangt die globale Lesbarkeit in den Abmessungen deutlich größere Transpondern im Vergleich zu den winzigen Designs für einen stark eingeschränkten Frequenzbereich (ETSI 868 MHz oder FCC 915 MHz). Dies führt nicht nur zu weiteren technischen Herausforderungen sondern stellt auch einen zusätzlichen Preisfaktor dar.

Die Europäische Kommission genehmigt 4W für RFID-Lesegeräte bei 916-919 MHz

Schließlich heißt es im lang erwarteten Durchführungsbeschluss [EU] 2018/1538 der Europäischen Kommission vom 11. Oktober 2018, dass die Mitgliedstaaten bis zum 1. Februar 2019 drei Kanäle innerhalb des Frequenzbandes 916,1 -918,9 MHz für RFID-Lesegeräte öffnen sollten. Damit wird die Norm ETSI EN 302 208 V3.1.0 ergänzt, die ebenfalls ein RFID-Band zwischen 915 und 921 MHz definiert, allerdings mit eingeschränktem Umsetzungsstatus innerhalb der EU und der CEPT-Länder.

Während all dies nach Jahren der technischen Argumentation und Lobbyarbeit nach einem ausgezeichnetem Ergebnis klingt, werden die Hersteller von Lesegeräten vor neue technische Herausforderungen gestellt. Jedoch wie wird sich diese Entscheidung langfristig auf die RFID-Transponder auswirken?

Der optimale Bereich für Tagging auf globaler Ebene

Wie beabsichtigt, wird mit dem oberen ETSI-Band ein global harmonisiertes Frequenzband eingeführt, in dem alle geografischen Regionen verfügbare Kanäle für RFID-Leser haben!

Auch in Europa bietet sich damit die Möglichkeit, das Transponder-Design speziell für den oberen Frequenzbereich zu optimieren. In Anwendungen, in denen die RFID RAIN Lesegeräte (Reader) viel Zeit haben eine Bestandsaufnahme (Inventory) aller Transponder im Lesefeld durchzuführen und durch alle ETSI-Frequenzen zu scannen, sollte eine solcherart eingeschränkte Reaktion von Transpondern, die nur bei den oberen ETSI-Frequenzen wirklich empfindlich sind, kein Problem darstellen. Dies setzt natürlich voraus, dass die ETSI-Lesegeräte in Zukunft sowohl das traditionelle Frequenzband 866-868 MHz als auch das neue obere 916-919 MHz Frequenzband nutzen werden.

Unbekannter Faktor Nr.1: Umsetzungszeitplan in Mitteleuropa

Derzeit nutzt die GSM-R(ailway) das 918-921 MHz Frequenzband in Deutschland, Österreich und Frankreich auf der Grundlage nationalen Rechts gemäß den Frequenz Verordnungen der Internationalen Fernmeldeunion (International Telecommunication Union, kurz: ITU). Leider überlappt sich dieses Frequenzband und das für Europa neue obere ETSI RFID-Band. Die militärische Nutzung desselben Frequenzbereiches in Deutschland ist ein weiteres Fragezeichen und möglicherweise auch ein Hindernis. Die Europäische Kommission hat dieses Problem erkannt und gibt den Mitgliedstaaten die Möglichkeit, die Nutzung von GSM-R und RFID auf der Grundlage von Geographie, spezifischer Installation, Betriebsanforderungen oder ähnlichem zu koordinieren.

Was bedeutet dies nun in der Praxis? Schwer zu sagen. In Deutschland, Österreich oder Frankreich sind noch keine RFID-Umsetzungsrichtlinien veröffentlicht, also ist es von Vorteil die GS1-Übersicht der Regularien für Updates im Auge zu behalten. Die gute Nachricht ist, dass sich das „Future Railway Mobile Communication System“ (FRMCS) nicht mehr mit RFID überschneiden sollte. Die schlechte Nachricht ist, dass noch nicht bekannt ist, wann die Bahnen ein solches System entwickeln oder einsetzen. Das FRMCS-Projekt ist erst seit 2012 im Gange…. Ich persönlich erwarte, dass der Umsetzungsplan in Mitteleuropa bis zur zweiten Jahreshälfte 2019 weiter an Klarheit gewinnt.

Unbekannter Faktor Nr.2: Auswirkung der Leserempfindlichkeit

Der Lesebereich ist oft mehr eine Abschätzung als eine Tatsache, aber die Sensitivität des Lesegeräts ist in der Tat bereits in vielen Anwendungen ein limitierender Faktor. Ein gutes Beispiel ist die Zeitmessung von Marathonläufen. Herr Nikias Klohr von der race result AG hat dieses Thema in seinen exzellenten Präsentationen bei der Konferenz RFID Tomorrow und dem RAIN Face-to-Face-Meeting in Wien 2018 wiederholt angesprochen.

