Automakers warned a push from the US Federal Communications Commission (FCC) to open up the 5.9GHz band for unlicensed use could undermine stateside investments in connected car technology.

In 1999, the FCC earmarked the 5.9GHz band for dedicated short-range communications (DSRC) systems, which use wireless links for auto safety technologies and vehicle to X (V2X) communication. The commission first revisited the band plan in 2013, seeking comment on whether it should be opened for sharing with unlicensed devices, and in 2015 launched an interference test plan.

Progress has been slow to date, but FCC Commissioners Michael O’Rielly and Jessica Rosenworcel noted in a recent letter to manufactuer Toyota the commission completed Phase I of its test plan and is set to move on to field trials in Phases II and III “in the coming months”.

“We are committed to finding the best method to deploy advanced automotive safety-of-life applications while working to meet existing and future demands for unlicensed spectrum,” they wrote. This involves exploring sharing techniques,“including those that would re-channelise the 5.9GHz band,” the pair added.

V2X surge
The potential changes come as interest in connected and autonomous cars soars and manufacturers push to integrate more intelligence into their vehicles.

Toyota, for instance, last month notified the FCC of its plans to use the 5.9GHz band to roll out vehicle-to-vehicle and vehicle-to-infrastructure capabilities in its Toyota and Lexus models sold in the US starting in 2021.

While the FCC’s sharing proposal received support from wireless groups such as NCTA – The Internet & Television Association, auto industry stakeholders including NXP Semiconductors, Panasonic, and the Safety Spectrum Coalition, along with state departments of transportation pushed back. Changes now, they said, would strand “significant investment[s]” already made in the band and threaten technology that can save lives.

“The ability to radically transform vehicular transportation in a way to make it safer to drivers, passengers, and vulnerable road users and pedestrians is at hand,” NXP wrote in an opposition filing.

“Lives are being lost, and a broader deployment of DSRC can reverse this trend.”