omnet++ veins - asking about the value of Recieved

问题:

I am working with Omnet++, veins. I use the code that exist here:

Flooding.ned also flooding.cc exist in same link.

I am working with flooding application, and I assigned sentbeacon true, and sent Data to false, to compute the probability of beacon delivery. all statistical are recorded in the mentioned project.

for flooding.cc I changed onBeacon function to record the recievedbeacon

void Flooding::onBeacon(WaveShortMessage *wsm)
{
    // not used for this algorithm

    // statistics recording
       emit(beaconReceivedSignal, 1);
       stats->updateAllBeaconsReceived();
}

Then I want to record the number of sent packet, so I changed in this file Mac1609_4.cc ( the code is part of this file and just the line that I changed).

void Mac1609_4::handleSelfMsg(cMessage* msg) 
{ 
    DBG_MAC << "Sending a Packet. Frequency " << freq << " Priority" << lastAC << std::endl;
    sendDelayed(mac, RADIODELAY_11P, lowerLayerOut);
    statsSentPackets++;
    stats->updateAllpacketsent();
}

My question is about the statistical number.I need the help with equation to compute the probability of beacon delivery correctly. I used realistic map, when I running the project and get results , I could not know how to compute the probability, I try to take part of area (RoiRect) but it still I have the same issue, may be I need to compute the probability for specific range or should I take small area, to have accurate results?

For the included results, I stopped the simulation with 36 nodes.

回答1:

It's because of broadcast nature of sending beacon.
Assuming that the network contains N nodes and there are ideal propagation conditions, when a node sends one beacon packet, it will be received by N-1 nodes (i.e. all other nodes). As a consequence:

• allSentBeacon = 1
• allReceivedBeacon = N-1

By the way: in that situation the delivery ratio should be defined as:
deliveryRatio = allReceivedBeacon / (allSentBeacon * (N-1))