As far as standards of RFID are concerned, an RFID system can use a few standards. Reason behind this being that there is no one universally accepted standard at the moment. Since years, competing standards have been one of the crucial challenges for RFID. The specifications and standards may be decided and composed at the national, international, industry or trade association level. The individual organizations may call their own specifications as “standard”. When these individual organizations set various industry standards and specifications, normally they are based on international standards in order to make implementation and support easier. Apart from this, there comes an added advantage of providing a wider choice of available products.
These standards can be applied to include the content and format of the codes placed on the tags, the frequencies and protocols that will be used by the tags and readers to transmit the RFID data, the applications use, and the security and tamper-resistance of tags on packaging and freight containers. Currently, Wal-Mart and the Department of Defense (DoD) are the two largest drivers of RFID. Both the Department of Defense (DoD) and Wal-Mart have issued mandates for their top suppliers to use RFID technology when shipping products to their distribution centers. With a slightly different long-term outlook, they are both looking to accomplish the same thing.
In the above mentioned RFID standards debate, the ISO (International Standards Organization) and the EPC Global have both been leading figures. The ISO has their 18000 standard and the EPC standard has been introduced by the EPC Global Center. Both of these RFID standards are further detailed below.
ELECTRONIC PRODUCT CODE (EPC) STANDARDS
The Auto-ID Center has proposed Electronic Product Code as the next standard for identifying products. The EPC, like the barcode, is divided into numbers and letters that identify the manufacturer, product, version and serial number. EPC uses an extra set of digits to identify unique objects. To keep the RFID tag costs down and due to limited memory, the EPC is the only information stored on the RFID tag’s microchip. Readers can then access an infinite amount of dynamic data associated with that individual object in a database via the internet. The development of a standard specification for item level tagging in the consumer goods industry called the Electronic Product Code (EPC) has been a driving force at the Auto-ID Center at MIT. This has further led to a new group called EPCglobal, which is a joint venture between the EAN International and Uniform Code Council (UCC). EPCglobal maintains bar code system amongst others. The primary goal of EPCglobal, as stated in its name, is to make the final EPC standard an official global standard.
EPC TAG CLASSES
Several classes of the RFID tags fall under the EPCglobal umbrella. Class 0, Class 1, Class 2, Class 3 and Class 4 are amongst the EPC Class type categories. If Class 0 and Class 1 are considered, then the difference arises from the data structure and operational perspective. The Class 0 RFID tags are passive read only tags. The Class 1 RFID tags are passive and one-time write able. The Class 2 (Gen2) tags are also passive but supports read and write features. The Class 3 semi active tags posses the enhanced range capabilities with the help of battery. The Class 4 active RFID tags have read write features with active transmitter.
EPC CODE STRUCTURE
The Electronic Product Code (EPC) is a globally unique serial number that identifies an item in numerous number of items. This precisely allows inquiries to be made about a single instance of an item, wherever it is within the supply chain. The EPC is a number made up of a header and three sets of data. The header is useful in identifying the EPC’s version number, and it further allows for different lengths or types of EPC’s later on. EPC Manager is identified by the second part of the number, and generally it is the manufacturer of the product. The third, called object class, directly refers to the exact type of the product. It most often specifies the Stock Keeping Unit (SKU). The fourth part is the serial number unique to the specific item. In general terms, currently, the 96-bit EPC is the most prevailing version and contains information about the manufacturer, the type of object and a specific serial number that relates to the specific object being monitored. Due to the fact that EPC can hold such detailed information, it is central to the RFID compliance initiatives set in motion by many leading retailers and the DoD. Moreover, it is not only that specific company can track its offerings down to the item level under this scheme, but the trading partners can also more precisely track inventory and supplies that spans across global borders. It is of utmost importance to note that once the EPC has been embedded on a RFID tag and read by the reader, it still only provides as much information as a random series of numbers does. Therefore, it demands for the computers for a way to associate the information on the tag to its corresponding information stored elsewhere. Moreover, software is required to source the information about the unique object and communicate it back to the user to make use of the data.
INTERNATIONAL STANDARDS ORGANIZATION (ISO) STANDARDS
The International Organization for Standardization (ISO) is based in Geneva, and its standards carry the weight of law in some countries. All ISO standards are required to be available for use around the world. Therefore, users of ISO RFID standards need not to worry if their systems comply with the different regulations on frequencies and power output for each country where they do business. Moreover, the ISO has created many standards for RFID that deal with both the air-interface protocol and applications for RFID.
ISO STANDARDS FOR RFID AIR INTERFACE
The ISO 18000 series is a set of proposed RFID specifications for item management that could be ratified as standards during 2004. The series includes different specifications that cover all popular frequencies, including 135 KHz, 13.56 MHz, 860-930 MHz and 2.45 GHz. This series is classified from ISO standards 18000-1 through 18000-7 as per the ISO standard. The ISO 18000 – Part 1 corresponds to the Generic Parameters for Air Interface Communication for Globally Accepted Frequencies. The 18000 – Part 2 supports the Parameters for Air Interface Communications below 135 KHz. It is primarily the ISO standard for Low Frequency. Following next is the 18000 – Part 3 ISO Standard, which allows the Parameters for Air Interface Communications at 13.56 MHz. It is the ISO standard for High Frequency and supports the Read \ Write capability. The ISO 18000 – Part 4 standard is designed to support Parameters for Air Interface Communications at 2.45 GHz which is an ISO standard for Microwave Frequency and supports the Read \ Write capability. The next standard in the series which is the ISO 18000 – Part 5 supports the Parameters for Air Interface Communications at 5.8 GHz. The ISO 18000 – Part 6 standard allows Parameters for Air Interface Communications at 860 – 930 MHz. It is the ISO standard for UHF Frequency and has Read \ Write capability. It is also targeted for same markets as EPC standards. Lastly, the ISO 18000 – Part 7 supports the Parameters for Air Interface Communications at 433.92 MHz. It is the Manifest tag for Department of Defense (DoD).