Fig. 4

Fuzzy member function for fuzzy input. For each of the mentioned criteria, the membership function is defined in the linguistic set. The words large, medium, and low are used to determine the rate of input criteria. The linguistic set of the member function of the fuzzy logic input parameters covers three values (low, medium, and high). The diagram of member functions of the speed difference, direction difference, and distance is presented in this figure. Although we could use other complex member functions as well, this triangular member function suits the proposed protocol, since it only needs to identify the best links