envío de paquetes a través de la red 3G

Estoy tratando de escribir un método que envíe un mensaje a través de una red 3G con una estación base al servidor. Estoy tratando de enviar el mensaje varias veces hasta que decido detenerme. Pero cuando probé esto, siempre se detiene después de un corto tiempo y deja de enviar el mensaje. ¿Alguien sabe por qué?

private Runnable commRunnable = new Runnable() {
public void run() {
    try {
        String message = "Just saying hello!";
        PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())), true);

        String startReceivingMessage = "Begin sending me data.";
        String stopReceivingMessage = "Stop sending me data.";

        startSend = false;
        stopSend = false;
        startReceive = false;
        stopReceive = false;

        while (!shouldDisconnect) {
            if (startSend) {
                sendData = true;
                startSend = false;
            }
            if (stopSend) {
                sendData = false;
                stopSend = false;
            }

            // Send a message that the server should start transmitting data
            // back to us. We only need to transmit this message once.
            if (startReceive) {
                out.println(startReceivingMessage);
                startReceive = false;
                receiveData = true;
                Thread receiveThread = new Thread(receiveRunnable);
                receiveThread.start();

            // Tell the server to stop transmitting data.
            } else if (stopReceive) {
                out.println(stopReceivingMessage);
                stopReceive = false;
                receiveData = false;
            }

            if (sendData) {
                out.println(message);
            }

            Thread.sleep(20);
        }                               
    } catch (Exception e) {
        Log.e("PowerMonitor", e.toString());
    } finally {
        try {
            socket.close();
            connected = false;
        } catch (Exception e) {
            Log.e("PowerMonitor", e.toString());
        }
    }
}

};

private Runnable receiveRunnable = new Runnable() {
    @Override
    public void run() {
        try {
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String reply = "";
            Log.d("PowerMonitor", "Starting to receive");
            while (receiveData) {
                Log.d("PowerMonitor", "Listening...");
                reply = in.readLine();
                Log.d("PowerMonitor", "Got message: " + reply);
            }
        } catch (Exception e) {
            Log.e("PowerMonitor", e.toString());
        }
    }
};