formula for calculate available bandwidth source code in vanet

[fekair mohammed]

i found this formula for calculate available bandwidth but i not understand how it is work . please any expert now how it work tell me

double DynVehApp::calculateStimulus(){

//remove old received messages

if(!recentMessageCount.empty()){

while((!recentMessageCount.empty()) && (recentMessageCount.front() < simTime().dbl() - pBandwidthLength)){

recentMessageCount.pop_front();

recentMessageSize.pop_front();

}

}

double totalBytesReceived = 0;

if(!recentMessageSize.empty()){

std::list<int>::iterator listIt;

for(listIt = recentMessageSize.begin(); listIt != recentMessageSize.end(); listIt++){

totalBytesReceived += (*listIt);

}

}

return  std::max((( (double)1 - ( ((double)totalBytesReceived) / (double)pStimulusConstant) ) ),0.0d);

}

 where in omnetpp.ini 

*.node[*].appl.pStimulusConstant = 1000

[fekair mohammed]

any help please