Wir alle haben in den letzten 15 Jahren gesehen, wie sich die erhöhte IC-Empfindlichkeit der Tags zur Entwicklung von Transpondern mit geringeren Abmessungen und nicht zu extrem langen >20 Meter-Lesereichweiten geführt hat. Wenn sich meine Vorhersage zur Optimierung des Tag-Designs für das 902-928 MHz-Band als richtig erweisen sollte, dann werden sich die Abmessungen und Kosten der Transponder weiter verringern.

Bis zum Jahr 2021 könnte die Stärke des rückgestrahlten Signals (Backscatter) von Miniatur-RAIN-Transpondern auf unter -90 dBm bis hinunter zu -100 dBm fallen. Die aktuelle Leserinfrastruktur wird solche geringen Transponder-Signale nicht so einfach interpretieren können. Daher müssen möglicherweise immer noch Transponder in den Abmessungen größer als notwendig verbunden mit höheren Kosten verwendet werden. Aus diesem Grund wird langfristig eine neue Gattung von Lesegeräten und eine Infrastruktur mit verbesserten Lesefähigkeiten benötigt, um die Gesamtkosten der RAIN RFID-Technologie weiter zu senken.

Fazit: Die Arbeit geht weiter

Wie schätzen Sie die Bedeutung der höheren ETSI-Frequenz ein? Haben Sie Einblicke in die regionalen Regulierungsdebatten in Deutschland oder Frankreich? Ich würde mich über einen Austausch zum Thema sehr freuen! Kontaktieren Sie uns dazu gerne.

Nov 23, 2018

Two Factors that Currently Prevent RAIN RFID End Users from Benefiting of the Upper ETSI Band

中文版 Chinese version

In January 2016 I wrote a blog about how RAIN RFID companies should defend their interests especially in Europe. Frequency regulation moves forward slowly, and now 2,5 years later it gives me great pleasure to conclude that the results so far are rather impressive. Let’s have a look at how the upper ETSI band potentially changes the way tagging is optimized. Surely the change is not immediate, and my story further highlights two factors that currently prevent end users from benefiting from this new regulation.

How Tags Are Traditionally Tuned

In 2005 RAIN tagging in Europe was largely optimized for the 866-868 MHz frequency band. Such tagging provided only very limited or non-existent readability in US, which quickly lead to emergence of global tag designs.

While global readability has not been a major technical challenge, it has forced antenna designers to sacrifice some of tag’s sensitivity. On the on-metal tag side global readability leads to significantly larger sized tags compared with the tiny one-band designs, which is both an inconvenience and a price factor.

The European Commission Permits 4W for RFID Readers at 916-919 MHz

Finally, the long-awaited COMMISSION IMPLEMENTING DECISION [EU] 2018/1538 dated 11th October 2018 says that member states should open three channels within the 916,1 -918,9 MHz frequency band for RFID readers by 1st February 2019. This comes on top of the ETSI EN 302 208 V3.1.0 standard which also defines a RFID band between 915 and 921 MHz, although with limited implementation status within the EU and CEPT countries.

While all this sounds like a fantastic outcome after years of technical argumentation and lobbying, a new variety of technical challenges are introduced for reader manufacturers. However, what will be the long term impact of this decision on the RFID tagging side?

Global Sweet Spot for Tagging

As intended, the upper ETSI band introduces a global harmonized frequency band, where all geographic regions have available channels for RFID readers!

Also in Europe this introduces a possibility to optimize tag designs specifically for the upper frequency range. In applications where readers have plenty of time to conduct inventory and scan through all the ETSI frequencies, such limited response from tags sensitive only at the upper ETSI frequencies should not be a problem. Naturally this assumes that in the future the ETSI readers will utilize both the traditional 866-868 MHz and the new upper 916-919 MHz frequency band.

Unknown Factor #1: Implementation Schedule in Middle-Europe

Currently the GSM-R(ailway) is using the 918-921 MHz band in Germany, Austria and France based on National Law in accordance with the ITU Radio Regulations. Unfortunately this band overlaps with the upper ETSI RFID band. The military usage of the same band in Germany is another question mark, and even a roadblock. The Commission recognizes the situation, and gives member states the possibility to coordinate the use of GSM-R and RFID based on geography, specific installation, operating requirements or something else.

What does this mean in practice? I actually do not know. No RFID implementation guidelines are yet published in Germany, Austria or France, but it’s good to keep an eye on the: GS1 regulatory overview for updates. Good news is that the Future Railway Mobile Communication System (FRMCS) should not overlap with RFID anymore. Bad news is that it’s now known when the railways will have such system designed or deployed – the FRMCS project has only been active since 2012… I personally anticipate that implementation schedule in Middle-Europe gains further clarity by second half of 2019.

