GRETEL: Graph-based Street Coverage Calculation for Vehicle-to-Infrastructure Communication

Connected vehicles will exchange large amounts of data with remote systems. This can include recent traffic information, search results, or software updates to the car. Data communications can, therefore, be expensive as currently all transmissions to and from the vehicles are done via mobile service providers. Wireless Local Area Network (WLAN) offloading to home deployed Access Points (APs) for internet connectivity can be a more affordable option, as the use of the frequency spectrum is free of charge. While the technology is already widely deployed, the outdoor availability on the street is critical for the use in vehicles. To analyze the street coverage we have developed GRETEL, a GRaph-based streET covErage caLculation. GRETEL enables the analysis of Vehicle-to-Infrastructure (V2I) communications by combining location data with signal measurements mapped to the relevant road topology. To test GRETEL's performance, we conducted test drives to measure WLAN beacon frames and identify receivable WLAN APs. We determine that more than 9 % of all APs in our data set are commercially available connection options. With GRETEL, we could determine that the subset of commercially available APs covers about 60 % of the street network. Therefore, we introduced a novel method for street coverage calculations called GRETEL and showed encouraging results for the use of commercially available WLAN APs for V2I communications.