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wifi: QosTxop does not return packets outside of the current transmit window

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Also, make use of the new variants of the WifiMacQueue methods and
remove unused BlockAckManager methods
This commit is contained in:
Stefano Avallone
2019-04-19 12:03:25 +02:00
parent 543cf34dcc
commit d6c31ad130
4 changed files with 151 additions and 263 deletions
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178
src/wifi/model/block-ack-manager.cc
View File

@@ -222,6 +222,12 @@ BlockAckManager::UpdateAgreement (const MgtAddBaResponseHeader *respHdr, Mac48Ad
m_unblockPackets (recipient, tid);
}
Ptr<WifiMacQueue>
BlockAckManager::GetRetransmitQueue (void)
{
return m_retryPackets;
}
void
BlockAckManager::StorePacket (Ptr<WifiMacQueueItem> mpdu)
{
@@ -252,178 +258,6 @@ BlockAckManager::StorePacket (Ptr<WifiMacQueueItem> mpdu)
}
}
Ptr<WifiMacQueueItem>
BlockAckManager::GetNextPacket (bool removePacket)
{
NS_LOG_FUNCTION (this << removePacket);
Ptr<WifiMacQueueItem> item;
uint8_t tid;
Mac48Address recipient;
CleanupBuffers ();
if (!m_retryPackets->IsEmpty ())
{
NS_LOG_DEBUG ("Retry buffer size is " << m_retryPackets->GetNPackets ());
WifiMacQueue::ConstIterator it = m_retryPackets->begin ();
while (it != m_retryPackets->end ())
{
if ((*it)->GetHeader ().IsQosData ())
{
tid = (*it)->GetHeader ().GetQosTid ();
}
else
{
NS_FATAL_ERROR ("Packet in blockAck manager retry queue is not Qos Data");
}
recipient = (*it)->GetHeader ().GetAddr1 ();
AgreementsI agreement = m_agreements.find (std::make_pair (recipient, tid));
NS_ASSERT (agreement != m_agreements.end ());
if (removePacket)
{
if (QosUtilsIsOldPacket (agreement->second.first.GetStartingSequence (), (*it)->GetHeader ().GetSequenceNumber ()))
{
//Standard says the originator should not send a packet with seqnum < winstart
NS_LOG_DEBUG ("The Retry packet have sequence number < WinStartO --> Discard "
<< (*it)->GetHeader ().GetSequenceNumber () << " "
<< agreement->second.first.GetStartingSequence ());
agreement->second.second.remove ((*it));
it = m_retryPackets->Remove (it);
continue;
}
else if (((((*it)->GetHeader ().GetSequenceNumber () - agreement->second.first.GetStartingSequence ()) + 4096) % 4096) > (agreement->second.first.GetBufferSize () - 1))
{
agreement->second.first.SetStartingSequence ((*it)->GetHeader ().GetSequenceNumber ());
}
}
item = *it;
item->GetHeader ().SetRetry ();
if (item->GetHeader ().IsQosData ())
{
tid = item->GetHeader ().GetQosTid ();
}
else
{
NS_FATAL_ERROR ("Packet in blockAck manager retry queue is not Qos Data");
}
recipient = item->GetHeader ().GetAddr1 ();
if (!agreement->second.first.IsHtSupported ()
&& (ExistsAgreementInState (recipient, tid, OriginatorBlockAckAgreement::ESTABLISHED)
|| SwitchToBlockAckIfNeeded (recipient, tid, item->GetHeader ().GetSequenceNumber ())))
{
item->GetHeader ().SetQosAckPolicy (WifiMacHeader::BLOCK_ACK);
}
else
{
/* From section 9.10.3 in IEEE802.11e standard:
* In order to improve efficiency, originators using the Block Ack facility
* may send MPDU frames with the Ack Policy subfield in QoS control frames
* set to Normal Ack if only a few MPDUs are available for transmission.[...]
* When there are sufficient number of MPDUs, the originator may switch back to
* the use of Block Ack.
