  Connectivity is a main driver for the ongoing megatrend of automated
mobility: future Cooperative Intelligent Transport Systems (C-ITS) will connect
road vehicles, traffic signals, roadside infrastructure, and even vulnerable
road users, sharing data and compute for safer, more efficient, and more
comfortable mobility. In terms of communication technology for realizing such
vehicle-to-everything (V2X) communication, the WLAN-based peer-to-peer approach
(IEEE 802.11p, ITS-G5 in Europe) competes with C-V2X based on cellular
technologies (4G and beyond). Irrespective of the underlying communication
standard, common message interfaces are crucial for a common understanding
between vehicles, especially from different manufacturers. Targeting this
issue, the European Telecommunications Standards Institute (ETSI) has been
standardizing V2X message formats such as the Cooperative Awareness Message
(CAM). In this work, we present V2AIX, a multi-modal real-world dataset of ETSI
ITS messages gathered in public road traffic, the first of its kind. Collected
in measurement drives and with stationary infrastructure, we have recorded more
than 285 000 V2X messages from more than 2380 vehicles and roadside units in
public road traffic. Alongside a first analysis of the dataset, we present a
way of integrating ETSI ITS V2X messages into the Robot Operating System (ROS).
This enables researchers to not only thoroughly analyze real-world V2X data,
but to also study and implement standardized V2X messages in ROS-based
automated driving applications. The full dataset is publicly available for
non-commercial use at v2aix.ika.rwth-aachen.de.
