In the late 1990’s wireless technology enthusiasts, appreciating the opportunities and capabilities inherent in the IEEE 802.11 wireless LAN standard, began thinking seriously about vehicular applications and promoted the idea of using this to improve road safety. In 2002, the CAR-2-CAR consortium was formed by a number of globally active, major car manufacturers with the goal for stimulating the development of vehicle-based communications that would make roads safer by using car to car communications. That would provide drivers with information about local conditions so that drivers could better avoid collisions with other cars, pedestrians, obstacles, find efficient routes, etc. In 2004 this led to the formation of IEEE 802.11p – the committee that would develop the first standard for vehicle to vehicle communications.
That is 15 years ago but in the meantime a lot has changed. First of all, the technology standards and agreements among the players have burgeoned into a complex of communications facilities that include car to car as well as car to roadside and vice versa. In addition to pure safety related messaging the same technology will also support – capacity permitting – information provision and entertainment. The spectrum for this technology lies in the 5.9GHz band. The communications technology that is slated to become operational in 2019 is now called ITS-G5. It is part of a larger concept called C-ITS – Cooperative Intelligent Transport Systems, a European Commission label announced in 2008 together with 30 MHz of safety dedicated spectrum at 5875-5905MHz – but the underlying technology is still very much like IEEE 802.11p of way back. In 2017 the consortium declared its strong support for the European Strategy on C-ITS Deployment, highlighting a hybrid communication approach for transmitting C-ITS messages using both direct vehicle communication using ITS-G5 technology as well as mobile radio communications. Mobile communications providers, recognizing the potential profits from new services, joined the fray. The latest “Delegated Regulation” from Brussels for ITS mentions that this regulation will be updated as necessary when new, promising technologies become available.
So today we have two basically different technologies, and possibly others later, competing for the use of the same spectrum and for investments. The deployment of C-ITS will entail large investments and operational costs, in particular for vehicle manufacturers, road and transport operators, public authorities, services providers/developers. Large investments require a predictable legal environment and a stable outlook and that seems to be a grey area now. Such uncertainty increases the attraction of self-driving care technologies developed by Tesla, Google, etc. Such self-driving systems do not require major investments in roadside communications infrastructure or vehicle to vehicle communications because the safety related decisions are taken autonomously by sensor-based on-board systems. That suggests a possible shift in the centre of gravity for driving automation: towards autonomous driving systems interacting with transport services and applications through whatever communications facilities are available, ITS-G5 or cellular networks.