*/
item->GetHeader ().SetQosAckPolicy (WifiMacHeader::NORMAL_ACK);
if (removePacket)
{
AgreementsI i = m_agreements.find (std::make_pair (recipient, tid));
i->second.second.remove (*it);
}
}
if (removePacket)
{
NS_LOG_INFO ("Retry packet seq = " << item->GetHeader ().GetSequenceNumber ());
it = m_retryPackets->Remove (it);
NS_LOG_DEBUG ("Removed one packet, retry buffer size = " << m_retryPackets->GetNPackets ());
}
break;
}
}
return item;
}
Ptr<const WifiMacQueueItem>
BlockAckManager::PeekNextPacketByTidAndAddress (uint8_t tid, Mac48Address recipient)
{
NS_LOG_FUNCTION (this);
Ptr<const WifiMacQueueItem> item = 0;
CleanupBuffers ();
AgreementsI agreement = m_agreements.find (std::make_pair (recipient, tid));
NS_ASSERT (agreement != m_agreements.end ());
WifiMacQueue::ConstIterator it = m_retryPackets->begin ();
for (; it != m_retryPackets->end (); it++)
{
if (!(*it)->GetHeader ().IsQosData ())
{
NS_FATAL_ERROR ("Packet in blockAck manager retry queue is not Qos Data");
}
if ((*it)->GetHeader ().GetAddr1 () == recipient && (*it)->GetHeader ().GetQosTid () == tid)
{
if (QosUtilsIsOldPacket (agreement->second.first.GetStartingSequence (), (*it)->GetHeader ().GetSequenceNumber ()))
{
//standard says the originator should not send a packet with seqnum < winstart
NS_LOG_DEBUG ("The Retry packet have sequence number < WinStartO --> Discard "
<< (*it)->GetHeader ().GetSequenceNumber () << " "
<< agreement->second.first.GetStartingSequence ());
agreement->second.second.remove ((*it));
it = m_retryPackets->Remove (it);
it--;
continue;
}
else if (((((*it)->GetHeader ().GetSequenceNumber () - agreement->second.first.GetStartingSequence ()) + 4096) % 4096) > (agreement->second.first.GetBufferSize () - 1))
{
agreement->second.first.SetStartingSequence ((*it)->GetHeader ().GetSequenceNumber ());
}
WifiMacHeader hdr = (*it)->GetHeader ();
hdr.SetRetry ();
item = Create<const WifiMacQueueItem> ((*it)->GetPacket (), hdr, (*it)->GetTimeStamp ());
NS_LOG_INFO ("Retry packet seq = " << hdr.GetSequenceNumber ());
if (!agreement->second.first.IsHtSupported ()
&& (ExistsAgreementInState (recipient, tid, OriginatorBlockAckAgreement::ESTABLISHED)
|| SwitchToBlockAckIfNeeded (recipient, tid, hdr.GetSequenceNumber ())))
{
hdr.SetQosAckPolicy (WifiMacHeader::BLOCK_ACK);
}
else
{
/* From section 9.10.3 in IEEE802.11e standard:
* In order to improve efficiency, originators using the Block Ack facility
* may send MPDU frames with the Ack Policy subfield in QoS control frames
* set to Normal Ack if only a few MPDUs are available for transmission.[...]
* When there are sufficient number of MPDUs, the originator may switch back to
* the use of Block Ack.
*/
hdr.SetQosAckPolicy (WifiMacHeader::NORMAL_ACK);
}
NS_LOG_DEBUG ("Peeked one packet from retry buffer size = " << m_retryPackets->GetNPackets () );
return item;
}
}
return item;
}
bool
BlockAckManager::RemovePacket (uint8_t tid, Mac48Address recipient, uint16_t seqnumber)
{
NS_LOG_FUNCTION (this << seqnumber);
WifiMacQueue::ConstIterator it = m_retryPackets->begin ();
for (; it != m_retryPackets->end (); it++)
{
if (!(*it)->GetHeader ().IsQosData ())
{
NS_FATAL_ERROR ("Packet in blockAck manager retry queue is not Qos Data");
}
if ((*it)->GetHeader ().GetAddr1 () == recipient && (*it)->GetHeader ().GetQosTid () == tid
&& (*it)->GetHeader ().GetSequenceNumber () == seqnumber)
{
WifiMacHeader hdr = (*it)->GetHeader ();
AgreementsI i = m_agreements.find (std::make_pair (recipient, tid));
i->second.second.remove ((*it));
m_retryPackets->Remove (it);
NS_LOG_DEBUG ("Removed Packet from retry queue = " << hdr.GetSequenceNumber () << " " << +tid << " " << recipient << " Buffer Size = " << m_retryPackets->GetNPackets ());
return true;
}
}
return false;
}
bool
BlockAckManager::HasBar (Bar &bar, bool remove)
{

38
src/wifi/model/block-ack-manager.h
View File

@@ -153,15 +153,6 @@ public:
* if the packet, in a block ack frame, is indicated by recipient as not received.
