wifimac::draftn::BlockACK Class Reference

Block ACK according to IEEE 802.11n Draft 8.0 / IEEE 802.11-2007. More...

#include <draftn/BlockACK.hpp>

Inheritance diagram for wifimac::draftn::BlockACK:

Collaboration diagram for wifimac::draftn::BlockACK:

List of all members.

Public Member Functions

BlockACK (const BlockACK &other)

Copy Constructor, required when std::auto_ptr is used.

BlockACK (wns::ldk::fun::FUN *fun, const wns::pyconfig::View &config)

Regular FU Constructor.

virtual void calculateSizes (const wns::ldk::CommandPool *commandPool, Bit &commandPoolSize, Bit &dataSize) const

SDU and PCI size calculation.

virtual void copyTransmissionCounter (const wns::ldk::CompoundPtr &src, const wns::ldk::CompoundPtr &dst)

Copy the tx counter to anther FU.

virtual bool doIsAccepting (const wns::ldk::CompoundPtr &compound) const

virtual wns::ldk::CompoundPtr getACK ()

Returns the pending BlockACK reply.

virtual wns::ldk::CompoundPtr getData ()

Returns the currently pending compound.

wifimac::lowerMAC::Manager * getManager () const

Returns the pointer to the wifimac::lowerMAC::Manager FU.

const size_t getMaxOnAir ()

wifimac::management::PERInformationBase * getPERMIB ()

virtual unsigned int getTransmissionCounter (const wns::ldk::CompoundPtr &compound) const

Read the tx counter.

virtual const wns::ldk::CompoundPtr hasACK () const

Queries the rxQueue for which a BlockACK request has been received for the BlockACK reply.

virtual bool hasCapacity () const

Sets the conditions to accept a new compound to transmit.

virtual const wns::ldk::CompoundPtr hasData () const

Checks if the current txQueue has pending compounds.

virtual void onFUNCreated ()

Initialization.

virtual void onRxEnd ()

Observe rxEnd to signal the upcoming ACK reception.

virtual void onRxError ()

Does nothing, required by IRxStartEnd interface.

virtual void onRxStart (wns::simulator::Time expRxTime)

Observe rxStart to stop the timeout for ACK reception.

virtual void onTimeout ()

CanTimeout interface realization, required for missing ACKs.

virtual void onTransmissionHasFailed (const wns::ldk::CompoundPtr &compound)

Signal from RTS/CTS that the transmission has failed.

virtual void onTxEnd (const wns::ldk::CompoundPtr &compound)

Signals end of own transmission -> set timeout for ACK.

virtual void onTxStart (const wns::ldk::CompoundPtr &compound)

Signals start of transmission.

virtual void processIncoming (const wns::ldk::CompoundPtr &compound)

Processing of incoming (received) compounds.

virtual void processOutgoing (const wns::ldk::CompoundPtr &compound)

Processing of outgoing (to be transmitted) compounds.

virtual void registerObserver (IBlockACKObserver *o)

observers get called after an (un)successful transmission

virtual ~BlockACK ()

Destructor.

Protected Types

enum BAState { idle, waitForACK, receiving, receptionFinished }

BlockACK state can be * idle: No ongoing transmission * waitForACK: Compound is send, waiting for beginning of reception of ACK * receiving: Reception has started, not sure if it is the (Block)ACK * receptionFinished: Got RxEndIndication and waiting for PHY to deliver the frame. More...

Protected Member Functions

virtual void processIncomingACKSNs (std::set< BlockACKCommand::SequenceNumber > ackSNs)

Manages an incoming ACK (or rather the set of SNs).

virtual unsigned int storageSize () const

Compute storage size (txQueue + sum(rxQueues).

Protected Attributes

enum
wifimac::draftn::BlockACK::BAState baState

const Bit capacity

Maximum number of stored bits (rx+tx+air).

