Index: /ns3_development/ns-3.1/src/devices/wifi/mac-rx-middle.cc
===================================================================
--- /ns3_development/ns-3.1/src/devices/wifi/mac-rx-middle.cc (revision 46)
+++ /ns3_development/ns-3.1/src/devices/wifi/mac-rx-middle.cc (revision 96)
@@ -307,4 +307,13 @@
       if (!hdr->GetAddr1 ().IsBroadcast ())
         {
+	// filter duplicates.
+        if (IsDuplicate (hdr, originator)) 
+          {
+            NS_LOG_DEBUG ("duplicate from="<<hdr->GetAddr2 ()<<
+                   ", seq="<<hdr->GetSequenceNumber ()<<
+                   ", frag="<<hdr->GetFragmentNumber ());
+            return;
+          }
+
           originator->SetSequenceControl (hdr->GetSequenceControl ());
         }