*/
void StorePacket (Ptr<WifiMacQueueItem> mpdu);
/**
* \param removePacket flag to indicate whether the packet should be removed from the queue.
*
* \return the packet
*
* This methods returns a packet (if exists) indicated as not received in
* corresponding block ack bitmap.
*/
Ptr<WifiMacQueueItem> GetNextPacket (bool removePacket);
/**
* Returns true if the BAR is scheduled. Returns false otherwise.
*
@@ -290,6 +281,12 @@ public:
* and buffered packets) is greater of <i>nPackets</i>, they are transmitted using block ack mechanism.
*/
void SetBlockAckThreshold (uint8_t nPackets);
/**
* \return the retransmit queue.
*
* Return the retransmit queue.
*/
Ptr<WifiMacQueue> GetRetransmitQueue (void);
/**
* \param queue The WifiMacQueue object.
@@ -355,27 +352,8 @@ public:
*/
bool AlreadyExists (uint16_t currentSeq, Mac48Address recipient, uint8_t tid) const;
/**
* Remove a packet after you peek in the queue and get it
* \param tid the Traffic ID
* \param recipient the destination address
* \param seqnumber sequence number
* \returns true if a packet was removed
*/
bool RemovePacket (uint8_t tid, Mac48Address recipient, uint16_t seqnumber);
/**
* Peek in retransmit queue and get the next packet having address indicated
* by <i>type</i> equals to <i>addr</i>, and tid equals to <i>tid</i>.
* This method doesn't remove the packet from this queue.
*
* \param hdr wifi mac header
* \param tid Traffic ID
* \param timestamp timestamp
*
* \returns Ptr<const WifiMacQueueItem>
*/
Ptr<const WifiMacQueueItem> PeekNextPacketByTidAndAddress (uint8_t tid, Mac48Address recipient);
/**
* This function returns true if the lifetime of the packets a BAR refers to didn't expire yet else it returns false.
* This function returns true if the lifetime of the packets a BAR refers to didn't
* expire yet otherwise it returns false.
* If it return false then the BAR will be discarded (i.e. will not be re-transmitted)
*
* \param tid Traffic ID

181
src/wifi/model/qos-txop.cc
View File

@@ -173,17 +173,36 @@ QosTxop::PeekNextSequenceNumberFor (const WifiMacHeader *hdr)
return m_txMiddle->PeekNextSequenceNumberFor (hdr);
}
Ptr<const WifiMacQueueItem>
QosTxop::PeekNextRetransmitPacket (uint8_t tid, Mac48Address recipient)
bool
QosTxop::IsQosOldPacket (Ptr<const WifiMacQueueItem> mpdu)
{
return m_baManager->PeekNextPacketByTidAndAddress (tid, recipient);
NS_LOG_FUNCTION (this << *mpdu);
if (!mpdu->GetHeader ().IsQosData ())
{
return false;
}
Mac48Address recipient = mpdu->GetHeader ().GetAddr1 ();
uint8_t tid = mpdu->GetHeader ().GetQosTid ();
if (!GetBaAgreementEstablished (recipient, tid))
{
return false;
}
if (QosUtilsIsOldPacket (GetBaStartingSequence (recipient, tid),
mpdu->GetHeader ().GetSequenceNumber ()))
{
return true;
}
return false;
}
Ptr<const WifiMacQueueItem>
QosTxop::PeekNextFrame (void)
{
NS_LOG_FUNCTION (this);
Ptr<const WifiMacQueueItem> item;
WifiMacQueue::ConstIterator it;
// check if there is a packet in the MacLow aggregation queue
@@ -192,92 +211,131 @@ QosTxop::PeekNextFrame (void)
if (QosUtilsMapTidToAc (tid) == m_ac)
{
it = m_low->GetAggregateQueue ()->PeekByTid (tid);
// remove old packets
while (it != m_low->GetAggregateQueue ()->end () && IsQosOldPacket (*it))
{
NS_LOG_DEBUG ("removing an old packet from MacLow aggregation queue: " << **it);
it = m_low->GetAggregateQueue ()->Remove (it);
it = m_low->GetAggregateQueue ()->PeekByTid (tid, it);
}
if (it != m_low->GetAggregateQueue ()->end ())
{
item = *it;
break;
NS_LOG_DEBUG ("packet peeked from MacLow aggregation queue: " << **it);
return *it;
}
}
}
if (item != 0)
{
NS_LOG_DEBUG ("packet peeked from MacLow aggregation queue, " << *item);
return item;
}
// otherwise, check if there is a packet in the BlockAckManager retransmit queue
item = m_baManager->GetNextPacket (false);
