Radio Frequency Identification (RFID) is a method of identification which utilises a signal transmitted between an electronic device (known as a "tag", "transponder" or "microchip") and a reading device (or "scanner"). The information provided by the transmitted signal identifies the transponder and, from by reference to stored data (a "database" or "registry"), identifies whatever is carrying that transponder.

RFID can be used to identify almost anything, be it car, animal, fish, bird, box, industrial sub-assembly or waste container. There is a range of RFID systems, and the nature of the thing to be identified and the circumstances under which the signal is transmitted determine the type of system used.

In situations where long distance identification is needed a battery operated device is preferred, as in tracking wild animals from a helicopter etc. This article does not deal with these "active" devices.

The RFID devices most widely used in animals are passive in nature. They have no battery or source of power of their own, but pick up the energy they require from the scanner. Devices of this type are called transponders, and small transponders are commonly called microchips. This method of energising the transponder severely limits the effective operating distance between the scanner and the transponder.

The scanner creates an energy field when it is turned on, and the transponder picks up energy when its antenna enters this energy field. The transponder uses the energy to power an integrated circuit attached to its antenna. The integrated circuit (the actual microchip) creates a signal of specific characteristics including the transponder's identification data and transmits it using the same antenna.

The signal is then received by the scanner, either by the same antenna that created the energy field or by a separate receiving antenna. The scanner interprets the signal, converting it from binary data to decimal or other format, and then sends it to a display, a computer, or other device. In some cases transponder data alone is sufficient to identify whatever is carrying the transponder. However, in many other situations, and in particular the identification of domestic animals, it is necessary to refer to information stored in a database registry to effect identification.

The International Standards Organisation (ISO) is an international association of national standards bodies. It has no regulatory authority. It limits itself to producing guidelines, procedures and policies on a wide range of issues and applications. These international standards provide a template for member bodies to develop their own standards. Regulators may adopt these ISO standards unchanged, or modify them to suit local conditions or requirements. The result is standards that are internationally compatible, consistent and clear.

ISO standards have no legal status on their own. When countries, regulators or users specify that products or services must conform to a standard, these organisations give their legal authority to the standard and they are responsible for enforcing the use of the standard, not ISO itself.

The ISO system does however provide for some degree of quality assurance. ISO may appoint other organisations to assess products or services and certify that they comply with particular standards. In this situation it is the registration organisation which bears the legal responsibility for the correctness of such certification.

This international standard describes the structure and the information content of the radio-frequency identification code for animals.

It sets the length of the 132-bit binary message sent by the transponder to the scanner and the meaning of every bit in it. The message is split into several sections with specific meanings, including indicating whether the transponder is for animal use, manufacturer and/or country code and the fixed transponder identification code. There is also an error detection section to ensure the message is read correctly by the scanner, and some sections that are reserved for future use.

ISO 11784 states that it is a national responsibility to ensure that transponders carry a unique number within that country, and says that ideally every country should maintain databases of information about all issued codes and the associated animals. Number uniqueness is supported by the use of a country code (based on another ISO standard) and/or a manufacturer code assigned by an organisation authorised by ISO.

This international standard defines the technical aspects of communication between transponder and scanner.

It sets the frequencies of activation and response, the encoding format, and the precise interaction between the scanner and the transponder. This standard permits either one-way at a time signal transmission (Half Duplex) or simultaneous two-way signal transmission (Full Duplex). There is an explanation of the combination of the two systems into one scanner.

ISO 11785 also discusses the problem presented by large numbers of animals having already been identified by various non ISO transponders (ones do not conform to ISO 11784), and shows how these technologies can be incorporated into a scanner in accordance with ISO 11785.

No. There is a range of transponder size, type and intended use. Within each type there will also be variations in terms of performance. Importantly, they will all transmit the same format of message at the same frequency, though they could be either FDX or HDX.

All transponders contain an integrated circuit (microchip) but these can differ widely in complexity and performance. They are made to specification in a specialised factory (a wafer fabricator) which makes chips for many other applications. These microchips are then assembled into transponders including an antenna of some type and packaged in the format required: glass rod, plastic ear tag, rumen bolus etc.

Some of the variations in construction will confer variations in performance characteristics such as read speed and distance - see 5. These variations will probably be reflected in prices.

No. An ISO reader must read both HDX and FDX transponders according to the ISO communication protocols. It may also read other types, but each additional technology reduces the overall efficiency of its operation (speed, range etc.) For a given transponder, scanner read distance can be enhanced by having a larger antenna which creates a larger, less intense electromagnetic field. Since the size and features of scanners can vary greatly, so does their cost.

ISO does not guarantee or regulate anything. The ISO standards and associated protocols provide a mechanism whereby countries can guarantee number uniqueness using a combination of country and manufacturer codes and database management.

If country codes are used, they are issued in accordance with a separate standard ISO 3166 ; Codes for the Representation of the Names of Countries.