Unknown Factor #2: Impact of Reader Sensitivity

The read range is often more an opinion than a fact, but the sensitivity of the reader is indeed already a limiting factor in many applications. An example is marathon race timing, and Mr. Nikias Klohr of race result AG has repeatedly raised this issue in his excellent presentations at the RFID Tomorrow and RAIN face-to-face meeting in Vienna 2018.

We all have seen over the past 15 years how the increased tag IC sensitivity has translated into smaller footprint tags rather than to ultra long >20 meter read ranges. If my prediction of tag design optimization for the 902-928 MHz band is correct, then the tag footprint will further shrink with the benefit of lower tagging costs.

By year 2021 backscatter signal strengths from miniature RAIN tags may fall below -90 dBm, even down to -100 dBm. The current reader infrastructure simply won’t be able to interpret such small tag responses, therefore larger-than-necessary tags may still need to be used at a higher expense. Therefore a new breed of readers and infrastructure with enhanced reading capabilities will be needed to continue drive down the overall cost of RAIN RFID technology.

Work Continues

What is your view on the significance of the upper ETSI band? Do you have insights into the local regulatory debates in Germany or France? Please contact us and let’s talk!

Sep 26, 2017

What Do Babies and RFID Have in Common?

Something worried me before my first daughter’s arrival, something I had been already warned: “Babies are born without a handbook”. I am used to working with procedures, methodologies or at least to have some standards to follow; and now I was going to face the most demanding challenge in my life without any kind of guidance.

But, I gradually noticed that it was not going to be that way, and that the parallelism between the technology I have been working with for more than 15 years, RFID ― those intelligent chips enabling the Internet of Things which we can find in more and more stores and warehouses every day ―, was clear from minute zero. Many companies, end users and system integrators think, like I did in early stage, that there are no rules nor guidelines for a project to become successful, but that trial and error is the only way to gain experience to face it with. Is that how I should bring my daughter up, by trial and error?

Look for Help – It Is Available!

As with RFID, when Carlota was born, tranquility came by being surrounded by experts in the field, and not just sympathizers who have faced that same situation. Firstly, I was provided with a handbook. Seriously! Guidelines about what to do in certain situations, such as tips to interpret the baby’s cries. Better than improvising with the newborn, right? Likewise, the handbook suggested the baby to sleep on her back, while just a few years ago it was suggested to sleep on her stomach.

Having professionals, who advise us following the latest recommendations and standards, gives us the peace of mind to do things well in RFID, too.

For example, some years ago it was always recommended to do pilot tests before deploying an RFID project, but then we realized that the results were conditioned by the selected reader and selected tags. Yes, it seems obvious, but before even starting those pilot tests, readers and tags had already been chosen within the wide spectrum of combinations existing in the market. Doesn’t it make sense to first know what we need before choosing them? For this reason, nowadays professional RFID companies use standards (have you heard about the TIPP methodology by GS1?) and laboratory equipment capable of determining which RFID readers and tags in the market will give better results in a real test.

To Do Comparison You Need a Reference

Carlota was weighed, her length was measured, the diameter of her head was measured… these were going to be the indicators that would tell us if her growth was adequate or not. It is not useful to keep trying things; we must measure, measure Carlota and RFID, and do it with the right tools. But not only that! What a surprise when the kilograms and centimetres at the hospital were not the same kilograms and centimetres at the drugstore, not even the same as those at the pediatrician. How should I decide if everything is okay or not when one tool tells me “yes” and another “no”?

And I remembered so many customers I have who do not worry about calibrating their RFID measuring equipment, and a tag that could work with any reader when tested with a given equipment, but the same tag that would only work with the most powerful and sensitive readers when tested with other equipment.

Define Your Requirements Before Selecting the Solution

I have always insisted on my clients that they should not choose the best tag, but the most appropriate tag for their application; with my daughter this situation happens from diapers to milk, but not only with her milk, also with the adults’ milk! What kind of milk do you have in your fridge? The one with more calcium, vitamins, etc. on the market; the cheapest one; or the one you consider good enough for you and your family? The same thing happens with RFID tags, where it makes no sense to pay more for the best tag on the market, because there is no such ideal tag, but the one that is the best one for your application, the best milk for you.

Regarding prices, what should we think of the cheapest ones? Again, if their quality and features are the most convenient for us, they are definitely the best choice. Please pay attention to both concepts: good quality and minimum required features.

And what about the quality? I do not mean good finishes or performance … but that once a model is chosen, every diaper, every tag, always perform the same way; their features do not vary among them and they have a certain margin of operation. It seems obvious, but the cheapest tags on the market are usually cheap because although they all work (i.e. a standard RFID reader can detect them), not all of them perform the same way; some tags can be detected at much longer distance than others, even though being the same model. I checked it when I bought some cheaper diapers than the usual ones, which seemed to absorb as much as the best ones, but it was not always like that, whether it was a discreet pee or a champion one.

