--- a/src/devices/wifi/edca-txop-n.cc	Sat Apr 17 11:37:15 2010 +0200
+++ b/src/devices/wifi/edca-txop-n.cc	Sat Apr 17 12:02:53 2010 +0200
@@ -362,7 +362,7 @@
     }
   MacLowTransmissionParameters params;
   params.DisableOverrideDurationId ();
-  if (m_currentHdr.GetAddr1 ().IsBroadcast ()) 
+  if (m_currentHdr.GetAddr1 ().IsGroup ()) 
     {
       params.DisableRts ();
       params.DisableAck ();