The Basics

What does a librarian really need to know about RFID?.

Despite being available for libraries to use for more than 20 years many librarians still seem to know very little about how the technology works or which elements of a typical RFID solution you really need to consider before you buy. This is perhaps in part due to a widespread belief that RFID is simply a barcode replacement technology, rather than a system component with the potential to change almost every aspect of service delivery – not just circulation.

To understand why this view is so popular, why it may have to change and how to avoid becoming trapped in a technological cul-de-sac there are a (relatively) few things that it’s worth investigating – and some initiatives of which you should be aware that are likely to change the way you think about those four letters – RFID.

As long ago as 2009 a Cisco TechWise webcast suggested that RFID was no longer just about identification. The true potential of attaching significant amounts of intelligence to assets was, even then, only just beginning to be realised – a lesson now slowly being learned in the library sector.

To understand why it’s not just an ID – and why that matters – it may help to understand how the technology currently fits into the workflow of the majority of library services – and how it’s likely to change.

This short guide is aimed at the largest single group of library RFID users – those who have already invested in a system to manage their library operations variously known as an LMS, ILS or ILMS in the English-speaking world. In this short piece I shall use the term ‘LMS’ as being interchangeable for all variant forms – because, as a Brit, that’s the one I used for much of my working life.

The first thing to understand is that RFID comes in various forms. It’s important to know this because it could matter A LOT if you decide to change things later on. The basic elements of every RFID solution are the tags, the frequency and the data model. There are a whole bunch of other things that could cause problems for the unwary but lets start with the easy stuff. But don’t worry too much – it’s not difficult to become a library RFID expert.

Let’s start with the tags…

The tag is the thing attached to the item you want to use RFID to manage. Called a ‘form factor’ tags come in a variety of shapes and sizes and operate at different radio frequencies.

UHF tags can be read at much longer range than the more common HF variety. Historically HF tags have been preferred for use in libraries as the long distance reading capability of UHF originally caused major problems when trying to identify individual items (when scanning shelf order for example). Newer UHF scanners now deal with that problem but UHF tags still don’t yet offer the same data storage capabilities as HF.


Like everything else on RFID tags security is managed by data and not by electromagnetism There are two systems in use:

  • Electronic Article Surveillance (EAS)  – essentially an “on/off” solution;
  • Application Family Indicator    (AFI)  – which allows the identification of assets as belonging to a library – ensuring that its tags are ignored in any other establishment using RFID security.

Until recently RFID was limited to being used mainly for circulation(primarily self-service). A data standard should help promote much wider use of the technology to facilitate acquisition and accession, stock management, in-house use monitoring, linking physical to virtual resources and much more.

What you need to know:

  • Whether UHF or HF suits your requirements best.
  • If you decide on HF, which data model will be supplied.
  • Buy tags that can support the data model you choose – and that they can be detected on the items you want to tag.

Tags dynamically store all the elements used by the RFID system to manage the function being provided (e.g. Self-service circulation, security, acquisition, in-house use monitoring etc.).

So that’s the tag, now all we need to start using them is a way to read the data over the airwaves.

This process uses something called the ‘Air Interface’

This is the (relatively) easy bit. That isn’t to say that the air interface is simple – like everything else in RFID world there are many standards around.  The good news is that for HF systems in libraries (the majority) the industry standard is ISO 18000-3.  Among other things the air interface – when libraries choose to use AFI security – ensures that only tags used by libraries are read by scanners.

So having been successfully read by an RFID scanner, over the air interface, our data has now arrived at the read/write unit. What happens next?

The Data Model

Well the next step is to examine the data we’ve just collected. This is a step that was (and still is) often overlooked by librarians and suppliers alike. Suppliers know what data they want – and how they want it to be organised, librarians usually simply cross their fingers and hope the supplier knows what they’re doing.

In the early days of RFID suppliers didn’t worry too much about what might happen if a library using their product decided to switch to a different supplier. Librarians knew that RFID tags aren’t all the same but assumed that, like barcodes, a way could be found to read them. But it wasn’t that easy at all.

The answer was/is a common data model – an agreed way in which data is written to and decoded from an RFID tag. The most widely used (note that word ‘widely’ – this is still not a universal standard) by libraries in the UK, most of Western Europe, Australia and New Zealand is the international standard ISO 28560 – which comes in four varieties.

If you are using a data model supported by your chosen supplier – and since 2011 that ia most likely to be one that uses ISO 28560-2 – then your tags should be able to be read (and indeed written) by any device sold by any RFID supplier that supports this standard. A cautious librarian will have sample tags checked to verify that this is the case.

What you need to know:

  • The data and data model used on your existing tags – or being proposed for a new installation.
  • Whether a new supplier can support this (Post 2011 UK, US and Australian installations are likely to be using ISO 28560-2, earlier installations will not).
  • If you’re extending a pre-2011 implementation will new installations support the ISO standard or continue to use the existing (proprietary) format.

