title: WiFi connection is dropped after user inactivity period
body: <p>My iPhone application establishes a TCP connection through wifi to a remote server. However, if there is no user activity for a certain time, the device closes wifi and drops the connection. Is it possible to prevent it? I need the connection to be persistent while the application is running. Setting <em>setIdleTimerDisabled:YES</em> doesn't help - it prevents the screen to go off, but still the wifi is closed.  </p>
  
  <p>Do you know if this is possible and how to achieve it?</p>