“Always” is an interesting and challenging concept, but at least we need to be prepared before the chosen diaper stops performing as expected and what would be acceptable. What if a customer makes the wrong choice and purchases 5 million reusable tags regardless of their operating margin? They could perform well today, and at the slightest change in the initial conditions of use, stop doing so.

Select Suppliers That You Can Trust

Finally, once the feeding bottles, diapers, milk were chosen, and their brands, prices and features were evaluated, we had to decide where to buy such an amount of supplies. I have to admit that we started buying some stuff online and taking advantage of promotions at the hypermarket, but it all depends on how seriously we want to get involved in bringing our daughter up. Right now, there are many things we decided to buy in pharmacies and specialized stores, not only for the qualified professionals who helped us from the beginning, but also for the access they have given us to brand events, training, samples of new products…

In the end, we are learning day by day. Carlota relies on us, and we rely on professionals and industry standards, because there is a reference for every industry. If in children’s upbringing references are driven by the WHO, which are followed by pediatricians; in RFID industry the guidelines are given by ISO, GS1 and RAIN RFID Alliance, and there are more and more system integrators and end users who, by following them, have stopped suffering with the deployment and adoption, respectively, of the technology. Why should we suffer as the result of improvising with our newborn instead of enjoying her growth without worries?

Welcome, Carlota.
RFID, it’s your time.

Aug 17, 2017

Using Tagging Performance Specifications to Secure 100% Readability of RFID Enabled Tires

中文版 Chinese version

Identification of tires has been one of the early use cases of RAIN RFID already back in 2005. It took almost ten years for the technology and value chain to mature to a state when this extremely challenging application became finally possible.

Million Reasons to Tag Tires

There are countless ways to utilize RFID enabled tires. Early deployments follow the use cases familiar in the generic retail business: improving the traceability in the supply chain and raising efficiency in warehouse inventory and management. Over time I bet we will also see use cases after distribution, such as tire fleet management, safety monitoring (pressure, wear, retreading), and eventually even in recycling.

Once tires are RFID enabled, it opens enormous possibilities for companies to streamline processes and even create new business models.

“Scrapping a Finished Tyre is Not an Option”

If an embedded RFID tag is defected, it cannot be replaced with a new one because of safety and practical reasons. At the same time, no manufacturer is willing to scrap a new baked tire because of a non-functional RFID tag. Is there a way to avoid such a situation?

A carefully implemented quality monitoring helps keep the tire manufacturing process lean and efficient. RFID is implemented in various ways within the tire industry. Thus, preparing the tagging specifications according to actual use cases of the complete value chain is a prerequisite. Read more of this framework:

What is the Framework of RFID Tagging in Tire Industry?

Learn how to prepare tagging specifications according to actual use cases of the complete value chain!

Embedding RFID UHF Tag into Rubber and RF Testing

Before embedding in rubber, the tire tags are tested in free-air conditions. UHF tire tags are typically over tuned to frequencies over 1 GHz. This makes RF testing a challenge because standard RFID readers operate at frequencies below 1 GHz.

Sensitivity of RAIN RFID UHF tag in different situations. The lower the graph, the higher the sensitivity and thus longer the read range.

From the manufacturing standpoint, additional requirements include:

  1. individual tag test should be wireless;
  2. test may be performed on trays with a large number of other tags in close proximity;
  3. the production flow cannot be slowed down.

The Voyantic solution is to utilize Tagsurance RFID tester together with the Snoop Pro near field coupling element. This enables accurate READ sensitivity tests for the complete dipole tag structure with excellent correlation to far-field performance.

RF testing used to be one of the bottlenecks in the tire tag production process. However, the sophisticated test features of the Tagsurance tester mean that the slowest processes are the mechanical ones.

Please read of our testing solution in more detail from our customer case study Michelin – Tire Tags with Consistent Quality!

Industry-Wide ISO Standards in the Horizon

The industry is currently waiting for the work group to finalize following standards, like

For an update on the ISO standards process, please stay tuned for an upcoming blog from Juho Partanen later this year.

If you’d like to hear how Voyantic can enable you to perform tire RFID testing in your facility, just drop us a line – it will be my pleasure to walk you through the process!

Nov 30, 2016

Vehicle RFID Tags – Big Benefits with Some Challenges

中文版 Chinese version

Electronic Vehicle Identification (EVI) is a perfect match for RAIN RFID (UHF RFID) technology. Once a vehicle is tagged, the possibility to identify the vehicle remotely enables a lot of applications and services. While vehicle tagging is of high interest, it is not the easiest task. In the past few months I have worked with some vehicle tagging projects and learned that the application requires some special attention from technology providers.

EVI Tag Types

The EVI tags come in different forms. Most common EVI tag types are

  • windshield tags attached to the windshield inside the car; and
  • license plate tags mounted on license plates outside the vehicle.

