keep track of the state needed for a single DCF function. More...

#include "dcf-manager.h"

Inheritance diagram for ns3::DcfState:

Collaboration diagram for ns3::DcfState:

Public Member Functions
	DcfState ()

virtual	~DcfState ()

uint32_t	GetAifsn (void) const
	Return the number of slots that make up an AIFS. More...

uint32_t	GetCw (void) const

uint32_t	GetCwMax (void) const
	Return the maximum congestion window size. More...

uint32_t	GetCwMin (void) const
	Return the minimum congestion window size. More...

Time	GetTxopLimit (void) const
	Return the TXOP limit. More...

bool	IsAccessRequested (void) const

virtual bool	IsEdca (void) const =0

void	ResetCw (void)
	Update the value of the CW variable to take into account a transmission success or a transmission abort (stop transmission of a packet after the maximum number of retransmissions has been reached). More...

void	SetAifsn (uint32_t aifsn)

void	SetCwMax (uint32_t maxCw)
	Set the maximum congestion window size. More...

void	SetCwMin (uint32_t minCw)
	Set the minimum congestion window size. More...

void	SetTxopLimit (Time txopLimit)
	Set the TXOP limit. More...

void	StartBackoffNow (uint32_t nSlots)

void	UpdateFailedCw (void)
	Update the value of the CW variable to take into account a transmission failure. More...

Private Member Functions
virtual void	DoNotifyAccessGranted (void)=0
	Called by DcfManager to notify a DcfState subclass that access to the medium is granted and can start immediately. More...

virtual void	DoNotifyChannelSwitching (void)=0
	Called by DcfManager to notify a DcfState subclass that a channel switching occured. More...

virtual void	DoNotifyCollision (void)=0
	Called by DcfManager to notify a DcfState subclass that a normal collision occured, that is, that the medium was busy when access was requested. More...

virtual void	DoNotifyInternalCollision (void)=0
	Called by DcfManager to notify a DcfState subclass that an 'internal' collision occured, that is, that the backoff timer of a higher priority DcfState expired at the same time and that access was granted to this higher priority DcfState. More...

virtual void	DoNotifySleep (void)=0
	Called by DcfManager to notify a DcfState subclass that the device has begun to sleep. More...

virtual void	DoNotifyWakeUp (void)=0
	Called by DcfManager to notify a DcfState subclass that the device has begun to wake up. More...

uint32_t	GetBackoffSlots (void) const
	Return the current number of backoff slots. More...

Time	GetBackoffStart (void) const
	Return the time when the backoff procedure started. More...

void	NotifyAccessGranted (void)
	Notify that access has been granted. More...

void	NotifyAccessRequested (void)
	Notify that access request has been received. More...

void	NotifyChannelSwitching (void)
	Notify that the device is switching channel. More...

void	NotifyCollision (void)
	Notify that collision has occurred. More...

void	NotifyInternalCollision (void)
	Notify that internal collision has occurred. More...

void	NotifySleep (void)
	Notify that the device has started to sleep. More...

void	NotifyWakeUp (void)
	Notify that the device has started to wake up. More...

void	UpdateBackoffSlotsNow (uint32_t nSlots, Time backoffUpdateBound)
	Update backoff slots that nSlots has passed. More...

Private Attributes
bool	m_accessRequested

uint32_t	m_aifsn

uint32_t	m_backoffSlots

Time	m_backoffStart

uint32_t	m_cw

uint32_t	m_cwMax

uint32_t	m_cwMin

Time	m_txopLimit

Friends
class	DcfManager

Detailed Description

keep track of the state needed for a single DCF function.

Multiple instances of a DcfState can be registered in a single DcfManager to implement 802.11e-style relative QoS. DcfState::SetAifsn and DcfState::SetCwBounds allow the user to control the relative QoS differentiation.

Definition at line 46 of file dcf-manager.h.

Constructor & Destructor Documentation

ns3::DcfState::DcfState ( )

Definition at line 41 of file dcf-manager.cc.

ns3::DcfState::~DcfState ( )

virtual

Definition at line 51 of file dcf-manager.cc.

