ns-3
ns3::BlockAckManager Class Reference

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

#include <block-ack-manager.h>

List of all members.

Classes

struct  Item

Public Member Functions

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

Detailed Description

Manages all block ack agreements for an originator station.


Member Function Documentation

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.

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.

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.

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.

References NS_FATAL_ERROR.

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.

References ExistsAgreement().

Referenced by SwitchToBlockAckIfNeeded().

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.

References ExistsAgreementInState(), NS_LOG_FUNCTION, NS_LOG_INFO, and SwitchToBlockAckIfNeeded().

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

Returns size of the next packet that needs retransmission.

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.

References ExistsAgreement().

Referenced by NotifyMpduTransmission().

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;

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.

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.

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.

References 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.

References NS_ASSERT, and NS_LOG_FUNCTION.

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.

References ExistsAgreementInState(), 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.

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

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.

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

See ctrl-headers.h for more details.

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.

References NS_LOG_FUNCTION.

Parameters:
queueThe WifiMacQueue object.
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.

References 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.

References ExistsAgreement(), ExistsAgreementInState(), GetNBufferedPackets(), ns3::WifiMacQueue::GetNPacketsByTidAndAddress(), 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.

References DestroyAgreement(), and NS_LOG_FUNCTION.

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.

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


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