Standards and RFIDAn Overview of EPCglobal

Prior to the development of standards for tags and readers, companies primarily developed proprietary RFID systems so that readers from one vendor often only read tags from the same vendor. Early RFID applications, such as those for electronic toll collection, railroad asset tracking, and livestock tracking, were based on such proprietary systems. Although RFID systems can be built to operate primarily in four frequency bands (135kHz, 13.56MHz, 900MHz, or 2.45GHz), only 13.56MHz enjoys worldwide acceptance as an ISO standard (see the section, "ISO and RFID Standards," in this chapter). This lack of interoperability limited incentives for companies to implement RFID solutions broadly, and for developers to create innovative RFID technology.

This situation started changing in the late 1990s with the creation of the Auto-ID Center, headquartered at the Massachusetts Institute of Technology (MIT). It initiated the creation of a standard to facilitate full-scale interoperability between multivendor RFID systems and to propel RFID technology into a broad array of markets, notably supply chain. In 2003, the work that started under the auspices of the Auto-ID Center developed into a separate non-profit organization, EPCglobal. A joint venture between the European Article Numbering (EAN) Council and the Uniform Code Council (UCC), EPCglobal established and supports the Electronic Product Code (EPC) as the worldwide standard for immediate, automatic, and accurate identification of any item in the supply chain. EPCglobal is sponsored by many of the world's leading corporations. It has published a set of protocol standards known as Version 1.0 specifications^[2]. The university lab of the former Auto-ID Center still exists at MIT, and is now referred to as Auto-ID Labs. It continues to do research on Auto-ID (RFID) related topics.

^[2] Since the organization is called EPCglobal, the standards and specifications developed by it should technically be called EPCglobal standards. However, they are commonly referred to as EPC standards. We use both terms interchangeably in this book.

Version 1.0/1.1 Specifications

EPCglobal's Version 1.0 specifications define the overall system and various functional requirements, such as specific encoding schemes, and communications interfaces for RFID systems using class 0 (read-only) or class 1 (read/write) tags. These specifications enable standards-based communication between tags and readers to enable interoperability. Key points are described here:

• Electronic Product Code (EPC) Tag Data Specification Version 1.1: A supplier can use these specifications to map various identification schemes (many of them used globally) into an Electronic Product Code (EPC) code that uniquely identifies each item. As explained in Chapter 3, "Components of RFID Systems," an RFID system identifies and tracks an item based on its EPC. The back-end software uses these specifications to associate the item and the corresponding data to other identification schemes used by many existing applications. These identification schemes include the following:

  • EAN.UCC Global Trade Item Number (GTIN)

  • EAN.UCC Serial Shipping Container Code (SSCC)

  • EAN.UCC Global Location Number (GLN)

  • EAN.UCC Global Returnable Asset Identifier (GRAI)

  • EAN.UCC Global Individual Asset Identifier (GIAI)

  • A General Identifier (GID)^[3]

    ^[3] Details of various existing numbering schemes such as GTIN, SSCC, and GID are not discussed here as these schemes are not created for RFID. Interested readers should refer to appropriate organizations' Web sites for details.

  One of the key benefits of this specification is the capability to uniquely identify and track each object (also known as serialization). Without this, item level tracking and anti-counterfeit measures would not be possible. Several other issues can also arise without these specifications. For example, the tag data wouldn't be understood or acted upon by other applications, diminishing its usefulness, or the existing applications would have to be rewritten to read the tag data, requiring a significant expenditure for companies.

• 900MHz Class 0 Radio Frequency (RF) Identification Tag Specification: Specifies the interface and the protocol (air interface and command set) for enabling communications between a tag and a reader for a 900MHz (UHF) Class 0 operation, including RF and tag requirements, and operational algorithms. Class 0 tags are read-only tags that are programmed with an EPC at manufacture time in the factory. The specifications also define 64- and 96-bit tag structures and functionalities required of the tag. Developers can use the test specifications provided to make sure that the tags comply with the specifications. Supply chain is the primary application of the tags conforming to these standards. The so-called Class 0+ tags provide both read and write capabilities.

• 13.56MHz ISM Band Class 1 Radio Frequency (RF) Identification Tag Specification: Specifies the interface and the protocol for enabling communications between a tag and the reader for a 13.56MHz (HF) Class 1 operation, including RF and tag requirements. Class 1 tags can be WORM (Write Once, Read Many) or Read/Write tags, that is, they allow writing of new information on the tag any time during their lives through an authorized reader. Such tags are quite useful for keeping item-related dynamic data, such as pedigree and modifications to the item due to assembly, on the tag. Because ISO standards on RFID also use this frequency band, you are likely to find many RFID applications in this frequency range today. This specification may provide a path to ensure interoperability among some of the infrastructure required for such applications.

• 860MHz930MHz Class 1 Radio Frequency (RF) Identification Tag Specification: Specifies the interface and protocol for enabling communications between a tag and the reader for a class 1 operation (that is, WORM or Read/Write), including RF and tag requirements. This frequency falls in the UHF range.

