Radio Frequency Identification (RFID)
RFID, Radio Frequency Identification, a non-contact technology which works on radio frequency to achieve auto-identification and data-gathering of a tagged object. An RFID system mainly consists of a tag, a reader, and an antenna. The reader sends an signal to the tag via the antenna, and the tag responds with its unique information. RFID tags can be divided into passive and active.
Passive RFID tags have no internal power supply, but are powered by the electromagnetic energy transmitted from an RFID reader. Passive RFID tags are used for applications such as access control, file tracking, supply chain management and so on.
Active RFID tags are powered by an internal battery to continuously broadcast their own signal, which usually operate in one of two main frequencies - 433 MHz or 915 MHz. Active RFID tags are commonly used as “beacons” to accurately track the real-time location of assets or in high-speed environments such as tolling. Active RFID tags possess their own power source - an internal battery that enables them to have extremely long reading range as well as large memory banks, but they are also much more expensive.
Near Field Communication (NFC)
NFC, Near Field Communication, is a communication protocol approved by the International Organization of Standardization (ISO 14443 & ISO 18000-3). NFC devices operate at the same frequency (13.56 MHz) as HF RFID readers and tags. As NFC devices must be in close proximity to each other, commonly no more than a few centimeters, it has become a good choice for secure communication between consumer devices such as smartphones.
An NFC enabled device can operate in three different modes - reader/writer mode, peer-to-peer mode and the all important card-emulation mode.
- In Reader/Writer mode, an NFC device behaves as a reader that detects a tag in close proximity by using collision avoidance mechanism, then available to read data from or write data to the NFC tag after detected.
NFC devices are able to read passive HF RFID tags that are compliant with ISO 15693, in which the data can contain commands for the devices such as opening a specific mobile application. You may start seeing NFC tags and HF RFID tags more usually in advertisements and posters, as it's an efficient way to pass along information to consumers.
- In Peer-to-Peer mode, two NFC enabled devices can exchange information between each other by tapping
the two devices together, which turns sharing data into a simple task. Exchanging photos, business cards and money transfer between friends are some of the applications for this mode.
- In Card-emulation mode, an NFC device behaves like a contactless smart card. In this mode, the mobile phone does not generate its own RF field, the NFC reader creates this field instead.
This unique ability has made NFC a popular option for contactless payment, which now enabled in many smartphones. As long as a mobile platform supports the emulation of protocols ISO/IEC 14443 regular contactless cards, we can use our mobile phone in place of credit cards, transit cards, access cards and so on.
In short, RFID is the process to uniquely identified items through radio waves, and NFC is a specialized subset within the family of RFID technology. Specifically, NFC is a branch of High-Frequency (HF) RFID, both of which operate at 13.56 MHz. NFC is designed to be a secure form of data exchange, and an NFC device can be available to act as both an NFC reader and an NFC tag.