TransmissionQueue * currentTxQueue

Storage of outgoing, non-ack'ed frames.

wns::logger::Logger logger

Logger.

const size_t maxOnAir

Window size of a link.

std::auto_ptr
< wns::ldk::buffer::SizeCalculator > sizeCalculator

calculation of size (e.g. by bits or pdus)

Private Types

typedef
wns::container::Registry
< wns::service::dll::UnicastAddress,
BlockACKCommand::SequenceNumber > AddrSNMap

Private Member Functions

bool isAccepting (const wns::ldk::CompoundPtr &compound) const

void printTxQueueStatus () const

Debug helper function.

Private Attributes

const wns::simulator::Time ackTimeout

Duration between start of preamble and rx indication.

const Bit baBits

size of BlockACK

const Bit baReqBits

size of BlockACKReques

const wifimac::convergence::PhyMode blockACKPhyMode

struct
wifimac::draftn::BlockACK::Friends friends

wns::service::dll::UnicastAddress hasACKfor

indication that ACK must be transmitted

const bool impatientBAreqTransmission

transmit as BAreq as early as possible without reaching maxOnAir

const std::string managerName

const wns::simulator::Time maximumACKDuration

Maximum expected duration of BlockACK.

const size_t maximumTransmissions

maximum number of transmissions before drop

AddrSNMap nextTransmissionSN

wns::probe::bus::ContextCollectorPtr numTxAttemptsProbe

std::vector< IBlockACKObserver * > observers

wifimac::management::PERInformationBase * perMIB

const std::string perMIBServiceName

wns::container::Registry
< wns::service::dll::UnicastAddress,
ReceptionQueue * > rxQueues

Storage of incoming, non-ordered frames.

const std::string rxStartEndName

const std::string sendBufferName

const wns::simulator::Time sifsDuration

Duration of the Short InterFrame Space.

const std::string txStartEndName

Friends

class ReceptionQueue

class TransmissionQueue

Classes

struct Friends

Detailed Description

This FU implements the block acknowledgement with direct BlockACK as described int IEEE 802.11-2007 and refined in IEEE 802.11n Draft 8.0. The Block ACK message sequence chart for an error-free channel is the following (assuming maxOnAir is given in number of frames):

Thus, the block ack decreases the overhead of IEEE 802.11 by reducing the multiple neccessary ACKs for each frame to one block ack request / reply for each maxOnAir frames. Furthermore, the BlockACK can be easily combined with a frame aggregation FU to further improve the efficiency, reducing the number of backoff attempts.

The BlockACK FU implementation follows the design of ARQs in the ldk by deriving from wns::ldk::arq::ARQ, but enhances it with the neccessary functionality for IEEE 802.11-style (i.e. immediate) ARQ, based on wifimac::convergence::ITxStartEnd and wifimac::convergence::IRxStartEnd. This is similar to the much simpler wifimac::lowerMAC::StopAndWaitARQ.

To handle outgoing and incoming compounds, the BlockACK uses the two classes wifimac::draftN::TransmissionQueue and wifimac::draftN::ReceptionQueue:

A BlockACK FU has at most one current receiver peer node and for this node one instance of wifimac::draftN::TransmissionQueue. This queue contains all compounds which are intended for this receiver, both not yet transmitted and on the air.
A BlockACK FU has multiple instances of wifimac::draftN::ReceptionQueue, one for each transmitter peer node. They are used to store out-of-order compounds and to generate the BlockACK reply.

A BlockACK FU can be set to patient or impatient:

If set to patient, it waits as long as possible with the transmission of the BlockACK request, i.e. until the limit of frames in the air is reached or a frame to a different receiving peer node is due.
If set to impatient, the BlockACK request is transmitted if no frames to the current receiver are pending in the upper FU.

Definition at line 113 of file BlockACK.hpp.

Member Typedef Documentation

typedef wns::container::Registry<wns::service::dll::UnicastAddress, BlockACKCommand::SequenceNumber> wifimac::draftn::BlockACK::AddrSNMap [private]

Definition at line 126 of file BlockACK.hpp.

Member Enumeration Documentation

enum wifimac::draftn::BlockACK::BAState [protected]

Enumerator:

idle
waitForACK
receiving
receptionFinished

Definition at line 319 of file BlockACK.hpp.

Constructor & Destructor Documentation

BlockACK::BlockACK	(	wns::ldk::fun::FUN *	fun,
		const wns::pyconfig::View &	config
	)

Definition at line 48 of file BlockACK.cpp.

