diff --git a/src/wifi/model/aarf-wifi-manager.cc b/src/wifi/model/aarf-wifi-manager.cc
index 838ffefd9..100058996 100644
--- a/src/wifi/model/aarf-wifi-manager.cc
+++ b/src/wifi/model/aarf-wifi-manager.cc
@@ -229,7 +229,7 @@ AarfWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
 {
   NS_LOG_FUNCTION (this << st << size);
   AarfWifiRemoteStation *station = (AarfWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 AarfWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -238,7 +238,7 @@ AarfWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   /// \todo we could/should implement the Aarf algorithm for
   /// RTS only by picking a single rate within the BasicRateSet.
   AarfWifiRemoteStation *station = (AarfWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/aarfcd-wifi-manager.cc b/src/wifi/model/aarfcd-wifi-manager.cc
index 976772e7b..3d4b16bc7 100644
--- a/src/wifi/model/aarfcd-wifi-manager.cc
+++ b/src/wifi/model/aarfcd-wifi-manager.cc
@@ -297,7 +297,7 @@ AarfcdWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
 {
   NS_LOG_FUNCTION (this << st << size);
   AarfcdWifiRemoteStation *station = (AarfcdWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 AarfcdWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -306,7 +306,7 @@ AarfcdWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   /// \todo we could/should implement the Aarf algorithm for
   /// RTS only by picking a single rate within the BasicRateSet.
   AarfcdWifiRemoteStation *station = (AarfcdWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/amrr-wifi-manager.cc b/src/wifi/model/amrr-wifi-manager.cc
index 0f2517192..bfdd8bc28 100644
--- a/src/wifi/model/amrr-wifi-manager.cc
+++ b/src/wifi/model/amrr-wifi-manager.cc
@@ -321,7 +321,7 @@ AmrrWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
         }
     }
 
-  return WifiTxVector (GetSupported (station, rateIndex), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, rateIndex), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 AmrrWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -330,7 +330,7 @@ AmrrWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   AmrrWifiRemoteStation *station = (AmrrWifiRemoteStation *)st;
   UpdateMode (station);
   /// \todo can we implement something smarter ?
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 
diff --git a/src/wifi/model/arf-wifi-manager.cc b/src/wifi/model/arf-wifi-manager.cc
index 6a2b4954a..d3b259d62 100644
--- a/src/wifi/model/arf-wifi-manager.cc
+++ b/src/wifi/model/arf-wifi-manager.cc
@@ -202,7 +202,7 @@ ArfWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
 {
   NS_LOG_FUNCTION (this << st << size);
   ArfWifiRemoteStation *station = (ArfWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 ArfWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -211,7 +211,7 @@ ArfWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   /// \todo we could/should implement the Arf algorithm for
   /// RTS only by picking a single rate within the BasicRateSet.
   ArfWifiRemoteStation *station = (ArfWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/cara-wifi-manager.cc b/src/wifi/model/cara-wifi-manager.cc
index db757223c..00fbcc6c4 100644
--- a/src/wifi/model/cara-wifi-manager.cc
+++ b/src/wifi/model/cara-wifi-manager.cc
@@ -176,7 +176,7 @@ CaraWifiManager::DoGetDataTxVector (WifiRemoteStation *st,
 {
   NS_LOG_FUNCTION (this << st << size);
   CaraWifiRemoteStation *station = (CaraWifiRemoteStation *) st;
-  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 CaraWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -184,7 +184,7 @@ CaraWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   NS_LOG_FUNCTION (this << st);
   /// \todo we could/should implement the Arf algorithm for
   /// RTS only by picking a single rate within the BasicRateSet.
-  return WifiTxVector (GetSupported (st, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (st), GetStbc (st));
+  return WifiTxVector (GetSupported (st, 0), GetDefaultTxPowerLevel (), GetLongRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNess (st), GetStbc (st));
 }
 
 bool
diff --git a/src/wifi/model/constant-rate-wifi-manager.cc b/src/wifi/model/constant-rate-wifi-manager.cc
index e53c53636..d0788e5f9 100644
--- a/src/wifi/model/constant-rate-wifi-manager.cc
+++ b/src/wifi/model/constant-rate-wifi-manager.cc
@@ -112,13 +112,13 @@ WifiTxVector
 ConstantRateWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
 {
   NS_LOG_FUNCTION (this << st << size);
-  return WifiTxVector (m_dataMode, GetDefaultTxPowerLevel (), GetLongRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (st), GetStbc (st));
+  return WifiTxVector (m_dataMode, GetDefaultTxPowerLevel (), GetLongRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNess (st), GetStbc (st));
 }
 WifiTxVector
 ConstantRateWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
 {
   NS_LOG_FUNCTION (this << st);
-  return WifiTxVector (m_ctlMode, GetDefaultTxPowerLevel (), GetShortRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (st), GetStbc (st));
+  return WifiTxVector (m_ctlMode, GetDefaultTxPowerLevel (), GetShortRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNess (st), GetStbc (st));
 }
 