ISO have appointed the International Committee on Animal Recording (ICAR) to issue manufacturer codes to manufacturers who can demonstrate that their transponders comply with the standards. The contract permits ICAR to check on any complaints, or randomly inspect transponders sold by that manufacturer. In addition, the contract requires the manufacturer to guarantee that all transponders he sells will have unalterable and unique code numbers. The manufacturer code is included in the message sent by the transponder instead of a country code. If anyone copies his manufacturer code, legal remedies are available based on product misrepresentation etc.

Countries can guarantee uniqueness by utilising country and manufacturer codes, database management and national laws and regulations. The national body may control the distribution of transponders under its jurisdiction, or it may have a contractual arrangement with all approved suppliers, and an approval system. It may require that all numbers to be used be recorded first on a national database, and then only eligible numbers can be registered. In any case, it must provide itself with legal remedies if any crime is committed, whether it is fraud, misrepresentation or other.

Some consumers have been reluctant to change from existing non ISO-compliant technologies of proven performance capabilities. ISO has authorised ICAR and other laboratories to test the field performance of ISO compliant transponders and scanners for which manufacturer numbers have been issued. When this process is complete, consumers should have objective analysis of the performance capabilities of these products.

There are obvious differences in performance due to differing types of transponders. For example, small transponders such as 12 mm glass rods cannot be read at as great a distance as those with large antennas such as plastic ear tags.

However, for transponders of each particular type there will also be variations in performance due to differing design. The most important variable is the antenna size and configuration, which determines the amount of energy captured by the transponder to operate the microchip. This in turn affects the strength of their signal transmission and hence the read distance..

Considering that ISO compliant products are made with the most recent components, are distributed in a rapidly expanding world market where product innovation and improvement are proceeding at a rapid pace, it is reasonable to expect improvements in performance. Intense competition enhances the likelihood of that outcome, and also reduces the price.

Registries and data base management are integral to the actual functioning of the system in the field, including ensuring uniqueness of code numbers. There is little merit in knowing the animal’s number if that number cannot be linked to the owner or other data. Since animal RFID exists to provide this link, it is essential that there be an integrated system of access to the other data needed to make use of the number. Moreover, as indicated above in section 4, there is a very important role for the database in preventing number duplication. Of course, the species and other circumstances will affect how the registry or database is used.

Some consumers have expressed concerns as to whether manufacturer's claims of ISO compliance are valid. As discussed in point 4. above, ISO have appointed ICAR to examine products submitted by manufacturers to ensure that they comply with ISO 11784 and 11785. Products that comply will be issued with a manufacturer number under contract to ICAR, who will be responsible for guaranteeing compliance as described under point 4.

See also point 11. below.

The ISO standards provide assurance that animals can be identified by any ISO scanner, anywhere, anytime. There are obvious implications for international livestock trade, commerce, residue management and disease control. Animal owners Consumers can be assured of several suppliers competing for their business with fully compatible products, rather than being limited to one manufacturer. Owners of companion animals can be assured that when all clinics, shelters, and border officials are equipped with ISO scanners the chance of missing or lost identification will be virtually eliminated; of course, there will be a long transition period as previous technologies gradually disappear.

While it is true that to a certain extent having fixed standards is intrinsically limiting to technological development, there is still room for some development within the parameters defined in the standard

Manufacturers now face a real challenge. As an increasing number of users insist on ISO products, manufacturers lose their ability to keep existing markets closed and extract maximum profits. They now have to compete with other manufacturers. However since the market for ISO products is now expanding quickly because of confidence that compatibility is assured, other manufacturers choose to join the race to serve them. They must all compete on quality, features, and price.

Yes, it already does. However, manufacturers have development costs to recoup. There is of course quite a price range relating to product design and hence performance.

This is the area of major new technological development. The key is the extra space in the message in ISO 11784. It permits the development of a virtually limitless number of new types of transponders with an enormous range of potential applications. A new standard which builds on ISO 11784 & 111785 is now under discussion to facilitate this progress.

At this point of time there seems little relevance to most consumers in these products. The development of these new standards is being pushed by the manufacturers involved in the ISO process, in order to avoid future incompatibility among devices. However they are reluctant to build new products until it is clear that there is a market for them.

Yes. There seems no doubt that ISO is coming, but while most countries are committed to the adoption of ISO some are taking their time to make the transition.

Companion animals dominate the RFID market in most countries and so are the first animals to face the need to convert. Commonly expressed concerns are lack of ISO reader network and non-conforming installed bases. There are few instances of compulsory RFID, but even amongst those countries that have formally endorsed ISO, only a few are implanting ISO transponders en masse at the present time. The stimulus for widespread implantation in Europe is the implementation of the policy for free movement of animals within the EU and the need for ID for rabies control. In Europe, the sale of non-ISO transponders for companion animals has effectively stopped.

In the case of livestock industries there is much less use of RFID and more of it is proprietary technology. A lot of testing and trialing is being done. There is not likely be massive usage of ISO product until the completion of current field trials and then almost exclusively only in Europe. Again, the EU ID (animal passport) changes coming in 2002 is a deadline. In countries where there is no compulsion to identify livestock, the economics do not generally support RFID at the present time.