diff --git a/src/wifi/model/mpdu-aggregator.cc b/src/wifi/model/mpdu-aggregator.cc
index 4ccd5d844..f530a03df 100644
--- a/src/wifi/model/mpdu-aggregator.cc
+++ b/src/wifi/model/mpdu-aggregator.cc
@@ -229,8 +229,16 @@ MpduAggregator::GetNextAmpdu(Ptr<WifiMpdu> mpdu,
     auto qosTxop = m_mac->GetQosTxop(tid);
     NS_ASSERT(qosTxop);
 
+    const auto isGcr = IsGcr(m_mac, header);
+    const auto bufferSize = qosTxop->GetBaBufferSize(origRecipient, tid, isGcr);
+    const auto startSeq = qosTxop->GetBaStartingSequence(origRecipient, tid, isGcr);
+
     // Have to make sure that the block ack agreement is established and A-MPDU is enabled
-    if (m_mac->GetBaAgreementEstablishedAsOriginator(recipient, tid) &&
+    auto apMac = DynamicCast<ApWifiMac>(m_mac);
+    const auto agreementEstablished =
+        isGcr ? apMac->IsGcrBaAgreementEstablishedWithAllMembers(header.GetAddr1(), tid)
+              : m_mac->GetBaAgreementEstablishedAsOriginator(recipient, tid).has_value();
+    if (agreementEstablished &&
         GetMaxAmpduSize(recipient, tid, txParams.m_txVector.GetModulationClass()) > 0)
     {
         /* here is performed MPDU aggregation */
@@ -238,6 +246,23 @@ MpduAggregator::GetNextAmpdu(Ptr<WifiMpdu> mpdu,
 
         while (nextMpdu)
         {
+            const auto isGcrUr = isGcr && (apMac->GetGcrManager()->GetRetransmissionPolicy() ==
+                                           GroupAddressRetransmissionPolicy::GCR_UNSOLICITED_RETRY);
+            if (isGcrUr && header.IsRetry() && !nextMpdu->GetHeader().IsRetry())
+            {
+                // if this is a retransmitted A-MPDU transmitted via GCR-UR, do not add new MPDU
+                break;
+            }
+            if (isGcr &&
+                apMac->GetGcrManager()->GetRetransmissionPolicyFor(header) !=
+                    apMac->GetGcrManager()->GetRetransmissionPolicyFor(nextMpdu->GetHeader()))
+            {
+                // if an MPDU has been previously transmitted using No-Ack/No-Retry,
+                // do not add a new MPDU that still needs to be transmitted using No-Ack/No-Retry,
+                // unless No-Ack/No-Retry is the only selected retransmission policy
+                break;
+            }
+
             // if we are here, nextMpdu can be aggregated to the A-MPDU.
             NS_LOG_DEBUG("Adding packet with sequence number "
                          << nextMpdu->GetHeader().GetSequenceNumber()
@@ -254,9 +279,8 @@ MpduAggregator::GetNextAmpdu(Ptr<WifiMpdu> mpdu,
             if (peekedMpdu)
             {
                 // PeekNextMpdu() does not return an MPDU that is beyond the transmit window
-                NS_ASSERT(IsInWindow(peekedMpdu->GetHeader().GetSequenceNumber(),
-                                     qosTxop->GetBaStartingSequence(origRecipient, tid),
-                                     qosTxop->GetBaBufferSize(origRecipient, tid)));
+                NS_ASSERT(
+                    IsInWindow(peekedMpdu->GetHeader().GetSequenceNumber(), startSeq, bufferSize));
 
                 peekedMpdu = m_htFem->CreateAliasIfNeeded(peekedMpdu);
                 // get the next MPDU to aggregate, provided that the constraints on size
diff --git a/src/wifi/model/qos-txop.cc b/src/wifi/model/qos-txop.cc
index 6dbe9ab27..8e83bed79 100644
--- a/src/wifi/model/qos-txop.cc
+++ b/src/wifi/model/qos-txop.cc
@@ -11,6 +11,7 @@
 
 #include "qos-txop.h"
 
+#include "ap-wifi-mac.h"
 #include "channel-access-manager.h"
 #include "ctrl-headers.h"
 #include "mac-tx-middle.h"
@@ -436,13 +437,25 @@ QosTxop::PeekNextMpdu(uint8_t linkId, uint8_t tid, Mac48Address recipient, Ptr<c
                 break;
             }
 
