WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();

WifiInfo wifiInfo = wifiManager.getConnectionInfo();
String tempSsidString = wifiInfo.getSSID();
if (tempSsidString != null && tempSsidString.length() > 2) {
wifiSsid = tempSsidString.substring(1, tempSsidString.length() - 1);
List<ScanResult> scanResults=wifiManager.getScanResults();
for(ScanResult scanResult:scanResults){
if(scanResult.SSID.equals(wifiSsid)){
scanResult.frequency;
break;
}
}
}

 /**
  * @hide
  * TODO: makes real freq boundaries
  */
 public boolean is5GHz() {
  return ScanResult.is5GHz(mFrequency);
 }