There are some specific design issues related to both of these tag types.

License plate tags must be on-metal tags, and very durable. They must survive weather conditions and car washing. Also, the position and the mounting angle are rarely ideal for readers. The natural best reading direction is straight backward (or forward), and at low height. In many applications the goal is to identify a vehicle approaching an identification point, for example an access gate or a road toll collection point. Reading would preferably be done from above or from side with an angle.

Windshield tags provide better reading angle. The challenge is to design a tag that works well with all possible windshields, regardless of the windshield’s angle, thickness, material, embedded technologies and type and proximity of the windshield frame to the tag position.

Both passive and semi-passive tags are commonly used. The semi-passive tags are battery powered; more of those can be read in earlier Voyantic Blog post.

EVI Tag Applications

Once the tagging is successful, it is easy to find use for the tags. Applications include road toll collection, tracking vehicle registrations and inspections, tracking tax payments, and parking control. Many of the applications are initially set for government purposes. Once the tags are in place, they can also be used in various value added applications of the private sector. Even if the tag is initially placed for registration, it can be used as a parking permit and gate access permit of a housing community.

Performance Testing of EVI Tags

A car is a special case of a tagged item. There are components that reflect RFID signals, absorb or block the signals, and may even resonate with RFID frequencies. These effects are different to different reading angles, they vary when a tag is attached to different position in a vehicle, and may even change when a tag’s mounting orientation changes. At Voyantic we have assisted several companies in defining test methods and processes for optimizing the EVI tag performance.

With the Voyantic Tagformance Pro system it is possible to test the sensitivity, tuning and backscatter signal strength of the car tag. The Tagformance system is an essential tool for evaluating effects of reading angles and mounting positions. The system can also be used for optimizing the EVI tag performance, finding optimal tag positions in the cars, and for finding optimal reader antenna positions for the applications.

Learn How to Test EVI Tags with Tagformance Pro

Download our application note to learn how to avoid the pitfalls of EVI tag testing!

Oct 31, 2016

RAIN RFID Tag Read Range: Opinion or Fact?

中文版 Chinese version

Creating a tagging solution for passive RAIN RFID tags to a particular application starts with understanding the application specific requirements. That involves plenty of process engineering, but also typically discussions around the expected read range between tagged items and reader antennas. The read range is impacted by several factors and many start the cooking process by looking at the properties of RAIN RFID tags.

Tag datasheets carry plenty of information: protocol, operating frequency, chip type, memory utilization, physical size and much more. Amongst all information on datasheet, I reckon tag dimensions and read range are typically the first ones checked. Both are relatively easy values to understand, although the first one is a fact, and the second more an opinion. In the following I explain how to interpret the tag read range right.

Classic Approach: Take a Tag and Walk Away

The simplest way to get an idea of the read range is to place a reader to the end of a hall, take a tag and walk away from the reader antenna to see how far the tag can still be successfully read. In this kind of empirical test the result is not a fixed distance under which the reading would always be successful, but instead the result typically varies as below:

Result of a “walk away” read range measurement using a lower end RFID reader. What would you choose for a read range value?

Obviously such a result leaves a problem: how to interpret the results? What in fact is the read range in this case? A bigger problem is that the result is actually a synthesis of so many factors, such as reader properties, tag alignment, other objects in the environment, illumination in the hall, settings in the reader… So, what was it again you wanted to see?

Very few halls, office spaces or basements are stable enough to reproduce the test from day to another with the same test result. Therefore, key delivered value of this approach is merely the physical exercise, and most vendors don’t use these results in their tag datasheets.

Laboratory vs. Real Life Performance

RFID measurement systems characterize tags at high precision after which read range is calculated based on a few assumptions. Laboratory measurements themselves are often performed in shielded and anechoic chambers to remove other variables from the test results, which greatly improves the value of the data and the repeatability of the test process.

Theoretical read range of two RAIN RFID tags designed for different applications. Tag 2 shows better max read range at the FCC band, but is too highly tuned to efficiently cover the whole band. Despite of its shorter read range, Tag 1 as a broadband design seems like a more reliable choice.

This kind of measurement does not emulate effects of environment where tags are used. Experts talk of multipath propagation and path loss, and some others may talk of reflections, shadowing and interior design. No matter which definition is used, the environment is the grand source of differences between laboratory and real life performance.

Practical Difference of ERP and EIRP

Theoretical read range values plotted by the Tagformance system are based on the Tag Performance Parameters and Test Methods Version 1.1.2, 2008, EPCGlobal Inc. For the read range standard specifies 35dBm EIRP transmit power to be used in the calculation. 35dBm EIRP transmit power equals 33dBm ERP power. 33dBm ERP equals 2W and 35dBm EIRP equals 3.28W. If maximum power 4W EIRP is allowed, as in the FCC band, theoretical read range results can be obtained by adding 11% on the figures shown in the Tagformance software.

