RFID Primer

What is it?

Radio Frequency Identification (RFID) systems are one technology many libraries use to make materials handling more efficient and to reduce staff workload.

Library RFID systems are composed of two primary components: tags and tag readers. The tags are placed inside library material. The readers are placed at staff workstations, self-check machines, and built into security gates. The readers are used to read the information on the tag. One piece of information on the tag is the item’s bar code number. In other words, the readers are used much like barcode scanners are used: to check items in and out, put items in transit to fill holds, and to verify that items have been properly checked out at each library exit.

The key difference between barcode scanners and RFID readers is that RFID readers are not optical and so do not require “line-of-sight” scanning of the barcode. RFID tags inside books can be read up to 18 inches away without having to pick it up or position it under the scanner.

Another important feature of RFID is that multiple bar code numbers (which are encoded on the RFID tag) can be read simultaneously. However, when using SIP2 to communicate with the ILS, the tags are still handled sequentially. To the end-user, it still seems like it is happening simultaneously because a patron or staff person can set 4-6 items on the RFID pad and they will all be read and fed into the ILS for processing. This results in a significant reduction in staff handling because several items can be checked in or out at once rather than being individually scanned.

While RFID technology has been available for a decades, it has only been used in libraries for the last 10 years or so. The slow updake in libraries are in part because of the price of the tags and the associated equipment required to make use of the technology and concerns about privacy.

In addition, there has been an ongoing problem with standards, or the lack thereof. This has resulted in vendor lock-in for largely proprietary systems until very recently. In March, 2012, the NISO RFID Revision Working Group issued NISO RP-6-2012 establishing ISO 28560-2 as the U.S. Data Profile. The objective of the new U.S. Data Model is to create an environment where every library can use every other library’s RFID tag regardless of the supplier. In addition, hardware from any RFID vendor should be interoperable and the systems should be free from proprietary interfaces that make the hardware work with any given ILS. If libraries adopt the U.S. Data Model, the library RFID market could move to an environment where vendor lock-in is a thing of the past. This will increase competition between vendors and result in lower prices and better products. It will also be possible to secure items across institutions during ILL transactions.

The document, available at NISO.org is entitled RFID in U.S. Libraries: A Recommended Practice of the National Information Standards Organization (NISO RP-6-2012) includes a description of the all the data elements included in the data profile and makes recommendations about how to use them. The document also specifies how the data should be encoded on the tag. The document recommends practices that might someday lead to getting RFID tags installed earlier in the lifecycle of the book so the tag could be used by publishers, distributors, and libraries (including for shelving, circulating, sorting, inventory, and security), as well as in interlibrary loan transactions. 

Types of Tags

RFID tags come in many sizes, shapes, and varying degrees of rigidity and flexibility depending on how they’ll be used. Tags can be “passive” or “active.” Passive systems rely on the reader to generate the energy that will allow the tag to transmit the data on the chip. Active tags have their own transmitter and a power source (possibly a battery) so they can transmit the information stored on the chip without relying on the reader’s power.  RFID tags can be low frequency (LF), high frequency (HF) or ultra high frequency (UHF). NFC (Near Field Communication) is a kind of HF RFID tag. 

When libraries first began using RFID, the only viable tag for item-level tracking was an HF tag. This is because the read range of UHF is longer and more unwieldy than HF tags, and because early UHF tags encountered problems around metal and water. However, UHF technology has evolved quite a bit and many RFID experts assert it is equally effective for item-level tracking. Some argue that it is a better choice for than HF because UHF tags are more universal. However, virtually all U.S. library RFID systems in production are based on HF tags (there are only two libraries in the U.S. working with UHF). 

Library book tags are designed to be placed into books. The antenna is tuned so that when the tag is placed inside the book, the book’s material (book cover and paper) won’t degrade, or detune, the signal. Items designed for CDs and DVDs are also specially tuned to work with the hard plastic that makes up a DVD or CD. Most libraries use HF tags for library applications because the read range is shorter and because the standards have thus far specified HF tags. However, the RFID marketplace is changing rapidly driven largely by the popularity of UHF applications.