Another EPC tag to reader interface standard that holds great promise for hardware interoperability is EPC UHF Generation 2 standard, commonly known as the gen 2 standard. Tags complying with this standard feature Read/Write capabilities (that is, Read and Write many times) and can communicate equally well with readers operating at various frequencies between 860 MHz and 930 MHz. This range includes UHF reader frequencies used in both North America and Europe. For global companies, the benefits are obvious. The goods tagged with gen 2 tags can be shipped globally, and be read by the local UHF reader infrastructure, eliminating the need for applying different types of tags on goods based on their destination. The gen 2 standard was ratified in December 2004, and will likely be aligned with ISO 180006 standards in the near future.

In addition, EPCglobal facilitates development of various other protocols and specifications, as follows:

• Reader Protocol defines the communications (messaging and protocol) between tag readers and EPC middleware.

• Middleware Specification (transformed from the old Savant Specification) defines the middleware services such as tag data collection, filtering, and reader management.

• Physical Markup Language (PML) Core Specification, and Extensible Markup Language (XML) Schema and Instance Files establish a vocabulary set to be used as a reference for communication between applications.

• Object Name Service (ONS) Specification specifies how the ONS is used to locate meta-data and services associated with an EPC.

These specifications provide the backbone for creating an EPC-compliant RFID implementation. Table 4.1 provides a summary of various EPC specifications, their status, and what parts of the RFID system they refer to.

Table 4.1. Summary of Various EPCglobal Standards

Standard	Status	Key Characteristics
EPC Tag Data Specification Version 1.1	Ratified March 2004	Allows companies to create a unique Electronic Product Code (EPC) for each item, enabling item serialization
900 MHz Class 0 Tag Specification (UHF) 13.56 MHz Class 1 Tag Specification (HF) 860930 MHz Class 1 Tag Specification (UHF) Class 1 = Read/Write tag Note: Class 0 = Read-only tag,	Ratified November 2004	Specifies air interface and protocols for communication between tags and readers at this frequency / frequency range Tags and readers complying with a specific frequency standard can interoperate with the same from another vendor Tags and readers generally cannot interoperate with the same from another manufacturer that operates at a slightly different frequency within the frequency range (e.g. UHF range of 860930 MHz) So called, generation 1 tags/readers. Class 0 tags feature Read-only capability. Class 1 feature WORM (Write Once, Read Many) capability. Some may allow Read / Write many times
UHF Generation 2 Standard	Ratified December 2004	Tags and readers can work equally well across the spectrum of EPC UHF frequency, providing maximum interoperability compared to generation 1 tags / readers Evolution of Class 0 and 1 UHF tag specifications Tags feature improved Read / Write (many times) capabilities Tags feature improved performance in dense reader environment
Middleware Specification	Application Level Events (ALE): In Development Reader Protocol: In Development Reader Management: In Development	Provides middleware specifications for filtering, data collection, and reader management Reader protocol (reader-middleware communication): upon ratification, software built on this specification will allow EPCglobal subscribers to purchase and install readers from many manufacturers and be assured they will be interchangeable. This specification will also allow reader manufacturers to build off a solid base and focus their efforts on additional functionality and lower cost. Reader management: Software built on the Reader Management Specification will allow companies to manage arrays of readers much like they do with personal computers and printers within their existing infrastructure.
EPC Information Services (EPCIS)	In Development	Provides a gateway between trading partners (via the EPCglobal Network) and the RFID infrastructure of tags and readers Defines a set of services to enable track and trace and other events based on raw tag data. Specifications useful in leveraging RFID data in decision support systems

EPCglobal continues to work on developing new standards and refining the existing ones in successive versions. Standards for semi-active (or semi-passive) and active tags are expected in future. For more details, see Standards Development Process Specification at www.epcglobalinc.org.

Several issues remain, though. Some of them are inherent to the standardization process, where vendors use the process to gain competitive advantagefor example, standards that result in royalties for one vendor or a small group of vendors, based on their patents. Many standardization bodies have gone around this issue by having the participating vendors donate their patents in a patent pool that is generally available to participating companies royalty-free, provided they reciprocate and use the patents to create standards-based products. However, if the resulting delay makes the standardization process too slow, some vendors may decide to bypass the standard altogether. Another issue that can hurt or slow down standardization is practicality of the implementation of a particular standard. For example, most countries have allocated 13.56MHz (HF) frequency for RFID use. However, the UHF frequency allocation is not consistent across the world. North America and Europe use 915MHz and 868MHz for UHF RFID systems (respectively), but other countries haven't followed suit. In some countries, this frequency range is already allocated for other uses, such as mobile phone or taxi communications. In these cases, government intervention will be required to sort out the resulting frequency conflict. Power generated by the antenna (reader) is another issue. European countries are stricter in terms of the amount of power an antenna is allowed to generate, compared to North America. The lower the power, the lesser the read range of the reader, affecting designs of RFID gates and other systems.