Forward Limited Read Range Is Not a Safe Assumption Anymore

As tag dimensions shrink and tag ICs become more sensitive, readers often become the limiting factor of read range. A reader with more sensitive receiver is able to pick up a tag’s reply from greater distance. When read range is analyzed it is typical to separate read range to forward (up) and reverse (down) links.

Picture below shows forward and reverse read range curves, which are calculated using 1W ERP transmit power, 2dBi antenna gain and -65dBm receiver sensitivity.

Separated forward, reverse and resulting read range curves. For ETSI range forward and reverse curves are equal, but for FCC range read range is reverse link limited – a reader with more sensitive receiver would improve read range on FCC band.

Tag Close Coupling Issues to Be Addressed by TIPP

As tagging spreads to new product categories in the retail industry, small tagged items are often brought into close proximity to each other. Just think about items boxed for transport. Especially when the distance between tags is less than 3 cm, the tags start to couple with each other.

The close coupling effects will be considered in the upcoming GS1 TIPP global standard. Stay put for Juho Partanen’s upcoming blog post regarding these issues!

From Opinions Back to the Facts

As you saw from the above, the read range is a factor of many issues. As you work yourself through the tag and reader datasheets with the aid of expert tools and good standards, you can connect the dots with relative ease. This process transforms opinions into facts.

I’d appreciate your comments and suggestions around these topics. New perspectives are always welcome.

Learn How to Test the Read Range with Tagformance

Download our application note “Read Range Test with Voyantic Tagformance” to learn how easy it is to test the read range!

Oct 07, 2016

Recommendation for RFID Reader Testing from RAIN RFID Alliance

中文版 Chinese version

The RAIN RFID Alliance recently published a recommendation for RFID reader sensitivity testing. But why is such a recommendation important for the RFID industry? I was deeply involved in its creation process, and can open up some of the reasoning behind it.

Reader Sensitivity Is Important

It is well known that the performance of a RAIN RFID system depends on

  • reader transmit power,
  • the path loss between the tag and the reader,
  • tag sensitivity,
  • tag backscatter power, and
  • reader sensitivity.

Now there is plenty of information available about tag performance, and tags are typically characterized in detail both in the design phase as well as in production. Measuring path loss (characterizing the environment) is relatively easy as well – simply measure a Voyantic Reference Tag with the Tagformance system in an unknown environment, and the result is the path loss between the reader and the tag (contact Voyantic for more information about the test process). But even though reader sensitivity is one of the main elements defining the overall performance of a RAIN RFID system, it has been given very little emphasis so far.

RAIN RFID Alliance Reader Sensitivity Test Recommendation

Almost all RFID reader datasheets report output power (TX power, radiated power, port power) somehow, but very few reader manufacturers report the receiver sensitivity of their reader. And without the sensitivity information, you can’t really be confident about the reliability of your RFID system. So RAIN RFID Alliance decided to take the initiative and publish a recommendation document “RAIN RFID Reader Sensitivity Testing” to get more companies to report their reader sensitivity.

Now reader sensitivity can be a complicated issue, but only if you let it.

It is well known that sensitivity varies (a little) as a function of the exact frequency, reader transmit power, and the choice of protocol parameters. However, the RAIN RFID Alliance workgroup that developed the recommendation, opted for simplicity and deemed sufficient to report a single sensitivity value. In order to make comparing reported sensitivity values easy, it was also required to report the used test parameters. As a result, RFID system integrators and end users can evaluate the usefulness of the sensitivity data by comparing the test parameters to those of their use case. And if needed, they can request further test data with other parameters.

Voyantic Readformance Reader Tester

Voyantic Readformance – Perfect Match with the RAIN RFID Alliance Recommendation

Voyantic has offered a solution for reader sensitivity testing, the Readformance, for several years. So with our experience in reader testing, it was natural for us to participate in developing the RAIN RFID Alliance test recommendation.

The approach taken in the recommendation was:

Easy and simple testing that anyone can perform without the most expensive test equipment.

This very same approach, combining simplicity and flexibility with fast and low cost testing, is exactly what we had in mind when designing the Readformance back in 2012.

In order to help the RFID industry, and to boost availability of reader sensitivity information, Voyantic is also offering reader sensitivity testing as a service, in addition to selling test equipment. Request a quotation for reader sensitivity testing!

Reader testing performed at the Voyantic lab

Learn How to Test RAIN RFID Reader Performance

Download our application note “Testing RAIN RFID Reader Performance with Voyantic Readformance” to learn how easy it is to test the sensitivity of a reader!

Jul 29, 2016

Battery Assisted Passive (BAP) Tags – Do You Know Your Reader Receiver Sensitivity?

