A brief introudction of RFID standards
Standards are crucial for many RFID applications, for example payment systems and tracking goods or reusable containers in open supply chains. A great deal of work has been happening in the last decade to build up standards for different RFID frequencies and applications.
There are existing and proposed RFID standards that cope with the air interface protocol (the way tags and readers communicate), data content (the way in which data is organized or formatted), conformance (methods to test that products satisfy the standard) and applications (how standards are utilized on shipping labels, for example).
The International Organization for Standardization (ISO) has established standards for tracking cattle with RFID. ISO 11784 defines how data is structured around the tag. ISO 11785 defines the air interface protocol. ISO has created a standard for the air interface protocol for RFID tags used in payment systems and contactless smart cards (ISO 14443) and in vicinity cards (ISO 15693). It also has established standards for testing the conformance of RFID tags and readers to a standard (ISO 18047), and for testing the performance of RFID tags and readers (ISO 18046).
Using RFID to track goods in open supply chains is relatively new and much less standards happen to be finalized. ISO has proposed standards for tracking 40-foot shipping containers, pallets, transport units, cases and different items. These are at various stages in the approval process.
The conventional situation was complicated because the Auto-ID Center, which developed Electronic Product Code technologies, chose to create its own air interface protocol for tracking goods through the international supply chain. This short article explains the evolution from the Electronic Product Code and also the importance of various ISO standards.
The Auto-ID Center was placed in 1999 to develop the Electronic Product Code and related technologies that could be used to identify products and track them through the global logistics. Its mission ended up being to create a low-cost RFID system, because the tags must be disposable (a manufacturer putting tags on products shipped to some retailer never was going to get those tags back to reuse them). It had to operate in the ultra-high frequency band, since UHF delivered the read range needed for supply chain applications, such as reading pallets coming through a dock door.
The Auto-ID Center also wanted its RFID system to become global and to depend on open standards. It needed to be global because the aim was to utilize it to track goods as they flowed from the manufacturer in one country or region to companies in other regions and eventually to store shelves. For Company A to see a tag placed on an item by Company B, the tag needed to make use of a standardized air interface protocol. The Auto-ID Center developed its own protocol and licensed it to EPCglobal on the condition that it would be provided royalty-free to manufacturers and end users.
The center also was charged with creating a network architecture?aa layer integrated using the Internet?athat would enable one to look up information of a serial number stored on the tag. The network, too, must be according to open standards utilized on the web, so companies could share information easily and also at low cost.
One option the Auto-ID Center had was to get the numbering system and network infrastructure and employ ISO protocols because the standard for that air interface. Earlier, EAN International and the Uniform Code Council had merged their efforts to produce the Global Tag (GTAG), with ISO’s UHF protocol. But the Auto-ID Center rejected this, since the ISO UHF protocol was too complex and would increase the cost of the tag unnecessarily.
The Auto-ID Center developed its very own UHF protocol. Originally, the center planned to possess one protocol that may be used to contact different classes of tags. Each successive type of tags would be more sophisticated compared to one below it. The classes changed with time, but here’s what was originally proposed.
Class 1: a simple, passive, read-only backscatter tag with one-time, field-programmable non-volatile memory.
Class 2: a passive backscatter tag with as many as 65 KB of read-write memory.
Class 3: a semi-passive backscatter tag, with up to 65 KB read-write memory; essentially, a category 2 tag having a built-in battery to aid increased read range.
Class 4: an energetic tag that uses a built-in battery to run the microchip’s circuitry and also to power a transmitter that broadcasts an indication to some reader.
Class 5: an active RFID tag that can communicate with other Class 5 tags and/or other devices.
Eventually, the Auto-ID Center adopted a Class 0 tag, that was a read-only tag which was programmed at the time the microchip is made. The Class 0 tag used another protocol in the Class 1 tag, which meant that end users needed to buy multiprotocol readers to see both Class 1 and Class 0 tags.
In 2003, the Auto-ID Center transitioned into two separate organizations. Auto-ID Labs at MIT along with other universities around the world continued primary research on EPC technologies. EPC technology was licensed towards the Uniform Code Council, which set up EPCglobal like a partnership with EAN International, to commercialize EPC technology. In September 2003, the Auto-ID Center handed off the Class 0 and Class 1 protocols to EPCglobal, and EPCglobal’s board subsequently approved Class 0 and Class 1 as EPC standards.
Class 1 and sophistication 0 have a handful of shortcomings, in addition to the fact that they are not interoperable. One issue is that they are incompatible with ISO standards. EPCglobal could publish them to ISO for approval as an international standard, but it’s likely that ISO would want to revise them to bring them into line with ISO RFID standards. Another issue is that they cannot be used globally. Class 0, for example, sends out an indication at one frequency and gets to be a signal back at a different frequency inside the UHF band; this really is prohibited in Europe, based on some experts (European Union regulations are open to interpretation).
In 2004, EPCglobal began creating a second-generation protocol (Gen 2), which may not be backward suitable for either Class 1 or Class 0. The aim ended up being to create a single, global standard that would be more closely aligned with ISO standards. Gen 2 was approved in December 2004. RFID vendors which had done the ISO UHF standard also done Gen 2. –
Gen 2 was designed to be fast-tracked within ISO, but a final minute disagreement over something called an Application Family Identifier (AFI) is likely to slow ISO approval. All ISO RFID standards come with an AFI, an 8-bit code that identifies the origin of the data on the tag. Gen 2 has an 8-bit block of code you can use to have an AFI, but it’s not necessary underneath the standard. (Requiring the eight bits to be used to have an ISO AFI might have limited EPCglobal’s treatments for EPCs.) But vendors are making product in line with the new Gen 2 standard, which makes way for global adoption of EPC technology in the supply chain.
ISO has developed RFID standards for automatic identification and item management. This standard, referred to as ISO 18000 series, covers the air interface protocol for systems apt to be used to track goods within the logistics. They cover the major frequencies used in RFID systems around the world. The seven parts are:
18000 C1: Generic parameters for air interfaces for globally accepted frequencies
18000 C2: Air interface for 135 KHz
18000 C3: Air interface for 13.56 MHz
18000 C4: Air interface for just two.45 GHz
18000 C5: Air interface for five.8 GHz
18000 C6: Air interface for 860 MHz to 930 MHz
18000 C7: Air interface at 433.92 MHz
EPCglobal’s Gen 2 standard might be submitted to ISO under 18000-6, but it’s unclear when which will happen or how fast it will be approved. ISO slowed approval of 18000-6 to ascertain if it may be aligned with Gen 2. EPCglobal provides a committee to try and resolve the issue. Requiring an AFI would require dealing with a formal procedure for amending the EPC standard. Customers would like there to become one international standard for tracking goods with the open logistics using UHF RFID tags. But it might take another year before that finally happens.