code: public synchronized void start() {
          // Cancel any thread attempting to make a connection
          if (mConnectThread != null) {
              mConnectThread.cancel();
              mConnectThread = null;
          }
  
          // Cancel any thread currently running a connection
          if (mEngConnectedThread != null) {
              mEngConnectedThread.cancel();
              mEngConnectedThread = null;
          }
          if (mImpConnectedThread != null) {
              mImpConnectedThread.cancel();
              mImpConnectedThread = null;
          }
  
          setState(STATE_LISTEN);
      }
docs: Start the chat service. Specifically start AcceptThread to begin a
  session in listening (server) mode. Called by the Activity onResume()