HF book tags come in two shapes. One is a square tag and one is a “credit card” sized tag. Both use NXP microchips, most often with 1024 bytes of memory, and operate at 13.56 MHz. The different shape is a result of the antenna design. The tags used for CDs and DVDs also come in two form factors:  disk hub tags, and full coverage tags. Hub tags fit on the inside ring of the CD/DVD and have not proven to be nearly as effective as the full coverage tags. The full coverage tags cover one side of the CD/DVD. The antenna is much bigger on these tags because it runs around the outside edge of the CD/DVD instead of the inside ring.

The U.S. Data Profile established ISO 18000-3, Mode 1 tags as the standard tag for U.S. libraries. Encoding of the tag should be compliant with ISO 28560-2.

RFID Equipment

Any piece of equipment that relies on a barcode must be modified or replaced to use an RFID system. This includes staff workstations, security gates, and self-check machines (both check-in and check-out). If your library has implemented the U.S. Data Profile and is therefore using ISO 18000-3, Mode tags and encoding their tags according to ISO 28560-2, then you should be able to use tags and equipment from any vendor.  It is not necessary to purchase everything from one place.  

Libraries and vendors that do not adhere to these standards will offer solutions that ultimately limit the libraries choices. If a vendor uses their own proprietary standard to write data to the tag, then the library will be locked in to equipment from that vendor only.  In some cases, vendors have managed to find ways to read the barcode off of each other's tags allowing for some measure of interoperability. However, even these vendors wouldn't be able to read all the data off the tag rendering the additional functionality inherent in an ISO 28560-2 compliant system (the U.S. Data Profile) useless. 

AMH and RFID Should be Separate Procurements

Many libraries are under the mistaken assumption that they must (or should) implement RFID when they move to automated materials handling. This is not only wrong but it can be a costly assumption. First, there are AMH vendors that provide excellent products but are not themselves RFID vendors.  If you put out an RFP for both RFID and AMH, you won't get proposals from the AMH-only vendors. This is extremely unfortunate because you will miss out on vendors that provide not only excellent products but competitive pricing.

AMH systems operate equally well with RFID and barcodes. There are differences in how certain functions work between the two systems but the differences are rarely significant enough to justify implementing RFID for the purposes of getting an AMH system installed.

RFID Procurement Planning

If you are about to initiate and RFID procurement, I recommend you include the following:

1. Tags must be ISO 180003, Mode 1 compliant
2. Encoding must be ISO 28560-2 compliant
3. Include the following data elements (at least): 
   - Primary Item Identifier (bar code)
   - Content Key
   - Owner Institution

There are 22 optional data elements included in the U.S. Data Profile and it is the libraries responsibility to decide which ones to use and how to use them. Vendors can provide some advice but it is really the library's job to decide how they want to use the tags to improve their workflows and to interoperate with other libraries.  For example, there are elements that could be used to support ILL transactions or to assist with weeding. In addition, it will be important to work with a library's resource-sharing partners to ensure that the security methodology being employed works across all the systems.

Also, be aware that a library can use more than one "data profile" to accommodate their needs.  ISO 28560-2 includes a data element called the Tag Content Key. This key provides a map of the data elements on the tag. Therefore, as long as you include the Content Key, you can use more than one data profile (e.g. include the "Set Information" element only on material that has multiple parts). Adding fields to the tag that won't be used just slows down the read time so it is important to think strategically about what to include on the tag and what NOT to include on the tag.

ROI and RFID

The return on investment for a library RFID system has thus far not been clearly established. While some have argued that a library RFID system will pay for itself within 2-3 years because of the reductions in staff time,  this is likely true in very few library environments. Libraries facing significant reductions in staff have found they were able to handle many more circulation transactions per person with RFID than without. In many cases, the RFID implementation is tied to a transition to more self-service making it difficult to tie the savings specifically to RFID.

Developing a cost estimate and real-life ROI story requires looking into the workflows of each library and evaluating many options related to the potential procurement choices.

That said, here are some of the reasons many libraries decide to move forward with RFID.

Potential Benefits of RFID

RFID (with or without AMH) provides many benefits, both tangible and intangible, to library staff and customers. The most significant tangible benefit is in reducing the need to grasp, pick up, and manipulate items during the check-in and check-out process. In addition to speeding up the process (by allowing staff to check out several items at a time, rather than having to scan each item individually), RFID reduces the potential for repetitive stress injuries because of the reduction in “grasping” motions.