BlockACK::BlockACK ( const BlockACK & other )

Definition at line 93 of file BlockACK.cpp.

BlockACK::~BlockACK ( ) [virtual]

Definition at line 125 of file BlockACK.cpp.

Member Function Documentation

void BlockACK::calculateSizes	(	const wns::ldk::CommandPool *	commandPool,
		Bit &	commandPoolSize,
		Bit &	dataSize
	)			const `[virtual]`

Implements wns::ldk::CommandTypeSpecifierInterface.

Definition at line 484 of file BlockACK.cpp.

void BlockACK::copyTransmissionCounter	(	const wns::ldk::CompoundPtr &	src,
		const wns::ldk::CompoundPtr &	dst
	)			`[virtual]`

Implements wifimac::lowerMAC::ITransmissionCounter.

Definition at line 529 of file BlockACK.cpp.

bool BlockACK::doIsAccepting ( const wns::ldk::CompoundPtr & ) const [virtual]

Part of CompoundHandlerInterface implementation.

Reimplemented from wns::ldk::Delayed< USER >.

Definition at line 177 of file BlockACK.cpp.

wns::ldk::CompoundPtr BlockACK::getACK ( ) [virtual]

Implements wns::ldk::arq::ARQ.

Definition at line 331 of file BlockACK.cpp.

wns::ldk::CompoundPtr BlockACK::getData ( ) [virtual]

Implements wns::ldk::arq::ARQ.

Definition at line 362 of file BlockACK.cpp.

wifimac::lowerMAC::Manager* wifimac::draftn::BlockACK::getManager ( ) const [inline]

Definition at line 269 of file BlockACK.hpp.

const size_t wifimac::draftn::BlockACK::getMaxOnAir ( ) [inline]

Definition at line 278 of file BlockACK.hpp.

wifimac::management::PERInformationBase* wifimac::draftn::BlockACK::getPERMIB ( ) [inline]

Definition at line 284 of file BlockACK.hpp.

unsigned int BlockACK::getTransmissionCounter ( const wns::ldk::CompoundPtr & compound ) const [virtual]

Implements wifimac::lowerMAC::ITransmissionCounter.

Definition at line 516 of file BlockACK.cpp.

const wns::ldk::CompoundPtr BlockACK::hasACK ( ) const [virtual]

Implements wns::ldk::arq::ARQ.

Definition at line 318 of file BlockACK.cpp.

bool BlockACK::hasCapacity ( ) const [virtual]

These conditions are #- The storage capacity of the FU (size txQueue + sizes rxQueues) is not exhausted. #- The last compound accepted has the same receiver as the current transmission queue #- The transmission queue does not wait for an ACK, i.e. there are no frames on the air. #- The number of frames in the txQueue is below the number which can be send in the next round.

Implements wns::ldk::DelayedInterface.

Definition at line 186 of file BlockACK.cpp.

const wns::ldk::CompoundPtr BlockACK::hasData ( ) const [virtual]

Implements wns::ldk::arq::ARQ.

Definition at line 339 of file BlockACK.cpp.

bool wifimac::draftn::BlockACK::isAccepting ( const wns::ldk::CompoundPtr & compound ) const [private]

void BlockACK::onFUNCreated ( ) [virtual]

Reimplemented from wns::ldk::FunctionalUnit.

Definition at line 136 of file BlockACK.cpp.

void BlockACK::onRxEnd ( ) [virtual]

Implements wifimac::convergence::IRxStartEnd.

Definition at line 455 of file BlockACK.cpp.

void BlockACK::onRxError ( ) [virtual]

Implements wifimac::convergence::IRxStartEnd.

Definition at line 469 of file BlockACK.cpp.

void BlockACK::onRxStart ( wns::simulator::Time expRxTime ) [virtual]

Implements wifimac::convergence::IRxStartEnd.

Definition at line 444 of file BlockACK.cpp.

void BlockACK::onTimeout ( ) [virtual]

Implements wns::events::CanTimeout.

