diff --git a/src/wifi/model/qos-utils.cc b/src/wifi/model/qos-utils.cc
index ad59b41c4..da235e98d 100644
--- a/src/wifi/model/qos-utils.cc
+++ b/src/wifi/model/qos-utils.cc
@@ -49,6 +49,79 @@ WifiAddressHash::operator()(const Mac48Address& address) const
   return std::hash<std::string>{} (s);
 }
 
+WifiAc::WifiAc (uint8_t lowTid, uint8_t highTid)
+  : m_lowTid (lowTid),
+    m_highTid (highTid)
+{
+}
+
+uint8_t
+WifiAc::GetLowTid (void) const
+{
+  return m_lowTid;
+}
+
+uint8_t
+WifiAc::GetHighTid (void) const
+{
+  return m_highTid;
+}
+
+uint8_t
+WifiAc::GetOtherTid (uint8_t tid) const
+{
+  if (tid == m_lowTid)
+    {
+      return m_highTid;
+    }
+  if (tid == m_highTid)
+    {
+      return m_lowTid;
+    }
+  NS_ABORT_MSG ("TID " << tid << " does not belong to this AC");
+}
+
+bool operator> (enum AcIndex left, enum AcIndex right)
+{
+  NS_ABORT_MSG_IF (left > 3 || right > 3, "Cannot compare non-QoS ACs");
+
+  if (left == right)
+    {
+      return false;
+    }
+  if (left == AC_BK)
+    {
+      return false;
+    }
+  if (right == AC_BK)
+    {
+      return true;
+    }
+  return static_cast<uint8_t> (left) > static_cast<uint8_t> (right);
+}
+
+bool operator>= (enum AcIndex left, enum AcIndex right)
+{
+  NS_ABORT_MSG_IF (left > 3 || right > 3, "Cannot compare non-QoS ACs");
+
+  return (left == right || left > right);
+}
+
+bool operator< (enum AcIndex left, enum AcIndex right)
+{
+  return !(left >= right);
+}
+
+bool operator<= (enum AcIndex left, enum AcIndex right)
+{
+  return !(left > right);
+}
+
+const std::map<AcIndex, WifiAc> wifiAcList = { {AC_BE, {0, 3}},
+                                               {AC_BK, {1, 2}},
+                                               {AC_VI, {4, 5}},
+                                               {AC_VO, {6, 7}} };
+
 AcIndex
 QosUtilsMapTidToAc (uint8_t tid)
 {
diff --git a/src/wifi/model/qos-utils.h b/src/wifi/model/qos-utils.h
index 6cde4266a..b28221ef8 100644
--- a/src/wifi/model/qos-utils.h
+++ b/src/wifi/model/qos-utils.h
@@ -22,6 +22,7 @@
 #define QOS_UTILS_H
 
 #include "ns3/ptr.h"
+#include <map>
 
 namespace ns3 {
 
@@ -69,6 +70,95 @@ enum AcIndex : uint8_t
   AC_UNDEF
 };
 
+/**
+ * \ingroup wifi
+ * This class stores the pair of TIDs of an Access Category.
+ */
+class WifiAc
+{
+public:
+  /**
+   * Constructor.
+   *
+   * \param lowTid the TID with lower priority
+   * \param highTid the TID with higher priority
+   */
+  WifiAc (uint8_t lowTid, uint8_t highTid);
+  /**
+   * Get the TID with lower priority
+   *
+   * \return the TID with lower priority
+   */
+  uint8_t GetLowTid (void) const;
+  /**
+   * Get the TID with higher priority
+   *
+   * \return the TID with higher priority
+   */
+  uint8_t GetHighTid (void) const;
+  /**
+   * Given a TID belonging to this Access Category, get the other TID of this AC.
+   *
+   * \param tid a TID belonging to this AC
+   * \return the other TID belonging to this AC
+   */
+  uint8_t GetOtherTid (uint8_t tid) const;
+
+private:
+  uint8_t m_lowTid;      //!< the TID with lower priority
+  uint8_t m_highTid;     //!< the TID with higher priority
+};
+
+/**
+ * \ingroup wifi
+ * Operator> overload returning true if the AC on the left has higher priority
+ * than the AC on the right.
+ *
+ * \param left the AC on the left of operator>
+ * \param right the AC on the right of operator>
+ * \return true if the AC on the left has higher priority than the AC on the right
+ */
+bool operator> (enum AcIndex left, enum AcIndex right);
+
+/**
+ * \ingroup wifi
+ * Operator>= overload returning true if the AC on the left has higher or the same
+ * priority than the AC on the right.
+ *
+ * \param left the AC on the left of operator>=
+ * \param right the AC on the right of operator>=
+ * \return true if the AC on the left has higher or the same priority than the AC on the right
+ */
+bool operator>= (enum AcIndex left, enum AcIndex right);
+
+/**
+ * \ingroup wifi
+ * Operator< overload returning true if the AC on the left has lower priority
+ * than the AC on the right.
+ *
+ * \param left the AC on the left of operator<
+ * \param right the AC on the right of operator<
+ * \return true if the AC on the left has lower priority than the AC on the right
+ */
+bool operator< (enum AcIndex left, enum AcIndex right);
+
+/**
+ * \ingroup wifi
+ * Operator<= overload returning true if the AC on the left has lower or the same
+ * priority than the AC on the right.
+ *
+ * \param left the AC on the left of operator<=
+ * \param right the AC on the right of operator<=
+ * \return true if the AC on the left has lower or the same priority than the AC on the right
+ */
+bool operator<= (enum AcIndex left, enum AcIndex right);
+
+/**
+ * Map containing the four ACs in increasing order of priority (according to
+ * Table 10-1 "UP-to-AC Mappings" of 802.11-2016)
+ */
+extern const std::map<AcIndex, WifiAc> wifiAcList;
+
 /**
  * \ingroup wifi
  * Maps TID (Traffic ID) to Access classes.