--- a/src/core/model/realtime-simulator-impl.cc	Wed Dec 17 12:17:11 2014 -0800
+++ b/src/core/model/realtime-simulator-impl.cc	Thu Dec 18 15:12:35 2014 -0800
@@ -36,6 +36,12 @@
 #include <cmath>
 
 
+/**
+ * \file
+ * \ingroup realtime
+ * ns3::RealTimeSimulatorImpl implementation.
+ */
+
 namespace ns3 {
 
 // Note:  Logging in this file is largely avoided due to the