if (item != 0)
it = m_baManager->GetRetransmitQueue ()->PeekFirstAvailable ();
// remove old packets
while (it != m_baManager->GetRetransmitQueue ()->end () && IsQosOldPacket (*it))
{
NS_LOG_DEBUG ("packet peeked from BlockAckManager retransmit queue: " << *item);
return item;
NS_LOG_DEBUG ("removing an old packet from BlockAckManager retransmit queue: " << **it);
it = m_baManager->GetRetransmitQueue ()->Remove (it);
it = m_baManager->GetRetransmitQueue ()->PeekFirstAvailable (nullptr, it);
}
if (it != m_baManager->GetRetransmitQueue ()->end ())
{
NS_LOG_DEBUG ("packet peeked from BlockAckManager retransmit queue: " << **it);
return *it;
}
// otherwise, check if there is a packet in the EDCA queue
it = m_queue->PeekFirstAvailable (m_qosBlockedDestinations);
if (it != m_queue->end ())
{
item = *it;
// set the sequence number by just peeking the next value
uint16_t sequence = m_txMiddle->PeekNextSequenceNumberFor (&item->GetHeader ());
WifiMacHeader 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 = m_txMiddle->PeekNextSequenceNumberFor (&(*it)->GetHeader ());
if ((*it)->GetHeader ().IsQosData ())
{
Mac48Address recipient = (*it)->GetHeader ().GetAddr1 ();
uint8_t tid = (*it)->GetHeader ().GetQosTid ();
if (GetBaAgreementEstablished (recipient, tid)
&& !IsInWindow (sequence, GetBaStartingSequence (recipient, tid), GetBaBufferSize (recipient, tid)))
{
NS_LOG_DEBUG ("packet beyond the end of the current transmit window");
return 0;
}
}
WifiMacHeader hdr = (*it)->GetHeader ();
hdr.SetSequenceNumber (sequence);
hdr.SetFragmentNumber (0);
hdr.SetNoMoreFragments ();
hdr.SetNoRetry ();
item = Create<const WifiMacQueueItem> (item->GetPacket (), hdr, item->GetTimeStamp ());
Ptr<const WifiMacQueueItem> item = Create<const WifiMacQueueItem> ((*it)->GetPacket (), hdr, (*it)->GetTimeStamp ());
NS_LOG_DEBUG ("packet peeked from EDCA queue: " << *item);
return item;
}
return item;
return 0;
}
Ptr<const WifiMacQueueItem>
QosTxop::PeekNextFrameByTidAndAddress (uint8_t tid, Mac48Address recipient)
{
NS_LOG_FUNCTION (this << +tid << recipient);
Ptr<const WifiMacQueueItem> item;
WifiMacQueue::ConstIterator it;
// check if there is a packet in the MacLow aggregation queue
WifiMacQueue::ConstIterator it = m_low->GetAggregateQueue ()->PeekByTidAndAddress (tid, recipient);
it = m_low->GetAggregateQueue ()->PeekByTidAndAddress (tid, recipient);
// remove old packets
while (it != m_low->GetAggregateQueue ()->end () && IsQosOldPacket (*it))
{
NS_LOG_DEBUG ("removing an old packet from MacLow aggregation queue: " << **it);
it = m_low->GetAggregateQueue ()->Remove (it);
it = m_low->GetAggregateQueue ()->PeekByTidAndAddress (tid, recipient, it);
}
if (it != m_low->GetAggregateQueue ()->end ())
{
item = *it;
NS_LOG_DEBUG ("packet peeked from MacLow aggregation queue, " << *item);
return item;
NS_LOG_DEBUG ("packet peeked from MacLow aggregation queue: " << **it);
return *it;
}
// otherwise, check if there is a packet in the BlockAckManager retransmit queue
item = m_baManager->PeekNextPacketByTidAndAddress (tid, recipient);
if (item != 0)
it = m_baManager->GetRetransmitQueue ()->PeekByTidAndAddress (tid, recipient);
// remove old packets
while (it != m_baManager->GetRetransmitQueue ()->end () && IsQosOldPacket (*it))
{
NS_LOG_DEBUG ("packet peeked from BlockAckManager retransmit queue: " << *item);
return item;
NS_LOG_DEBUG ("removing an old packet from BlockAckManager retransmit queue: " << **it);
it = m_baManager->GetRetransmitQueue ()->Remove (it);
it = m_baManager->GetRetransmitQueue ()->PeekByTidAndAddress (tid, recipient, it);
}
if (it != m_baManager->GetRetransmitQueue ()->end ())
{
NS_LOG_DEBUG ("packet peeked from BlockAckManager retransmit queue: " << **it);
return *it;
}
// otherwise, check if there is a packet in the EDCA queue
