This book introduces the impact of channel aggregation (CA) and channel fragmentation (CF) on traffic flows, through analytical models, computer simulations, and test-bed implementations. Its content includes the concept of CA and CF, the basic concept and calculation of Markov chains (MCs), the modeling process of the CA and CF enabled system via MCs, the process of simulations, and a test-bed study based on a software defined radio. This book can serve as a study guide for advanced-level students, who are interested in studying the impact of CA and CF techniques on traffic flows. This book would also interest communication engineers, who would like to learn MC modeling for performance evaluations, as it includes a step-by-step guidance for the modeling process via MCs, as well as its simulation approaches.