ADAS technology is advancing at an almost unprecedented rate. Speaking in 2016, chairman and CEO of General Motors, Mary Barras wrote: “The auto industry will change more in the next 5 to 10 years than it has in the past 50.”
While Barras was also referring to the electrification of vehicles, at the heart of her statement was the drive towards creating safer cars, and safer roads, through ADAS and self-driving technology.
As Barras noted, the next step-change for the advancement of ADAS technologies will be the advent of the so-called connected car, made possible by the widespread adoption of:
- vehicle-to-vehicle (V2V),
- vehicle-to-infrastructure (V2I) and
- vehicle-to-everything (V2X) communications.
Current ADAS functions are limited by what the vehicle’s own sensors can detect, which today extends to a useful forward range of around 250 metres. V2V communication has the potential to expand on that exponentially by allowing appropriately equipped vehicles to communicate with each other directly and share information on relative speeds, positions, directions of travel and even control inputs, such as sudden braking, accelerations or changes in direction. By fusing this data with the vehicle’s own sensor inputs it will become possible to create a much wider and more detailed picture of the surrounding area and provide earlier and more accurate warnings, or even corrective actions, to avoid collisions.
As an extension of V2V, V2I provides vehicles with information from the road network’s infrastructure, such as traffic lights and signals, variable speed limits and congestion information. Such information is expected to not only improve safety but also reduce congestion by enabling a freer flow of traffic, and it is also recognised as a key driver towards full autonomy. V2X, meanwhile, adds data streams from beyond the immediate road network, including cloud-stored information, meteorological updates and possibly cyclists, pedestrians and other vulnerable road users (VRUs).
However, in order for the connected car to be realised, a consensus still needs to be reached on which communication system the industry will adopt in order to enable V2V, V2I or V2X. Originally it looked like a standardised system called dedicated short-range communications (DRSC) would win favour. Operating in a 75 MHz-wide band around 5.9 GHz, DRSC would allow V2V communication and a V2I interface via dedicated roadside beacons (although it’s unclear who would pay for, operate and maintain them). In the United States the frequency was allocated for transport system use as long ago as 1999, then it received approval for the same use in Europe in 2008. Since then much work has been carried out by developers and manufacturers to ensure DRSC’s robustness and reliability for V2V and V2I communication.
In the meantime, V2V’s rollout has been clouded by the arrival of an alternative system with greater potential benefits. C-V2X (‘C’ standing for ‘cellular) was conceived using the LTE 4G mobile phone network. LTE not only allows direct device-to-device communication (i.e. not via the mobile phone network’s communication infrastructure) but it can also, importantly for V2V and V2I, broadcast from one device to multiple recipients. C-V2X also opens up the possibility of incorporating pedestrians and cyclist data in the V2X loop via smartphone integration, thus enhancing VRU safety. It should be noted that in terms of both hardware and infrastructure, C-V2X’s LTE technology has no compatibility with DRSC – the two systems are, in effect, mutually exclusive.
But even LTE 4G is bordering on redundancy as the next-generation 5G networks arrived, with selected area coverage from 2019 prior to a more widespread rollout. 5G is set to offer all of LTE 4G’s benefits but with significantly lower latency – as low as 1 ms compared with 30-100 ms for LTE 4G – along with a data rate of up to 20 Gbps. Such is 5G’s appeal that an increasing number of technology companies, telecommunications firms and car manufacturers have been showing their support for it, not least by joining the 5G Automotive Association (5GAA) that was formed late in 2016. 5GAA membership continues to grow and now includes Audi, BMW Daimler, Ford, Honda, Jaguar Land Rover and Volkswagen, along with AT&T, Bosch, Samsung, Telefonica, LG, Intel and Huawei.
Connected ADAS undoubtedly opens up a new world of opportunity in enhancing road safety and paves the way for full autonomy, but until a technology pathway is agreed upon, its widespread adoption remains some way off.
This article is part of the ‘What is ADAS?‘ series.
