Wi-Fi Direct: Because DIRECT is better way to ACT…

When we use a conventional Wi-Fi network we need a controller device known as WAP (Wireless Access Point). In a scenario where just two devices want to be connected with each other there must WAP to provide support. To avoid this complexity, Wi-Fi Alliance introduced a certification for wireless devices known as Wi-Fi Direct which allows two devices connect directly.

This is a game-changing technology for Wi-Fi devices to connect directly, making it simple and convenient to do things like print, share, synch and display.

Wi-Fi Direct in Android:

Wi-Fi Direct allows Android 4.0 (API level 14) or later devices with the appropriate hardware to connect directly to each other via Wi-Fi without an intermediate access point.

API Overview:

• WifiP2pManager class provides all methods to discover , request and connect to peers.
• Each method in WifiP2pManager implements a specific listener which is passed as parameter to allow you to be notified of the success or failure of method calls,
• Intents that notify you of specific events detected by the Wi-Fi Direct framework, such as a dropped connection or a newly discovered peer.

Connecting via Wi-Fi Direct:

• Application Permissions :
• To use Wi-Fi Direct, we need to add the CHANGE_WIFI_STATE, ACCESS_WIFI_STATE, and INTERNET permissions to your manifest. Wi-Fi Direct doesn’t require an internet connection, but it does use standard Java sockets, which require the INTERNET permission.
• Broadcast Receiver and Peer-To-Peer manager :
• We have to listen particular broadcasts when we use Wi-Fi Directs. These Broadcasts tell us about certain event that occurred.
• WIFI_P2P_STATE_CHANGED_ACTION
• WIFI_P2P_PEERS_CHANGED_ACTION
• WIFI_P2P_CONNECTION_CHANGED_ACTION
• WIFI_P2P_THIS_DEVICE_CHANGED_ACTION
• At the end of the onCreate() method, get an instance of the WifiP2pManager, and call its initialize() method. This method returns a WifiP2pManager.Channel object, which you’ll use later to connect your app to the Wi-Fi Direct Framework.
• Initiate Peer Discovery :
• To search near by Peers, WifiP2pManager class has one method discoverPeers() method. There are two argument supposed to be passed in this method:
• The WifiP2pManager.Channel you received back when you initialized the peer-to-peer WifiP2pManager.
• An implementation of WifiP2pManager.ActionListener with methods the system invokes for successful and unsuccessful discovery.
• Fetch list of Peers :
• Implement the WifiP2pManager.PeerListListener interface, which provides information about the peers that Wi-Fi Direct has detected.
• Connect to Peer :
• In order to connect to a peer, create a new WifiP2pConfig object, and copy data into it from the WifiP2pDevice representing the device you want to connect to. Then call the connect() method.