I thought that I should use NetworkInterface::getDisplayName. I got some name, but this name is different that this name which I can see, when I choosing to which network I want to connect.
acording to Loxley answer:
WifiManager wifiMgr = (WifiManager) getActivity().getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiMgr.getConnectionInfo();
String name = wifiInfo.getSSID();