 bool
diff --git a/src/wifi/model/ideal-wifi-manager.cc b/src/wifi/model/ideal-wifi-manager.cc
index b4a540e39..e09efcab0 100644
--- a/src/wifi/model/ideal-wifi-manager.cc
+++ b/src/wifi/model/ideal-wifi-manager.cc
@@ -160,7 +160,7 @@ IdealWifiManager::DoGetDataTxVector (WifiRemoteStation *st, uint32_t size)
           maxMode = mode;
         }
     }
-  return WifiTxVector (maxMode, GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (maxMode, GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 IdealWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -182,7 +182,7 @@ IdealWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
           maxMode = mode;
         }
     }
-  return WifiTxVector (maxMode, GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (maxMode, GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/minstrel-wifi-manager.cc b/src/wifi/model/minstrel-wifi-manager.cc
index e11d595b1..c01cb9821 100644
--- a/src/wifi/model/minstrel-wifi-manager.cc
+++ b/src/wifi/model/minstrel-wifi-manager.cc
@@ -482,7 +482,7 @@ MinstrelWifiManager::DoGetDataTxVector (WifiRemoteStation *st,
       station->m_txrate = m_nsupported / 2;
     }
   UpdateStats (station);
-  return WifiTxVector (GetSupported (station, station->m_txrate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_txrate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 WifiTxVector
@@ -491,7 +491,7 @@ MinstrelWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   MinstrelWifiRemoteStation *station = (MinstrelWifiRemoteStation *) st;
   NS_LOG_DEBUG ("DoGetRtsMode m_txrate=" << station->m_txrate);
 
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/onoe-wifi-manager.cc b/src/wifi/model/onoe-wifi-manager.cc
index 725abaa03..8c9559137 100644
--- a/src/wifi/model/onoe-wifi-manager.cc
+++ b/src/wifi/model/onoe-wifi-manager.cc
@@ -268,7 +268,7 @@ OnoeWifiManager::DoGetDataTxVector (WifiRemoteStation *st,
           rateIndex = station->m_txrate;
         }
     }
-  return WifiTxVector (GetSupported (station, rateIndex), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, rateIndex), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 OnoeWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
@@ -276,7 +276,7 @@ OnoeWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
   OnoeWifiRemoteStation *station = (OnoeWifiRemoteStation *)st;
   UpdateMode (station);
   /// \todo can we implement something smarter ?
-  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 
 bool
diff --git a/src/wifi/model/rraa-wifi-manager.cc b/src/wifi/model/rraa-wifi-manager.cc
index c417e4c63..455935c91 100644
--- a/src/wifi/model/rraa-wifi-manager.cc
+++ b/src/wifi/model/rraa-wifi-manager.cc
@@ -284,12 +284,12 @@ RraaWifiManager::DoGetDataTxVector (WifiRemoteStation *st,
     {
       ResetCountersBasic (station);
     }
-  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (station), GetStbc (station));
+  return WifiTxVector (GetSupported (station, station->m_rate), GetDefaultTxPowerLevel (), GetLongRetryCount (station), GetShortGuardInterval (station), Min (GetNumberOfReceiveAntennas (station),GetNumberOfTransmitAntennas()), GetNess (station), GetStbc (station));
 }
 WifiTxVector
 RraaWifiManager::DoGetRtsTxVector (WifiRemoteStation *st)
 {
-  return WifiTxVector (GetSupported (st, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNumberOfTransmitAntennas (st), GetStbc (st));
+  return WifiTxVector (GetSupported (st, 0), GetDefaultTxPowerLevel (), GetShortRetryCount (st), GetShortGuardInterval (st), Min (GetNumberOfReceiveAntennas (st),GetNumberOfTransmitAntennas()), GetNess (st), GetStbc (st));
 }
 
 bool
diff --git a/src/wifi/model/wifi-remote-station-manager.cc b/src/wifi/model/wifi-remote-station-manager.cc
index 91bb566ab..9596fa122 100644
--- a/src/wifi/model/wifi-remote-station-manager.cc
+++ b/src/wifi/model/wifi-remote-station-manager.cc
@@ -1204,6 +1204,7 @@ WifiRemoteStationManager::LookupState (Mac48Address address) const
   state->m_greenfield=m_wifiPhy->GetGreenfield();
   state->m_rx=1;
   state->m_tx=1;
+  state->m_ness=0;
   state->m_stbc=false;
   const_cast<WifiRemoteStationManager *> (this)->m_states.push_back (state);
   NS_LOG_DEBUG ("WifiRemoteStationManager::LookupState returning new state");
@@ -1415,6 +1416,11 @@ WifiRemoteStationManager::GetNumberOfTransmitAntennas (const WifiRemoteStation *
   return station->m_state->m_tx;
 }
 uint32_t 
+WifiRemoteStationManager::GetNess (const WifiRemoteStation *station) const
+{
+  return station->m_state->m_ness;
+}
+uint32_t 
 WifiRemoteStationManager::GetShortRetryCount (const WifiRemoteStation *station) const
 {
   return station->m_ssrc;
diff --git a/src/wifi/model/wifi-remote-station-manager.h b/src/wifi/model/wifi-remote-station-manager.h
index 533362501..93660d87f 100644
--- a/src/wifi/model/wifi-remote-station-manager.h
+++ b/src/wifi/model/wifi-remote-station-manager.h
@@ -637,6 +637,13 @@ public:
    * \return the number of transmit antenna the station has
    */
   uint32_t GetNumberOfTransmitAntennas (const WifiRemoteStation *station) const;
+  /**
+   * Return the Number of extension spatial streams (Ness) the station has.
+   *
+   * \param station the station being queried
+   * \return the number of Ness the station has
+   */
+  uint32_t GetNess (const WifiRemoteStation *station) const;
   /**
    * Return the long retry limit of the given station.
    *
@@ -999,6 +1006,7 @@ struct WifiRemoteStationState
   bool m_shortGuardInterval;  //!< Flag if short guard interval is supported by the remote station
   uint32_t m_rx;  //!< Number of RX antennas of the remote station
   uint32_t m_tx;  //!< Number of TX antennas of the remote station
+  uint32_t m_ness;  //!< Number of streams in beamforming of the remote station
   bool m_stbc;  //!< Flag if STBC is used by the remote station
   bool m_greenfield;  //!< Flag if green field is used by the remote station