It seems that you are referring to this File Exchange submission:
I cross-referenced the model in R2010a (the release in which the model was created) and R2016b, and I found those blocks with unresolved library links are indeed referring to a library at the following path:
"<MATLABROOT>\toolbox\comm\commdemos\commwlan80211a_lib.mdl"
It means that even though there is a library file named "wlan80211g_lib" provided by the author in the File Exchange submission, this library is not being used at all during the simulation. The model simply referencing a library file shipped with the Communications System Toolbox. I verified this by deleting "wlan80211g_lib" from the folder and then running model "wlan80211g" in R2010a. The model runs successfully.
In R2016b, the files shipped with the Communications System Toolbox are structured differently than R2010a, and there is no library file named "commwlan80211a_lib" on MATLAB path either. You can verify this by entering the following command in MATLAB R2016b:
>> which -all commwlan80211a_lib
'commwlan80211a_lib' not found.
However, if you execute the same command in R2010a, it will show you the path to that file.
The newest release in which the model runs successfully is R2015a. I would recommend you to use an older release in which the model runs fine. Or as an alternative, if you understand how the model works, you can try to resolve the library links by using the available library files in R2016b.
