wifi: Fix EIFS computation

EIFS depends on the modulation class of the PPDU whose reception failed
rather than on the latest standard supported by a device

RELEASE_NOTES.md

@@ -42,6 +42,7 @@ The required Doxygen version for documentation generation is now version 1.13.
 - (wifi) #2368 - Fix various issues related to Content Channels and RU allocation. Fixes mostly covers cases where OFDMA is used with central 26 tones, where a single user is being assigned the whole PPDU bandwidth or where a RU is larger than 20 MHz.
 - (zigbee) !2383 - Fix malformed RREP command with missing command options field.
 - (wifi) Fix the time the `NSlotsLeftAlert` trace source of `ChannelAccessManager` is fired (it cannot be earlier than the access grant start time)
+- (wifi) Fix the EIFS computation, which depends on the modulation class of the PPDU whose reception failed rather than on the latest standard supported by a device
 
 ## Release 3.44
 

src/wifi/model/channel-access-manager.cc

@@ -90,11 +90,11 @@ class PhyListener : public ns3::WifiPhyListener
         }
     }
 
-    void NotifyRxEndError() override
+    void NotifyRxEndError(const WifiTxVector& txVector) override
     {
         if (m_active)
         {
-            m_cam->NotifyRxEndErrorNow();
+            m_cam->NotifyRxEndErrorNow(txVector);
         }
     }
 
@@ -985,14 +985,14 @@ ChannelAccessManager::NotifyRxEndOkNow()
 }
 
 void
-ChannelAccessManager::NotifyRxEndErrorNow()
+ChannelAccessManager::NotifyRxEndErrorNow(const WifiTxVector& txVector)
 {
     NS_LOG_FUNCTION(this);
     NS_LOG_DEBUG("rx end error");
     // we expect the PHY to notify us of the start of a CCA busy period, if needed
     m_lastRx.end = Simulator::Now();
     m_lastRxReceivedOk = false;
-    m_eifsNoDifs = m_phy->GetSifs() + m_phy->GetAckTxTime();
+    m_eifsNoDifs = m_phy->GetSifs() + GetEstimatedAckTxTime(txVector);
 }
 
 void

src/wifi/model/channel-access-manager.h

@@ -33,6 +33,7 @@ class WifiPhy;
 class PhyListener;
 class Txop;
 class FrameExchangeManager;
+class WifiTxVector;
 enum AcIndex : uint8_t; // opaque enum declaration
 
 /**
@@ -236,8 +237,10 @@ class ChannelAccessManager : public Object
     /**
      * Notify the Txop that a packet reception was just
      * completed unsuccessfuly.
+     *
+     * @param txVector the TXVECTOR used for transmission
      */
-    void NotifyRxEndErrorNow();
+    void NotifyRxEndErrorNow(const WifiTxVector& txVector);
     /**
      * @param duration expected duration of transmission
      *

src/wifi/model/eht/advanced-emlsr-manager.cc

@@ -63,7 +63,7 @@ class EmlsrPhyListener : public WifiPhyListener
                             m_emlsrManager);
     }
 
-    void NotifyRxEndError() override
+    void NotifyRxEndError(const WifiTxVector& /* txVector */) override
     {
     }
 

src/wifi/model/he/he-phy.cc

@@ -873,7 +873,7 @@ HePhy::RxPayloadFailed(Ptr<const WifiPsdu> psdu, double snr, const WifiTxVector&
     NS_LOG_FUNCTION(this << *psdu << txVector << snr);
     if (!txVector.IsUlMu())
     {
-        m_state->SwitchFromRxEndError();
+        m_state->SwitchFromRxEndError(txVector);
     }
 }
 
@@ -906,7 +906,7 @@ HePhy::DoEndReceivePayload(Ptr<const WifiPpdu> ppdu)
             }
             else
             {
-                m_state->SwitchFromRxEndError();
+                m_state->SwitchFromRxEndError(ppdu->GetTxVector());
             }
             NotifyInterferenceRxEndAndClear(true); // reset WifiPhy
             m_rxHeTbPpdus = 0;

src/wifi/model/phy-entity.cc

@@ -785,7 +785,7 @@ void
 PhyEntity::RxPayloadFailed(Ptr<const WifiPsdu> psdu, double snr, const WifiTxVector& txVector)
 {
     NS_LOG_FUNCTION(this << *psdu << txVector << snr);
-    m_state->SwitchFromRxEndError();
+    m_state->SwitchFromRxEndError(txVector);
 }
 
