Android fast switch to known wifi network

Question

I am trying to write some code that will disconnect current wifi network (if any) and reconnect to a specific wifi network with known SSID.

I have been following the code used here; How do I connect to a specific Wi-Fi network in Android programmatically?

which works but the connection takes several seconds, upto about 10 seconds.

Specifically, I use the code as follows;

WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
WifiConfiguration config;

I obtain the config, whether by creating a new one and setting the SSID and KeyMgmt to NONE and then adding it;

wifiManager.add(config);

or by getting a config that already exists;

List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for( WifiConfiguration i : list ) {
    if(i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
         config = i;
         break;
    }           
 }

Then I call;

wifiManager.disconnect();
wifiManager.enableNetwork(i.networkId, true);
wifiManager.reconnect();

I have a broadcast received checking the wifi state and when i get a connected for my correct SSID i can continue, however, this process takes upto 10 seconds, how can i set up the config or wifimanager to connect to this much quicker?

Thanks

Did you find the answer for your question? Have you tried turning the dhcp off to improve the time that it takes to connect? I want to do the same thing to quickly consume a service hosted in a different network, I'm thinking mDNS. — Rinaldi Segecin, Jan 30 '17 at 06:28
@Hamid Does this code work for you, to switch from one network to another ? — Rohit Singh, Apr 09 '17 at 07:07

score 0 · Answer 1 · answered Apr 05 '12 at 13:40

I think this code is help to you..

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.network_test);
    context = this;
    mUpdate = new UpdateTimeTask();
    mHandler = new Handler();
    mHandler.post(mUpdate);
    }
public Boolean isNetAvailable(Context con) {
    try{
        connectivityManager = (ConnectivityManager) con.getSystemService(Context.CONNECTIVITY_SERVICE);
        wifiInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        mobileInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        if(wifiInfo.isConnected() || mobileInfo.isConnected()) {
            return true;
            }
        }catch(Exception e){
            e.printStackTrace();
            }
    return false;
    }
private class UpdateTimeTask implements Runnable{

    public void run() {
        boolean net = isNetAvailable(context);


        if(net != false) {
        Toast.makeText(getBaseContext(), "network Available", Toast.LENGTH_SHORT).show();
        }
        else
        {
            Toast.makeText(getBaseContext(), "network Not Available", Toast.LENGTH_SHORT).show();
        }
        mHandler.postDelayed(mUpdate, 30000);
    }
}

}

Sorry, I don't see how this is relevant to my question. It's not whether or not the internet is connected that I need to know, I can do that already, which is what this code appears to do. I need a way of fast switching the wifi, faster than the current method I'm using which takes a good while to associate. — Hamid, Apr 05 '12 at 16:13

score -1 · Answer 2 · answered Feb 24 '14 at 06:33

-1

Have you tried adding startScan() to your routine to force an immediate rescan for available networks at the time you wish to connect? I imagine forcing that command repeatedly with an alarmManager or something similar is possible, but I would think that has the potential to have an expensive performance/battery impact. If you have a specific trigger, it could be a solution.

See here: http://developer.android.com/reference/android/net/wifi/WifiManager.html#startScan()

answered Feb 24 '14 at 06:33

mike47

2,217
1
27
50

The scanning was not the issue. The question is a little old now, but I believe, though I can't recall, that it was solved by statically setting the IP so that it didn't rely on DHCP to assign one, which took time. – Hamid Feb 24 '14 at 12:00

Android fast switch to known wifi network

2 Answers2