Which spectrum bands will connected cars use?
by Martha DeGrasse
Autonomous vehicles are on the roads in several U.S. cities, and they are on the roadmaps for most major automakers. Tesla already sells a car that can drive itself on the highway, Ford says it will test a self-driving car this year, and GM plans to launch self-driving taxis next year.
Makers of wireless networking equipment know the connected car is a huge opportunity, but there are many questions to answer. One of the most important questions is what spectrum bands cars will use to communicate with one another and with the wider internet. Wireless connectivity chipsets are specific to certain frequency bands, and while modem makers will try to pack as many bands as they can into some chipsets, one-size-fits-all solutions are rare.
Connected cars may use different frequencies in different geographies. Automakers already design different models for different countries, and this will be important as cellular networks evolve to support autonomous cars. 5G networks are not expected to operate on the same frequencies worldwide, but so far this is not a huge concern for the auto industry.
"Cars tend to stay in one country except perhaps in Europe, where I would expect the EU to drive harmonization," said James Kimery, director of marketing, RF and communication at National Instruments. National Instruments has a unique perspective on 5G because its proprietary equipment and software are used by carriers, chipmakers and equipment vendors to test 5G hardware and protocols.
Kimery said the auto industry is very excited about the use of millimeter wave frequencies for connected cars. These are short range frequencies that offer high capacity and superfast response times, but do not transmit over long distances. Kimery said millimeter wave frequencies are well-suited for quick downloads of data from a wide variety of sensors.
In the early stages of 5G, millimeter wave may be a better fit for cars than for smartphones, Kimery said. Automakers can pay more for the radios than smartphone makers can, and cars can accommodate larger radios with more antennas.
Landon Garner, CMO at antenna maker Taoglas, agreed that millimeter wave frequencies will be of interest to the auto industry, but added that many are still exploring a wide range of frequency bands.
"Millimeter wave is for sure going to be of interest to them, but right now it's maybe a little early to say," Garner said. "They're all over the board."
Automakers may start to introduce "self-driving cars" even before cellular vehicle-to-vehicle communication is in place. Tesla's Model S cars use onboard sensors, processors and GPS when the vehicle's AutoPilot feature is enabled. The Model S also connects to cellular networks, but at this time the cars do not communicate directly with one another.
