Radio-identification

The radio-identification , coming from the English radio frequency identification (usually shortened RFID ), is a method to store and recover given remotely by using markers called “radio-labels” (“ RFID tag ” or “ RFID transponder ” in English). The radio-labels are small objects, such as autoadhésives label S , which can be stuck or built-in products. The radio-labels include/understand a antenna associated with an electronic chip which enable them to receive and to answer the radio requests emitted since the transmitter-receiver.

These electronic chips contain an identifier of the type EPC ( electronic product code ).

Principle

A system of radio-identification is composed markers, named radio-labels (or tag, transponder) and of one or more readers. A marker is composed of a chip and a antenna.

Readers

In fact devices active, transmitting radio frequency S will activate the markers who pass in front of them of providing them to short distance the energy which those need. The Fréquence used is, according to the generations:

125 Khz;
134,2 Khz for the load of the transponder; 134,2 Khz for a bit 0 and 123,2 Khz for a bit 1 for the answer of the transponder in the case of a transmission FSK (Texas Instruments Series 2000);
13,56 MHz (ISO 14443A 1-4, ISO 14443B 1-4, ISO 15693-3 and ISO 18000-3);
915 MHz with the the United States, of 865 MHz with 868 MHz in the European Union for the UHF (EPCglobal and ISO 18000-6c; the frequencies and the powers of emission depend on the legislations in force);
2,45 GHz.

A higher Fréquence has the advantage of allowing an information exchange (between reader and marker) Débit S more important than in low frequency. The important flows allow the implementation of new functionalities within the markers (Cryptographie, more important, anti-collision memory). On the other hand a lower frequency will profit from a better penetration of the matter.

The anti-collision one is the possibility for a reader of being able to dialog with a marker when more than one marker are in his field of detection. The algorithms the anti-collision one are described by the standards (ISO 14443 and ISO 15693).

One of course avoids any frequency which would be in Résonance with that of the Molécule S of Eau contained inter alia in the human body for safety reasons (principle of the Microwawe oven).

Radio-labels

They are passive devices, not requiring any energy source apart from that provided by the readers at the time of their interrogation.

In addition to energy for the label, the reader sends a particular signal of interrogation which the label answers. One of the simplest possible answers is the reference of a numerical identification, for example that of the standard EPC-96 which uses 96 Bit S. a table or a Database can then be consulted to ensure a Access control, a counting or a follow-up given on a Ligne of assembly, like all desirable Statistique.

The marker is extremely discrete by his smoothness (sometimes that of a piece of Rhodoïd), his reduced size (a few millimetres), and his negligible Masse. Its cost having become tiny, one can plan to make it disposable, although the re-use is more “ecologically correct”.

The marker is composed:

of a antenna;
of a chip of Silicon;
of a substrate and/or a encapsulation.

Let us note also the existence of active” and “semi-active” tags the “(also called BAP, battery-assisted passivates tags ).

The active labels are equipped with a battery enabling them to emit a signal. So they can be read since long distances, contrary to the passive tags. However, an active data transmission announces to all the presence of the tags and raises questions as for the safety of the goods.

The semi-active labels do not use their battery to emit signals. They act like passive labels on the level communication. But their battery allows them, for example, to record data during transport. These labels are used in the sendings of products under controlled temperature and record the temperature of the goods with regular interval.

Constraints

Obstacles

Metal environment

The reading of radio-labels posed on objects located in a metal container is more difficult. The possible distance from communication is decreased.

Collisions

When several markers are in the field of the same reader, the Communication S are scrambled by the simultaneous activity of the markers.

The collision detection is in fact a detection of error of Transmission, using a bit of parity or of a Hachage (CRC…). As soon as an error is detected, the algorithm the anti-collision one is applied.

