From b1b21c4883938f74241a257f6efa9d62caaffe28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= <sebastien.deronne@gmail.com>
Date: Wed, 13 Sep 2023 12:43:47 +0200
Subject: [PATCH] wifi: Configure interfaces of all spectrum PHYs when the
 channel of one instance has changed

---
 examples/wireless/examples-to-run.py    |  2 +-
 src/wifi/helper/spectrum-wifi-helper.cc | 30 +++++++++++++++++++++++++
 src/wifi/helper/spectrum-wifi-helper.h  |  6 +++++
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/examples/wireless/examples-to-run.py b/examples/wireless/examples-to-run.py
index 7eef186fe..3acd036ee 100755
--- a/examples/wireless/examples-to-run.py
+++ b/examples/wireless/examples-to-run.py
@@ -60,7 +60,7 @@ cpp_examples = [
     ("wifi-eht-network --simulationTime=0.1 --frequency=5 --useRts=1 --minExpectedThroughput=6 --maxExpectedThroughput=547", "True", "True"),
     ("wifi-eht-network --simulationTime=0.1 --frequency=2.4 --useRts=0 --useExtendedBlockAck=1 --frequency2=5 --minExpectedThroughput=12 --maxExpectedThroughput=500", "True", "True"),
     ("wifi-eht-network --simulationTime=0.1 --frequency=2.4 --useRts=1 --minExpectedThroughput=6 --maxExpectedThroughput=212", "True", "True"),
-    ("wifi-eht-network --simulationTime=0.22 --udp=0 --downlink=1 --useRts=0 --nStations=4 --dlAckType=ACK-SU-FORMAT --enableUlOfdma=1 --enableBsrp=0 --mcs=4 --frequency2=6  --minExpectedThroughput=35 --maxExpectedThroughput=280", "True", "True"),
+    ("wifi-eht-network --simulationTime=0.23 --udp=0 --downlink=1 --useRts=0 --nStations=4 --dlAckType=ACK-SU-FORMAT --enableUlOfdma=1 --enableBsrp=0 --mcs=4 --frequency2=6  --minExpectedThroughput=35 --maxExpectedThroughput=280", "True", "True"),
     ("wifi-eht-network --simulationTime=0.25 --frequency=2.4 --udp=0 --downlink=1 --useRts=0 --nStations=5 --dlAckType=MU-BAR --enableUlOfdma=1 --enableBsrp=1 --mcs=5 --frequency2=5 --useExtendedBlockAck=1 --minExpectedThroughput=40 --maxExpectedThroughput=100", "True", "True"),
     ("wifi-eht-network --simulationTime=0.3 --udp=0 --downlink=1 --useRts=1 --nStations=5 --dlAckType=AGGR-MU-BAR --enableUlOfdma=1 --enableBsrp=0 --mcs=6 --muSchedAccessReqInterval=50ms --frequency2=2.4 --minExpectedThroughput=50 --maxExpectedThroughput=140", "True", "True"),
     ("wifi-eht-network --simulationTime=0.2 --udp=1 --downlink=0 --useRts=0 --nStations=5 --dlAckType=AGGR-MU-BAR --enableUlOfdma=1 --enableBsrp=1 --mcs=5 --muSchedAccessReqInterval=50ms --frequency2=6 --minExpectedThroughput=70 --maxExpectedThroughput=715", "True", "True"),
diff --git a/src/wifi/helper/spectrum-wifi-helper.cc b/src/wifi/helper/spectrum-wifi-helper.cc
index dad7ccc4d..abd21004d 100644
--- a/src/wifi/helper/spectrum-wifi-helper.cc
+++ b/src/wifi/helper/spectrum-wifi-helper.cc
@@ -147,6 +147,8 @@ SpectrumWifiPhyHelper::Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const
             phy->SetPreambleDetectionModel(preambleDetection);
         }
         InstallPhyInterfaces(i, phy);
+        phy->SetChannelSwitchedCallback(
+            MakeCallback(&SpectrumWifiPhyHelper::SpectrumChannelSwitched, this).Bind(phy));
         phy->SetDevice(device);
         phy->SetMobility(node->GetObject<MobilityModel>());
         ret.emplace_back(phy);
@@ -175,4 +177,32 @@ SpectrumWifiPhyHelper::InstallPhyInterfaces(uint8_t linkId, Ptr<SpectrumWifiPhy>
     }
 }
 
+void
+SpectrumWifiPhyHelper::SpectrumChannelSwitched(Ptr<SpectrumWifiPhy> phy) const
+{
+    NS_LOG_FUNCTION(this << phy);
+    for (const auto& otherPhy : phy->GetDevice()->GetPhys())
+    {
+        auto spectrumPhy = DynamicCast<SpectrumWifiPhy>(otherPhy);
+        NS_ASSERT(spectrumPhy);
+        if (spectrumPhy == phy)
+        {
+            // this is the PHY that has switched
+            continue;
+        }
+        if (spectrumPhy->GetCurrentFrequencyRange() == phy->GetCurrentFrequencyRange())
+        {
+            // this is the active interface
+            continue;
+        }
+        if (const auto& interfaces = spectrumPhy->GetSpectrumPhyInterfaces();
+            interfaces.count(phy->GetCurrentFrequencyRange()) == 0)
+        {
+            // no interface attached to that channel
+            continue;
+        }
+        spectrumPhy->ConfigureInterface(phy->GetFrequency(), phy->GetChannelWidth());
+    }
+}
+
 } // namespace ns3
diff --git a/src/wifi/helper/spectrum-wifi-helper.h b/src/wifi/helper/spectrum-wifi-helper.h
index 0985a3c1f..481f2ece2 100644
--- a/src/wifi/helper/spectrum-wifi-helper.h
+++ b/src/wifi/helper/spectrum-wifi-helper.h
@@ -119,6 +119,12 @@ class SpectrumWifiPhyHelper : public WifiPhyHelper
      */
     void InstallPhyInterfaces(uint8_t linkId, Ptr<SpectrumWifiPhy> phy) const;
 
+    /**
+     * Function that is notified when a spectrum channel switched
+     * \param phy spectrum PHY instance that has switched its channel
+     */
+    void SpectrumChannelSwitched(Ptr<SpectrumWifiPhy> phy) const;
+
     /**
      * \param channel The channel to inspect to possibly add a WifiBandwidthFilter
      *