 void

src/wifi/model/wifi-phy-listener.h

@@ -17,6 +17,8 @@
 namespace ns3
 {
 
+class WifiTxVector;
+
 /**
  * @brief receive notifications about PHY events.
  */
@@ -51,11 +53,13 @@ class WifiPhyListener
      */
     virtual void NotifyRxEndOk() = 0;
     /**
+     * @param txVector the TXVECTOR used for transmission
+     *
      * We have received the last bit of a packet for which
      * NotifyRxStart was invoked first and, the packet has
      * _not_ been successfully received.
      */
-    virtual void NotifyRxEndError() = 0;
+    virtual void NotifyRxEndError(const WifiTxVector& txVector) = 0;
     /**
      * @param duration the expected transmission duration.
      * @param txPower the nominal TX power

src/wifi/model/wifi-phy-state-helper.cc

@@ -482,11 +482,11 @@ WifiPhyStateHelper::SwitchFromRxEndOk()
 }
 
 void
-WifiPhyStateHelper::SwitchFromRxEndError()
+WifiPhyStateHelper::SwitchFromRxEndError(const WifiTxVector& txVector)
 {
     NS_LOG_FUNCTION(this);
     NS_ASSERT(m_endRx == Simulator::Now());
-    NotifyListeners(&WifiPhyListener::NotifyRxEndError);
+    NotifyListeners(&WifiPhyListener::NotifyRxEndError, txVector);
     DoSwitchFromRx();
 }
 

src/wifi/model/wifi-phy-state-helper.h

@@ -246,8 +246,10 @@ class WifiPhyStateHelper : public Object
     void SwitchFromRxEndOk();
     /**
      * Switch from RX after the reception failed.
+     *
+     * @param txVector the TXVECTOR used for transmission of failed frame
      */
-    void SwitchFromRxEndError();
+    void SwitchFromRxEndError(const WifiTxVector& txVector);
     /**
      * Abort current reception following a CCA reset request.
      * @param operatingWidth the channel width the PHY is operating on

src/wifi/model/wifi-radio-energy-model.cc

@@ -514,7 +514,7 @@ WifiRadioEnergyModelPhyListener::NotifyRxEndOk()
 }
 
 void
-WifiRadioEnergyModelPhyListener::NotifyRxEndError()
+WifiRadioEnergyModelPhyListener::NotifyRxEndError(const WifiTxVector& /* txVector */)
 {
     NS_LOG_FUNCTION(this);
     if (m_changeStateCallback.IsNull())

src/wifi/model/wifi-radio-energy-model.h

@@ -56,7 +56,7 @@ class WifiRadioEnergyModelPhyListener : public WifiPhyListener
 
     void NotifyRxStart(Time duration) override;
     void NotifyRxEndOk() override;
-    void NotifyRxEndError() override;
+    void NotifyRxEndError(const WifiTxVector& txVector) override;
     void NotifyTxStart(Time duration, dBm_u txPower) override;
     void NotifyCcaBusyStart(Time duration,
                             WifiChannelListType channelType,

src/wifi/model/wifi-utils.cc

@@ -13,6 +13,7 @@
 #include "gcr-manager.h"
 #include "wifi-mac-header.h"
 #include "wifi-mac-trailer.h"
+#include "wifi-tx-vector.h"
 
 #include "ns3/packet.h"
 
@@ -109,6 +110,61 @@ GetCtsSize()
     return size;
 }
 
+Time
+GetEstimatedAckTxTime(const WifiTxVector& txVector)
+{
+    auto modClass = txVector.GetModulationClass();
+
+    switch (modClass)
+    {
+    case WIFI_MOD_CLASS_DSSS:
+    case WIFI_MOD_CLASS_HR_DSSS:
+        if (txVector.GetMode().GetDataRate(txVector) == 1e6)
+        {
+            return MicroSeconds(304);
+        }
+        else if (txVector.GetPreambleType() == WIFI_PREAMBLE_LONG)
+        {
+            return MicroSeconds(248);
+        }
+        else
+        {
+            return MicroSeconds(152);
+        }
+        break;
+    case WIFI_MOD_CLASS_ERP_OFDM:
+    case WIFI_MOD_CLASS_OFDM:
+        if (auto constSize = txVector.GetMode().GetConstellationSize(); constSize == 2)
+        {
+            return MicroSeconds(44);
+        }
+        else if (constSize == 4)
+        {
+            return MicroSeconds(32);
+        }
+        else
+        {
+            return MicroSeconds(28);
+        }
+        break;
+    default: {
+        auto staId = (txVector.IsMu() ? txVector.GetHeMuUserInfoMap().begin()->first : SU_STA_ID);
+        if (const auto constSize = txVector.GetMode(staId).GetConstellationSize(); constSize == 2)
+        {
+            return MicroSeconds(68);
+        }
+        else if (constSize == 4)
+        {
+            return MicroSeconds(44);
+        }
+        else
+        {
+            return MicroSeconds(32);
+        }
+    }
+    }
+}
+
 bool
 IsInWindow(uint16_t seq, uint16_t winstart, uint16_t winsize)
 {

src/wifi/model/wifi-utils.h

@@ -27,6 +27,7 @@ class Mac48Address;
 class WifiMacHeader;
 class Packet;
 class WifiMac;
+class WifiTxVector;
 
