--- a/src/devices/wifi/edca-txop-n.cc	Wed Aug 04 21:34:52 2010 +0400
+++ b/src/devices/wifi/edca-txop-n.cc	Thu Aug 05 15:32:06 2010 +0200
@@ -33,7 +33,6 @@
 #include "msdu-aggregator.h"
 #include "mgt-headers.h"
 #include "qos-blocked-destinations.h"
-#include "block-ack-manager.h"
 
 NS_LOG_COMPONENT_DEFINE ("EdcaTxopN");
 
@@ -320,10 +319,9 @@
           NS_LOG_DEBUG ("queue is empty");
           return; 
         }
-      struct Bar bar;
-      if (m_baManager->HasBar (bar))
+      if (m_baManager->HasBar (m_currentBar))
         {
-          SendBlockAckRequest (bar);
+          SendBlockAckRequest (m_currentBar);
           return;
         }
       /* check if packets need retransmission are stored in BlockAckManager */
@@ -378,6 +376,10 @@
       StartAccessIfNeeded ();
       NS_LOG_DEBUG ("tx broadcast");
     }
+  else if (m_currentHdr.GetType() == WIFI_MAC_CTL_BACKREQ)
+    {
+      SendBlockAckRequest (m_currentBar);
+    }
   else
     {
       if (m_currentHdr.IsQosData () && m_currentHdr.IsQosBlockAck ())