  Recently,smart roadside infrastructure (SRI) has demonstrated the potential
of achieving fully autonomous driving systems. To explore the potential of
infrastructure-assisted autonomous driving, this paper presents the design and
deployment of Soar, the first end-to-end SRI system specifically designed to
support autonomous driving systems. Soar consists of both software and hardware
components carefully designed to overcome various system and physical
challenges. Soar can leverage the existing operational infrastructure like
street lampposts for a lower barrier of adoption. Soar adopts a new
communication architecture that comprises a bi-directional multi-hop I2I
network and a downlink I2V broadcast service, which are designed based on
off-the-shelf 802.11ac interfaces in an integrated manner. Soar also features a
hierarchical DL task management framework to achieve desirable load balancing
among nodes and enable them to collaborate efficiently to run multiple
data-intensive autonomous driving applications. We deployed a total of 18 Soar
nodes on existing lampposts on campus, which have been operational for over two
years. Our real-world evaluation shows that Soar can support a diverse set of
autonomous driving applications and achieve desirable real-time performance and
high communication reliability. Our findings and experiences in this work offer
key insights into the development and deployment of next-generation smart
roadside infrastructure and autonomous driving systems.