-            // if no BA agreement, we cannot have multiple MPDUs in-flight
-            if (item->GetHeader().IsQosData() &&
-                !m_mac->GetBaAgreementEstablishedAsOriginator(item->GetHeader().GetAddr1(),
-                                                              item->GetHeader().GetQosTid()))
+            if (item->GetHeader().IsQosData())
             {
-                NS_LOG_DEBUG("No BA agreement and an MPDU is already in-flight");
-                return nullptr;
+                auto apMac = DynamicCast<ApWifiMac>(m_mac);
+                const auto isGcr = IsGcr(m_mac, item->GetHeader());
+                const auto agreementEstablished =
+                    isGcr
+                        ? apMac->IsGcrBaAgreementEstablishedWithAllMembers(
+                              item->GetHeader().GetAddr1(),
+                              item->GetHeader().GetQosTid())
+                        : m_mac
+                              ->GetBaAgreementEstablishedAsOriginator(item->GetHeader().GetAddr1(),
+                                                                      item->GetHeader().GetQosTid())
+                              .has_value();
+                // if no BA agreement, we cannot have multiple MPDUs in-flight
+                if (!agreementEstablished)
+                {
+                    NS_LOG_DEBUG("No BA agreement and an MPDU is already in-flight");
+                    return nullptr;
+                }
             }
 
             NS_LOG_DEBUG("Skipping in flight MPDU: " << *item);
@@ -467,21 +480,24 @@ QosTxop::PeekNextMpdu(uint8_t linkId, uint8_t tid, Mac48Address recipient, Ptr<c
         return nullptr;
     }
 
-    WifiMacHeader& hdr = item->GetHeader();
+    auto& hdr = item->GetHeader();
 
     // peek the next sequence number and check if it is within the transmit window
     // in case of QoS data frame
-    uint16_t sequence = item->HasSeqNoAssigned() ? hdr.GetSequenceNumber()
-                                                 : m_txMiddle->PeekNextSequenceNumberFor(&hdr);
+    const auto sequence = item->HasSeqNoAssigned() ? hdr.GetSequenceNumber()
+                                                   : m_txMiddle->PeekNextSequenceNumberFor(&hdr);
     if (hdr.IsQosData())
     {
-        Mac48Address recipient = hdr.GetAddr1();
-        uint8_t tid = hdr.GetQosTid();
-
-        if (m_mac->GetBaAgreementEstablishedAsOriginator(recipient, tid) &&
-            !IsInWindow(sequence,
-                        GetBaStartingSequence(recipient, tid),
-                        GetBaBufferSize(recipient, tid)))
+        const auto recipient = hdr.GetAddr1();
+        const auto tid = hdr.GetQosTid();
+        const auto isGcr = IsGcr(m_mac, hdr);
+        const auto bufferSize = GetBaBufferSize(recipient, tid, isGcr);
+        const auto startSeq = GetBaStartingSequence(recipient, tid, isGcr);
+        auto apMac = DynamicCast<ApWifiMac>(m_mac);
+        const auto agreementEstablished =
+            isGcr ? apMac->IsGcrBaAgreementEstablishedWithAllMembers(recipient, tid)
+                  : m_mac->GetBaAgreementEstablishedAsOriginator(recipient, tid).has_value();
+        if (agreementEstablished && !IsInWindow(sequence, startSeq, bufferSize))
         {
             NS_LOG_DEBUG("Packet beyond the end of the current transmit window");
             return nullptr;
diff --git a/src/wifi/model/wifi-default-ack-manager.cc b/src/wifi/model/wifi-default-ack-manager.cc
index e4e51deff..dd03e4fcf 100644
--- a/src/wifi/model/wifi-default-ack-manager.cc
+++ b/src/wifi/model/wifi-default-ack-manager.cc
@@ -292,8 +292,8 @@ WifiDefaultAckManager::TryAddMpdu(Ptr<const WifiMpdu> mpdu, const WifiTxParamete
 
     if (receiver.IsGroup())
     {
-        NS_ABORT_MSG_IF(!txParams.LastAddedIsFirstMpdu(receiver),
-                        "Unicast frames only can be aggregated");
+        NS_ABORT_MSG_IF(!IsGcr(m_mac, hdr) && !txParams.LastAddedIsFirstMpdu(receiver),
+                        "Unicast frames only can be aggregated if GCR is not used");
         auto acknowledgment = std::make_unique<WifiNoAck>();
         if (hdr.IsQosData())
         {