it = m_queue->PeekByTidAndAddress (tid, recipient);
if (it != m_queue->end ())
{
item = *it;
// set the sequence number by just peeking the next value
uint16_t sequence = m_txMiddle->PeekNextSequenceNumberFor (&item->GetHeader ());
WifiMacHeader 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 = m_txMiddle->PeekNextSequenceNumberFor (&(*it)->GetHeader ());
if ((*it)->GetHeader ().IsQosData ()
&& GetBaAgreementEstablished (recipient, tid)
&& !IsInWindow (sequence, GetBaStartingSequence (recipient, tid), GetBaBufferSize (recipient, tid)))
{
NS_LOG_DEBUG ("packet beyond the end of the current transmit window");
return 0;
}
WifiMacHeader hdr = (*it)->GetHeader ();
hdr.SetSequenceNumber (sequence);
hdr.SetFragmentNumber (0);
hdr.SetNoMoreFragments ();
hdr.SetNoRetry ();
item = Create<const WifiMacQueueItem> (item->GetPacket (), hdr, item->GetTimeStamp ());
Ptr<const WifiMacQueueItem> item = Create<const WifiMacQueueItem> ((*it)->GetPacket (), hdr, (*it)->GetTimeStamp ());
NS_LOG_DEBUG ("packet peeked from EDCA queue: " << *item);
return item;
}
return item;
return 0;
}
bool
@@ -356,6 +414,7 @@ QosTxop::DequeuePeekedFrame (Ptr<const WifiMacQueueItem> peekedItem, WifiTxVecto
Mac48Address recipient = peekedItem->GetHeader ().GetAddr1 ();
Ptr<WifiMacQueueItem> item;
Ptr<const WifiMacQueueItem> testItem;
WifiMacQueue::ConstIterator testIt;
// the packet can only have been peeked from the Block Ack manager retransmit
// queue or the MacLow aggregation queue if:
@@ -366,26 +425,32 @@ QosTxop::DequeuePeekedFrame (Ptr<const WifiMacQueueItem> peekedItem, WifiTxVecto
&& GetBaAgreementEstablished (recipient, peekedItem->GetHeader ().GetQosTid ()))
{
uint8_t tid = peekedItem->GetHeader ().GetQosTid ();
WifiMacQueue::ConstIterator testIt = m_low->GetAggregateQueue ()->PeekByTidAndAddress (tid, recipient);
testIt = m_low->GetAggregateQueue ()->PeekByTidAndAddress (tid, recipient);
if (testIt != m_low->GetAggregateQueue ()->end ())
{
testItem = *testIt;
// if not null, the test packet must equal the peeked packet
NS_ASSERT (testItem->GetPacket () == peekedItem->GetPacket ());
item = m_low->GetAggregateQueue ()->DequeueByTidAndAddress (tid, recipient);
// we should not be asked to dequeue an old packet
NS_ASSERT (!QosUtilsIsOldPacket (GetBaStartingSequence (recipient, tid),
testItem->GetHeader ().GetSequenceNumber ()));
item = m_low->GetAggregateQueue ()->Dequeue (testIt);
NS_LOG_DEBUG ("dequeued from aggregation queue: " << *item);
return item;
}
testItem = m_baManager->PeekNextPacketByTidAndAddress (tid, recipient);
testIt = m_baManager->GetRetransmitQueue ()->PeekByTidAndAddress (tid, recipient);
if (testItem)
if (testIt != m_baManager->GetRetransmitQueue ()->end ())
{
testItem = *testIt;
// if not null, the test packet must equal the peeked packet
NS_ASSERT (testItem->GetPacket () == peekedItem->GetPacket ());
item = Create<WifiMacQueueItem> (*peekedItem);
m_baManager->RemovePacket (tid, recipient, testItem->GetHeader ().GetSequenceNumber ());
// we should not be asked to dequeue an old packet
NS_ASSERT (!QosUtilsIsOldPacket (GetBaStartingSequence (recipient, tid),
testItem->GetHeader ().GetSequenceNumber ()));
item = m_baManager->GetRetransmitQueue ()->Dequeue (testIt);
NS_LOG_DEBUG ("dequeued from BA manager queue: " << *item);
return item;
}
@@ -394,15 +459,26 @@ QosTxop::DequeuePeekedFrame (Ptr<const WifiMacQueueItem> peekedItem, WifiTxVecto
// NOTE if frames other than QoS Data frame can be aggregated into A-MPDUs and hence
// potentially stored in the MacLow aggregation queue, then handle them here
// the packet has been peeked from the EDCA queue. If it is a QoS Data frame and
// it is not a broadcast frame, attempt A-MSDU aggregation if aggregate is true
// the packet has been peeked from the EDCA queue.
