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）的技术成熟度与其实际采纳和部署之间的差距，已导致至少两类网络接入技术必须共存的现象。此外，就ETSI智能交通系统协议而言，规范第2版的编制工作即将完成，而第1版的部署仍在进行中。这一状况，加之汽车行业的产业与消费趋势，势必造成完全支持C-ITS的车辆不得不与非C-ITS的道路使用者，至少是与不同版本的C-ITS共存的情形。本文分析了ETSI GeoNetworking协议两个版本在效率和安全性方面的性能表现，并探讨了解决即将出现的兼容性及共存问题的可能路径。