Contention¶

Package: inet.linklayer.ieee80211.mac.contention

simple module Contention

The default implementation of IContention.

Usage diagram¶

Inheritance diagram¶

Used in compound modules¶

Name	Type	Description
Dcaf	compound module	Implements the DCAF (Distributed Channel Access Function) for IEEE 802.11.
Edcaf	compound module	Implements EDCAF (Enhanced Distributed Channel Access Function) for IEEE 802.11. EDCAF represents one access category within EDCA.

Extends¶

Name	Type	Description
SimpleModule	simple module	Base module for all INET simple modules.

Parameters¶

Name	Type	Default value	Description
displayStringTextFormat	string	“{fsmState}”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
initialChannelBusy	bool	true	Assume that the channel was busy before the simulation started
backoffOptimization	bool	true	We can pretend the frame has arrived into the queue a little bit earlier, and maybe able to start transmitting immediately

Properties¶

Name	Value	Description
class	Contention
defaultStatistic	stateChanged:vector
display	i=block/timer

Signals¶

Name	Type	Unit	Description
backoffPeriodGenerated	long
backoffStarted	simtime_t
backoffStopped	simtime_t
channelAccessGranted
stateChanged	long

Statistics¶

Name	Title	Source	Record	Interpolation Mode
backoffActive	backoff active	warmup(count(backoffStarted)-count(backoffStopped))	vector	sample-hold
backoffPeriodGenerated	backoff periods		vector	none
channelAccessGranted	channel access granted		count,vector?
stateChanged	contention state changed		count,vector	none

Source code¶

//
// The default implementation of IContention.
//
simple Contention extends SimpleModule like IContention
{
    parameters:
        @class(Contention);
        displayStringTextFormat = default("{fsmState}");
        bool initialChannelBusy = default(true); // Assume that the channel was busy before the simulation started
        bool backoffOptimization = default(true);    // We can pretend the frame has arrived into the queue a little bit earlier, and maybe able to start transmitting immediately
        @display("i=block/timer");
        @signal[backoffPeriodGenerated](type=long);
        @signal[backoffStarted](type=simtime_t);
        @signal[backoffStopped](type=simtime_t);
        @signal[channelAccessGranted];
        @signal[stateChanged](type=long; enum=inet::ieee80211::Contention::State);
        @statistic[backoffPeriodGenerated](title="backoff periods"; record=vector; interpolationmode=none);
        @statistic[backoffActive](title="backoff active"; source=warmup(count(backoffStarted)-count(backoffStopped)); record=vector; interpolationmode=sample-hold; autoWarmupFilter=false);
        @statistic[channelAccessGranted](title="channel access granted"; record=count,vector?);
        @statistic[stateChanged](title="contention state changed"; type=enum; enum=IDLE, DEFER, IFS_AND_BACKOFF; record=count,vector; interpolationmode=none);
        @defaultStatistic(stateChanged:vector);
}

File: src/inet/linklayer/ieee80211/mac/contention/Contention.ned