Find available wifi connections in Android - android

I am trying to create a help wizard to recover from bad network connections in the app. One test case I hope to handle is the case where an end user has WiFi turned off, WiFi is available, and the mobile network is slower than the WiFi network. In this event, I want to be able to (1) discover the available WiFi network s, (2) find the WiFi network speed, (3) Compare its speed to the mobile network speed, (4) digest the user changes to the faster network.
For this to work, I need to know how to programmatically get information on available connections. Is that something we can do? If so, how can we tell what connections are available? Thanks in advance.

Task-1: Discover the available WiFi network
This can be done by getting WifiManager's instance from the System.
WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
wifiManager.getScanResults();
// The above is an async call and will results are available System will broadcast `SCAN_RESULTS_AVAILABLE` intent and you need to set a `BroadCastReceiver` for it.
// And get the results like this
List<ScanResult> results = wifiManager.getScanResults();
Task-2&3: find the network speed
This link gives an answer to your question about how to get network speeds of wifi and mobile network
Wifi:
WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
int linkSpeed = wifiManager.getConnectionInfo().getRssi();
In case of mobile it should work:
TelephonyManager telephonyManager = (TelephonyManager)this.getSystemService(Context.TELEPHONY_SERVICE);
CellInfoGsm cellinfogsm = (CellInfoGsm)telephonyManager.getAllCellInfo().get(0);
CellSignalStrengthGsm cellSignalStrengthGsm = cellinfogsm.getCellSignalStrength();
cellSignalStrengthGsm.getDbm();
Then You should compare this signal levels and if WIFI signal is better keep it turn on, but if mobile is better disconnect wifi
Task-4: Switching to the option with higher speed
In Android by default, if wifi is on and connected then your mobile network won't be used. Hence to use mobile data you must either disconnect from all available wifi-networks or switch off the wifi.
I will also suggest you to read link this, this and this for getting more information on how to get connection speed.

Related

Android WiFi Connection Info

I'm getting wifi connection info this way:
WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
WifiInfo info = wifiManager.getConnectionInfo();
But, could getConnectionInfo method return null in any case? Android documentation reference say this:
Return dynamic information about the current Wi-Fi connection, if any
is active.
I guess if the device is not connected to any network it will return null, won't it?
Thanks
Yes it will return null, if it is not connected to the wi-fi.
But if you are also checking whether internet is available by using above code, then it is not 100% correct way to do so.
Cause it may happen that your device is connected to wifi but no internet is available. so for that
you have to ping any live site (such as google,facebook, or any other trusted website) and check if the returned status code is 200.
I hope this helps.

Uniquely identify a particular wifi source using Android devices

I am working on an app that would allow indoor navigation using hardware devices that emit wifi signals in large public places such as hotels and hospitals. Each location would have multiple devices and each device would be unique so that we can identify the exact location of the device/person.
For this I don't want the user to connect to the wifi, if only a scan of the network was possible which could determine the current wifi beacon the mobile is closest to would do the job. I decided to use Android's WifiManager for the task:
WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
wifi.setWifiEnabled(true);
wifi.startScan() ;
List<ScanResult> mScanResults = wifi.getScanResults();
String s = "" ;
for(ScanResult result: mScanResults){
Log.d("Wifi", result.SSID) ;
}
None of the attributes for result seem to be appropriate for use as a UID for Wifi Beacon, I have two questions:
a) Can we use something like a BSSID for this purpose?
b) Can I write my own wifi manager class and then somehow negotiate a handshake with the wifi where it just tells me who it is without connecting? If so please share resources for doing the same.

Scan all wifi devices near the phone

Company http://renewlondon.com/ have the terminal stations that collect all near by mac addresses
Can I via iOS SDK, and Android SDK,do the same thing?
You can access the wifi data using 'WifiManager' and after the scanning the scanresult contain all the data like
BSSID The address of the access point.
SSID The network name.
capabilities Describes the authentication, key management, and encryption schemes supported by the access point.
frequency The frequency in MHz of the channel over which the client is communicating with the access point.
level The detected signal level in dBm.
timestamp Time Synchronization Function (tsf) timestamp in microseconds when this result was last seen.
about the wifi devices.
if you need more related to coding, I think I can help you...
Sample code
WifiManager wManager;
List<ScanResult> wifiList;
wManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
// Inside BroadcastReceiver()
wifiList = wManager.getScanResults();
for (int i=0; i<wifiList.size(); i++){
ScanResult scanresult = wifiList.get(i);
System.out.println("SSID: "+ssid);
System.out.println("RSSI: "+scanresult.level);
System.out.println("Frequency: "+scanresult.frequency);
System.out.println("BSSID: "+scanresult.BSSID);
System.out.println("Capability: "+scanresult.capabilities);
}
Also checkout the BroadcastReceiver().
One way i can think of doing this is making your device as wifi hotspot and use some hidden api to discover devices.You are basically trying to mimic an access point.
Otherwise each device would need some p2p framework on them-either wifi direct on or some other framework like alljoyn or samsung chord which helps in peer to peer discovery

Android: How to determine which Wi-Fi network is connected

I know how to determine if a wi-fi connection is the active connection. However, can someone tell how to determine which wi-fi network is the current active?
Use WifiManager.getConnectionInfo(). This returns a WifiInfo object which contains all the info you need about the active wifi connection; in particular, WifiInfo.getSSID() will give you the SSID.
WifiManager wifiManager = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);
String BSSID=wifiManager.getConnectionInfo().getBSSID();

Android WifiLock WIFI_MODE_SCAN_ONLY not working

I'm trying to block the wifi connections. I want my application to turn on the wifi, but does not connect to any network that is already stored on the smartphone. But even after I use the SCAN_ONLY mode, he continues to connect to networks that already "know".
.....
wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
.....
wifiManager.setWifiEnabled(true);
WifiLock scanOnly = wifiManager.createWifiLock(WifiManager.WIFI_MODE_SCAN_ONLY, "scanOnly");
scanOnly.acquire();
Already in despair i tried to disconnect after to make sure that the state is WIFI_STATE_ENABLED wifi. That the app can not connect for a few seconds, but after some time it connects to a network in the same ...
wifiManager.setWifiEnabled(true);
....
WHEN (WIFI STATE == WIFI_STATE_ENABLED)
{wifiManager.disconnect();
scanOnly.acquire();}
Can someone help me?
Tks
WifiLock not for this. Only for "Allows an application to keep the Wi-Fi radio awake". This does not forbid anyone to connect to wifi. Only says "I want to be able to do at least this in sleep mode".
You have to do what you said Peanut above: get the list of all the stored networks and then disable wifi in BroadcastReceiver.
#Override
public void onReceive(Context c, Intent intent) {
saveWifiList(mainWifi.getScanResults());
unregisterReceiver(this);
mainWifi.setWifiEnabled(false);
showWifiList();
}
One way would be to get the list of all the stored networks and then disable them. You might want to store their state somewhere so you can restore the initial state after you're done.

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