In this paper, we consider 3GPP LTE cellular system where machine-to-machine (M2M) devices and human-to-human (H2H) users transmit their data into the network. By contrast to previous studies which primarily focused on M2M overload protection and respective control mechanisms, this work concentrates on system operation when M2M and H2H data flows coexist in the network. In particular, we propose an integrated simulation-analytical framework to evaluate relevant performance characteristics (data transmission delays, blocking probabilities, etc.) with both Markov process based analysis and system-level simulations. Our results indicate that the proposed methodology demonstrates acceptable levels of convergence between analytical and simulations components, as well as becomes useful to characterize impacts of M2M/H2H coexistence on radio resource allocation in 3GPP LTE across a number of important M2M-centric scenarios.