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
bool	m_sleeping
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.

ns3::DcfManager::~DcfManager ( )

Definition at line 277 of file dcf-manager.cc.

References m_lowListener, and m_phyListener.

Member Function Documentation

void ns3::DcfManager::AccessTimeout ( void )

private

Definition at line 470 of file dcf-manager.cc.

References DoGrantAccess(), DoRestartAccessTimeoutIfNeeded(), 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 320 of file dcf-manager.cc.

References m_states.

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 416 of file dcf-manager.cc.

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

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 552 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::Now(), ns3::Simulator::Now(), 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 478 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(), and NS_LOG_INFO.

Referenced by GetBackoffStartFor().

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

private

Definition at line 525 of file dcf-manager.cc.

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

Referenced by DoGrantAccess(), and DoRestartAccessTimeoutIfNeeded().

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

private

Definition at line 516 of file dcf-manager.cc.

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

Referenced by GetBackoffEndFor(), and UpdateBackoff().

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Time ns3::DcfManager::GetEifsNoDifs ( ) const

Returns: value set previously using SetEifsNoDifs.

Definition at line 314 of file dcf-manager.cc.

References m_eifsNoDifs.

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

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

private

Definition at line 370 of file dcf-manager.cc.

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

Referenced by RequestAccess().

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

private

Definition at line 326 of file dcf-manager.cc.

References ns3::Max().

Referenced by GetAccessGrantStart(), and GetBackoffStartFor().

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

private

Definition at line 331 of file dcf-manager.cc.

References ns3::Max().

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

private

Definition at line 339 of file dcf-manager.cc.

References ns3::Max().

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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 347 of file dcf-manager.cc.

References ns3::Max().

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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 358 of file dcf-manager.cc.

References ns3::Max().

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void ns3::DcfManager::NotifyAckTimeoutResetNow ( )

Definition at line 740 of file dcf-manager.cc.

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

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

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

Definition at line 734 of file dcf-manager.cc.

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

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

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void ns3::DcfManager::NotifyCtsTimeoutResetNow ( )

Definition at line 751 of file dcf-manager.cc.

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

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

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

Definition at line 746 of file dcf-manager.cc.

References m_lastCtsTimeoutEnd, and ns3::Now().

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 635 of file dcf-manager.cc.

References m_lastBusyDuration, m_lastBusyStart, MY_DEBUG, ns3::Now(), 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 704 of file dcf-manager.cc.

References DoRestartAccessTimeoutIfNeeded(), m_lastNavDuration, m_lastNavStart, MY_DEBUG, ns3::Now(), 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 720 of file dcf-manager.cc.

References m_lastNavDuration, m_lastNavStart, MY_DEBUG, ns3::Now(), ns3::Simulator::Now(), NS_ASSERT, 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 608 of file dcf-manager.cc.

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

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 600 of file dcf-manager.cc.

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

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 591 of file dcf-manager.cc.

References m_lastRxDuration, m_lastRxStart, m_rxing, MY_DEBUG, ns3::Now(), 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 645 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::Now(), NS_ASSERT, 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 616 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::Now(), ns3::Simulator::Now(), NS_ASSERT, 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 393 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, and UpdateBackoff().

Referenced by ns3::DcfManagerTest::DoAccessRequest(), ns3::EdcaTxopN::RestartAccessIfNeeded(), ns3::DcaTxop::RestartAccessIfNeeded(), ns3::EdcaTxopN::StartAccessIfNeeded(), and ns3::DcaTxop::StartAccessIfNeeded().

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