Definition at line 399 of file BlockACK.cpp.

void BlockACK::onTransmissionHasFailed ( const wns::ldk::CompoundPtr & compound ) [virtual]

A failed CTS is handled in the same way as a missing ACK or a BlockACK reply with an empty SN-set

Implements wifimac::lowerMAC::ITransmissionCounter.

Definition at line 423 of file BlockACK.cpp.

void BlockACK::onTxEnd ( const wns::ldk::CompoundPtr & compound ) [virtual]

Implements wifimac::convergence::ITxStartEnd.

Definition at line 380 of file BlockACK.cpp.

void BlockACK::onTxStart ( const wns::ldk::CompoundPtr & compound ) [virtual]

Implements wifimac::convergence::ITxStartEnd.

Definition at line 374 of file BlockACK.cpp.

void BlockACK::printTxQueueStatus ( ) const [private]

Definition at line 503 of file BlockACK.cpp.

void BlockACK::processIncoming ( const wns::ldk::CompoundPtr & compound ) [virtual]

Depending on the compound type and its transmitter, the correct function is applied:

processIncomingACKSNs in case of a received ACK
processIncomingACKreq of the matching rxQueue in case of ACKreq
processIncomingData of the matching rxQueue otherwise

Implements wns::ldk::DelayedInterface.

Definition at line 237 of file BlockACK.cpp.

void BlockACK::processIncomingACKSNs ( std::set< BlockACKCommand::SequenceNumber > ackSNs ) [protected, virtual]

After the forwarding of the set of SNs to the current txQueue with processIncomingACK(), the function checks if the txQueue has finished processing the current row of frames. If yes, it is deleted and the current receiver is reset, so that a new round of transmissions can start (possible with the one compound for a different receiver that has been stored temporarily)

Definition at line 286 of file BlockACK.cpp.

void BlockACK::processOutgoing ( const wns::ldk::CompoundPtr & compound ) [virtual]

The BlockACK FU owns only one transmission queue which is operated on until all compounds are either successfully transmitted or discarded. Hence, if a compound for a different receiving peer node arrives, it is temporary stored until the current txQueue has finished operation.

As speciallity, the function tries to get as much frames as possible from the upper FU before starting the transmission using a getReceptor()->wakeup() recursion.

Implements wns::ldk::DelayedInterface.

Definition at line 196 of file BlockACK.cpp.

virtual void wifimac::draftn::BlockACK::registerObserver ( IBlockACKObserver * o ) [inline, virtual]

Definition at line 145 of file BlockACK.hpp.

unsigned int BlockACK::storageSize ( ) const [protected, virtual]

Definition at line 156 of file BlockACK.cpp.

Friends And Related Function Documentation

friend class ReceptionQueue [friend]

Definition at line 124 of file BlockACK.hpp.

friend class TransmissionQueue [friend]

Definition at line 123 of file BlockACK.hpp.

Member Data Documentation

const wns::simulator::Time wifimac::draftn::BlockACK::ackTimeout [private]

Definition at line 360 of file BlockACK.hpp.

const Bit wifimac::draftn::BlockACK::baBits [private]

Definition at line 363 of file BlockACK.hpp.

const Bit wifimac::draftn::BlockACK::baReqBits [private]

Definition at line 365 of file BlockACK.hpp.

enum wifimac::draftn::BlockACK::BAState wifimac::draftn::BlockACK::baState [protected]

const wifimac::convergence::PhyMode wifimac::draftn::BlockACK::blockACKPhyMode [private]

Definition at line 353 of file BlockACK.hpp.

const Bit wifimac::draftn::BlockACK::capacity [protected]

Definition at line 301 of file BlockACK.hpp.

TransmissionQueue* wifimac::draftn::BlockACK::currentTxQueue [protected]

Definition at line 294 of file BlockACK.hpp.

struct wifimac::draftn::BlockACK::Friends wifimac::draftn::BlockACK::friends [private]

wns::service::dll::UnicastAddress wifimac::draftn::BlockACK::hasACKfor [private]

Definition at line 377 of file BlockACK.hpp.

const bool wifimac::draftn::BlockACK::impatientBAreqTransmission [private]

Definition at line 371 of file BlockACK.hpp.

wns::logger::Logger wifimac::draftn::BlockACK::logger [protected]

Definition at line 291 of file BlockACK.hpp.

const std::string wifimac::draftn::BlockACK::managerName [private]

Definition at line 347 of file BlockACK.hpp.

const wns::simulator::Time wifimac::draftn::BlockACK::maximumACKDuration [private]

Definition at line 358 of file BlockACK.hpp.

const size_t wifimac::draftn::BlockACK::maximumTransmissions [private]

Definition at line 368 of file BlockACK.hpp.

const size_t wifimac::draftn::BlockACK::maxOnAir [protected]

Definition at line 307 of file BlockACK.hpp.

