RFID History and Standards

History

Radio-frequency identification, or RFID, is the offspring of the marriage of two technologies: radio technology and electronics which has now been superseded by micro-electronics.

The table below gives a rapid historical overview of the development of RFID.

 

1948

The RFID system was first designed in the 40s to differentiate between friendly and enemy aircraft. Large tags or transponders were placed in friendly planes to give a friendly response to radar interrogation. This IFF (Identify: Friend or Foe) system was the first use of RFID. Air traffic control is based on this principle even today.

1970

During the 70s, RFID systems were still a restricted technology for military use operated by national governments for the security of sensitive sites, particularly in the nuclear field.

1980

The invention of micro-systems and the advance of technology led to the use of the passive tag. The absence of an on-board power supply made the tag less expensive but forced it to receive power through the reader signal. Reading distances obtained were then a few centimetres.

At the end of the 70s, the technology was transferred to the private sector. One of the very first commercial applications was the identification of cattle in Europe.

The early 80's saw tags being manufactured and marketed by a large number of European and American companies.

1990

Standardisation started in terms of the interoperability of RFID equipment initially with smart cards then tag-reader systems in general.

RFID and its components

Radiofrequency identification (RFId) is an automatic identification technology which first saw the light of day in the 1950?s  but which has only come to the fore in relatively recent times.
It is a technology based on the emission of electromagnetic fields received by an aerial coupled to a microchip (transponder or tag). The field acts as a vector for information between chip and reader, and for the power activating these chips.

An automatic radio-frequency identification application therefore consists of a reader which transmits a signal on a set frequency to one or more radio labels located in its read field.
These send a signal back. When the labels are "awakened" by the reader, a dialogue starts using a pre-set communication protocol and data is exchanged.

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the  electronic label is an information medium combining signal processing and data storage. It consists of an electronic circuit (or "integrated circuit"), distributed on a printed circuit and coupled to an aerial.
Often known as "transponders" (TRANSmitter/resPONDER) owing to their response and transmission functions, the radio label or tag responds to a request sent by the reader and relating to the data it contains. The transponder memory generally comprises a ROM (Read Only Memory), a RAM (Random Access Memory) and a non-volatile programmable memory for the retention of data according to the type and degree of complexity of the product. The ROM contains the security data and instructions for the OS (Operating System) of the label responsible for basic functions such as response time, data flow control, and power management. The RAM memory is used for the temporary storage of data during the interrogation and response processes. The power required for the tag to operate is supplied either by an internal cell (or battery) for active or semi-active tags, or supplied from a remote power supply via the electromagnetic field emitted by the reader (passive tags).

The base station emits radio waves within an area ranging from a few centimetres to several dozen metres, depending on the power of the supply and radio-frequency used. When an RF label enters the electromagnetic field, it detects the signal from the base station. The reader reads the data encoded in the transponder and it is then sent to the server for processing. The base station may also participate in signal processing, and in parity checks, error detection and correction.

An RFID system therefore allows information to be written and stored on and deleted from the tag microchip. In addition to contactless data transfer, communication via the aerial also allows sightless transfers between reader and label through materials that are opaque to the light, with several labels being able to be read simultaneously.

The different RFID systems are characterised mainly by their communication frequency. However, apart from this carrier frequency, other characteristics also define RFID labels and  constitute the basis of their specifications:

  • the origin and type of power used

  • reading distance

  • programmability

  • physical form

  • memory size

  • packaging properties (material)

  • number of tags read simultaneously (collision avoidance)

  • and of course cost

Communication frequencies

The transponder aerial is the means through which it detects the field and transmits its response to the interrogation. It emits radio signals to activate it and to read and write data. The aerial is also integrated into the base station to become a reader which can be configured as fixed or mobile equipment. It is therefore the link between the transponder and the base station. The electromagnetic field produced by an aerial can be maintained continuously or activated by a sensor if interrogation is not required on a constant basis.

communication protocol whose main characteristic is the exchange radio frequency.

