Good news for people in the car just ahead of the driver who is texting.
It’s the future, now, for those of us who were kids several decades ago, looking forward eagerly to having flying cars. We’re still waiting. But another automotive promise of that era – self-driving cars – is coming closer to reality. And self-stopping cars are here. You can be behind the wheel at 75 mph, unaware the semi in front of you has come to a sudden halt because you are busy texting, or watching that video of a surprised kitten, when the car knows enough to jam on the brakes by itself, with no help from you.
That technology just got a little help from the FCC.
The car knows about the stopped semi ahead because it scans the road with radar. One of the favored frequency bands for this application is 76-77 GHz, well up into the nosebleed spectrum. Radio waves in that range can use small antennas and give precise radar readings. They also form tight beams and don’t travel far, which helps to keep the radars in nearby cars from interfering with each other.
The current FCC rules for this band are complicated. Power limits depend on whether the vehicle is stopped or moving, and on whether the radar is aimed forward or in some other direction.
The FCC now proposes to set the same 100 watt power limit for vehicle radars aimed in any direction, all the time, moving or stopped. This should simplify the design of the radars and thus bring the cost down, which might eventually help to make them available in more cars. (We hope so, because we’d like the car behind us to have one.)
The same FCC notice also responds to a request to allow stationary versions of a similar radar technology for use in tracking ground vehicles around airport ramp and gate areas, as we reported a couple of years ago. The FCC now proposes to allow the same 100 watt power limit for any fixed 76-77 GHz radar anywhere, not just at airports, and for any purpose.
Early opposition to the change in rules for the vehicle radars came from a radio astronomy group, whose members fear interference to their observations in the band.
The FCC’s Notice of Proposed Rulemaking is here. Comments and replies will be due 30 and 45 days, respectively, after publication in the Federal Register. We will let you know.