Other potential benefits include:

Check-in and Check-out is Easier for Customers

Both check-in and check-out are easier for customers in an RFID environment. As a result, self-check is expected to increase. Some RFID libraries have achieved 99% and even 100% self-check use after implementing RFID.

RFID tagged material improves the self check-out process for customers. Not only are the tags more easily read by the self check-out machines but multiple items can be read at once making self check-out even faster and easier.

Some self check-in machines require customers to orient the material face-up with the spine against the left side. With an RFID-enabled self check-in system, customers can feed the items in without regard to orienting them left or right, or face up or face down. They simply feed the items in as soon as the light indicates it is ready for the next item.

Better Security Options

RFID tags can be used for material identification as well as material security. Libraries no longer need an EM security strip for security. Instead of the additional step of sensitizing or desensitizing materials at check-in and check-out, security is enabled or disabled automatically as part of the check-in and check-in process.No additional handling and no EM equipment is necessary. Security is enabled or disabled as the items are stacked upon or slid over an RFID enabled pad at each workstation.

"Budgets keep shrinking and library use is increasing [...]. With barcodes and EM (Tattle-tape) we handle and manipulate each item multiple times. With RFID you do it in batches of 5-10 and set the circ status and security at the same time. Worker’s compensation issues are lower at our RFID libraries. As a manager that worked many years at the circ desk I see the benefit of less physical stress and strain on our employees."

Sloan Sakamoto, Manager, Automated Services, Long Beach Public Library. From “Power and Pitfalls of RFID [webinar], Library Journal, March 16, 2010.

“Pull Holds” Process Faster

As more and more customers take advantage of their ability to place holds on material, the burden falls on the staff not only to shelve material but to pull material for customers. The library system generates lists of all the items that need to be pulled from the shelves to fill patron requests. Some items are pulled to fill requests at the local library; other items are for requests at one of the other libraries.

With RFID, pulling holds is faster because the device can locate the item when it is within 8-12 inches from it and the staff don’t have to strain to read the spine labels. Items that are misshelved are more likely to be found because the device looks for every item on the list, not just the items that a person would expect to see shelved in that section.

In addition, many of today’s handheld RFID devices make it possible to preload several lists into the device so that lost items can be found at the same time as items that need to be pulled to fill a hold or items targeted for weeding are encountered.

Inventory is More Likely with RFID

How long it takes to pull all the items on a library’s pull list or weed list depends on how well the shelves match what the catalog says.

Few libraries inventory their entire collection regularly. Many haven’t inventoried their collection in years. Inventory is one of the tasks that have fallen by the wayside as libraries struggle to keep up with the challenges associated with holds processing, delivery, web-based services, and in-library services. Without regular inventories, it is almost impossible to know how much material is lost due to theft. In addition, many libraries don’t know an item has gone missing from the collection until it turns up on their Pull List and it’s nowhere to be found. Without frequent and accurate inventories, the Pull List workflow is very inefficient. In addition, customers can be frustrated when an item they’ve had in their holds queue ends up being designated “missing” only after it has risen to the top of the queue and the staff spends several days trying to locate it.

Using RFID-enabled handheld devices makes is much more likely that libraries will conduct routine inventories which ensure that the items on the shelves match what is in the catalog. This is a big benefit for staff as well as customers.

Implementing RFID

It is no longer necessary procure a vendor for the tags as well as every piece of equipment that will use those tags. As long as you require adherence to ISO 28560-2 (the U.S. Data Profile) throughout your process, you will be able to purchase tags from the most competitive supplier and select equipment that makes the most sense for your situation.

Tags and Tagging Costs

As of November, 2021, the price of ISO 18000-3, Mode 1 RFID book tags cost under eighteen cents each. Media tags are under forty-vive cents (X-Range and Stingray tags, aka "full-coverage" tags versus the little ring tags). I do not recommend the ring (or donut tags). Go with the full coverage tags. Most library RFID vendors resell one or both of these full-coverage tags.  

Once you have the right tags (ISO 180003, Mode 1), you'll need to decide which data elements you will use. ISO 28560-1 two mandataory elements (Primary Objective ID which is usually your barcode) and Tag Content Key (which provides a map of any other data stored on the tag). There are also 22 optional data elements.