AddrSNMap wifimac::draftn::BlockACK::nextTransmissionSN [private]

mapping from unicast addresses to compound transmission SNs for each link (receiver), the first SN of the next transmission round is stored

Definition at line 382 of file BlockACK.hpp.

wns::probe::bus::ContextCollectorPtr wifimac::draftn::BlockACK::numTxAttemptsProbe [private]

probing the number of tx attempts until successfull transmission or retry abort

Definition at line 398 of file BlockACK.hpp.

std::vector<IBlockACKObserver *> wifimac::draftn::BlockACK::observers [private]

Definition at line 400 of file BlockACK.hpp.

wifimac::management::PERInformationBase* wifimac::draftn::BlockACK::perMIB [private]

Signalling successfull/failed transmission attempts to the management information base

Definition at line 394 of file BlockACK.hpp.

const std::string wifimac::draftn::BlockACK::perMIBServiceName [private]

Definition at line 351 of file BlockACK.hpp.

wns::container::Registry<wns::service::dll::UnicastAddress, ReceptionQueue*> wifimac::draftn::BlockACK::rxQueues [private]

Definition at line 374 of file BlockACK.hpp.

const std::string wifimac::draftn::BlockACK::rxStartEndName [private]

Definition at line 348 of file BlockACK.hpp.

const std::string wifimac::draftn::BlockACK::sendBufferName [private]

Definition at line 350 of file BlockACK.hpp.

const wns::simulator::Time wifimac::draftn::BlockACK::sifsDuration [private]

Definition at line 356 of file BlockACK.hpp.

std::auto_ptr<wns::ldk::buffer::SizeCalculator> wifimac::draftn::BlockACK::sizeCalculator [protected]

Definition at line 304 of file BlockACK.hpp.

const std::string wifimac::draftn::BlockACK::txStartEndName [private]

Definition at line 349 of file BlockACK.hpp.

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

modules/dll/wifimac/src/draftn/BlockACK.hpp
modules/dll/wifimac/src/draftn/BlockACK.cpp


