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ns3::BlockAckManager Class Reference
Wifi Models

Manages all block ack agreements for an originator station. More...

#include <block-ack-manager.h>

Classes

struct  Item
 

Public Member Functions

void CreateAgreement (const MgtAddBaRequestHeader *reqHdr, Mac48Address recipient)
 
void DestroyAgreement (Mac48Address recipient, uint8_t tid)
 
bool ExistsAgreement (Mac48Address recipient, uint8_t tid) const
 
bool ExistsAgreementInState (Mac48Address recipient, uint8_t tid, enum OriginatorBlockAckAgreement::State state) const
 
uint32_t GetNBufferedPackets (Mac48Address recipient, uint8_t tid) const
 
Ptr< const Packet > GetNextPacket (WifiMacHeader &hdr)
 
uint32_t GetNextPacketSize (void) const
 
uint32_t GetNRetryNeededPackets (Mac48Address recipient, uint8_t tid) const
 
uint16_t GetSeqNumOfNextRetryPacket (Mac48Address recipient, uint8_t tid) const
 
bool HasBar (struct Bar &bar)
 
bool HasOtherFragments (uint16_t sequenceNumber) const
 
bool HasPackets (void) const
 
void NotifyAgreementEstablished (Mac48Address recipient, uint8_t tid, uint16_t startingSeq)
 
void NotifyAgreementUnsuccessful (Mac48Address recipient, uint8_t tid)
 
void NotifyGotBlockAck (const CtrlBAckResponseHeader *blockAck, Mac48Address recipient)
 
void NotifyMpduTransmission (Mac48Address recipient, uint8_t tid, uint16_t nextSeqNumber)
 
void SetBlockAckInactivityCallback (Callback< void, Mac48Address, uint8_t, bool > callback)
 
void SetBlockAckThreshold (uint8_t nPackets)
 
void SetBlockAckType (enum BlockAckType bAckType)
 
void SetBlockDestinationCallback (Callback< void, Mac48Address, uint8_t > callback)
 
void SetMaxPacketDelay (Time maxDelay)
 
void SetQueue (Ptr< WifiMacQueue > queue)
 
void SetTxMiddle (MacTxMiddle *txMiddle)
 
void SetUnblockDestinationCallback (Callback< void, Mac48Address, uint8_t > callback)
 
void StorePacket (Ptr< const Packet > packet, const WifiMacHeader &hdr, Time tStamp)
 
bool SwitchToBlockAckIfNeeded (Mac48Address recipient, uint8_t tid, uint16_t startingSeq)
 
void TearDownBlockAck (Mac48Address recipient, uint8_t tid)
 
void UpdateAgreement (const MgtAddBaResponseHeader *respHdr, Mac48Address recipient)
 

Private Types

typedef std::map< std::pair
< Mac48Address, uint8_t >
, std::pair
< OriginatorBlockAckAgreement,
PacketQueue > > 		Agreements
 
typedef std::map< std::pair
< Mac48Address, uint8_t >
, std::pair
< OriginatorBlockAckAgreement,
PacketQueue >
>::const_iterator 		AgreementsCI
 
typedef std::map< std::pair
< Mac48Address, uint8_t >
, std::pair
< OriginatorBlockAckAgreement,
PacketQueue > >::iterator 		AgreementsI
 
typedef std::list< Item > PacketQueue
 
typedef std::list< Item >
::const_iterator 		PacketQueueCI
 
typedef std::list< Item >::iterator PacketQueueI
 

Private Member Functions

 BlockAckManager (const BlockAckManager &)
 
void CleanupBuffers (void)
 
void InactivityTimeout (Mac48Address, uint8_t)
 
BlockAckManager & operator= (const BlockAckManager &)
 
Ptr< Packet > ScheduleBlockAckReqIfNeeded (Mac48Address recipient, uint8_t tid)
 

Private Attributes

Mac48Address m_address
 
Agreements m_agreements
 
std::list< Bar > m_bars
 
Callback< void, Mac48Address,
uint8_t, bool > 		m_blockAckInactivityTimeout
 
uint8_t m_blockAckThreshold
 
enum BlockAckType m_blockAckType
 
Callback< void, Mac48Address,
uint8_t > 		m_blockPackets
 
Time m_maxDelay
 
Ptr< WifiMacQueue > m_queue
 
std::list< PacketQueueI > m_retryPackets
 
MacTxMiddle * m_txMiddle
 
Callback< void, Mac48Address,
uint8_t > 		m_unblockPackets
 

Detailed Description

Manages all block ack agreements for an originator station.

