From 5439c98fe5a6998ebe0186cfcd167b710667486b Mon Sep 17 00:00:00 2001
From: Sharan Naribole <sharan.naribole@gmail.com>
Date: Mon, 7 Aug 2023 20:13:21 +0200
Subject: [PATCH] wifi: Extend helper to configure mapping between spectrum PHY
 interfaces and PHY instances

---
 src/wifi/helper/spectrum-wifi-helper.cc | 40 +++++++++++++++++++++----
 src/wifi/helper/spectrum-wifi-helper.h  | 27 +++++++++++++++++
 2 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/src/wifi/helper/spectrum-wifi-helper.cc b/src/wifi/helper/spectrum-wifi-helper.cc
index 56b3aa266..6a6d7ff03 100644
--- a/src/wifi/helper/spectrum-wifi-helper.cc
+++ b/src/wifi/helper/spectrum-wifi-helper.cc
@@ -104,6 +104,19 @@ SpectrumWifiPhyHelper::AddWifiBandwidthFilter(Ptr<SpectrumChannel> channel)
     }
 }
 
+void
+SpectrumWifiPhyHelper::AddPhyToFreqRangeMapping(uint8_t linkId, const FrequencyRange& freqRange)
+{
+    if (auto it = m_interfacesMap.find(linkId); it == m_interfacesMap.end())
+    {
+        m_interfacesMap.insert({linkId, {freqRange}});
+    }
+    else
+    {
+        it->second.emplace(freqRange);
+    }
+}
+
 std::vector<Ptr<WifiPhy>>
 SpectrumWifiPhyHelper::Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const
 {
@@ -114,7 +127,7 @@ SpectrumWifiPhyHelper::Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const
         auto phy = m_phys.at(i).Create<SpectrumWifiPhy>();
         auto interference = m_interferenceHelper.Create<InterferenceHelper>();
         phy->SetInterferenceHelper(interference);
-        Ptr<ErrorRateModel> error = m_errorRateModel.at(i).Create<ErrorRateModel>();
+        auto error = m_errorRateModel.at(i).Create<ErrorRateModel>();
         phy->SetErrorRateModel(error);
         if (m_frameCaptureModel.at(i).IsTypeIdSet())
         {
@@ -127,10 +140,7 @@ SpectrumWifiPhyHelper::Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const
                 m_preambleDetectionModel.at(i).Create<PreambleDetectionModel>();
             phy->SetPreambleDetectionModel(preambleDetection);
         }
-        for (const auto& [freqRange, channel] : m_channels)
-        {
-            phy->AddChannel(channel, freqRange);
-        }
+        InstallPhyInterfaces(i, phy);
         phy->SetDevice(device);
         phy->SetMobility(node->GetObject<MobilityModel>());
         ret.emplace_back(phy);
@@ -139,4 +149,24 @@ SpectrumWifiPhyHelper::Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const
     return ret;
 }
 
+void
+SpectrumWifiPhyHelper::InstallPhyInterfaces(uint8_t linkId, Ptr<SpectrumWifiPhy> phy) const
+{
+    if (m_interfacesMap.count(linkId) == 0)
+    {
+        // default setup: set all interfaces to this link
+        for (const auto& [freqRange, channel] : m_channels)
+        {
+            phy->AddChannel(channel, freqRange);
+        }
+    }
+    else
+    {
+        for (const auto& freqRange : m_interfacesMap.at(linkId))
+        {
+            phy->AddChannel(m_channels.at(freqRange), freqRange);
+        }
+    }
+}
+
 } // namespace ns3
diff --git a/src/wifi/helper/spectrum-wifi-helper.h b/src/wifi/helper/spectrum-wifi-helper.h
index a58cfeed7..fd628b803 100644
--- a/src/wifi/helper/spectrum-wifi-helper.h
+++ b/src/wifi/helper/spectrum-wifi-helper.h
@@ -22,10 +22,14 @@
 
 #include "wifi-helper.h"
 
+#include <map>
+#include <set>
+
 namespace ns3
 {
 
 class SpectrumChannel;
+class SpectrumWifiPhy;
 
 /**
  * \brief Make it easy to create and manage PHY objects for the spectrum model.
@@ -81,6 +85,16 @@ class SpectrumWifiPhyHelper : public WifiPhyHelper
     void AddChannel(const std::string& channelName,
                     const FrequencyRange& freqRange = WHOLE_WIFI_SPECTRUM);
 
+    /**
+     * Add a given spectrum PHY interface to the PHY instance corresponding of a given link.
+     * If no mapping has been specified for a given link, all spectrum PHY interfaces will
+     * be added to the PHY instance of that link.
+     *
+     * \param linkId ID of the link to setup
+     * \param freqRange frequency range handled by of the spectrum PHY interface
+     */
+    void AddPhyToFreqRangeMapping(uint8_t linkId, const FrequencyRange& freqRange);
+
   private:
     /**
      * \param node the node on which we wish to create a wifi PHY
@@ -90,6 +104,16 @@ class SpectrumWifiPhyHelper : public WifiPhyHelper
      * This method implements the pure virtual method defined in \ref ns3::WifiPhyHelper.
      */
     std::vector<Ptr<WifiPhy>> Create(Ptr<Node> node, Ptr<WifiNetDevice> device) const override;
+
+    /**
+     * \brief Install PHY interfaces to the PHY instance of a given link
+     * based on the currently configured mapping (\see AddPhyInterface).
+     *
+     * \param linkId ID of the link to setup
+     * \param phy spectrum PHY instance of the link
+     */
+    void InstallPhyInterfaces(uint8_t linkId, Ptr<SpectrumWifiPhy> phy) const;
+
     /**
      * \param channel The channel to inspect to possibly add a WifiBandwidthFilter
      *
@@ -99,6 +123,9 @@ class SpectrumWifiPhyHelper : public WifiPhyHelper
     void AddWifiBandwidthFilter(Ptr<SpectrumChannel> channel);
 
     std::map<FrequencyRange, Ptr<SpectrumChannel>> m_channels; ///< the spectrum channels
+    std::map<uint8_t /* linkId */, std::set<FrequencyRange>>
+        m_interfacesMap; ///< map of the spectrum PHY interfaces to be added to the PHY instance
+                         ///< corresponding to a given link ID
 };
 
 } // namespace ns3