A Distance-Based Mode Selection Scheme for D2D-Enabled Networks With Mobility

In this paper, a new mode selection scheme for device-to-device (D2D)-enabled cellular communications with mobility is proposed and evaluated. The new scheme is based on an average threshold D2D distance between two given users to trigger the D2D mode. Besides, a tractable analytical framework considering relative movement for mode selection in moving D2D scenarios is presented. Under the proposed model, the expressions of the average threshold D2D distance, the probability of using D2D mode, the successful transmission probability, and the minimum D2D mode residence time are derived, which are the key parameters to evaluate the performance of D2D-enabled networks. Monte Carlo simulations are conducted to confirm the analytical results and the advantages of the proposed scheme over previously proposed ones. They show also the importance of studying the dynamic performance of the system in terms of user mobility as articulated in the calculated minimum D2D residence time.