Throughput and Cost-Effectiveness of Vehicular Mesh Networks for Internet Access

Vehicular mesh networks can be used to carry Internet data traffic for mobile users. We use data from a real vehicular network that is operating in Portugal to estimate the relationship between network throughput and offered load of Internet traffic, quantity of vehicles, quantity of infrastructure and the use of Request-to-Send/Clear-to- Send (RTS/CTS) handshaking. We show that achievable throughput remains close to its maximum even for high levels of offered load per vehicle or high density of vehicles, so congestion control mechanisms in mesh networks can effectively prevent throughput from collapsing as these factors increase over time. This achievable throughput can be increased with the deployment of additional roadside infrastructure that serves as a gateway to the Internet, although the throughput gain per gateway decreases as more are added. Deploying these gateways is cost-effective, i.e. economic benefits of the resulting throughput exceed costs of infrastructure, when vehicle density is sufficiently high. We also find that use of RTS/CTS decreases achievable throughput in this scenario.