Using Telstra’s 4G phone network, the companies conducted a trial in South Australia that involved delivery of driver alerts, green light priority for high-priority vehicles and “green wave” traffic management where drivers are advised about the correct speed to travel in order to catch the green light ahead.
The trial points to the possibility of ITS utilising a hybrid system of communications, with drivers receiving messages both from 4G sources and also the faster 5.9Ghz dedicated short-range communications (DSRC) system originally envisaged for ITS use.
Telstra believes its 4G and future 5G networks can help deliver a faster rollout of some ITS systems and help keep costs down, said Telstra director of technology Andrew Scott.
“While there has been a lot of focus around future transport technology, there has not been much work done to date in Australia on supporting ITS via existing 4G mobile networks,” Mr Scott said.
He said the South Australian trial demonstrated that 4G could support some V2I (vehicle to infrastructure) applications.
Up to now, the concept of ITS communications to and from vehicles was based around the use of DSRC communications using the 5.9GHz band, which has been reserved in many countries for use in ITS applications.
The first car to come equipped with an in-built 5.9GHz system will be the 2017 Cadillac CTS, which will use Cohda’s chipset built into a Delphi connected-car module.
Mr Scott said that using the 4G network can extend the benefits of ITS to road-users other than drivers. New trials would be conducted in coming months to establish the feasibility of vehicle-to-vulnerable road users, in particular pedestrians and cyclists.
“We are particularly excited about the upcoming vehicle-to-vulnerable testing as we will be able to showcase the Australian-first sending of standardised intelligent transport systems messages over the 4G network to enable interaction of vehicles with smartphone-equipped bicycles.”
Essentially, drivers would be warned if there was a bicycle rider with a smartphone in the vicinity.
Cohda chief executive Paul Gray said the trial conducted with Telstra used Cohda’s ITS software, but in a 4G format.
“There are two components to our ITS system, the chips we make and then there’s all the software stacks that sit on top of the chip,” he said. “The software formats the messages that go between the vehicles or to the infrastructure, and the applications that detect the threat to your vehicle and generate the alert.
“This trial used our software stacks and applications communicating over 4G rather than 5.9Ghz. That means it could be deployed earlier because we don’t have to deploy the 5.9GHz infrastructure. The cellular stuff is already there.”
Mr Gray said that a hybrid system would include two chips, one 4G chip and one 5.9GHz chip, with the Cohda software running on both.
There were a number of V2X cases that could be deployed immediately using 4G, but Mr Gray said that 4G communications would not be ideal for time-critical situations like warnings of an imminent collision. However, some applications such as road works warnings would be suitable for 4G.
“Road works warnings would be an ideal application because that’s not latency-critical. It doesn’t matter if it takes half a second for the message to get from Point A to point B.”
The half-second delay is the result of the 4G message having to go to a tower for routing to the 4G chip in the car.
“The 5.9Ghz (DSRC) system is designed to be very low latency. That’s important if you have two cars about to collide and so maybe 4G is not the best choice for that.
“But if you are talking to the road works or talking to the traffic lights to find out what is the best speed to catch the next green light, it doesn’t hurt you to have a bit of delay in there.
“There are a bunch of apps that need low latency, the safety critical ones, but there’s a whole range of apps that aren’t so sensitive to latency and it may make sense to deploy them over cellular networks because you can do it now and really start to create some benefits right away.”
Mr Gray said the 4G chips in the car would be able to display the warning or message on the dashboard screen in the same way the 5.9GHz chip would do.
“Ideally you would have both communication links available and you would use the one that is most suitable for the particular application.
“There are production vehicles that have 4G links in them already.”
All European cars now have to have a phone chip in them so that emergency services can automatically be alerted if there is a major collision.
The South Australian minister for transport and infrastructure Stephen Mulligan said the government was positioning South Australia to become a leader in ITS and autonomous car technology.
“Last year we hosted the first on-road trials of autonomous vehicles in the southern hemisphere and this year we became the first Australian jurisdiction to legislate to allow further on-road trials,” he said.
Mr Mulligan added that it had been forecast that autonomous technologies could support an industry worth $90 billion a year and he wanted South Australia to win a slice of that business.
Telstra, Cohda Wireless and the South Australian department of planning, transport and infrastructure were all partners of the Australian Driverless Vehicle Initiative which has been created to research and influence the construction of robust national policy, regulation and operational procedures to support the introduction of driverless vehicles.
By Ian Porter