Definition at line 64 of file block-ack-manager.h.

Member Function Documentation

void ns3::BlockAckManager::CleanupBuffers ( void  )
private

This method removes packets whose lifetime was exceeded.

Definition at line 592 of file block-ack-manager.cc.

References m_agreements, m_retryPackets, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by GetNextPacket().

void ns3::BlockAckManager::CreateAgreement ( const MgtAddBaRequestHeader *  reqHdr,
Mac48Address  recipient 
)
Parameters
reqHdrRelative Add block ack request (action frame).
recipientAddress of peer station involved in block ack mechanism.

Creates a new block ack agreement in pending state. When a ADDBA response with a successful status code is received, the relative agreement becomes established.

Definition at line 112 of file block-ack-manager.cc.

References m_agreements, and NS_LOG_FUNCTION.

void ns3::BlockAckManager::DestroyAgreement ( Mac48Address  recipient,
uint8_t  tid 
)
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTid Traffic id of transmitted packet.

Invoked when a recipient reject a block ack agreement or when a Delba frame is Received/Transmitted.

Definition at line 139 of file block-ack-manager.cc.

References m_agreements, m_retryPackets, and NS_LOG_FUNCTION.

Referenced by TearDownBlockAck().

bool ns3::BlockAckManager::ExistsAgreement ( Mac48Address  recipient,
uint8_t  tid 
) const
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID.

Checks if a block ack agreement exists with station addressed by recipient for tid tid.

Definition at line 79 of file block-ack-manager.cc.

References m_agreements, and NS_LOG_FUNCTION.

Referenced by GetNBufferedPackets(), GetNRetryNeededPackets(), and SwitchToBlockAckIfNeeded().

bool ns3::BlockAckManager::ExistsAgreementInState ( Mac48Address  recipient,
uint8_t  tid,
enum OriginatorBlockAckAgreement::State  state 
) const
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID.
stateThe state for block ack agreement

Checks if a block ack agreement with a state equals to state exists with station addressed by recipient for tid tid.

Definition at line 86 of file block-ack-manager.cc.

References m_agreements, NS_FATAL_ERROR, and NS_LOG_FUNCTION.

Referenced by GetNextPacket(), NotifyGotBlockAck(), and SwitchToBlockAckIfNeeded().

uint32_t ns3::BlockAckManager::GetNBufferedPackets ( Mac48Address  recipient,
uint8_t  tid 
) const
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID.

Returns number of packets buffered for a specified agreement. This methods doesn't return number of buffered MPDUs but number of buffered MSDUs.

Definition at line 280 of file block-ack-manager.cc.

References ExistsAgreement(), m_agreements, and NS_LOG_FUNCTION.

Referenced by SwitchToBlockAckIfNeeded().

Ptr< const Packet > ns3::BlockAckManager::GetNextPacket ( WifiMacHeader &  hdr)
Parameters
hdr802.11 header of returned packet (if exists).

This methods returns a packet (if exists) indicated as not received in corresponding block ack bitmap.

Definition at line 221 of file block-ack-manager.cc.

References CleanupBuffers(), ExistsAgreementInState(), m_agreements, m_retryPackets, NS_LOG_FUNCTION, NS_LOG_INFO, and SwitchToBlockAckIfNeeded().

uint32_t ns3::BlockAckManager::GetNextPacketSize ( void  ) const

Returns size of the next packet that needs retransmission.

Definition at line 579 of file block-ack-manager.cc.

References ns3::Packet::GetSize(), m_retryPackets, and NS_LOG_FUNCTION.

uint32_t ns3::BlockAckManager::GetNRetryNeededPackets ( Mac48Address  recipient,
uint8_t  tid 
) const
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID.

Returns number of packets for a specific agreement that need retransmission. This method doesn't return number of MPDUs that need retransmission but number of MSDUs.

Definition at line 305 of file block-ack-manager.cc.

References ExistsAgreement(), m_retryPackets, and NS_LOG_FUNCTION.

Referenced by NotifyMpduTransmission(), and ScheduleBlockAckReqIfNeeded().

uint16_t ns3::BlockAckManager::GetSeqNumOfNextRetryPacket ( Mac48Address  recipient,
uint8_t  tid 
) const

Returns the sequence number of the next retry packet for a specific agreement. If there are no packets that need retransmission for the specified agreement or the agreement doesn't exist the function returns 4096;

Definition at line 669 of file block-ack-manager.cc.

