--- a/src/spectrum/model/spectrum-propagation-loss-model.h	Wed May 18 20:01:44 2011 -0400
+++ b/src/spectrum/model/spectrum-propagation-loss-model.h	Wed May 18 17:24:04 2011 -0700
@@ -32,6 +32,8 @@
 
 
 /**
+ * \ingroup spectrum
+ *
  * \brief spectrum-aware propagation loss model
  *
  * Interface for propagation loss models to be adopted when