title: Android: slow network during phone calls
body: <p>We're working on an app that streams a large amount of data out via UDP for GSM-based phones. The idea is to use it while in conjunction with a voice call. If no voice call is present, things are good. However, if a voice call is active, it seems that most of the data we're sending out simply never makes it, even on HSPA+. If we enable Wifi, then everything is good.</p>
  
  <p>I'm worried that this is a physics problem, rather than a phone one. I ruled out CPU contention by inserting a log statement after we send a chunk of data, and saw that it appeared plenty of times.</p>
  
  <p>Is the 3G radio capable of sending data and voice simultaneously well? We tried a speed test during a voice call and saw a huge drop in bandwidth.</p>