Member Function Documentation

virtual void ns3::DcfState::DoNotifyAccessGranted ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that access to the medium is granted and can start immediately.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifyAccessGranted().

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virtual void ns3::DcfState::DoNotifyChannelSwitching ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that a channel switching occured.

The subclass is expected to flush the queue of packets.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifyChannelSwitching().

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virtual void ns3::DcfState::DoNotifyCollision ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that a normal collision occured, that is, that the medium was busy when access was requested.

This may also be called if the request for access occurred within the DIFS or AIFS between two frames.

The subclass is expected to start a new backoff by calling DcfState::StartBackoffNow and DcfManager::RequestAccess is access is still needed.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifyCollision().

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virtual void ns3::DcfState::DoNotifyInternalCollision ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that an 'internal' collision occured, that is, that the backoff timer of a higher priority DcfState expired at the same time and that access was granted to this higher priority DcfState.

The subclass is expected to start a new backoff by calling DcfState::StartBackoffNow and DcfManager::RequestAccess is access is still needed.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifyInternalCollision().

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virtual void ns3::DcfState::DoNotifySleep ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that the device has begun to sleep.

The subclass is expected to re-insert the pending packet into the queue

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifySleep().

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virtual void ns3::DcfState::DoNotifyWakeUp ( void )

privatepure virtual

Called by DcfManager to notify a DcfState subclass that the device has begun to wake up.

The subclass is expected to restart a new backoff by calling DcfState::StartBackoffNow and DcfManager::RequestAccess is access is still needed.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by NotifyWakeUp().

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uint32_t ns3::DcfState::GetAifsn ( void ) const

Return the number of slots that make up an AIFS.

Returns: the number of slots that make up an AIFS

Definition at line 91 of file dcf-manager.cc.

References m_aifsn.

Referenced by ns3::DcaTxop::GetAifsn(), ns3::EdcaTxopN::GetAifsn(), ns3::DcfManager::GetBackoffStartFor(), and ns3::DcfManager::IsWithinAifs().

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uint32_t ns3::DcfState::GetBackoffSlots ( void ) const

private

Return the current number of backoff slots.

Returns: the current number of backoff slots

Definition at line 157 of file dcf-manager.cc.

References m_backoffSlots.

Referenced by ns3::DcfManager::DoGrantAccess(), ns3::DcfManager::GetBackoffEndFor(), ns3::DcfManager::NotifySwitchingStartNow(), ns3::DcfManager::NotifyWakeupNow(), ns3::DcfManager::RequestAccess(), and ns3::DcfManager::UpdateBackoff().

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Time ns3::DcfState::GetBackoffStart ( void ) const

private

Return the time when the backoff procedure started.

Returns: the time when the backoff procedure started

Definition at line 163 of file dcf-manager.cc.

References m_backoffStart.

Referenced by ns3::DcfManager::GetBackoffStartFor().

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uint32_t ns3::DcfState::GetCw ( void ) const

Returns: the current value of the CW variable. The initial value is minCW.

Definition at line 151 of file dcf-manager.cc.

References m_cw.

Referenced by ns3::DcaTxop::DoInitialize(), ns3::EdcaTxopN::DoInitialize(), ns3::DcaTxop::EndTxNoAck(), ns3::EdcaTxopN::EndTxNoAck(), ns3::DcaTxop::GotAck(), ns3::EdcaTxopN::GotAck(), ns3::EdcaTxopN::GotBlockAck(), ns3::DcaTxop::MissedAck(), ns3::EdcaTxopN::MissedAck(), ns3::EdcaTxopN::MissedBlockAck(), ns3::DcaTxop::MissedCts(), ns3::EdcaTxopN::MissedCts(), ns3::DcaTxop::NotifyCollision(), ns3::EdcaTxopN::NotifyCollision(), and ns3::EdcaTxopN::NotifyInternalCollision().

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uint32_t ns3::DcfState::GetCwMax ( void ) const

Return the maximum congestion window size.

Returns: the maximum congestion window size

Definition at line 109 of file dcf-manager.cc.

