Changes in connectivity, including the bandwidth, latency, and availability of an Internet connection, can be significant signals for your application. In particular, you might choose to suspend recurring updates when you lose connectivity or to delay downloads of significant size until you have a Wi-Fi connection
To monitor changes in connectivity, register a Broadcast Receiver (either within your application or within the manifest) to listen for the android.net.conn.CONNECTIVITY_CHANGE (ConnectivityManager.CONNECTIVITY_ACTION) action.
Determining connectivity state information
String svcName = Context.CONNECTIVITY_SERVICE;
ConnectivityManager cm = (ConnectivityManager)context.getSystemService(svcName);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
boolean isConnected = activeNetwork.isConnectedOrConnecting();
boolean isMobile = activeNetwork.getType() ==
ConnectivityManager.TYPE_MOBILE;