The “new” UHF Standard

UHF RFID has taken off in a big way. Many of us have been saying that RFID is the way of the future and now it is starting to be real. The standard for UHF is ISO/IEC 18000-6 (equivalent to the EPCglobal Gen 2 UHF standard). This standard is one of the air interface standards in the ISO/IEC 18000 series for all of the various frequencies.
 
ISO/IEC 18000-6 is a very large standard. It is available from ISO for about $306.00 and it contains 470 pages. The standard has information and specifications on four different air interfaces (types A, B, C, and D). Type C is the equivalent of the EPCglobal standard and is now the most prevalent UHF standard.
 
The latest version of ISO/IEC 18000-6 contains enhancements to the Type C air interface that are not included in the EPCglobal version. These enhancements allow the use of sensors and provide details of battery assisted passive RFID tags.
 
So with ISO/IEC 18000-6 only having been published in 2010 why am I talking about a new standard?
 
As I explained above, the standard has grown over the years both in size and in price. This has made it difficult to use and with the new enhancements coming, the decision was taken to split the standard into several parts. The new standard will have five parts as follows:
 
ISO/IEC 18000 – General information
ISO/IEC 18000-61 – Type A
ISO/IEC 18000-62 – Type B
ISO/IEC 18000-63 – Type C
ISO/IEC 18000-64 – Type D
 
Part 63 – Type C is the equivalent of the EPCglobal Gen 2 standard and it includes the sensor and battery assist specifications.
 
The revisions to break the original standard into these parts are currently in progress. The work has just passed the first level of balloting at ISO. This means that early in 2012 the new standards should be approved and we will all be using a new number for the UHF standard.  
 
If you want to know more about the new enhancements to the standard then watch for another article on this subject.
 
If you have questions about the new standards or how you can be a part of the standards efforts then let me know.

Loss of a Great Man – Alan Haberman

Alan Haberman's first claim to fame should be that he was instrumental in bringing bar code scanning to our lives. Although he did not invent bar codes, he lead the charge to get the U.P.C. symbol accepted by everyone and was part of the movement that has made bar code scanning in retail a part of our everyday life. Alan was president of Hills-Korvette Supermarkets and then the CEO of First National Supermarkets and in the early 1970s he became the chairman of an executive committee in the Uniform Code Council (now GS1) to select a standard symbol. The committee reviewed more than a dozen symbols and eventually chose what we recognize today. The first time the bar code was used in areal system was on June 26, 1974 when a pack of Wrigley's Juicy Fruit was purchased and scanned at Marsh Supermarket in Troy OH. That package is currently in the Smithsonian Institute's National Museum of American History.

Alan was a founder member of the UCC and he became a member of the Board of Governors. His work did not stop with bar codes and he was one of the first people to recognize the importance of RFID. He led an investigation for a University to help solve some of the problems with RFID. He setup an alliance with Massachusetts Institute of Technology and funded the Auto-ID Labs to investigate the creation of a system for retail use of RFID. This later became EPCglobal and the Electronic Product Code (EPC) system was created.Alan in Edinburgh

In 1996 talks were started with an intent to create a home in ISO for AIDC standards. The Uniform Code Council was chosen to be the Secretariat for this international work and Alan was chosen to be the first chairman of the committee. He retained that position for the next nine years, leading the standardization efforts with a force that everyone rallied around. He was well respected in the position and even when some health issues put him on the sidelines for a while, he continued to drive everyone forward from his home office.

I first met Alan Haberman when he was chosen to be the first chairman of ISO/IEC SC 31. He became a great friend and a mentor to me and several others. His straightforward way of doing business didn't always make him the most popular guy in town, but his knowledge and management skills always won through. Alan's interest in the technologies did not stop when he passed on the chairmanship of the committee. He continued to call many of us with questions and ideas. He even acted as a confidant for many of us as we tried to resolve issues.

Alan passed away on Sunday (12 June, 2011) at age 81, he will be missed by many of us. Rest in Peace, Alan.

 

UHF (Ultra High Frequency) (860 – 960 MHz) air interface standards

UHF RFID is probably the most noticed RFID at this time.  While there have been more HF tags issued, the high profile nature of UHF has meant that many more people are aware of UHF RFID.

In the world of RFID, UHF is the newcomer to the fold. HF and LF tags were is use in many places when UHF started to become available. The industry needed a longer range passive tag and UHF is the answer.

The technology normally uses propogative technology like 2.45 GHz, and so like 2.45 GHz it has problems around liquids and materials that absorb the frequency. However it is possible to use the technology in a near field (or inductive) mode similar to LF and HF and this gets around the liquid problems.

The technology in Propogative mode can work at distances of 6 – 8 metres which is a big step up from the range of the other technologies. In Near Field mode this is much less (only 10s of centimeters) but it is possible to build tags with antennas that have the capabilities of both modes.

The frequency range 860 – 960 MHz is a very large range, but it is necessary to have a range this large to encompass all of the regulatory areas in the world.  In the USA, the frequency is 902 – 928 MHz, but in Europe it is 865 – 868 MHz, and in Japan the frequency available is 952 – 957.6 Mhz. So if an UHF tag is going to work all over the world it has to be able to work from 860 – 960 MHz. If you are interested in the various UHF frequencies available around the world you can see them here.

UHF has gained a lot of publicity and use with the release of the EPCglobal UHF Gen 2 standard. This standards improved the performance of the original ISO/IEC 18000-6 Type A and Type B air interface protocols.  ISO took the work of EPCglobal, and suggested some changes which were then incorporated back into the EPCglobal standard. ISO released this work as Type C in ISO/IEC 18000-6.

