--- orig/ns-3.14.1/src/wifi/model/wifi-remote-station-manager.h	2012-06-07 01:09:45.000000000 -0400
+++ mod/ns-3.14.1/src/wifi/model/wifi-remote-station-manager.h	2012-06-22 10:22:54.666363010 -0400
@@ -96,7 +96,8 @@
   void SetMaxSlrc (uint32_t maxSlrc);
   void SetRtsCtsThreshold (uint32_t threshold);
   void SetFragmentationThreshold (uint32_t threshold);
-
+  void UpdateFragmentationThreshold(void);
+  
   // Invoked in a STA upon dis-association
   // or in an AP upon reboot
   void Reset (void);
@@ -426,6 +427,7 @@
   uint32_t m_maxSlrc;
   uint32_t m_rtsCtsThreshold;
   uint32_t m_fragmentationThreshold;
+  uint32_t m_nextFragmentationThreshold;
   WifiMode m_nonUnicastMode;
   double m_avgSlrcCoefficient;
   /**
--- orig/ns-3.14.1/src/wifi/model/wifi-remote-station-manager.cc	2012-06-07 01:09:45.000000000 -0400
+++ mod/ns-3.14.1/src/wifi/model/wifi-remote-station-manager.cc	2012-06-22 10:28:01.186368765 -0400
@@ -165,7 +165,8 @@
                    "than this value, as per IEEE Std. 802.11-2007, Section 9.4. "
                    "This value will not have any effect on some rate control algorithms.",
                    UintegerValue (2346),
-                   MakeUintegerAccessor (&WifiRemoteStationManager::m_fragmentationThreshold),
+                   MakeUintegerAccessor (&WifiRemoteStationManager::SetFragmentationThreshold,
+                                          &WifiRemoteStationManager::GetFragmentationThreshold),
                    MakeUintegerChecker<uint32_t> ())
     .AddAttribute ("NonUnicastMode", "Wifi mode used for non-unicast transmissions.",
                    WifiModeValue (),
@@ -259,7 +260,13 @@
 void
 WifiRemoteStationManager::SetFragmentationThreshold (uint32_t threshold)
 {
-  m_fragmentationThreshold = threshold;
+  m_nextFragmentationThreshold = threshold;
+}
+
+void
+WifiRemoteStationManager::UpdateFragmentationThreshold (void)
+{
+  m_fragmentationThreshold = m_nextFragmentationThreshold;
 }
 
 void
--- orig/ns-3.14.1/src/wifi/model/dca-txop.cc	2012-06-07 01:09:45.000000000 -0400
+++ mod/ns-3.14.1/src/wifi/model/dca-txop.cc	2012-06-22 10:32:19.914373622 -0400
@@ -380,6 +380,7 @@
       NS_ASSERT (m_currentPacket != 0);
       uint16_t sequence = m_txMiddle->GetNextSequenceNumberfor (&m_currentHdr);
       m_currentHdr.SetSequenceNumber (sequence);
+      m_stationManager->UpdateFragmentationThreshold();
       m_currentHdr.SetFragmentNumber (0);
       m_currentHdr.SetNoMoreFragments ();
       m_currentHdr.SetNoRetry ();