OK. We’ve captured the data from the tag and have been able to figure out what that data is by referencing the data model that was used to create it. now we want to put it to use in an application.

The application

The most commonly used by far is self-service circulation, but other applications have been, and are being developed. Shelf scanners, sorters, accession tunnels, intelligent shelving, and many other devices all contain readers capable of reading and writing data to tags.

In all these cases a scanner/reader will usually be built into a hardware device to read the tags and software will process the data it finds ready for consumption by an application.

Let’s look at how that process works in self-service circulation.

Having read the tags in the item(s) being borrowed and identified the reader that wants to borrow them (note that readers may be identified in a variety of ways – cards, barcodes, smartphone, fingerprint…) the self-service provider now assembles a database query to send to the library computer for it to decide whether the item(s) can be loaned. 

So how exactly does it do that?


For over twenty years self-service operations have been mostly supported by a protocol called SIP (Standard Interchange Protocol). Although originally devised by 3M to support their (non-RFID) self-service solutions it has now been in the public domain since the 1990s and remains the most popular means of connecting RFID and library management systems (usually abbreviated to LMS or ILS).

In our example the data we’ve collected from our reader(s) and item(s) are assembled into a ‘packet’ of data that is passed to the library LMS (ILS) using either SIP, another specially written API, XML or some other means. The reply is returned (after the system has made its checks) to the RFID system which will implement the decision (i.e. allow or disallow the loan).

SIP was (and still is) designed primarily to support only one activity – self-service circulation so if you want more from your RFID investment you will invariably need the (often expensive) assistance of your LMS provider to write an interface to manage additional data elements and processes. Many system suppliers offer an API to satisfy client demands for new functionality but the  difficulty with this approach is that it may create a solution that will only work for one pair of suppliers. You may find yourself having to  stay with both your suppliers or risk losing functionality.

Book Industry Communication (BIC) – a UK charity supported by libraries, publishers and booksellers and a number of professional and commercial organisations – have developed a solution to this problem. Called the Library Communication Framework (LCF) this seeks to codify the data elements and values needed to communicate effectively between RFID (and other third party) applications) and the LMS. Unlike SIP it does not prescribe a transport mechanism for the data..

What you need to know:

  • How does your RFID solution communicate with the LMS? If using SIP – which version? If not, is full documentation of the process, elements and values used available?
  • Do your LMS and RFID providers support  LCF?
  • Do your LMS and RFID providers intend to implement NISO’s version of SIP once published?
  • If you switch LMS or RFID systems in the future which functionality will be vulnerable to this change?

LMS communication is always a two-way and often iterative process so it’s really quite important to understand how this process is managed. Some protocols (SIP included) still construct multiple queries to process individual items – because the protocol was developed long before RFID gave us the ability to process large numbers of items simultaneously. If your plans are too ambitious you may find that the weak link is communication between the LMS and the RFID systems.

In summary

That’s a brief summary of the architecture of a typical RFID installation. We’ve talked mainly about self-service circulation but that’s likely to change in the near future – and here’s some of the areas that are changing:


Many suppliers have seen the potential for development of new functionality and services offered by the growing adoption of ISO data standards.  At the most basic level this includes flagging restricted items to prevent them from being loaned during system downtime (i.e. when loan policy rules are suspended). Inter Library Loan tracking solutions already use routing information on tags, more ambitious plans to link physical stock to the virtual world (like these in Norway and Hollandalso signpost the way to integrating physical and virtual resources in more imaginative ways.

What you need to know:

  • Not all RFID suppliers subscribe to the use of standards so it’s wise to check what data is being written to tags to enable new services as they appear. Remember – just because there is a standard doesn’t compel anyone to use it.


The advent of Near Field Communication (NFC) has provided both an opportunity and a threat to library collections using HF tags. Since NFC read/write capabilities are now available in a number of portable devices the opportunity lies in developing applications that can interact directly with stock. That’s also a threat of course (one the industry is tackling) but NFC is a very personal technology – requiring contact with the items to operate so the advantages of delivering a highly tailored service to individual clients probably outweighs the risk of any malicious attack.


The EU has been slowly developing a response to the use of RFID in Europe. In 2014 they will be issuing recommendations for organisations using RFID in their establishments. The two main elements to these recommendations concern displaying signs to indicate that RFID is in use coupled with a Privacy Impact Statement (PIS) advising people where they can find out more detail about how the technology is being used.

What you need to know:

  • What’s on your tags!

That’s the quick guide! More information on all of the issues is available on my RFID blogPlease contact me directly if you’re unsure about any of this – or have additional questions. You can download a copy of the latest procurement guide here.