Recently the ISO workgroup has just finished work on changes to ISO/IEC 18000-6 and a new version was published on December 1, 2010. This new version includes several new features:

  • Support for sensors
  • Support for battery assist
  • New Type D air interface based on the TOTAL (Tag Only Talks After Listen) protocol of iPico.

The release of the EPCglobal standard lead to the adoption of UHF by several groups. First of these was Wal-Mart.  Their mandates to force suppliers into tagging cases and pallets were the first time that RFID was seriously used in the retail market place. The US Department of Defense followed shortly after with a mandate to tag items over a specified value. Other organizations have also taken the use of UHF RFID to heart and required the tagging of items to the standards for this frequency.

The latest use of UHF is the tagging of apparel in a test of item level tagging. Wal-Mart has lead the charge with the decision to tag specialty jeans and underwear.  This was quickly adopted by other retailers and is rapidly becoming a major test for RFID.

Information technology — Radio frequency identification for item management — Part 6:Parameters for air interface communications at 860 MHz to 960 MHz

Scope

This part of ISO/IEC 18000 defines the air interface for radio frequency identification (RFID) devices operating in the 860 MHz to 960 MHz Industrial, Scientific, and Medical (ISM) band used in item management applications. It provides a common technical specification for RFID devices that can be used by ISO committees developing RFID application standards. This part of ISO/IEC 18000 is intended to allow for compatibility and to encourage inter-operability of products for the growing RFID market in the international marketplace. It defines the forward and return link parameters for technical attributes including, but not limited to, operating frequency, operating channel accuracy, occupied channel bandwidth, maximum effective isotropic radiated power (EIRP), spurious emissions, modulation, duty cycle, data coding, bit rate, bit rate accuracy, bit transmission order, and, where appropriate, operating channels, frequency hop rate, hop sequence, spreading sequence, and chip rate. It further defines the communications protocol used in the air interface.

This part of ISO/IEC 18000 specifies the physical and logical requirements for a passive-backscatter, Interrogator-Talks-First (ITF) or tag-talks-only-after-listening (TOTAL) RFID system. The system comprises Interrogators, and tags, also known as labels. An Interrogator receives information from a tag by transmitting a continuous-wave (CW) RF signal to the tag; the tag responds by modulating the reflection coefficient of its antenna, thereby backscattering an information signal to the Interrogator. The system is ITF, meaning that a tag modulates its antenna reflection coefficient with an information signal only after being directed to do so by an Interrogator, or TOTAL, meaning that a tag modulates its antenna reflection coefficient with an information signal upon entering an Interrogator's field after first listening for Interrogator modulation in order to determine if the system is ITF or not.

In detail, this part of ISO/IEC 18000 contains one mode with four types. The detailed technical differences between the four types are shown in the associated parameter tables.

Types A, B and C are ITF. Type A uses Pulse-Interval Encoding (PIE) in the forward link and an adaptive ALOHA collision-arbitration algorithm. Type B uses Manchester in the forward link and an adaptive binary-tree collision-arbitration algorithm. Type C uses PIE in the forward link and a random slotted collision-arbitration algorithm.

Type D is TOTAL based on Pulse Position Encoding or Miller M=2 encoded subcarrier.

 

Low-Level Reader Protocol 1.1 just published

A new standard has just been ratified by the GS1 EPCglobal Board:

Low-Level Reader Protocol 1.1 (LLRP 1.1) is the new upgraded version of the GS1 EPCglobal software interface standard that is used in RFID readers. It uses features in the latest version of the air interface protocol for UHF Class 1 Gen 2 RFID tags version 1.2.0 and is also backward compatible with LLRP 1.0.1, the last ratified version.

To get the standard or understand more about it you can visit the EPCglobal web site

Who else is involved in RFID Standards – EPCglobal™

Another arena is the work of EPCglobal™. This organization was founded in November 2003 to answer the needs of the GS1 community as to how RFID would be used moving forwards. The organization is now a full part of GS1.

The Auto-ID Labs at MIT were formed from a grant by GS1 to investigate RFID. When the work of the labs started to look as if it had practical commercial use, then EPCglobal was formed to take the results to the public.

Rapidly growing, the organization quickly established standards for UHF RFID. As time moved on and variations to the standard were being proposed and published, it became clear that a single standard that encompassed all the perceived requirements of the retail supply chain (and more) was needed. This lead to the development of the Gen 2 air interface standard. Older (Gen 1) standards, as developed by the AutoID Labs, are available for reference.

However, the GS1/EPCglobal system is more than just air interface standards, and a complete suite of standards was identified to include Tag Data, Reader Control, Application Level Events, and the IS system that would hold all of the data (EPCIS). The full spectrum of EPCglobal standards can be seen here.

EPCglobal has managed to achieve something that the ISO community has found very hard to do – get users involved. With a basic philosophy that standards are only created from a user requirements document, this has led to standards that are really needed in the industry and wide acceptance of them when they are available.

The one drawback that has been felt is that many companies and countries want to see standards with an ISO imprimatur on them. To help solve this problem, EPCglobal has worked with JTC 1/SC 31 to ensure that the equivalent standard exists in ISO as well. So UHF Gen 2 is the same (at the base level) as ISO/IEC 18000-6 type C, HF Gen 2 is equivalent to ISO/IEC 18000-3 mode 3. The same kind of mapping exists for some of the data and reader level standards as well.

So if you are involved in RFID in the retail supply chain or another area that is looking at GS1/EPCglobal for its standards then look at GS1/EPCglobal for the link to your way to get involved.