diff --git a/src/wifi/model/he/rr-multi-user-scheduler.cc b/src/wifi/model/he/rr-multi-user-scheduler.cc
index e851247e5..d7815f91c 100644
--- a/src/wifi/model/he/rr-multi-user-scheduler.cc
+++ b/src/wifi/model/he/rr-multi-user-scheduler.cc
@@ -221,6 +221,15 @@ RrMultiUserScheduler::GetTxVectorForUlMu(Func canbeSolicited)
             continue;
         }
 
+        if (txVector.GetPreambleType() == WIFI_PREAMBLE_EHT_TB &&
+            !m_apMac->GetEhtSupported(staIt->address))
+        {
+            NS_LOG_DEBUG(
+                "Skipping non-EHT STA because this Trigger Frame is only soliciting EHT STAs");
+            staIt++;
+            continue;
+        }
+
         uint8_t tid = 0;
         while (tid < 8)
         {
@@ -239,6 +248,17 @@ RrMultiUserScheduler::GetTxVectorForUlMu(Func canbeSolicited)
             continue;
         }
 
+        // if the first candidate STA is an EHT STA, we switch to soliciting EHT TB PPDUs
+        if (txVector.GetHeMuUserInfoMap().empty())
+        {
+            if (m_apMac->GetEhtSupported() && m_apMac->GetEhtSupported(staIt->address))
+            {
+                txVector.SetPreambleType(WIFI_PREAMBLE_EHT_TB);
+                txVector.SetEhtPpduType(0);
+            }
+            // TODO otherwise, make sure the TX width does not exceed 160 MHz
+        }
+
         // prepare the MAC header of a frame that would be sent to the candidate station,
         // just for the purpose of retrieving the TXVECTOR used to transmit to that station
         WifiMacHeader hdr(WIFI_MAC_QOSDATA);
@@ -616,6 +636,14 @@ RrMultiUserScheduler::TrySendingDlMuPpdu()
     {
         NS_LOG_DEBUG("Next candidate STA (MAC=" << staIt->address << ", AID=" << staIt->aid << ")");
 
+        if (m_txParams.m_txVector.GetPreambleType() == WIFI_PREAMBLE_EHT_MU &&
+            !m_apMac->GetEhtSupported(staIt->address))
+        {
+            NS_LOG_DEBUG("Skipping non-EHT STA because this DL MU PPDU is sent to EHT STAs only");
+            staIt++;
+            continue;
+        }
+
         HeRu::RuType currRuType = (m_candidates.size() < count ? ruType : HeRu::RU_26_TONE);
 
         // check if the AP has at least one frame to be sent to the current station
@@ -670,6 +698,17 @@ RrMultiUserScheduler::TrySendingDlMuPpdu()
             }
         }
 
+        // the first candidate STA determines the preamble type for the DL MU PPDU
+        if (m_candidates.size() == 1)
+        {
+            if (m_apMac->GetEhtSupported() && m_apMac->GetEhtSupported(staIt->address))
+            {
+                m_txParams.m_txVector.SetPreambleType(WIFI_PREAMBLE_EHT_MU);
+                m_txParams.m_txVector.SetEhtPpduType(0); // indicates DL OFDMA transmission
+            }
+            // TODO otherwise, make sure the TX width does not exceed 160 MHz
+        }
+
         // move to the next station in the list
         staIt++;
     }
diff --git a/src/wifi/model/he/rr-multi-user-scheduler.h b/src/wifi/model/he/rr-multi-user-scheduler.h
index bba425659..a470f1c35 100644
--- a/src/wifi/model/he/rr-multi-user-scheduler.h
+++ b/src/wifi/model/he/rr-multi-user-scheduler.h
@@ -34,8 +34,9 @@ namespace ns3
  * transmission if the AP has frames to transmit to at least one station.
  * RrMultiUserScheduler assigns RUs of equal size (in terms of tones) to stations to
  * which the AP has frames to transmit belonging to the AC who gained access to the
- * channel or higher. The maximum number of stations that can be granted an RU
- * is configurable. Associated stations are served in a round robin fashion.
+ * channel or higher. The maximum number of stations that can be granted an RU is
+ * configurable. Associated stations are served based on their priority. The priority is
+ * determined by the credits/debits a station gets when it is selected or not for transmission.
  *
  * \todo Take the supported channel width of the stations into account while selecting
  * stations and assigning RUs to them.