The entropy rate of a random process shows how the entropy of the sequence grows with time. The entropy rate can be used to estimate the complexity of a random process. In this paper, the entropy rate of multiple, intermittent frequency hopping (FH), stationary, and Markov model (MM) random process sources, is presented in a closed form. Also, an upperbound of the entropy rate of the multiple hidden Markov model (HMM) sequences corresponding to the multiple MM sources is presented. © 2024 IEEE.