Manage a set of ns3::DcfStateHandle a set of independent ns3::DcfState, each of which represents a single DCF within a MAC stack. Each ns3::DcfState has a priority implicitely associated with it (the priority is determined when the ns3::DcfState is added to the DcfManager: the first DcfState to be added gets the highest priority, the second, the second highest priority, and so on.) which is used to handle "internal" collisions. i.e., when two local DcfState are expected to get access to the medium at the same time, the highest priority local DcfState wins access to the medium and the other DcfState suffers a "internal" collision. More...

#include <dcf-manager.h>

Collaboration diagram for ns3::DcfManager:

Public Member Functions
	DcfManager ()

	~DcfManager ()

void	Add (DcfState *dcf)

Time	GetEifsNoDifs () const

void	NotifyAckTimeoutResetNow ()

void	NotifyAckTimeoutStartNow (Time duration)

void	NotifyCtsTimeoutResetNow ()

void	NotifyCtsTimeoutStartNow (Time duration)

void	NotifyMaybeCcaBusyStartNow (Time duration)

void	NotifyNavResetNow (Time duration)

void	NotifyNavStartNow (Time duration)

void	NotifyRxEndErrorNow (void)

void	NotifyRxEndOkNow (void)

void	NotifyRxStartNow (Time duration)

void	NotifySwitchingStartNow (Time duration)

void	NotifyTxStartNow (Time duration)

void	RequestAccess (DcfState *state)

void	SetEifsNoDifs (Time eifsNoDifs)

void	SetSifs (Time sifs)

void	SetSlot (Time slotTime)

void	SetupLowListener (Ptr< MacLow > low)

void	SetupPhyListener (Ptr< WifiPhy > phy)

Private Types
typedef std::vector< DcfState * >	States

Private Member Functions
void	AccessTimeout (void)

void	DoGrantAccess (void)

void	DoRestartAccessTimeoutIfNeeded (void)

Time	GetAccessGrantStart (void) const

Time	GetBackoffEndFor (DcfState *state)

Time	GetBackoffStartFor (DcfState *state)

bool	IsBusy (void) const

Time	MostRecent (Time a, Time b) const

Time	MostRecent (Time a, Time b, Time c) const

Time	MostRecent (Time a, Time b, Time c, Time d) const

Time	MostRecent (Time a, Time b, Time c, Time d, Time e, Time f) const

Time	MostRecent (Time a, Time b, Time c, Time d, Time e, Time f, Time g) const

void	UpdateBackoff (void)

Private Attributes
EventId	m_accessTimeout

Time	m_eifsNoDifs

Time	m_lastAckTimeoutEnd

Time	m_lastBusyDuration

Time	m_lastBusyStart

Time	m_lastCtsTimeoutEnd

Time	m_lastNavDuration

Time	m_lastNavStart

Time	m_lastRxDuration

Time	m_lastRxEnd

bool	m_lastRxReceivedOk

Time	m_lastRxStart

Time	m_lastSwitchingDuration

Time	m_lastSwitchingStart

Time	m_lastTxDuration

Time	m_lastTxStart

LowDcfListener *	m_lowListener

PhyListener *	m_phyListener

bool	m_rxing

Time	m_sifs

uint32_t	m_slotTimeUs

States	m_states

Detailed Description

Manage a set of ns3::DcfState

Handle a set of independent ns3::DcfState, each of which represents a single DCF within a MAC stack. Each ns3::DcfState has a priority implicitely associated with it (the priority is determined when the ns3::DcfState is added to the DcfManager: the first DcfState to be added gets the highest priority, the second, the second highest priority, and so on.) which is used to handle "internal" collisions. i.e., when two local DcfState are expected to get access to the medium at the same time, the highest priority local DcfState wins access to the medium and the other DcfState suffers a "internal" collision.

Definition at line 173 of file dcf-manager.h.

Member Typedef Documentation

typedef std::vector<DcfState *> ns3::DcfManager::States

private

Definition at line 309 of file dcf-manager.h.

Constructor & Destructor Documentation

ns3::DcfManager::DcfManager ( )

Definition at line 254 of file dcf-manager.cc.

References NS_LOG_FUNCTION.

ns3::DcfManager::~DcfManager ( )

Definition at line 278 of file dcf-manager.cc.

References m_lowListener, and m_phyListener.

Member Function Documentation

void ns3::DcfManager::AccessTimeout ( void )

private

Definition at line 494 of file dcf-manager.cc.