中文版 Chinese version

One of my customers in Taiwan is developing battery-assisted passive (BAP) tags. He called me recently and asked why the read range that they reach with their RFID reader is only a quarter (1/4) of the distance that they measure with their Tagformance RFID measurement system. I answered him with another question: “Do you know your reader receiver sensitivity…?”

What Is a BAP Tag?

A BAP tag has an on-board battery to power its IC, but like a passive tag, it does not have an active transmitter. BAP tags are generally used to reach longer read ranges than what passive tags can provide, or for logging some physical quantity when a reader is not present. As known, the typical limiting factor for the read range of a passive tag is the forward link. In other words, the read range of a normal passive tag is determined by how far the passive tag can be powered or activated, i.e., the tag sensitivity is the limiting factor. Therefore, by default designing the passive tag to receive power from an on-board battery as a BAP tag, read range could be increased.

However, since the on-board battery is only used to power-on the RFID IC or to increase the BAP tag sensitivity, the battery does not really increase the tag backscatter power. As a result, the return link will become the limiting factor for the read range of a BAP tag. In order to fully realize the maximum read range of a BAP tag, the reader receiver sensitivity becomes crucial.

BAP – Battery Assisted Passive – Tag

The Performance of a BAP Tag

When evaluating the performance of an RFID tag, the starting point is usually measuring the sensitivity of the tag as a function of frequency. The graph below shows the Tagformance Pro’s Threshold Sweep measurement results of one BAP tag. As can be seen, the theoretical read range for this BAP tag is close to 37 meters at 930 MHz. That is a lot; the read range of a good passive tag is around 10 meters.

Sensitivity of a BAP RFID Tag Measured with Tagformance Pro

But the forward link read range above is only the theoretical upper limit of the read range that can be reached. Below we use the Tagformance Pro’s Read Range measurement functionality to test the BAP tag with different reader parameter settings. The radiated power is set at 2W ERP. The yellow curve below shows that the read range is about 19 meters at 930 MHz if the reader receiver (RX) sensitivity is -85 dBm.

Read Range of a BAP Tag Measured with Tagformance Pro; 2W ERP & -85 dBm Sensitivity

By changing the reader sensitivity in the Tagformance software, we can see what reader sensitivity would be needed to reach the theoretical read range maximum. This situation is shown in the yellow curve below. The reader sensitivity required to reach the 37-meter read range is -97 dBm.

Read Range of a BAP Tag Measured with Tagformance Pro; 2W ERP & -97 dBm Sensitivity

From my experiences, it may not be easy nowadays to find a reader with the RX sensitivity of -97 dBm. Therefore, in order to reach the read range of 37 meters, I have suggested my customer redesign the BAP tag’s antenna to make the tag having stronger backscatter power and use a higher sensitivity reader if possible.

Reader receiver sensitivity is getting more attention in the RFID market after the increase of tag sensitivity both in BAP tags and normal passive tags. This means that the limiting factor for the read range is the return link. Receiver sensitivity is the key to optimizing the read range. Interestingly, most system integrators and even UHF reader suppliers do not know how to measure the receiver sensitivity. Voyantic’s Readformance reader tester is designed to tackle this challenge.

How to Measure Reader Receiver Sensitivity?

Do you want to learn how to measure the receiver sensitivity of RFID readers? Download the Voyantic Readformance datasheet

May 20, 2016

Passive RFID Sensors and Tags with a 100m Read Range A Geeks Report from RFID Journal Live! 2016

中文版 Chinese version

Two weeks ago was again the time of year when the RFID industry met at RFID Journal Live! in Orlando, Florida. The show is one of the main events of the year for Voyantic as well. But what were the hot topics this year?

As always, several new products were presented at the show. A significant trend for the last few years has been UHF RFID finding its way into mobile phones, first as add-on modules, but now also integrated into the phones. Another new product category was inventory robots that were seen roaming the aisles of the show. Mikel Choperena of Farsens writes about these trends in more detail in his trade show review.

Industry-wise, the airlines seem to be currently on the up in RFID adoption. Delta was one of the keynote speakers of the conference, and several companies were presenting SAE AS5678 certified tags meant to be used in airplanes. But other industries, such as manufacturing, healthcare RFID, and retail were also well represented.

Passive Sensors Steal the Spotlight

After last year’s show, I wrote that one of the hot topics was (link: http://voyantic.com/blog/posts/is-now-the-time-for-passive-rfid-sensing text: passive RFID sensing popup:yes), and noted that sensing occupied four of the ten Best New Product nominations.

It looks like sensing picked up where it left off last year.

