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The A to Z of wireless
Updated: Everything you need to know from A to Zigbee, and plenty in between...

By Natasha Lomas

Published: Tuesday 11 August 2009

R is for RFID

Radio frequency identification tags are tiny microchips equipped with antennae allowing data - typically a unique code or identifier - to be transferred wirelessly to a reader.

The tags are typically attached to objects to enable machines to automatically identify what they are. However, tags have also been attached to animals and even humans.

RFID tags can be passive or active. Active tags incorporate a battery meaning data can be transmitted over greater distances than their passive counterparts. Passive tags are smaller and cheaper - having no battery and relying on drawing power from the RFID reader instead - but they need to be brought much closer to the reader as a result. Passive tags typically have a very long shelf life (of up to a decade) but are able to store less data than the more expensive active tags.

As well as being contactless, RFID does not require line-of-sight between tag and reader - making it a more flexible technology than the more common (and much less expensive) alternative: barcodes.

However RFID's cost per tag is still too high for retailers to ditch barcodes - and instead RFID tends to be used for inventory of larger items, such as pallets in warehouses, or to keep track of more costly goods, such as military equipment.

The technology has applications outside supply chain management too. Back in 2006 the UK government introduced a RFID chipped passport using the chip to store a facial biometric of the passport holder, along with basic ID information contained on the paper passport. Second generation ePassports, due to be introduced in 2011/12, will have a chip containing fingerprint scans and personal details.

The financial services industry is also interested in RFID. Earlier this year, Barclays bank announced it would be replacing all debit and credit cards by 2011 with ones that incorporate a RFID chip to enable contactless payments.

Close up of an RFID chip inside a credit card keychain (Photo credit: oskay via Flickr.com under the following Creative Commons licence)