>> Hi all,
>>
>> I noticed that sometimes when I generate two link gain model files
>> ("linkgain.out")
>> by the "LinkLayerModel" java class for the same configuration, then
>> I ran a simulation to compute for example the packet delivery rate
>> of my application, I obtained incomparable results.
>>
>> Let me give you an example for best understanding:
>> A simulation with the first linkgain file lets me get an PDR=0,6.....
>> in contrast, a simulation with a second linkgain file (I repeat: for
>> the same configuration) lets me get an PDR=0,05....
>>
>>
>>
>> It is a strange thing which lets Tossim simulation results to be not
>> RELIABLE!!!!!
>>
>Do you mean "deterministic?"
>Of course the link model generator is not deterministic; it considers
>hardware variations. The point is that two sets of nodes, placed in
>identical physical layouts, might have different packet reception
>ratios due to sensitivity variation across the nodes. You're testing
>two different networks, and so the results are, well, different. If
>you want to test the same network, use the same link gain file.
>Phil
Thanks professor,
But the amazing thing is the huge difference between the two results (0.6 and
0.05)
Normally, results should be comparable (0.6 , 0.5, 0.7 in the worst case 0.3).
Hence, I couldn't trust the performance difference of my application
1. if I change channel parameters (i.e did my application performs well in
indoor or outdoor environment?)
or
2. if I change radio parameters (i.e did my application performs well with
high, low asymmetric links?)
I mean
I could find a PDR of my application equals to 0.5 in outdoor environment but
0.1 in indoor environment.
However theoretically, my application should perform well in indoor environment
So, my application is neither verified nor validate !!
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