It is up each library to evaluate these optional data elements and decide how to use them. One of the advantages of the U.S. Data Model is that it is extremely flexible yet provides a standard that makes interoperability between libraries, and cross vendors, a real possiblity. One library may choose to use only the two mandatory data elements while another may use those two plus several others (e.g. they plan to use their tags to optimize their ILL and sorting operations).  Regardless of these differences between the two libraries, if both encode the data to the tags according to ISO 28560-2 (as called for in the U.S. Data Profile), these libraries could read each other's tags. 

Encoding according to ISO 28560-2 is not necessarily easy. You may need to experiment with different ways of storing your data to optimize performance.  This means working with a vendor who is willing to work with you to do some testing.  You might also consider using a third party to verify that your tags are indeed being encoded correctly.

Libraries that do their own tagging report tagging speeds of 350-400 items per hour. The most efficient way to do the tagging is to have a two-person team use a mobile cart with a laptop and RFID reader, a roll of tags, and a barcode scanner. Many RFID vendors sell or lease mobile carts that can be used for RFID conversions.  Programming the tags involves scanning the barcode to encode the barcode number on the tag, and then placing the tag inside the book.  Many libraries mark the book so they know which ones have been tagged before reshelving them.

Tagging can also be outsourced for a set amount per tag applied (around 30 cents each). 

Leveraging Your Use of RFID

We have an opportuniy in libraries to do much more with our RFID technology and to change our relationship with RFID vendors. We no longer need to be limited to using it as an expensive place to store a barcode and to secure library materials. And we don't have to restrict ourselves to a single vendor for all things RFID.

Here's some ways we could be leveraging our RFID technology:

1. Use Set Info to improve security of multi-part sets
2. Eliminate the use of routing slips in libraries.  By using Owner Library, ILL Borrowing Institution and possibly Subsidiary of an Owner Library, and Shelf Location to sort material.  The library system’s sort facilities could be equipped with RFID-based sorters (human or automated) capable of sorting material without either routing slips or a connection to the ILS. The U.K. and the Danes are already using Owner Library and ILL Borrowing Institution this way.
3. Develop a library app for RFID-enabled smartphones that allow users to check out items with their phones eliminating the need to stop at a self-check machine or without needing to turn off security at a special kiosk. (Tech-Logic/Boopsie currently support self-checkout with a user’s smartphone but they have to turn off security at a special kiosk.)
4. Use UCC, ISBN, or ISSN numbers on non-circulating items that work with RFID-enabled smartphones and library-developed apps that link to enhanced content such as reviews or recommendations.
5. Use of Type of Usage to provide better control of items when the ILS is down
6. Use Title on non-circulating items to provide support for mobile devices that could help staff and perhaps even patrons locate specific items 
7. Set up Reader’s Advisory kiosks in the library or vending machines in other locations that can be used to “find me more books like this one” while accepting returns 
8. Use Shelf Location to provide more granular sorting of returned items to more quickly move items back to the Hold shelf or display area, or up to the third floor.
9. Receive new acquisitions box-by-box instead of item-by- item using Supplier Identifier and Order number in combination with the unique identifier on each new item.
10. Eliminate much of the paperwork involved in ILL processing by encoding the ILL Transaction number on the tag and using the ILL or ILS software to track the transaction.  
11. Use a Local Data Fields to count circulations or “data last circulated” to support weeding functions without requiring a connection to the ILS.
12. Use a Local Data Field to indicate special handling requirements for items in the back office.

For the U.S. Data Model to have these positive effects, libraries must act. Here's what libraries must do:

1. New RFID procurements must insist on adherence to the NISO March 2012 RFID in U.S. Libraries recommendations.  
2. Libraries must insist on ISO 180003, Mode 1 tags (as specified by ISO 28560 and the new U.S. Data Model).  
3. Libraries must learn what the data elements are that are specified in ISO 28560-1
4. Libraries must decide which data elements they want so use and how they will use them (there is a lot of flexilibity in the standard)
5. Libraries must verify that their vendors are propertly encoding the tag per ISO 28560-2 (again, there is a lot of flexibility in the standard)

The U.S. Data Profile is only useful if libraries make use of it. It's time for everyone to learn about the new standard and educate themselves about RFID technology and how it is being used in libraries, and more importantly, how it COULD be used.

For an even more complete look at RFID and Libraries, please take a look at the 2012 issue of Library Technology Reports which Lori Ayre authored entitled "RFID - One Step Closier to Interoperability." 

[Updated 6/26/2016]