References m_cwMax.

Referenced by ns3::DcaTxop::GetMaxCw(), and ns3::EdcaTxopN::GetMaxCw().

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uint32_t ns3::DcfState::GetCwMin ( void ) const

Return the minimum congestion window size.

Returns: the minimum congestion window size

Definition at line 103 of file dcf-manager.cc.

References m_cwMin.

Referenced by ns3::DcaTxop::GetMinCw(), and ns3::EdcaTxopN::GetMinCw().

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Time ns3::DcfState::GetTxopLimit ( void ) const

Return the TXOP limit.

Returns: the TXOP limit

Definition at line 97 of file dcf-manager.cc.

References m_txopLimit.

Referenced by ns3::DcaTxop::GetTxopLimit(), and ns3::EdcaTxopN::GetTxopLimit().

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bool ns3::DcfState::IsAccessRequested ( void ) const

Returns: true if access has been requested for this DcfState and has not been granted already, false otherwise.

Definition at line 169 of file dcf-manager.cc.

References m_accessRequested.

Referenced by ns3::DcfManager::DoGrantAccess(), ns3::DcfManager::DoRestartAccessTimeoutIfNeeded(), ns3::DcfManager::RequestAccess(), ns3::DcaTxop::RestartAccessIfNeeded(), ns3::EdcaTxopN::RestartAccessIfNeeded(), ns3::DcaTxop::StartAccessIfNeeded(), and ns3::EdcaTxopN::StartAccessIfNeeded().

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virtual bool ns3::DcfState::IsEdca ( void ) const

pure virtual

Returns: whether this DCF state is an EDCA state

This method, which must be overridden in derived classes, indicates whether DCF or EDCAF rules should be used for this channel access function. This affects the behavior of DcfManager when dealing with this instance.

Implemented in ns3::EdcaTxopN::Dcf, ns3::DcaTxop::Dcf, and DcfStateTest.

Referenced by ns3::DcfManager::UpdateBackoff().

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void ns3::DcfState::NotifyAccessGranted ( void )

private

Notify that access has been granted.

Definition at line 180 of file dcf-manager.cc.

References DoNotifyAccessGranted(), m_accessRequested, and NS_ASSERT.

Referenced by ns3::DcfManager::DoGrantAccess().

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void ns3::DcfState::NotifyAccessRequested ( void )

private

Notify that access request has been received.

Definition at line 174 of file dcf-manager.cc.

References m_accessRequested.

Referenced by ns3::DcfManager::RequestAccess().

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void ns3::DcfState::NotifyChannelSwitching ( void )

private

Notify that the device is switching channel.

Definition at line 200 of file dcf-manager.cc.

References DoNotifyChannelSwitching().

Referenced by ns3::DcfManager::NotifySwitchingStartNow().

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void ns3::DcfState::NotifyCollision ( void )

private

Notify that collision has occurred.

Definition at line 188 of file dcf-manager.cc.

References DoNotifyCollision().

Referenced by ns3::DcfManager::RequestAccess().

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void ns3::DcfState::NotifyInternalCollision ( void )

private

Notify that internal collision has occurred.

Definition at line 194 of file dcf-manager.cc.

References DoNotifyInternalCollision().

Referenced by ns3::DcfManager::RequestAccess().

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void ns3::DcfState::NotifySleep ( void )

private

Notify that the device has started to sleep.

Definition at line 206 of file dcf-manager.cc.

References DoNotifySleep().

Referenced by ns3::DcfManager::NotifySleepNow().

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void ns3::DcfState::NotifyWakeUp ( void )

private

Notify that the device has started to wake up.

Definition at line 212 of file dcf-manager.cc.

References DoNotifyWakeUp().

Referenced by ns3::DcfManager::NotifyWakeupNow().

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void ns3::DcfState::ResetCw ( void )

Update the value of the CW variable to take into account a transmission success or a transmission abort (stop transmission of a packet after the maximum number of retransmissions has been reached).

By default, this resets the CW variable to minCW.

Definition at line 115 of file dcf-manager.cc.

References m_cw, and m_cwMin.