Several methods of anti-collision were developed. Here are the four principal ones.

frequential method: Each marker communicates on a beach of Fréquence S different with the reader. In practice, it is unusable with large scales.
space method: With a directional antenna and at variable power, the reader gradually will cover each part of space to communicate with each marker and to inhibit it, while waiting to reactivate it for then communicating with. In practice, the presence of two markers at short distance one of the other makes this method ineffective.
temporal method: The reader proposes to the markers a series of channels of time in which they can answer. The markers choose in a random way the channel of time in which they will answer. If a marker is the only one to answer in this channel of time, it is detected and inhibited by the reader. If there are several markers who answer at the same time, it will be necessary to carry out this method again. Gradually, all the markers are known and inhibited; it is then enough for the reader to reactivate the marker with whom it wishes to communicate. In practice, the random side makes that the duration of this method is unknown.
systematic method: There exist many patents describing of the systematic methods. This method consists in detecting then to inhibit in turn all the markers by traversing the tree of all the possibilities of identifiers (for example, the reader sends to a request of the type “All the markers whose first bit of identification is 1 must appear. ” So only one marker appears, the reader inhibits it, and is interested then in the markers with for first bit 0, and so on). In practice, this method can sometimes prove to be long.

Uses

The versions Low frequency (125 with 135 Khz) are used for the Identification pets (Chat S, Chien S: marker posed into subcutaneous in the neck), of wild animals (Stork S, Penguin S), of the cattle (Cow S, pig S), the traceability of the barrels of Beer or quite simply for the Access control by badge proximity or hand-free. They are also this class of markers who are at the base of the electronic systems of key “without locks” that one sees appearing on certain models Automobile S. the hand-free Badge S, according to the type of antenna used, allow a use until 150 cm.

The class High frequency (13,56 MHz) is used for the traceability of the books in the Librairie S and the Bibliothèque S and for the localization of the luggage in the Aéroport S. the access control to sensitive buildings is also a field where the system of radio-identification replaces the magnetic badges, allowing the authentification of the people without contact. On the other hand, the badges of Access control to this frequency do not allow a use more few centimetres. They have the advantage of allowing the operations of read-write in the chip, to store biometric information , for example.

The markers UHF (Ultra high frequency) are used for the Traçabilité pallets and Conteneur S in the Entrepôt S and on the docks. At this frequency, the reading is not possible through water (and thus the human body).

The last class of the markers uses the microwaves (2,45 GHz) for the Access control to long distance of the Vehicle S, such as for example on the great industrial parks. These markers are generally active.

One will be able to also note the use of markers like ideal means of Communication for the collection of the Donnée S exits of the scientific statements produced by the autonomous measuring sites (weather stations, volcanic or polar).

There exists with HongKong and the Netherlands of the markers having the shape of credit cards. These charts were democratized like electronic means of payment (equivalent of Moneo in France).

Lastly, the subcutaneous radio-labels, designed initially for the traceability of the animal , can without any technical constraint being used on human . The company Applied DIGITAL Solutions proposes for example its subcutaneous radio-labels under the trade name of VeriChip. They are intended for the human ones as a solution to identify the Fraude S, to ensure the access protected to confidential sites, storage of the medical data and also like a means of solving removals of important personalities quickly. Combined with sensors sensitive to the principal functions of the Human body, these systems are also proposed as an integrated solution of supervision of the health condition of a patient.

The use of these chips started right now. Thus Baja Beach Club, a Nightclub located at Barcelona, uses subcutaneous chips with radio frequency to even offer to its customers VIP a function of electronic porte-monnaie established in their body. In the same way, the town of Mexico City established a hundred and seventy of these radio-labels on its Officier S of police force in order to control the access to the databases and also with an aim of implementing means of localization in the event of Kidnapping.

Applications

Existing applications

Access to the public transport
Followed industrial in assembly line
Inventory S: An academic analysis carried out at Wal-Mart showed that the RFID can reduce the ruptures of inventory of 30% for the products having a rate of rotation between 0,1 and 15 units/day.
automatic Saisie of a list of products bought or left stock
In universities like Cornell, of the charts with radio-identification makes it possible to the students of the university to reach without formality the Bibliothèque twenty-four hours out of twenty-four and seven days over Sept. the books are of course provided them also with radio-labels, which eliminates any administrative waste of time during the loans. Several libraries are also equipped in the Netherlands, where, since January 1st 2004, each work bought comprises a radio-label (containing a chip SLI of Philips). In France, several libraries they crossed also the step and are equipped with materials of radio-identification. The movement is in real acceleration, because of the great functional interest which this technology for the libraries and of the price of the labels presents, in perpetual fall.
the management of the parks of Vélib in Paris uses chips RFID.

