You can try xfuzzy tool for designing fuzzy logic logic engine. xfuzzy tools generates C/C++ and java source codes of the fuzzy logic engine. You can use generated source code files of fuzzy logic engine in network simulator 2 or omnet.
You can use xfuzzy tool instead of using matlab fuzzy logic toolbox. xfuzzy can generate C/C++ or java source code file of fuzzy logic engine designed in its graphical interface. These source code files can be further used in network simulator 2 or Omnet.