1page.title=Near Field Communication 2@jd:body 3 4 <p>Near Field Communication (NFC) is a set of short-range wireless technologies, typically 5 requiring a distance of 4cm or less to initiate a connection. NFC allows you to share small 6 payloads of data between an NFC tag and an Android-powered device, or between two Android-powered 7 devices. 8 9 <p>Tags can range in complexity. Simple tags offer just read and write semantics, sometimes with 10 one-time-programmable areas to make the card read-only. More complex tags offer math operations, 11 and have cryptographic hardware to authenticate access to a sector. The most sophisticated tags 12 contain operating environments, allowing complex interactions with code executing on the tag. 13 The data stored in the tag can also be written in a variety of formats, but many of the Android 14 framework APIs are based around a <a href="http://www.nfc-forum.org/">NFC Forum</a> standard 15 called NDEF (NFC Data Exchange Format).</p> 16 17 <dl> 18 <dt><strong><a href="{@docRoot}guide/topics/connectivity/nfc/nfc.html">NFC Basics</a></strong></dt> 19 <dd>This document describes how Android handles discovered NFC tags and how it notifies 20applications of data that is relevant to the application. It also goes over how to work with the 21NDEF data in your applications and gives an overview of the framework APIs that support the basic 22NFC feature set of Android.</dd> 23 24 <dt><strong><a href="{@docRoot}guide/topics/connectivity/nfc/advanced-nfc.html">Advanced 25 NFC</a></strong></dt> 26 <dd>This document goes over the APIs that enable use of the various tag technologies that 27 Android supports. When you are not working with NDEF data, or when you are working with NDEF 28 data that Android cannot fully understand, you have to manually read or write to the tag in raw 29 bytes using your own protocol stack. In these cases, Android provides support to detect 30 certain tag technologies and to open communication with the tag using your own protocol 31 stack.</dd> 32 </dl> 33</p>