References DoGrantAccess(), DoRestartAccessTimeoutIfNeeded(), NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by DoRestartAccessTimeoutIfNeeded().

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void ns3::DcfManager::Add ( DcfState * dcf )

Parameters

dcf	a new DcfState.

The DcfManager does not take ownership of this pointer so, the callee must make sure that the DcfState pointer will stay valid as long as the DcfManager is valid. Note that the order in which DcfState objects are added to a DcfManager matters: the first DcfState added has the highest priority, the second DcfState added, has the second highest priority, etc.

Definition at line 335 of file dcf-manager.cc.

References m_states, and NS_LOG_FUNCTION.

Referenced by ns3::DcfManagerTest::AddDcfState(), ns3::DcaTxop::SetManager(), and ns3::EdcaTxopN::SetManager().

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void ns3::DcfManager::DoGrantAccess ( void )

private

This is the first dcf we find with an expired backoff and which needs access to the medium. i.e., it has data to send.

all other dcfs with a lower priority whose backoff has expired and which needed access to the medium must be notified that we did get an internal collision.

Now, we notify all of these changes in one go. It is necessary to perform first the calculations of which states are colliding and then only apply the changes because applying the changes through notification could change the global state of the manager, and, thus, could change the result of the calculations.

Definition at line 439 of file dcf-manager.cc.

References GetBackoffEndFor(), ns3::DcfState::GetBackoffSlots(), ns3::DcfState::IsAccessRequested(), m_states, MY_DEBUG, ns3::DcfState::NotifyAccessGranted(), ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by AccessTimeout(), and RequestAccess().

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void ns3::DcfManager::DoRestartAccessTimeoutIfNeeded ( void )

private

Is there a DcfState which needs to access the medium, and, if there is one, how many slots for AIFS+backoff does it require ?

Definition at line 580 of file dcf-manager.cc.

References AccessTimeout(), ns3::EventId::Cancel(), GetBackoffEndFor(), ns3::Simulator::GetDelayLeft(), ns3::Simulator::GetMaximumSimulationTime(), ns3::DcfState::IsAccessRequested(), ns3::EventId::IsExpired(), ns3::EventId::IsRunning(), m_accessTimeout, m_states, MY_DEBUG, ns3::Simulator::Now(), NS_LOG_FUNCTION, and ns3::Simulator::Schedule().

Referenced by AccessTimeout(), NotifyAckTimeoutResetNow(), NotifyCtsTimeoutResetNow(), NotifyNavResetNow(), and RequestAccess().

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Time ns3::DcfManager::GetAccessGrantStart ( void ) const

private

Access will never be granted to the medium before the time returned by this method.

Returns: the absolute time at which access could start to be granted

Definition at line 503 of file dcf-manager.cc.

References m_eifsNoDifs, m_lastAckTimeoutEnd, m_lastBusyDuration, m_lastBusyStart, m_lastCtsTimeoutEnd, m_lastNavDuration, m_lastNavStart, m_lastRxDuration, m_lastRxEnd, m_lastRxReceivedOk, m_lastRxStart, m_lastSwitchingDuration, m_lastSwitchingStart, m_lastTxDuration, m_lastTxStart, m_rxing, m_sifs, MostRecent(), NS_LOG_FUNCTION, and NS_LOG_INFO.

Referenced by GetBackoffStartFor().

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Time ns3::DcfManager::GetBackoffEndFor ( DcfState * state )

private

Definition at line 552 of file dcf-manager.cc.

References ns3::DcfState::GetBackoffSlots(), GetBackoffStartFor(), and m_slotTimeUs.

Referenced by DoGrantAccess(), and DoRestartAccessTimeoutIfNeeded().

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Time ns3::DcfManager::GetBackoffStartFor ( DcfState * state )

private

Definition at line 542 of file dcf-manager.cc.

References GetAccessGrantStart(), ns3::DcfState::GetAifsn(), ns3::DcfState::GetBackoffStart(), m_slotTimeUs, MostRecent(), and NS_LOG_FUNCTION.

Referenced by GetBackoffEndFor(), and UpdateBackoff().

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Time ns3::DcfManager::GetEifsNoDifs ( ) const

Returns: value set previously using SetEifsNoDifs.

Definition at line 328 of file dcf-manager.cc.

References m_eifsNoDifs, and NS_LOG_FUNCTION.

Referenced by ns3::RegularWifiMac::GetEifsNoDifs().

