Wi-Fi Hotspot at Signalized Intersection: Cost-Effectiveness for Vehicular Internet Access

In this paper, we investigate the cost-effectiveness of a Wi-Fi solution for vehicular Internet access. We define the cost-effectiveness as the cost saving by deploying and operating a low-cost Wi-Fi infrastructure instead of a costly benchmark cellular network. To characterize the service quality of Wi-Fi deployment, we also define the normalized service delay (NSD), which is the service time to fulfill a data application via the Wi-Fi network normalized by that via the cellular network. To derive the service time, we analyze the average throughput capacity of a generic vehicle in the Wi-Fi network and the average downlink capacity in the cellular network. In particular, we propose deploying Wi-Fi access point (AP) at signalized intersection and study the fundamental influence of traffic signals (which yield an interrupted vehicle traffic) on Wi-Fi access. Then, we examine the tradeoff between cost-effectiveness and NSD by identifying interplays between controllable (e.g., the density of Wi-Fi deployment and user's satisfaction) and uncontrollable parameters (e.g., vehicle traffic statistics). Our results are very useful for network operators to make strategic planning of Wi-Fi deployment for vehicular Internet Access.