Several communication frequencies cohabit in RFID technology. The main ones are:
< 135 KHz    13.56 MHz     863 915 MHz    2.45 GHz

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In the knowledge that each country retains the possibility to assign these frequencies to other specific uses and with different transmitting powers.
A degree of standardisation in the use of frequencies is in the process of being defined by dividing the world into three regions:

Region 1 = Europe, former Soviet Union and Africa
Region 2 = North and South America
Region 3 = Asia and Australia

The table below gives an overview of the advantages and disadvantages of tags by communication frequency:

   

LF< 135 kHz

HF13.56 MHz

UHF863 to 915 MHz

SHF2.45 GHz

Data capacity

From 64 bits read-only to 2kbits read-write

Conventionally read-write tags  with 512 bits of memory (max: 8kbits partitioned)

Conventionally read-write tags with 32 bits of memory (max: 4kbits partitioned into 128 bits)

From 128 bits to 32 kbits partitioned

Products available

Read-only and read/write

Read-only and read/write

Read-only and read/write

Read-only and read/write, power supplied from a remote power supply and battery assisted

Data transfer

Low rate of transfer: less than 1kbits/s (~200bits/s)

About 25 kbits/s in general (exists in 100 kbits/s)

About 28 kbits/s

Generally < 100 kbits/s but can rise to 1 Mbits/s

Read distance

Typically to 0.5 m from the contact for tags powered by a remote power supply, otherwise ~ 2 m

For tags powered by a remote power supply about one metre

For tags powered by a remote power supply about one metre

A few tens of centimetres for the passive ones and a few tens of metres for theactive ones

Read Mode

ingle read and multiple read versions are available

Single read and multiple read versions are available

Single read and multiple read omni-directional

Single read and multiple read

Operational limits

- 40 to + 85 C

Insensitive to industrial electomagnetic disturbance

- 25 to + 70 C

Slightly sensitive to industrial electromagnetic disturbance

- 25 to + 70 C

Sensitive to electromagnetic disturbance.
May be disturbed by other UHF systems in proximity

- 25 to + 70 C

Highly senstive to electromagnetic disturbance reflected by metal and absorbed by water

Applications

Manufacturing process
Vehicle and container identification
Access control
Animal identification

Monitoring
Vehicle fleet
Luggage
Bookshop
Rental Service Launderettes
Logistics

Logistics
Vehicle fleet monitoring

Business automation
Access control
Military logistics
Automatic pay tolls

Standards

For interoperability, it is essential for RFID equipment (readers and tags) to be standardised in terms of their operating mode, in other words, in respect of a given frequency of use, for any tag to be read by any reader. We then talk of a communication protocol.

Standardising communication protocols between tags and readers is the work of a joint technical committee set up between the ISO (International Organization for Standardization) and the IEC (International Electrotechnical Commission) known as JTC1 and covering the information technologies. The sub-committee which is of interest to us is SC31 which deals with automatic data identification and data input techniques.

proposals, votes etc.) between all the national commissions of the member states. For France, the body hosting this Standardisation Commission (SC31) is AFNOR (Association Franaise de Normalisation).

The standards relating to the communication protocols (air-interface) are designated as follows:

  • ISO 18000-1: the lexis

  • ISO 18000-2: for communication frequencies below 135 KHz

  • ISO 18000-3: for an operational frequency at 13.56 MHz

  • ISO 18000-4: for a frequency of 2.45 GHz

  • ISO 18000-6: for frequencies between 860 and 930 MHz

  • ISO 18000-7: for an operation at 433 MHz

Contact: Neeli Prasad [Project Coordinator] np(at)es.aau.dk
Center for TeleInFrastruktur (CTiF)   Aalborg University Niels Jernes Vej 12 9220 Aalborg East, Denmark
Phone: +45 9940 7506 Fax: +45 9815 1583 e-mail: aspire_office(at)es.aau.dk ASPIRE 2009

Last updated: 01.12.2009