Does setting length of WSM via setWsmLength
or adding a large payload via setWsmData
makes any difference during simulation? I am trying to simulate a heavily used network, but changing any of those two values doesn't seem to make any difference. I found this, but wanted to confirm this. And If I wanted to change the size of the WSM do I have to implement it?
问题:
回答1:
You can implement a packet for your application in a .msg
file as follows:
cplusplus {{
#include "veins/modules/messages/WaveShortMessage_m.h"
}}
class WaveShortMessage;
message MyAppsPacket extends WaveShortMessage {
string sourceAddress;
string destinationAddress;
simtime_t sendingTime;
}
Then in your code you can use the built-in setByteLength()
. Use cPacket subclass for your messages because:
(cPacket is) A subclass of cMessage that can be used to represent packets (frames, * datagrams, application messages, etc). cPacket adds length (measured in * bits or bytes), bit error flag, and encapsulation capability to cMessage. * Length and bit error flag are significant when the packet travels through * a cDatarateChannel or another channel that supports data rate and/or * error modelling. *
Related Q&A which shows the casting from cMessage
to cPacket
.
回答2:
I know it is decades later, but maybe it can help some new vanets lovers like me.
In omnet++5.4.1 and Veins 4.7.1, in the function
populateWSM()
defined in BaseWaveApplLayer.cc (veins/modules/application/ieee80211p), you can set the bit length with the
wsm->setBitLength()
method and it changes the size of the wsm packet. By default, it has the length of the header
wsm->setBitLength(headerLength)
I have played with this and could obtain different packet sizes.
Hope this is useful.