From 47ebdfbbf04cba1d7639fd003884df021ba25c22 Mon Sep 17 00:00:00 2001
From: Stefano Avallone <stavallo@unina.it>
Date: Thu, 30 Nov 2023 18:01:59 +0100
Subject: [PATCH] wifi: Do not start access on a link on which no PHY is
 operating

---
 src/wifi/model/txop.cc | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/wifi/model/txop.cc b/src/wifi/model/txop.cc
index 653e922ec..cfbfa426a 100644
--- a/src/wifi/model/txop.cc
+++ b/src/wifi/model/txop.cc
@@ -25,6 +25,7 @@
 #include "wifi-mac-queue.h"
 #include "wifi-mac-trailer.h"
 #include "wifi-mac.h"
+#include "wifi-phy.h"
 
 #include "ns3/attribute-container.h"
 #include "ns3/log.h"
@@ -602,6 +603,12 @@ Txop::StartAccessAfterEvent(uint8_t linkId, bool hadFramesToTransmit, bool check
 {
     NS_LOG_FUNCTION(this << linkId << hadFramesToTransmit << checkMediumBusy);
 
+    if (!m_mac->GetWifiPhy(linkId))
+    {
+        NS_LOG_DEBUG("No PHY operating on link " << +linkId);
+        return;
+    }
+
     if (GetLink(linkId).access != NOT_REQUESTED)
     {
         NS_LOG_DEBUG("Channel access already requested or granted on link " << +linkId);