The next section describes the roles that several of the EPC elements play in the creation of an EPC compliant RFID implementation.

Implementation of EPC through EPCglobal Network

Key components that enable the creation of RFID systems compliant with EPCglobal standards are collectively referred to as the EPCglobal Network. The collection includes five key components: the Electronic Product Code (EPC) itself, the identification system (EPC-compliant tags and readers), EPC Middleware, the Object Name Service (ONS), and the EPC Information Services (EPCIS). These five components, all described in Chapter 3, "Components of RFID Systems," comprise a reference architecture that businesses worldwide can use to design their RFID deployments.

Are all five elements required for an enterprise to deploy a standards-compliant RFID solution? That depends on your requirements. As a practice, we think that the standards-based approach provides the best investment protection in the long run and should be followed. However, the whole architecture may not be needed from the start to get an RFID deployment underway in the enterprise.

For example, the first phase of an RFID deployment project may only use the EPC specifications (to tag the relevant items), the EPC compliant tags and readers (to detect and track them), the EPC Middleware (to collect the item-related information, process it, and transmit it to other decision support systems), and EPCIS. However, ONS need not be used. In fact, Wal-Mart is using this approach (explained in more detail in Chapter 9, "Mandates as Business Catalysts"). After the RFID deployment gets integrated in the business processes, you may further enhance it by leveraging a service such as ONS.

In a slightly different scenario, you may have a business need that requires the use of both active and passive tags. The EPC specifications for active tags are not finalized, so part of your deployment may not be EPC compliant. Because you have a business need, it is prudent to proceed with proper planning that allows flexibility. For example, you may deploy such an environment after checking with your middleware vendor and verifying that it has an acceptable roadmap for supporting EPC standards as they are finalized. When the vendor supports the finalized EPC standard for active tags at a future date, your deployment may become EPC compliant with a middleware upgrade. In the following chapters, we provide a framework to enable you to look for and address such issues.

Functions and Features of EPCglobal

EPCglobal continues to work with Auto-ID Labs and the industry to facilitate the creation of EPCglobal standards and related specifications. This is achieved through ongoing communications between the researchers and end users via technical committees, action groups, and steering committees. Each group focuses on a specific area or topic, ensuring that the organization's standards creation process is primarily user-driven. The following list describes the groups as well as the structure of EPCglobal as some of you may decide to get more closely involved in the standards creation process through participation in these groups:

• Business Steering Committee (BSC) oversees the Business Action Group (BAG) and related working groups. It ensures synergy across various groups and drives proper prioritization of deliverables and resources. It also makes recommendations to the president and the board.

• Technical Steering Committee (TSC) reviews standards requests and functional requirements, and ensures that the proposed solution is consistent with EPCglobal Network architecture. It oversees and assigns technical development tasks to Technical Action Group (TAG). The committee also has representatives from the Auto-ID Labs and EAN.UCC.

• The Business Action Group (BAG) identifies industry needs, gathers requirements, develops use cases, and drives consensus on best practices. The use cases are submitted as vertical or horizontal industry-specific standards development requests. It also reviews and approves technical specifications against use cases and other business requirement documents. The BAG members are required to be EPCglobal subscribers. BAG also creates working groups focused on specific topics, as needed.

• The Technical Action Group (TAG) facilitates the development of technical standards based on business needs and requirements. A Hardware Action Group focuses on standards and specifications related to hardware issues, whereas a Software Action Group focuses on standards and specifications related to software interoperability. The action group members are required to be EPCglobal subscribers. Additionally, the Technical Action Group members are required to sign EPCglobal's Intellectual Property policy.

• Each working group, composed of a subset of action group members and EPC staff members, is responsible for completing specific tasks specified by the action groups. For example, business focused working groups create use cases, whereas technically focused workgroups create draft specifications for various standards.

• In addition, a Policy Steering Committee (PSC) works on issues that span business and technology charters, for example, privacy.

• All the steering committees, action groups, and working groups are overseen by the president of EPCglobal and a board of governors. They are responsible for setting the strategic direction of EPCglobal and ratification of the standards. The board is comprised of representatives from end-user companies and EAN organizations.

EPCglobal also offers training and education on implementing and using the EPC and EPCglobal Network to its subscribers. The organization's Web site (www.epcglobalinc.org) provides further contact and cost information for becoming a subscriber.

Although EPCglobal focuses on developing the comprehensive standards for interoperability among different components of an RFID implementation, various other related organizations are also focusing on standards related to RFID. It is critical that the EPC standards co-exist with them in order to ensure end-to-end interoperability of RFID systems. The world's largest developer of standards, International Organization for Standardization (ISO), has developed several standards around RFID. Because of ISO's role in the development of global standards, EPCglobal officials have decided to align their proposed standards with those of ISO. In addition, EPCglobal plans to ratify and use all applicable ISO standards. The next section provides an overview of existing ISO standards related to RFID.