Modeling Trajectory-Based I2V Message Delivery Over VANETs with Vehicle Detours

Abstract

Vehicular ad-hoc networking (VANET) is an effective and green approach to supporting the communication requirements of networked electric vehicles (EVs). This paper studies trajectory-based infrastructure-to-vehicle (I2V) message delivery over VANETs, whose operations can be summarized as follows: 1) the server first selects an appropriate roadside unit on the destination vehicle's subsequent trajectory as the rendezvous point (RP); 2) the server then transmits the message to the RP and expects that when the vehicle passes through the RP later, the message can be delivered from the RP to the vehicle. Such existing protocols commonly assume that vehicles move strictly following the suggested routes, without detours. Consequently, the delivery performance can be overestimated. This paper proposes an analytic model to investigate the impacts of vehicle detours on trajectory-based VANET I2V message delivery. The model derives the probability that a destination vehicle will pass through its RP, and thus receive the message successfully, considering the fact that the vehicle may detour during the movement. We validate the analytic model against simulation. Finally, several numerical examples are presented to quantitatively show how the message reception performance is affected by vehicle detours.