On the feasibility of Vehicle-to-Internet communications using unplanned wireless networks

Advances in wireless communication technologies as well as the low cost of wireless equipment have increased the ubiquity of network connectivity, as is illustrated by the large deployment of IEEE 802.11 access points (APs). Anytime, anywhere, users are being connected to networks and consequently they expect more services on their mobile devices. Internet access from vehicles, in particular short lived connections, to roadside APs is one of the most challenging of these services. We wonder if those APs could offer Internet connectivity to vehicular networks especially for delay-tolerant applications. A preliminary requirement to make this possible is to provide the vehicle communication router with a list of available APs in its neighborhood. In this paper, we introduce ScanCar, a layered measurement system for wireless infrastructure discovery, which is integrated in the vehicle´s router to build and maintain a database of WiFi APs within the vehicle´s range. Then, we report the results of a real measurement study conducted on the data set ScanCar provided through wardriving in different regions of the French Riviera. For instance, in Antibes Juan-les-Pins, which is a residential city, our findings show that the scan duration of the 2369 discovered APs, varies between 200 ms and 664 ms. Despite that among those APs only 8.2% were not protected, we found that on average, clients can potentially remain in at least one AP´s coverage area for 23.86 seconds, which can be considered as a very promising result toward the development of services for vehicle-to-Internet opportunistic communications.