javaandroidsocketsmobile-data

Cannot open socket when incoming call

I try to send data to server when incoming call through mobile data (4G). I get one of these errors:

java.net.UnknownHostException: Host is unresolved: xyz.xy

or

java.net.SocketTimeoutException: failed to connect to /xxx.xxx.xxx.xxx (port yyyyyy) after 15000ms

When is WIFI on, data is sending during incoming call.

Here is part of code:

Socket socket = new Socket();
DataOutputStream dos;
DataInputStream dis;
try {
    socket.connect(new InetSocketAddress(SERVER_IP, SERVER_PORT), CONNECTION_TIMEOUT);
    socket.setTcpNoDelay(true);
    socket.setSoTimeout(READ_TIMEOUT);
    dos = new DataOutputStream(socket.getOutputStream());
    dis = new DataInputStream(socket.getInputStream());

    int count = text.getBytes("UTF-8").length;
    ByteBuffer data = ByteBuffer.allocate(count);
    data.put(text.getBytes("UTF-8"));

    dos.write(data.array(), 0, data.array().length);

Is a problem send data through mobile data (4G) when incomming call? Or I am missing any settings?

EDIT

I was reading, if phone support SVDO technology or 4G LTE, modem can accepting call and send data. My phone Xiaomi Redmi 3S has this technology.

Solution

  • I found problem. Problem is in operator and technology VoLTE. In Czech Republic can do that only with O2 operator see forum. In Samsung Galaxy S7 it's working.