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UK plumps for WiFi instead of LTE in connected car corridor pilot

Connected vehicle corridors are becoming as renowned for the proxy war being fought between the WiFi and cellular camps as for the more interesting higher level V2X communications and overlying applications. Each side pumps out propaganda highlighting its supposed benefits or greater maturity, while warning that more accidents are likely if the other is adopted.

The UK’s first significant connected vehicle pilot, for which Costain has just won the contract, is therefore notable for running with the WiFi option IEEE 802.11p, also known as DSRC or ITS-G5. The cellular option is 3GPP LTE-V2X PC5, also referred to as LTE side-link or sometimes, especially in the US, just as C2VX. Both operate in the 5.9 GHz band for the provision of direct communications between road users, and offer comparable features, which is perhaps why each side has worked so hard to promote marginal advantages.

We won’t rehash the arguments here, except to point out that whichever prevails, it will be necessary to integrate these short-range radio protocols with longer range communications, and that inevitably means cellular. This will yield additional benefits and however much fatalities and serious injuries are reduced through short range V2X, they will be cut further when longer-range C-ITS (Cooperative Intelligent Transport Systems) are enabled through interactions with a LTE cellular network.

Such integration is not being tested directly in the UK pilot, running on its A2/M2 highway running about 80 miles (128 Kms) from Blackwall Tunnel in SE London to the Port of Dover. However, London-based professional services firm Arup is working with Costain to review best practice within the pilot, including vehicle-to-infrastructure technologies, back-office platforms and business models.

It is also preparing the economic case for additional development of an information hub to facilitate the development of connected services. This would feature 250 datasets with potential to deliver what it calls smart mobility on the A2/M2 corridor, which boils down at present to information on road works, road conditions, temporary speed limits and time remaining before a traffic light turns to green.

The intention is to try this out on limited autonomous driving, varying vehicle speed for example to take account of these parameters about conditions. Information gleaned from the project will also be used to recommend connected vehicle standards, within the UK at least, and facilitate more widescale deployment of connected vehicle technology.

Trial vehicles will be fitted with onboard technology that will communicate with roadside units, via the ITS G5 WiFi communication, and with the service provider via cellular communication, although as we said without integration between the two at present.

The contract was awarded by Highways England, which is providing part of the funding, working with the Department for Transport, Transport for London (TfL) and Kent County Council, to test the wireless transmission of data to and from travelling vehicles.

Elsewhere in Europe it seems that cellular is prevailing for such corridors, at least as an enabler for cross-border trials. This reflects the fact that it is relatively easy to get bilateral agreement between countries as they are used to collaborating over cross-border mobile services.

Accordingly, on so called Digital Day 2018, organized by the European Commission in April 2018, several EU member states signed regional agreements on 5G corridors for connected vehicles with a view to establishing a pan European network comprising hundreds of miles of motorways capable of supporting tests up to SAE Level 3 autonomy, where a car can operate itself with a driver present under certain conditions.

Similar moves are afoot in the US, although with states tending to go it alone there. The country’s largest network of corridors so far has been set up by the Michigan Department of Transportation, General Motors, Ford and the University of Michigan, comprising over 120 miles of connected freeways in Southeast Michigan, to evaluate various options for vehicles to communicate with nearby infrastructure and other vehicles. The project is aiming for extension to 350 miles by the end of 2018 and is providing drivers with forward collision warnings, left-turn assist, work-zone warnings, signal phase and timing and border-wait applications.

As it happens, there is greater momentum behind WiFi for V2X in the US than elsewhere. This is because in March 2017 the country’s National Highway Traffic Safety Administration (NHTSA) announced it was considering requiring new light vehicles to have DSRC in the belief that the communications to from and between vehicles enabled as a result would cut non-impaired crashes by 80%, meaning those involving drivers supposedly in full possession of their faculties and not under the influence of alcohol or drugs.

Of course, this same benefit would be achieved by LTE and it may well be that the US does come around more to that. However, lingering doubts over the future of the protected DSRC band in the 5.9GHz spectrum remain, with many expecting the FCC to sell off the valuable spectrum band to MNOs.

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