you can create a simple wireless scenario without using any model. in this case, instead of send() use sendDirect command
target = getParentModule()->getSubmodule("wireless1"); // defining a module
cMessage *msg = new cMessage("tictocMsg");
sendDirect(msg,target,"radioIn"); // sendDirect message
cMessage *msg2 = new cMessage();
scheduleAt(simTime()+par("sendInterval"),msg2);