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bool ns3::DcfManager::IsBusy ( void ) const

private

Definition at line 391 of file dcf-manager.cc.

References m_lastNavDuration, m_lastNavStart, m_lastTxDuration, m_lastTxStart, m_rxing, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by RequestAccess().

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Time ns3::DcfManager::MostRecent	(	Time	a,
		Time	b
	)		const

private

Definition at line 342 of file dcf-manager.cc.

References ns3::Max(), and NS_LOG_FUNCTION.

Referenced by GetAccessGrantStart(), and GetBackoffStartFor().

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Time ns3::DcfManager::MostRecent	(	Time	a,
		Time	b,
		Time	c
	)		const

private

Definition at line 348 of file dcf-manager.cc.

References ns3::Max(), and NS_LOG_FUNCTION.

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Time ns3::DcfManager::MostRecent	(	Time	a,
		Time	b,
		Time	c,
		Time	d
	)		const

private

Definition at line 357 of file dcf-manager.cc.

References ns3::Max(), and NS_LOG_FUNCTION.

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Time ns3::DcfManager::MostRecent	(	Time	a,
		Time	b,
		Time	c,
		Time	d,
		Time	e,
		Time	f
	)		const

private

Definition at line 366 of file dcf-manager.cc.

References ns3::Max(), and NS_LOG_FUNCTION.

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Time ns3::DcfManager::MostRecent	(	Time	a,
		Time	b,
		Time	c,
		Time	d,
		Time	e,
		Time	f,
		Time	g
	)		const

private

Definition at line 378 of file dcf-manager.cc.

References ns3::Max(), and NS_LOG_FUNCTION.

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void ns3::DcfManager::NotifyAckTimeoutResetNow ( )

Definition at line 778 of file dcf-manager.cc.

References DoRestartAccessTimeoutIfNeeded(), m_lastAckTimeoutEnd, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by ns3::LowDcfListener::AckTimeoutReset(), and ns3::DcfManagerTest::AddAckTimeoutReset().

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void ns3::DcfManager::NotifyAckTimeoutStartNow ( Time duration )

Definition at line 771 of file dcf-manager.cc.

References m_lastAckTimeoutEnd, ns3::Simulator::Now(), NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by ns3::LowDcfListener::AckTimeoutStart(), and ns3::DcfManagerTest::NotifyAccessGranted().

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void ns3::DcfManager::NotifyCtsTimeoutResetNow ( )

Definition at line 791 of file dcf-manager.cc.

References DoRestartAccessTimeoutIfNeeded(), m_lastCtsTimeoutEnd, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by ns3::LowDcfListener::CtsTimeoutReset().

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void ns3::DcfManager::NotifyCtsTimeoutStartNow ( Time duration )

Definition at line 785 of file dcf-manager.cc.

References m_lastCtsTimeoutEnd, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by ns3::LowDcfListener::CtsTimeoutStart().

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void ns3::DcfManager::NotifyMaybeCcaBusyStartNow ( Time duration )

Parameters

duration expected duration of cca busy period

Notify the DCF that a CCA busy period has just started.

Definition at line 668 of file dcf-manager.cc.

References m_lastBusyDuration, m_lastBusyStart, MY_DEBUG, ns3::Simulator::Now(), NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::AddCcaBusyEvt(), and ns3::PhyListener::NotifyMaybeCcaBusyStart().

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void ns3::DcfManager::NotifyNavResetNow ( Time duration )

Parameters

duration the value of the received NAV.

Called at end of rx

If the nav reset indicates an end-of-nav which is earlier than the previous end-of-nav, the expected end of backoff might be later than previously thought so, we might need to restart a new access timeout.

Definition at line 739 of file dcf-manager.cc.

References DoRestartAccessTimeoutIfNeeded(), m_lastNavDuration, m_lastNavStart, MY_DEBUG, ns3::Simulator::Now(), NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::AddNavReset(), ns3::LowDcfListener::NavReset(), and ns3::MeshWifiInterfaceMac::SwitchFrequencyChannel().

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void ns3::DcfManager::NotifyNavStartNow ( Time duration )

Parameters

duration the value of the received NAV.

Called at end of rx

Definition at line 756 of file dcf-manager.cc.

References m_lastNavDuration, m_lastNavStart, MY_DEBUG, ns3::Simulator::Now(), NS_ASSERT, NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::AddNavStart(), and ns3::LowDcfListener::NavStart().

