  The gap between technology readiness level in Cooperative Intelligent
Transport Systems (C-ITS) and its adoption and deployment has caused a
phenomenon where at least two types of network access technologies have to
coexist. Furthermore, for the case of ETSI Intelligent Transport Systems
protocols, work is being completed in Release 2 of the specification while
Release 1 deployments are still underway. This, coupled with industry and
consumer trends in the vehicle industry, is bound to cause a scenario where
fully C-ITS-enabled vehicles have to coexist with non-C-ITS road users and, at
the very least, with different versions of C-ITS. In this paper, we analyze the
performance in terms of efficiency and safety of two releases of the ETSI
GeoNetworking protocol, as well as a discussion on possible paths to tackle the
upcoming compatibility and coexistence problems.