Potential applications

The intelligent labels are often considered like a means of replacing and of improving the code-bars of standard UPC/EAN. The radio-identifiers are indeed rather long and countable to plan to give to each object a single number, whereas the UPC codes currently used only make it possible to give a number for a class of products. This property of the radio-identification makes it possible to trace the displacement of the objects of a place with another, since the line production to the ultimate consumer. It is this property which makes that technology is regarded by many industrialists of the supply chain as the ultimate technological solution with all the problems of traceability, essential concept since the medical crises related to the food dies.

However the solutions of radio-identification, although operational, suffer from a lack of standardization. The jungle of the solutions suggested by the various manufacturers makes the traceability universal difficult to realize.

EPCglobal is an organization which works in this direction on a proposal of international standard in order to standardize the technical uses of radio-identification. The goal is to be able to have a homogeneous delivery system of the identifiers in order to have a EPC ( electronic product code or codes electronic product) for each object present in the supply chain of each company of the world.

The properties of the radio-labels would also make it possible to consider applications bound for the ultimate consumer, like:

a Refrigerating able automatically to recognize the products which it contains, but also able to control the deadlines of optimal use (DLUO) of the perishable food products,
identification of the animals thanks to the establishment of a chip (already obligatory in Belgium and Suisse for the dogs and the cats),
the marking of clothing.
identification of postal addresses (UAID), the indentity cards (INNATE)

Another proposal for a use of this innovation is inclusion in the documents in official matter of tags RFID like system of identification and validation, in particular for the passports, but also for the driving licenses. One can thus plan to include biometric data of authentification in order to reinforce the provisions of safety.

Controversies

Technologies RFID could prove to be dangerous for the individual:

Possibility of attack to the Private life in the case of “furtive” markers
Use of the contained informations by the markers of Passport S to attack selectively and by simple physical proximity nationals of certain nationalities
abusive Marking people having borrowed certain types of books (policy, etc) like undesirable in the files of potential employers or of a repressive State
potential Problems of numerical/economic sovereignty related to the infrastructure of the EPCGlobal network, in particular being the administration, by contract, of its root (onsepc.com) by a private actor (American)
the case of subcutaneous labels RFID raises questions of naturally ethical and raises of the Droit to the physical integrity. The limitation with voluntariate does not ensure of sufficient guarantee, any person refusing these subcutaneous labels risking extremely well by this fact of being victim of Discrimination S.
Identification of people by a signature of the whole of labels RFID (bank cards, mobile, not public transport…) usually carried (cf patent IBM " Identification and Alignment off Persons Using RFID Tagged Objects" e.g.)
Generation of signals radio frequencies being able to prove to be dangerous for health (cancers,…)

Protection of the individuals

The French legislation provides a certain protection of the private life while prohibiting:

clandestine control (any identification must be the visible indication object);
the use of the same apparatuses for the access control and the control of presence.

According to German association foebud the legislation is not restrictive enough for technology RFID and the protection of the personal informations

Certain associations propose tools to protect from use a not - authorized radio-identification, such as RFID Guardian

Other associations propose the boycott of this technology which they estimate liberticides. According to them the pointing of noncontrollable information in a chart of electronic identity would be prejudicial with the freedom of the individuals.

Safety

A group of hacker S.A. announced with biannual convention Sixth HOPE with New York to have cracké (broken) the safety measures of the famous subcutaneous chip. Moreover, they also claim to have made a success of with cloner this one. They estimate that the legislation is too flexible with this technology taking into consideration its potential attack to the private life.

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