Near Field Communication is a short-range (up to 20 cm), high-frequency, wireless communication technology. It is a standard that extends the Radio Frequency Identification (RFID) standard by combining the interface of a smartcard and a reader into a single device. This standard is primarily built for mobile phone use, and thus is attracting a lot of attention among vendors that are interested in contactless data transmission (such as credit card sales). The standard enables NFC to be used in three specific ways:
The device is a contactless card (and thus can be read by other readers).
The device can read RFID tags.
Two devices can communicate back and forth and exchange data.
In Android 2.3 (API level 9), Google introduced the Reader Mode NFC functionality. Starting in Android 2.3.3 (API level 10), the ability to write data to an NFC tag and exchange data via P2P mode is also available.
NFC tags consist of data encoded in NFC Data Exchange Format (NDEF), a message format specified by the NFC Forum Type 2 Specification. Each NDEF message consists of one or more NDEF records. The official technical specification for NFC can be found at http://www.nfc-forum.org/. To develop and test an NFC reading application it is highly suggested that you get an NFC-compliant device (such as the Nexus S, at http://www.google.com/phone/detail/nexus-s) and an NFC-compliant tag.
To use NFC functionality in your application, you need to declare ...