References m_retryPackets, and NS_LOG_FUNCTION.

Referenced by NotifyMpduTransmission().

bool ns3::BlockAckManager::HasOtherFragments ( uint16_t  sequenceNumber) const
Parameters
sequenceNumberSequence number of the packet which fragment is part of.

Returns true if another fragment with sequence number sequenceNumber is scheduled for retransmission.

Definition at line 563 of file block-ack-manager.cc.

References m_retryPackets, and NS_LOG_FUNCTION.

bool ns3::BlockAckManager::HasPackets ( void  ) const

Returns true if there are packets that need of retransmission or at least a BAR is scheduled. Returns false otherwise.

Definition at line 273 of file block-ack-manager.cc.

References m_retryPackets, and NS_LOG_FUNCTION.

void ns3::BlockAckManager::NotifyAgreementEstablished ( Mac48Address  recipient,
uint8_t  tid,
uint16_t  startingSeq 
)
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID of transmitted packet.
startingSeqstarting sequence field

Puts corresponding agreement in established state and updates number of packets and starting sequence field. Invoked typically after a block ack refresh.

Definition at line 482 of file block-ack-manager.cc.

References m_agreements, NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by SwitchToBlockAckIfNeeded().

void ns3::BlockAckManager::NotifyAgreementUnsuccessful ( Mac48Address  recipient,
uint8_t  tid 
)
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID of transmitted packet.

Marks an agreement as unsuccessful. This happens if recipient station reject block ack setup by an ADDBAResponse frame with a failure status code. FOr now we assume that every QoS station accepts a block ack setup.

Definition at line 493 of file block-ack-manager.cc.

References m_agreements, NS_ASSERT, and NS_LOG_FUNCTION.

void ns3::BlockAckManager::NotifyGotBlockAck ( const CtrlBAckResponseHeader *  blockAck,
Mac48Address  recipient 
)
Parameters
blockAckThe received block ack frame.
recipientSender of block ack frame.

Invoked upon receipt of a block ack frame. Typically, this function, is called by ns3::EdcaTxopN object. Performs a check on which MPDUs, previously sent with ack policy set to Block Ack, were correctly received by the recipient. An acknowledged MPDU is removed from the buffer, retransmitted otherwise.

Definition at line 338 of file block-ack-manager.cc.

References ExistsAgreementInState(), m_agreements, m_retryPackets, ns3::MicroSeconds(), NS_FATAL_ERROR, NS_LOG_FUNCTION, ns3::Simulator::Schedule(), and SwitchToBlockAckIfNeeded().

void ns3::BlockAckManager::NotifyMpduTransmission ( Mac48Address  recipient,
uint8_t  tid,
uint16_t  nextSeqNumber 
)
Parameters
recipientAddress of peer station involved in block ack mechanism.
tidTraffic ID of transmitted packet.
nextSeqNumberSequence number of the next packet that would be trasmitted by EdcaTxopN.

This method is typically invoked by ns3::EdcaTxopN object every time that a MPDU with ack policy subfield in Qos Control field set to Block Ack is transmitted. The nextSeqNumber parameter is used to block transmission of packets that are out of bitmap.

Definition at line 505 of file block-ack-manager.cc.

References GetNRetryNeededPackets(), GetSeqNumOfNextRetryPacket(), m_agreements, NS_ASSERT, NS_LOG_FUNCTION, and ScheduleBlockAckReqIfNeeded().

Ptr< Packet > ns3::BlockAckManager::ScheduleBlockAckReqIfNeeded ( Mac48Address  recipient,
uint8_t  tid 
)
private

Checks if all packets, for which a block ack agreement was established or refreshed, have been transmitted. If yes, adds a pair in m_bAckReqs to indicate that at next channel access a block ack request (for established agreement recipient,tid) is needed.

Definition at line 434 of file block-ack-manager.cc.

References ns3::Packet::AddHeader(), GetNRetryNeededPackets(), m_agreements, NS_ASSERT, NS_FATAL_ERROR, and NS_LOG_FUNCTION.

Referenced by NotifyMpduTransmission().

void ns3::BlockAckManager::SetBlockAckThreshold ( uint8_t  nPackets)
Parameters
nPacketsMinimum number of packets for use of block ack.

Upon receipt of a block ack frame, if total number of packets (packets in WifiMacQueue and buffered packets) is greater of nPackets, they are transmitted using block ack mechanism.

