From a10f0b9ad9353d41de4e6704f9888004e15be95c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Sun, 7 Aug 2022 13:00:50 +0200
Subject: [PATCH] wifi: Add missing condition to HtPhy::GetCcaIndication to
 skip CCA sensitivity check if PPDU does not occupy neither primary nor
 secondary 20 MHz subchannels

---
 src/wifi/model/ht/ht-phy.cc   | 18 +++++++++++++-----
 src/wifi/model/vht/vht-phy.cc |  6 +++---
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/wifi/model/ht/ht-phy.cc b/src/wifi/model/ht/ht-phy.cc
index e13f1cb54..cfcd848fc 100644
--- a/src/wifi/model/ht/ht-phy.cc
+++ b/src/wifi/model/ht/ht-phy.cc
@@ -797,7 +797,7 @@ HtPhy::GetCcaIndication (const Ptr<const WifiPpdu> ppdu)
     {
       return std::make_pair (delayUntilCcaEnd, WIFI_CHANLIST_PRIMARY); //if Primary is busy, ignore CCA for Secondary
     }
-  if (ppdu != nullptr)
+  if (ppdu)
     {
       const uint16_t primaryWidth = 20;
       uint16_t p20MinFreq =
@@ -814,11 +814,19 @@ HtPhy::GetCcaIndication (const Ptr<const WifiPpdu> ppdu)
         }
     }
 
-  ccaThresholdDbm = GetCcaThreshold (ppdu, WIFI_CHANLIST_SECONDARY);
-  delayUntilCcaEnd = GetDelayUntilCcaEnd (ccaThresholdDbm, GetSecondaryBand (20));
-  if (delayUntilCcaEnd.IsStrictlyPositive ())
+  const uint16_t secondaryWidth = 20;
+  uint16_t s20MinFreq =
+      m_wifiPhy->GetOperatingChannel ().GetSecondaryChannelCenterFrequency (secondaryWidth) - (secondaryWidth / 2);
+  uint16_t s20MaxFreq =
+      m_wifiPhy->GetOperatingChannel ().GetSecondaryChannelCenterFrequency (secondaryWidth) + (secondaryWidth / 2);
+  if (!ppdu || ppdu->DoesOverlapChannel (s20MinFreq, s20MaxFreq))
     {
-       return std::make_pair (delayUntilCcaEnd, WIFI_CHANLIST_SECONDARY);
+      ccaThresholdDbm = GetCcaThreshold (ppdu, WIFI_CHANLIST_SECONDARY);
+      delayUntilCcaEnd = GetDelayUntilCcaEnd (ccaThresholdDbm, GetSecondaryBand (20));
+      if (delayUntilCcaEnd.IsStrictlyPositive ())
+        {
+           return std::make_pair (delayUntilCcaEnd, WIFI_CHANLIST_SECONDARY);
+        }
     }
 
   return std::nullopt;
diff --git a/src/wifi/model/vht/vht-phy.cc b/src/wifi/model/vht/vht-phy.cc
index 5d72747d3..261f313a6 100644
--- a/src/wifi/model/vht/vht-phy.cc
+++ b/src/wifi/model/vht/vht-phy.cc
@@ -532,7 +532,7 @@ VhtPhy::GetMaxPsduSize (void) const
 double
 VhtPhy::GetCcaThreshold (const Ptr<const WifiPpdu> ppdu, WifiChannelListType channelType) const
 {
-  if (ppdu != nullptr)
+  if (ppdu)
     {
       const uint16_t ppduBw = ppdu->GetTxVector ().GetChannelWidth ();
       switch (channelType)
@@ -586,7 +586,7 @@ VhtPhy::GetCcaIndication (const Ptr<const WifiPpdu> ppdu)
       return std::make_pair (delayUntilCcaEnd, WIFI_CHANLIST_PRIMARY); //if Primary is busy, ignore CCA for Secondary
     }
 
-  if (ppdu != nullptr)
+  if (ppdu)
     {
       const uint16_t primaryWidth = 20;
       uint16_t p20MinFreq =
@@ -604,7 +604,7 @@ VhtPhy::GetCcaIndication (const Ptr<const WifiPpdu> ppdu)
     }
 
   std::vector<uint16_t> secondaryWidthsToCheck;
-  if (ppdu != nullptr)
+  if (ppdu)
     {
       for (const auto& secondaryChannel : secondaryChannels)
         {