D2D in LTE vehicular networking: System model and upper bound performance

The Device-to-Device (D2D) communication over the Long Term Evolution (LTE) cellular system is emerging as a key technology to support safety and traffic efficiency applications in Vehicular Ad-hoc NETworks (VANETs). By offering a flexible usage of the radio interface, it allows vehicles to directly communicate each other, while experiencing low-latency and highly reliable data delivery. Anyway, the impact that application traffic patterns and transmission settings have on the overall performance is still unclear and in this context it is necessary a deep study for driving future research activities. To this end, the present contribution proposes a flexible methodology that characterizes, from a system level point of view, the upper bound performance of vehicular D2D communications as a function of the application, the access layer settings, and the channel behavior. Model outcomes have been used to provide insights about the most suitable transmission parameters, the achievable transmission range, and the supported vehicles density in VANETs scenarios.