No Simultion and Trace output

[engrmasood2002]

Hi,
I am running example program and it displays packet transmit and receive packets statistics on console as implemented through callback functions. However, trace file is generated of 0 bytes and simulation file just shows no data flow. Here is my modification in code to get trace file and simulation file.
AsciiTraceHelper ascii;
wifiPhy.EnableAsciiAll(ascii.CreateFileStream ("simpleStdmaTrace.tr") );
std::string animFile = "simpleSTDMA.xml";
AnimationInterface anim (animFile);