Definition at line 331 of file block-ack-manager.cc.

References NS_LOG_FUNCTION.

void ns3::BlockAckManager::SetBlockAckType ( enum BlockAckType  bAckType)
Parameters
bAckTypeType of block ack

See ctrl-headers.h for more details.

Definition at line 427 of file block-ack-manager.cc.

References NS_LOG_FUNCTION.

void ns3::BlockAckManager::SetMaxPacketDelay ( Time  maxDelay)
Parameters
maxDelayMax delay for a buffered packet.

This method is always called by ns3::WifiMacQueue object and sets max delay equals to ns3:WifiMacQueue delay value.

Definition at line 634 of file block-ack-manager.cc.

References NS_LOG_FUNCTION.

void ns3::BlockAckManager::SetQueue ( Ptr< WifiMacQueue >  queue)
Parameters
queueThe WifiMacQueue object.

Definition at line 531 of file block-ack-manager.cc.

References NS_LOG_FUNCTION.

void ns3::BlockAckManager::StorePacket ( Ptr< const Packet >  packet,
const WifiMacHeader &  hdr,
Time  tStamp 
)
Parameters
packetPacket to store.
hdr802.11 header for packet.
tStamptime stamp for packet

Stores packet for a possible future retransmission. Retransmission occurs if the packet, in a block ack frame, is indicated by recipient as not received.

Definition at line 206 of file block-ack-manager.cc.

References m_agreements, NS_ASSERT, and NS_LOG_FUNCTION.

bool ns3::BlockAckManager::SwitchToBlockAckIfNeeded ( Mac48Address  recipient,
uint8_t  tid,
uint16_t  startingSeq 
)

Checks if there are in the queue other packets that could be send under block ack. If yes adds these packets in current block ack exchange. However, number of packets exchanged in the current block ack, will not exceed the value of BufferSize in the corresponding OriginatorBlockAckAgreement object.

Definition at line 538 of file block-ack-manager.cc.

References ExistsAgreement(), ExistsAgreementInState(), GetNBufferedPackets(), NotifyAgreementEstablished(), NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by GetNextPacket(), and NotifyGotBlockAck().

void ns3::BlockAckManager::TearDownBlockAck ( Mac48Address  recipient,
uint8_t  tid 
)
Parameters
recipientAddress of station involved in block ack mechanism.
tidTraffic ID.

This method is invoked by EdcaTxopN object upon receipt of a DELBA frame from recipient. The relative block ack agreement is destroyed.

Definition at line 556 of file block-ack-manager.cc.

References DestroyAgreement(), and NS_LOG_FUNCTION.

void ns3::BlockAckManager::UpdateAgreement ( const MgtAddBaResponseHeader *  respHdr,
Mac48Address  recipient 
)
Parameters
respHdrRelative Add block ack response (action frame).
recipientAddress of peer station involved in block ack mechanism.

Invoked upon receipt of a ADDBA response frame from recipient.

Definition at line 173 of file block-ack-manager.cc.

References m_agreements, ns3::MicroSeconds(), NS_LOG_FUNCTION, and ns3::Simulator::Schedule().

Member Data Documentation

Agreements ns3::BlockAckManager::m_agreements
private

This data structure contains, for each block ack agreement (recipient, tid), a set of packets for which an ack by block ack is requested. Every packet or fragment indicated as correctly received in block ack frame is erased from this data structure. Pushed back in retransmission queue otherwise.

Definition at line 296 of file block-ack-manager.h.

Referenced by CleanupBuffers(), CreateAgreement(), DestroyAgreement(), ExistsAgreement(), ExistsAgreementInState(), GetNBufferedPackets(), GetNextPacket(), NotifyAgreementEstablished(), NotifyAgreementUnsuccessful(), NotifyGotBlockAck(), NotifyMpduTransmission(), ScheduleBlockAckReqIfNeeded(), StorePacket(), and UpdateAgreement().

std::list<PacketQueueI> ns3::BlockAckManager::m_retryPackets
private

This list contains all iterators to stored packets that need to be retransmitted. A packet needs retransmission if it's indicated as not correctly received in a block ack frame.

Definition at line 302 of file block-ack-manager.h.

Referenced by CleanupBuffers(), DestroyAgreement(), GetNextPacket(), GetNextPacketSize(), GetNRetryNeededPackets(), GetSeqNumOfNextRetryPacket(), HasOtherFragments(), HasPackets(), and NotifyGotBlockAck().

The documentation for this class was generated from the following files: