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.

翻译：合作式智能交通系统（C-ITS）的技术就绪水平与其实际应用部署之间的差距，导致至少两类网络接入技术必须共存的局面。此外，在ETSI智能交通系统协议方面，规范第2版的工作即将完成，而第1版部署仍在进行中。这一现状结合汽车行业的产业与消费趋势，必然导致完全支持C-ITS的车辆必须与非C-ITS道路使用者、至少与不同版本的C-ITS系统共存的场景。本文从效率与安全性两个维度分析了ETSI GeoNetworking协议两个版本的性能，并探讨了应对即将到来的兼容性与共存问题的可能路径。