This brief introduction on NFC technology will help designers select the best connectivity implementation amongst the plethora of today’s wireless standards.
What is it?
Near field communication (NFC) is a set of close-range wireless standards that enables electronic devices to establish connections by touching or moving within a proximity of 10cm or less (about ½ the width of a typical page). Since NFC only works when two devices are brought close together, this “tap to connect” technology increases security by making it difficult for intruders to ease-drop at a distance.
In addition to data, two devices using NFC can also share power. The mechanism for wireless power transfer occurs through electromagnetic induction: a current is transmitted by a coil in a charging device to a second receiving coil embedded in a nearby device. As Richard Stockdill notes in his blog, “… an efficiency of greater than 90% can be achieved at close distance and for coils of similar size.” [Telsa was one of the first to realize the possibilities of wireless power transfer.]
NFC is a newer version or extension of radio frequency identification (RFID) technology. But there are several key differences. For example, NFC is for very short range communication, while RFID devices can have very long ranges, e.g., between your car’s toll pass and the highway toll readers. Further, NFC allows two-way communication, as opposed to RFID’s one-way reading technology. This means that NFC can also be used to transfer photos and contacts between devices.
Why Is It Needed?
According to market research, more users will access the Internet wirelessly via mobile devices than from wired Ethernet connections. These mobile devices offer several different wireless connectivity options, each with their different strengths and capabilities. But only NFC is specifically engineered to provide zero power operation and maximize privacy, both at a very low cost.
What Can It Do?
One of the most touted applications for NFC is the “mobile wallet” in which your smartphone will replace your cash and credit cards. For example, uses can pay for coffee with just on tap or wave of your phone instead of with credit cards or physical money. Such applications benefit from the very close proximity needed to secure the transaction.
Other uses for NFC include:
- Parking meter payments
- Airline boarding passes and similar transportation tickets.
- Automotive connectivity that should enable a range of comfort and convenience applications including keyless entry and vehicle settings.
- Downloading information, similar to QR codes.
How Does It Compare to Other Wireless Protocols?
Designers have several choices for connectivity, all with trade-offs (see figure). WiFi, ZigBee, and Bluetooth all have different strengths and capabilities. None, however, were specifically engineered to provide low cost zero-power operation and maximize privacy.
For more information, please visit these sites:
- NFC Forum – The Near Field Communication Forum was formed to advance the use of Near Field Communication technology by developing specifications, ensuring interoperability among devices and services, and educating the market about NFC technology.
- Use Cases – The range and variety of existing and potential NFC applicationscontinues to grow. The examples presented here are just a small subset of the existing and emerging applications that are being enabled by NFC.