Performance analysis of 802.11-based Internet access for highways with multiclass traffic flows

Several vehicular applications rely on vehicle-to-infrastructure (V2I) communications. So far, most existing work focused on analyzing the performance of V2I communications when very few vehicles are involved. However, as the market penetration rate of cars equipped with wireless communication devices increases, it is reasonable to envisage that packet collisions due to multiple contending vehicles can cause significant performance degradation. Thus, in this paper we formulate exact and approximate models to estimate the MAC-layer upload capacity and the total amount of bytes transferred by a vehicle during its sojourn within the coverage area of a roadside AP, taking into account spatial distribution of vehicles, as well as traffic and road characteristics. In particular we consider a multilane freeway with two classes of vehicles with different driving characteristics (e.g., passenger cars and trucks or buses). We validate our proposed models through extensive simulations, which show that there are substantial differences between the total amount of bytes that vehicles of different classes can transfer to the roadside AP. Our results also indicate that a simplified average-value analysis may well approximate the network performance.