This year’s award was shared between two innovative sensing products:

  • The first winner was SMARTRAC Technologies, for its Sensor Tadpole, a passive UHF sensor that can detect the presence of moisture. The sensor tag has been used by automobile manufacturers for ensuring that the cars leave the factory watertight.
  • The other winner was Phase IV Engineering for its RFID Sensor Reader, which is designed to collect accurate data from passive RFID sensor tags. Think of it as the missing piece that links passive RFID sensors to industrials PLCs, converting sensor readings from a tag’s memory to industry standard voltage or current levels. Keep your eye on this company!

Bubbling Under in the Academic Scene

RFID Journal Live! was co-located with several smaller conferences, one of them the IEEE International Conference on RFID, “the premier conference for exchanging all technical research in RFID”. My colleagues were kind enough to relieve me from booth duty, so I had a chance to attend the conference, and spend some time with my fellow geeks.

This year was the 10th occurrence of IEEE RFID, and I can proudly say that I have participated in pretty much all of them in some role: in the Technical Program Committee, as a session chair, or as an invited speaker. The conference covers different aspects of RFID research; this year the largest amount of presentations fell under the categories of

  • antennas & propagation
  • circuits
  • devices & readers
  • protocols & security and
  • energy harvesting & wireless power.

For me, the most interesting talk was given by Dr. Greg Durgin of Georgia Tech. He received the best paper award for his paper titled “RF Thermoelectric Generation for Passive RFID”. The paper proposes a new way to power passive tags based on thermoelectric generation instead of traditional diode rectification. To put it in perspective, Alien Technology presented their new Higgs-EC tag IC at the show, reported to have best in class read sensitivity of -22.5 dBm with a dipole antenna. Dr. Durgin’s proposal could bring sensitivity down to -34 dBm, allowing read ranges of up to 100 m.

Think about all the applications that a passive 100 m read range could allow.

RFID has definitely not seen its limits yet!

Apr 21, 2016

RFID, Love or Die

Dear reader, my name is Lluis Bueno, and I love RFID. Do you? I belong to the Spanish company NextPoints, and in my work I have met hundreds of professionals and companies working in the RFID market without any passion for the technology… and most of them are not working in the RFID market anymore. So, why is love required for RFID business to survive? Let me share a few real stories with you.

Without any doubt, RFID is living its best moment: Internet of Things is more real than ever, RAIN RFID Alliance has more than 100 members, GS1 released TIPP guidelines for RFID tagging in retail, RFID inlays reached the lowest price ever without losing any quality… but perhaps, even with this friendly environment, the RFID company you created or joined some time ago is not alive anymore.

What was the reason for failure then? All of them had something in common: their lack of love towards the technology. Focusing on the product is of course important, but prioritizing price and forgetting collaboration with other players did kill them.

RFID is not just one more technology, it still needs your support to develop the market, and you need the market to be developed to make business.

RFID has its professional tools and methods of doing measurements, and this is something many of the professionals in the market are not aware of. There are only two ways to work with RFID: the right way or the wrong one, and there is no midway. Fortunately, I met Voyantic years ago and they showed the right way to me. Doesn’t it sound like some kind of religion? That was exactly what I felt the first time I met Mr. Juho Partanen: I had always thought I was doing things, if not the best way, then good enough for my RFID business. But I was doing wrong until he opened my eyes and he led me on the right track.

Most of the RFID companies ─ large end users, system integrators and even manufacturers of RFID readers or tags ─ are still using the same methods for testing their products and solutions which they used 5 years ago: conventional readers instead of professional testing systems, trial and error instead of real measurements, empirical reading distance instead of other key measured parameters. They think they are getting enough information from those old methods to understand how RFID works, but they really have no idea of what is happening. Why are they not taking their own business seriously? Is lack of budget the reason? No. Lack of love towards RFID is.

Most of the RFID companies think that purchasing RFID products at the best price will turn their company into a successful one. Forget it! Price just helps. Qualified partners, not only products but business providers, RFID alliances involvement, real RFID measurement tools…. You are missing much more aspects than just price. Are you aware of the changes in RFID ETSI frequencies, TIPP guidelines, RAIN RFID Alliance…? Information, commitment, involvement… definitely, love. Love is missing all along the supply chain, so we need to spread love since the beginning.

Please, you have chosen RFID as a driver technology for your projects, products and solutions. Love it and it will love you back with everlasting business. Take it seriously, or partner with companies who take it seriously for you, but do not ignore RFID and treat it as any other technology or it will die and make your business pass away.

In my work I have heard dozens of questions of RFID – why is it not performing as expected? What should be done differently to make my RFID business bloom? Download the “Questions of RFID – Loving Wisdom” document below to read the commonly asked questions with my answers.

Download Lluis Bueno’s RFID Q&A!

Download Lluis Bueno’s loving wisdom for frequently asked questions of RFID. You’ll find answers to many baffling RFID questions regarding tag and reader selection, system setups, link margins, and troubleshooting.
For your convenience, many of the answers come with pictures, too!