RFID and Near-Field Communication

Related to radio-frequency identification (RFID) is near-field communication (NFC)—an evolved form of the RFID solutions used for open-road tolling on highways. Since gaining mainstream traction two years ago, NFC technology is bundled into more and more smartphones, including the Android-powered Samsung Galaxy S4. As a result, consumers are beginning to use NFC for more than mobile payments. What if you could tap your phone to unlock a door, sans keys? That reality may not be far away, thanks to NFC. In a real-world example, an Asian library has enabled a new use of the wireless technology, which is akin to a low-power Bluetooth that can transfer small amounts of information, such as a URL or a payment. The key to NFC is that the item sending the information does not need any power: Badges and stickers can deliver information to a phone with a tap.

Hanno Library has installed approximately 100 tags, called “Tatchitagu” and provided by Fujitsu, on its shelves in Japan, where mobile phones with NFC are more common. There, the technology is employed to replace credit cards and subway passes. Library visitors can tap their phones on the tags to receive all kinds of information, including Wikipedia links to authors, pictures, and reviews.

The tags also access services: If someone wants to review books or recommend them to other readers, he or she just taps and types. The system even facilitates check-out.


How NFC works

Here’s how it works, as described by Popular Science: NFC is a short-range, low-power communications protocol between two devices. One device, the initiator, uses magnetic induction to create a radio-wave field that the target can detect and access, allowing small amounts of data to be transferred wirelessly over a relatively short distance. (In NFC’s case, the distance must be less than 4".) The difference between NFC and RFID is that the latter is a one-way street: The EZ-Pass transmitter beams the $4.25 toll to the tollbooth’s receiver, for instance, and that’s the extent of the transaction. But NFC is two-way, allowing NFC-enabled gadgets to send and receive information.

Compared to other wireless protocols like Wi-Fi or Bluetooth, NFC is exceedingly slow, with a maximum data transfer speed of 0.424 Mbps (or less than a quarter that of Bluetooth). But NFC has several key advantages: It consumes a mere 15 mA of power, which is practically nothing for today’s jumbo smartphone batteries; it has the possibility for greater security; and it forgoes the involved “pairing” process of Bluetooth entirely. Bluetooth needs to be configured; NFC is completely effort-free, requiring nothing more than a tap.