uint16_t sequence = m_txMiddle->GetNextSequenceNumberFor (&peekedItem->GetHeader ());
// If it is a QoS Data frame and it is not a broadcast frame, attempt A-MSDU
// aggregation if aggregate is true
if (peekedItem->GetHeader ().IsQosData ())
{
uint8_t tid = peekedItem->GetHeader ().GetQosTid ();
WifiMacQueue::ConstIterator testIt = m_queue->PeekByTidAndAddress (tid, recipient);
testIt = m_queue->PeekByTidAndAddress (tid, recipient);
NS_ASSERT (testIt != m_queue->end () && (*testIt)->GetPacket () == peekedItem->GetPacket ());
// check if the peeked packet is within the transmit window
if (GetBaAgreementEstablished (recipient, tid)
&& !IsInWindow (sequence, GetBaStartingSequence (recipient, tid), GetBaBufferSize (recipient, tid)))
{
NS_LOG_DEBUG ("packet beyond the end of the current transmit window");
return 0;
}
// try A-MSDU aggregation
if (m_low->GetMsduAggregator () != 0 && !recipient.IsBroadcast () && aggregate)
{
@@ -415,7 +491,7 @@ QosTxop::DequeuePeekedFrame (Ptr<const WifiMacQueueItem> peekedItem, WifiTxVecto
}
else // aggregation was not attempted or failed
{
item = m_queue->DequeueByTidAndAddress (tid, recipient);
item = m_queue->Dequeue (testIt);
}
}
else
@@ -428,7 +504,6 @@ QosTxop::DequeuePeekedFrame (Ptr<const WifiMacQueueItem> peekedItem, WifiTxVecto
// Assign a sequence number to the MSDU or A-MSDU dequeued from the EDCA queue
NS_ASSERT (item != 0);
uint16_t sequence = m_txMiddle->GetNextSequenceNumberFor (&item->GetHeader ());
item->GetHeader ().SetSequenceNumber (sequence);
item->GetHeader ().SetFragmentNumber (0);
item->GetHeader ().SetNoMoreFragments ();

17
src/wifi/model/qos-txop.h
View File

@@ -379,14 +379,6 @@ public:
* \return the next sequence number.
*/
uint16_t PeekNextSequenceNumberFor (const WifiMacHeader *hdr);
/**
* Peek in retransmit queue and get the next packet without removing it from the queue.
*
* \param tid traffic ID.
* \param recipient the receiver station address.
* \returns the packet.
*/
Ptr<const WifiMacQueueItem> PeekNextRetransmitPacket (uint8_t tid, Mac48Address recipient);
/**
* Peek the next frame to transmit from the Block Ack manager retransmit
* queue first and, if not found, from the EDCA queue.
@@ -541,6 +533,15 @@ private:
* \param bar the block ack request.
*/
void SendBlockAckRequest (const Bar &bar);
/**
* Check if the given MPDU is to be considered old according to the current
* starting sequence number of the transmit window, provided that a block ack
* agreement has been established with the recipient for the given TID.
*
* \param mpdu the given MPDU
* \return true if the MPDU is to be considered old, false otherwise
*/
bool IsQosOldPacket (Ptr<const WifiMacQueueItem> mpdu);
/**
* For now is typically invoked to complete transmission of a packets sent with ack policy
* Block Ack: the packet is buffered and dcf is reset.