 /**
  * Wifi direction. Values are those defined for the TID-to-Link Mapping Control Direction
@@ -195,6 +196,13 @@ uint32_t GetRtsSize();
  * @return the total CTS size in bytes
  */
 uint32_t GetCtsSize();
+
+/**
+ * @param txVector the TXVECTOR used to transmit a frame whose reception failed
+ * @return the estimated Ack TX time, based on Table 10-8 of IEEE 802.11REVme D7.0
+ */
+Time GetEstimatedAckTxTime(const WifiTxVector& txVector);
+
 /**
  * @param seq MPDU sequence number
  * @param winstart sequence number window start

src/wifi/test/channel-access-manager-test.cc

@@ -732,7 +732,21 @@ ChannelAccessManagerTest<TxopType>::AddRxErrorEvt(uint64_t at, uint64_t duration
                         MicroSeconds(duration));
     Simulator::Schedule(MicroSeconds(at + duration) - Now(),
                         &ChannelAccessManager::NotifyRxEndErrorNow,
-                        m_ChannelAccessManager);
+                        m_ChannelAccessManager,
+                        WifiTxVector(OfdmPhy::GetOfdmRate6Mbps(),
+                                     1,
+                                     WIFI_PREAMBLE_LONG,
+                                     NanoSeconds(800),
+                                     1,
+                                     1,
+                                     0,
+                                     MHz_u{20},
+                                     false,
+                                     false,
+                                     false,
+                                     0,
+                                     0,
+                                     false));
 }
 
 template <typename TxopType>
@@ -747,7 +761,21 @@ ChannelAccessManagerTest<TxopType>::AddRxErrorEvt(uint64_t at,
                         MicroSeconds(duration));
     Simulator::Schedule(MicroSeconds(at + timeUntilError) - Now(),
                         &ChannelAccessManager::NotifyRxEndErrorNow,
-                        m_ChannelAccessManager);
+                        m_ChannelAccessManager,
+                        WifiTxVector(OfdmPhy::GetOfdmRate6Mbps(),
+                                     1,
+                                     WIFI_PREAMBLE_LONG,
+                                     NanoSeconds(800),
+                                     1,
+                                     1,
+                                     0,
+                                     MHz_u{20},
+                                     false,
+                                     false,
+                                     false,
+                                     0,
+                                     0,
+                                     false));
     Simulator::Schedule(MicroSeconds(at + timeUntilError) - Now(),
                         &ChannelAccessManager::NotifyCcaBusyStartNow,
                         m_ChannelAccessManager,

src/wifi/test/spectrum-wifi-phy-test.cc

@@ -327,9 +327,9 @@ class TestPhyListener : public ns3::WifiPhyListener
         ++m_notifyRxEndOk;
     }
 
-    void NotifyRxEndError() override
+    void NotifyRxEndError(const WifiTxVector& txVector) override
     {
-        NS_LOG_FUNCTION(this);
+        NS_LOG_FUNCTION(this << txVector);
         ++m_notifyRxEndError;
     }
 

src/wifi/test/wifi-phy-cca-test.cc

@@ -627,9 +627,9 @@ class CcaTestPhyListener : public ns3::WifiPhyListener
         NS_LOG_FUNCTION(this);
     }
 
-    void NotifyRxEndError() override
+    void NotifyRxEndError(const WifiTxVector& txVector) override
     {
-        NS_LOG_FUNCTION(this);
+        NS_LOG_FUNCTION(this << txVector);
     }
 
     void NotifyTxStart(Time duration, dBm_u txPower) override

src/wifi/test/wifi-phy-ofdma-test.cc

@@ -2890,9 +2890,9 @@ class OfdmaTestPhyListener : public ns3::WifiPhyListener
         m_lastRxSuccess = true;
     }
 
-    void NotifyRxEndError() override
+    void NotifyRxEndError(const WifiTxVector& txVector) override
     {
-        NS_LOG_FUNCTION(this);
+        NS_LOG_FUNCTION(this << txVector);
         m_lastRxEnd = Simulator::Now();
         ++m_notifyRxEnd;
         m_lastRxSuccess = false;