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void ns3::DcfManager::NotifyRxEndErrorNow ( void )

Notify the DCF that a packet reception was just completed unsuccessfully.

Definition at line 639 of file dcf-manager.cc.

References m_lastRxEnd, m_lastRxReceivedOk, m_rxing, MY_DEBUG, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by ns3::DcfManagerTest::AddRxErrorEvt(), and ns3::PhyListener::NotifyRxEndError().

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void ns3::DcfManager::NotifyRxEndOkNow ( void )

Notify the DCF that a packet reception was just completed successfully.

Definition at line 630 of file dcf-manager.cc.

References m_lastRxEnd, m_lastRxReceivedOk, m_rxing, MY_DEBUG, ns3::Simulator::Now(), and NS_LOG_FUNCTION.

Referenced by ns3::DcfManagerTest::AddRxOkEvt(), and ns3::PhyListener::NotifyRxEndOk().

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void ns3::DcfManager::NotifyRxStartNow ( Time duration )

Parameters

duration expected duration of reception

Notify the DCF that a packet reception started for the expected duration.

Definition at line 620 of file dcf-manager.cc.

References m_lastRxDuration, m_lastRxStart, m_rxing, MY_DEBUG, ns3::Simulator::Now(), NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::AddRxErrorEvt(), ns3::DcfManagerTest::AddRxInsideSifsEvt(), ns3::DcfManagerTest::AddRxOkEvt(), ns3::DcfManagerTest::AddRxStartEvt(), and ns3::PhyListener::NotifyRxStart().

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void ns3::DcfManager::NotifySwitchingStartNow ( Time duration )

Parameters

duration expected duration of channel switching period

Notify the DCF that a channel switching period has just started. During switching state, new packets can be enqueued in DcaTxop/EdcaTxop but they won't access to the medium until the end of the channel switching.

Definition at line 679 of file dcf-manager.cc.

References ns3::EventId::Cancel(), ns3::DcfState::GetBackoffSlots(), ns3::EventId::IsRunning(), ns3::DcfState::m_accessRequested, m_accessTimeout, m_lastAckTimeoutEnd, m_lastBusyDuration, m_lastBusyStart, m_lastCtsTimeoutEnd, m_lastNavDuration, m_lastNavStart, m_lastRxDuration, m_lastRxEnd, m_lastRxReceivedOk, m_lastRxStart, m_lastSwitchingDuration, m_lastSwitchingStart, m_lastTxDuration, m_lastTxStart, m_rxing, m_states, MY_DEBUG, ns3::DcfState::NotifyChannelSwitching(), ns3::Simulator::Now(), NS_ASSERT, NS_LOG_FUNCTION, ns3::DcfState::ResetCw(), and ns3::DcfState::UpdateBackoffSlotsNow().

Referenced by ns3::DcfManagerTest::AddSwitchingEvt(), and ns3::PhyListener::NotifySwitchingStart().

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void ns3::DcfManager::NotifyTxStartNow ( Time duration )

Parameters

duration expected duration of transmission

Notify the DCF that a packet transmission was just started and is expected to last for the specified duration.

Definition at line 648 of file dcf-manager.cc.

References m_lastRxDuration, m_lastRxEnd, m_lastRxReceivedOk, m_lastRxStart, m_lastTxDuration, m_lastTxStart, m_rxing, m_sifs, MY_DEBUG, ns3::Simulator::Now(), NS_ASSERT, NS_LOG_FUNCTION, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::AddTxEvt(), ns3::DcfManagerTest::NotifyAccessGranted(), and ns3::PhyListener::NotifyTxStart().

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void ns3::DcfManager::RequestAccess ( DcfState * state )

Parameters

state a DcfState

Notify the DcfManager that a specific DcfState needs access to the medium. The DcfManager is then responsible for starting an access timer and, invoking DcfState::DoNotifyAccessGranted when the access is granted if it ever gets granted.

If there is a collision, generate a backoff by notifying the collision to the user.

Definition at line 415 of file dcf-manager.cc.

References DoGrantAccess(), DoRestartAccessTimeoutIfNeeded(), ns3::DcfState::GetBackoffSlots(), ns3::DcfState::IsAccessRequested(), IsBusy(), MY_DEBUG, ns3::DcfState::NotifyAccessRequested(), ns3::DcfState::NotifyCollision(), NS_ASSERT, NS_LOG_FUNCTION, and UpdateBackoff().