Public Member Functions
	BlockACK (const BlockACK &other)
	Copy Constructor, required when std::auto_ptr is used.
	BlockACK (wns::ldk::fun::FUN *fun, const wns::pyconfig::View &config)
	Regular FU Constructor.
virtual void	calculateSizes (const wns::ldk::CommandPool *commandPool, Bit &commandPoolSize, Bit &dataSize) const
	SDU and PCI size calculation.
virtual void	copyTransmissionCounter (const wns::ldk::CompoundPtr &src, const wns::ldk::CompoundPtr &dst)
	Copy the tx counter to anther FU.
virtual bool	doIsAccepting (const wns::ldk::CompoundPtr &compound) const
virtual wns::ldk::CompoundPtr	getACK ()
	Returns the pending BlockACK reply.
virtual wns::ldk::CompoundPtr	getData ()
	Returns the currently pending compound.
wifimac::lowerMAC::Manager *	getManager () const
	Returns the pointer to the wifimac::lowerMAC::Manager FU.
const size_t	getMaxOnAir ()
wifimac::management::PERInformationBase *	getPERMIB ()
virtual unsigned int	getTransmissionCounter (const wns::ldk::CompoundPtr &compound) const
	Read the tx counter.
virtual const wns::ldk::CompoundPtr	hasACK () const
	Queries the rxQueue for which a BlockACK request has been received for the BlockACK reply.
virtual bool	hasCapacity () const
	Sets the conditions to accept a new compound to transmit.
virtual const wns::ldk::CompoundPtr	hasData () const
	Checks if the current txQueue has pending compounds.
virtual void	onFUNCreated ()
	Initialization.
virtual void	onRxEnd ()
	Observe rxEnd to signal the upcoming ACK reception.
virtual void	onRxError ()
	Does nothing, required by IRxStartEnd interface.
virtual void	onRxStart (wns::simulator::Time expRxTime)
	Observe rxStart to stop the timeout for ACK reception.
virtual void	onTimeout ()
	CanTimeout interface realization, required for missing ACKs.
virtual void	onTransmissionHasFailed (const wns::ldk::CompoundPtr &compound)
	Signal from RTS/CTS that the transmission has failed.
virtual void	onTxEnd (const wns::ldk::CompoundPtr &compound)
	Signals end of own transmission -> set timeout for ACK.
virtual void	onTxStart (const wns::ldk::CompoundPtr &compound)
	Signals start of transmission.
virtual void	processIncoming (const wns::ldk::CompoundPtr &compound)
	Processing of incoming (received) compounds.
virtual void	processOutgoing (const wns::ldk::CompoundPtr &compound)
	Processing of outgoing (to be transmitted) compounds.
virtual void	registerObserver (IBlockACKObserver *o)
	observers get called after an (un)successful transmission
virtual	~BlockACK ()
	Destructor.
Protected Types
enum	BAState { idle, waitForACK, receiving, receptionFinished }
	BlockACK state can be * idle: No ongoing transmission * waitForACK: Compound is send, waiting for beginning of reception of ACK * receiving: Reception has started, not sure if it is the (Block)ACK * receptionFinished: Got RxEndIndication and waiting for PHY to deliver the frame. More...
Protected Member Functions
virtual void	processIncomingACKSNs (std::set< BlockACKCommand::SequenceNumber > ackSNs)
	Manages an incoming ACK (or rather the set of SNs).
virtual unsigned int	storageSize () const
	Compute storage size (txQueue + sum(rxQueues).
Protected Attributes
enum wifimac::draftn::BlockACK::BAState	baState
const Bit	capacity
	Maximum number of stored bits (rx+tx+air).
TransmissionQueue *	currentTxQueue
	Storage of outgoing, non-ack'ed frames.
wns::logger::Logger	logger
	Logger.
const size_t	maxOnAir
	Window size of a link.
std::auto_ptr < wns::ldk::buffer::SizeCalculator >	sizeCalculator
	calculation of size (e.g. by bits or pdus)
Private Types
typedef wns::container::Registry < wns::service::dll::UnicastAddress, BlockACKCommand::SequenceNumber >	AddrSNMap
Private Member Functions
bool	isAccepting (const wns::ldk::CompoundPtr &compound) const
void	printTxQueueStatus () const
	Debug helper function.
Private Attributes
const wns::simulator::Time	ackTimeout
	Duration between start of preamble and rx indication.
const Bit	baBits
	size of BlockACK
const Bit	baReqBits
	size of BlockACKReques
const wifimac::convergence::PhyMode	blockACKPhyMode
struct wifimac::draftn::BlockACK::Friends	friends
wns::service::dll::UnicastAddress	hasACKfor
	indication that ACK must be transmitted
const bool	impatientBAreqTransmission
	transmit as BAreq as early as possible without reaching maxOnAir
const std::string	managerName
const wns::simulator::Time	maximumACKDuration
	Maximum expected duration of BlockACK.
const size_t	maximumTransmissions
	maximum number of transmissions before drop
AddrSNMap	nextTransmissionSN
wns::probe::bus::ContextCollectorPtr	numTxAttemptsProbe
std::vector< IBlockACKObserver * >	observers
wifimac::management::PERInformationBase *	perMIB
const std::string	perMIBServiceName
wns::container::Registry < wns::service::dll::UnicastAddress, ReceptionQueue * >	rxQueues
	Storage of incoming, non-ordered frames.
const std::string	rxStartEndName
const std::string	sendBufferName
const wns::simulator::Time	sifsDuration
	Duration of the Short InterFrame Space.
const std::string	txStartEndName
Friends
class	ReceptionQueue
class	TransmissionQueue
Classes
struct	Friends