diff --git a/src/wifi/model/qos-txop.cc b/src/wifi/model/qos-txop.cc
index 8bd719693..4ebd13da1 100644
--- a/src/wifi/model/qos-txop.cc
+++ b/src/wifi/model/qos-txop.cc
@@ -729,12 +729,10 @@ QosTxop::NotifyMissedCts (std::list<Ptr<WifiMacQueueItem>> mpduList)
       //to reset the Txop.
       m_currentPacket = 0;
       ResetCw ();
-      m_cwTrace = GetCw ();
     }
   else
     {
       UpdateFailedCw ();
-      m_cwTrace = GetCw ();
       // if a BA agreement is established, store the MPDUs in the block ack manager
       // retransmission queue. Otherwise, this QosTxop will handle the retransmission
       // of the (single) frame
@@ -1680,7 +1678,6 @@ QosTxop::DoInitialize (void)
 {
   NS_LOG_FUNCTION (this);
   ResetCw ();
-  m_cwTrace = GetCw ();
   GenerateBackoff ();
 }
 
diff --git a/src/wifi/model/regular-wifi-mac.h b/src/wifi/model/regular-wifi-mac.h
index d8407153c..b75a50b24 100644
--- a/src/wifi/model/regular-wifi-mac.h
+++ b/src/wifi/model/regular-wifi-mac.h
@@ -87,6 +87,21 @@ public:
   // Should be implemented by child classes
   virtual void Enqueue (Ptr<Packet> packet, Mac48Address to) = 0;
 
+  /**
+   * The packet we sent was successfully received by the receiver
+   * (i.e. we received an Ack from the receiver).
+   *
+   * \param hdr the header of the packet that we successfully sent
+   */
+  virtual void TxOk (const WifiMacHeader &hdr);
+  /**
+   * The packet we sent was successfully received by the receiver
+   * (i.e. we did not receive an Ack from the receiver).
+   *
+   * \param hdr the header of the packet that we failed to sent
+   */
+  virtual void TxFailed (const WifiMacHeader &hdr);
+
   /**
    * Enable or disable CTS-to-self feature.
    *
@@ -238,20 +253,6 @@ protected:
    * \param mpdu the MPDU that has been received.
    */
   virtual void Receive (Ptr<WifiMacQueueItem> mpdu);
-  /**
-   * The packet we sent was successfully received by the receiver
-   * (i.e. we received an Ack from the receiver).
-   *
-   * \param hdr the header of the packet that we successfully sent
-   */
-  virtual void TxOk (const WifiMacHeader &hdr);
-  /**
-   * The packet we sent was successfully received by the receiver
-   * (i.e. we did not receive an Ack from the receiver).
-   *
-   * \param hdr the header of the packet that we failed to sent
-   */
-  virtual void TxFailed (const WifiMacHeader &hdr);
 
   /**
    * Forward the packet up to the device.
diff --git a/src/wifi/model/txop.cc b/src/wifi/model/txop.cc
index aad31bf0d..85ded1293 100644
--- a/src/wifi/model/txop.cc
+++ b/src/wifi/model/txop.cc
@@ -191,7 +191,6 @@ Txop::SetMinCw (uint32_t minCw)
   if (changed == true)
     {
       ResetCw ();
-      m_cwTrace = GetCw ();
     }
 }
 
@@ -204,7 +203,6 @@ Txop::SetMaxCw (uint32_t maxCw)
   if (changed == true)
     {
       ResetCw ();
-      m_cwTrace = GetCw ();
     }
 }
 
@@ -219,6 +217,7 @@ Txop::ResetCw (void)
 {
   NS_LOG_FUNCTION (this);
   m_cw = m_cwMin;
+  m_cwTrace = m_cw;
 }
 
 void
@@ -227,6 +226,7 @@ Txop::UpdateFailedCw (void)
   NS_LOG_FUNCTION (this);
   //see 802.11-2012, section 9.19.2.5
   m_cw = std::min ( 2 * (m_cw + 1) - 1, m_cwMax);
+  m_cwTrace = m_cw;
 }
 
 uint32_t
@@ -373,7 +373,6 @@ Txop::DoInitialize ()
 {
   NS_LOG_FUNCTION (this);
   ResetCw ();
-  m_cwTrace = GetCw ();
   GenerateBackoff ();
 }
 
@@ -622,12 +621,10 @@ Txop::MissedCts (void)
       //to reset the Txop.
       m_currentPacket = 0;
       ResetCw ();
-      m_cwTrace = GetCw ();
     }
   else
     {
       UpdateFailedCw ();
-      m_cwTrace = GetCw ();
     }
   GenerateBackoff ();
   RestartAccessIfNeeded ();
@@ -651,7 +648,6 @@ Txop::GotAck (void)
        */
       m_currentPacket = 0;
       ResetCw ();
-      m_cwTrace = GetCw ();
       GenerateBackoff ();
       RestartAccessIfNeeded ();
     }
@@ -678,7 +674,6 @@ Txop::MissedAck (void)
       //to reset the Txop.
       m_currentPacket = 0;
       ResetCw ();
-      m_cwTrace = GetCw ();
     }
   else
     {
@@ -687,7 +682,6 @@ Txop::MissedAck (void)
                                           m_currentHdr));
       m_currentHdr.SetRetry ();
       UpdateFailedCw ();
-      m_cwTrace = GetCw ();
     }
   GenerateBackoff ();
   RestartAccessIfNeeded ();
@@ -769,7 +763,6 @@ Txop::EndTxNoAck (void)
   NS_LOG_DEBUG ("a transmission that did not require an ACK just finished");
   m_currentPacket = 0;
   ResetCw ();
-  m_cwTrace = GetCw ();
   GenerateBackoff ();
   if (!m_txOkCallback.IsNull ())
     {
diff --git a/src/wifi/model/txop.h b/src/wifi/model/txop.h
index 74c593b82..349b3c2e9 100644
--- a/src/wifi/model/txop.h
+++ b/src/wifi/model/txop.h
@@ -205,6 +205,19 @@ public:
    * \return the TXOP limit.
    */
   Time GetTxopLimit (void) const;
+  /**
+   * Update the value of the CW variable to take into account
+   * a transmission success or a transmission abort (stop transmission
+   * of a packet after the maximum number of retransmissions has been
+   * reached). By default, this resets the CW variable to minCW.
+   */
+  void ResetCw (void);
+  /**
+   * Update the value of the CW variable to take into account
+   * a transmission failure. By default, this triggers a doubling
+   * of CW (capped by maxCW).
+   */
+  void UpdateFailedCw (void);
 
   /**
    * When a channel switching occurs, enqueued packets are removed.
@@ -394,19 +407,6 @@ protected:
    *          minCW.
    */
   uint32_t GetCw (void) const;
-  /**
-   * Update the value of the CW variable to take into account
-   * a transmission success or a transmission abort (stop transmission
-   * of a packet after the maximum number of retransmissions has been
-   * reached). By default, this resets the CW variable to minCW.
-   */
-  void ResetCw (void);
-  /**
-   * Update the value of the CW variable to take into account
-   * a transmission failure. By default, this triggers a doubling
-   * of CW (capped by maxCW).
-   */
-  void UpdateFailedCw (void);
   /**
    * Return the current number of backoff slots.
    *