From 39800ef31d524affc19c0fda2224b6a89ad11d78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Tue, 24 Mar 2020 09:31:28 +0100
Subject: [PATCH] wifi: Reset PHY internals at the end of the detected packet
 if PHY header reception failed

---
 src/wifi/model/wifi-phy.cc | 17 +++++++++++++----
 src/wifi/model/wifi-phy.h  |  7 +++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/wifi/model/wifi-phy.cc b/src/wifi/model/wifi-phy.cc
index 22ac4bea3..576a68674 100644
--- a/src/wifi/model/wifi-phy.cc
+++ b/src/wifi/model/wifi-phy.cc
@@ -2852,6 +2852,7 @@ WifiPhy::StartReceivePayload (Ptr<Event> event)
       //If we are here, this means non-HT PHY header was already successfully received
       canReceivePayload = true;
     }
+  Time payloadDuration = event->GetEndTime () - event->GetStartTime () - CalculatePhyPreambleAndHeaderDuration (txVector);
   if (canReceivePayload) //PHY reception succeeded
     {
       if (txVector.GetNss () > GetMaxSupportedRxSpatialStreams ())
@@ -2871,7 +2872,6 @@ WifiPhy::StartReceivePayload (Ptr<Event> event)
         }
       else
         {
-          Time payloadDuration = event->GetEndTime () - event->GetStartTime () - CalculatePhyPreambleAndHeaderDuration (txVector);
           m_state->SwitchToRx (payloadDuration);
           m_endRxEvent = Simulator::Schedule (payloadDuration, &WifiPhy::EndReceive, this, event);
           NS_LOG_DEBUG ("Receiving payload");
@@ -2890,9 +2890,7 @@ WifiPhy::StartReceivePayload (Ptr<Event> event)
       NS_LOG_DEBUG ("Drop packet because HT PHY header reception failed");
       NotifyRxDrop (event->GetPsdu (), SIG_A_FAILURE);
     }
-  m_interference.NotifyRxEnd ();
-  m_currentEvent = 0;
-  MaybeCcaBusyDuration ();
+  m_endRxEvent = Simulator::Schedule (payloadDuration, &WifiPhy::ResetReceive, this, event);
 }
 
 void
@@ -3010,6 +3008,17 @@ WifiPhy::EndReceiveInterBss (void)
     }
 }
 
+void
+WifiPhy::ResetReceive (Ptr<Event> event)
+{
+  NS_LOG_FUNCTION (this << *event);
+  NS_ASSERT (event->GetEndTime () == Simulator::Now ());
+  NS_ASSERT (!IsStateRx ());
+  m_interference.NotifyRxEnd ();
+  m_currentEvent = 0;
+  MaybeCcaBusyDuration ();
+}
+
 void
 WifiPhy::NotifyChannelAccessRequested (void)
 {
diff --git a/src/wifi/model/wifi-phy.h b/src/wifi/model/wifi-phy.h
index 9dd19f581..79e9c7ccc 100644
--- a/src/wifi/model/wifi-phy.h
+++ b/src/wifi/model/wifi-phy.h
@@ -177,6 +177,13 @@ public:
    */
   void EndReceive (Ptr<Event> event);
 
+  /**
+   * Reset PHY at the end of the packet under reception after it has failed the PHY header.
+   *
+   * \param event the corresponding event of the first time the packet arrives (also storing packet and TxVector information)
+   */
+  void ResetReceive (Ptr<Event> event);
+
   /**
    * For HE receptions only, check and possibly modify the transmit power restriction state at
    * the end of PPDU reception.