UK’s largest autonomous car trial moves onto public roads
As an extension of V2V, V2I will add information from traffic lights and signals, variable speed limits and congestion monitors to enable a freer flow of traffic. Throw in V2P and V2X, including cloud-stored information on anything from the weather to the nearest available parking space, plus data sent via smartphones in people’s pockets, and we’re on our way to a fully autonomous, accident-free utopia. Or at least that’s the idea.
But for this to happen, the industry still needs to reach a consensus on how all of this data will be transmitted and shared.
Originally it looked like a system using an agreed wireless local area network standard known as IEEE 802.11p, commonly referred to as dedicated short-range communications, or DSRC, would win favour. DSRC would allow V2V communication and a V2I interface via roadside beacons (although it’s never been clear who would pay for, operate or maintain those). In the US a frequency was allocated for transport use as long ago as 1999, then it received approval for the same in Europe in 2008.
More recently the DSRC option has been overshadowed by C-V2X (‘C’ standing for cellular) C-V2X was originally conceived using the LTE 4G mobile phone network but has since evolved to encompass the almost-imminent 5G rollout. One of the appeals of C-V2X is that it introduces the possibility of adding pedestrian and cyclist data via smartphone integration, which DSRC wouldn’t allow. In terms of hardware and infrastructure, C-V2X’s LTE technology has no compatibility with DRSC – the two systems are mutually exclusive – “hence the dilemma,” says Colin Lee, Jaguar Land Rover’s V2X manager.
“The debate has rumbled on for some time and continues to do so,” says Lee. “At present, China have elected for C-V2X and are moving very quickly. They may soon be joined by the US, who are exploring C-V2X to share the Intelligent Transport System (ITS) spectrum, while they already have vehicles with 802.11p [DSRC] in the market.”
DSRC has its advantages. It’s a robust, cost-effective and proven technology but has little scope for growth in terms of its capabilities – something that C-V2X has in spades. The allocation of radio frequencies is a pretty big deal, though, and some quarters of the industry are reluctant to relinquish of control of the 75 MHz-wide band (in the 5.9 GHz region, if you’re interested) that has been ring-fenced for DSRC use.
Such is C-V2X’s appeal, though, that a significant number of car makers and tech firms have registered their support for it, a backing represented by the growing membership of the 5G Automotive Association (5GAA) that was formed late in 2016.