India, Jan. 15 -- During a round of pre-Christmas drinks with a belligerent motoring-and-technology journalist and a marketing executive from a major telecom association, the topic of 5G for self-driving cars came up. 5G will never help cars drive themselves, said the journalist, because (among other things) the cost of providing wide-area coverage with low-latency guarantees will remain prohibitive. Nonsense, said the marketing executive. 5G will certainly figure in the urban self-driving experience, even if that takes another few years. Just in time for 6G, then?

This lively, alcohol-fueled discussion highlighted much of the concern that still surrounds 5G as a breakthrough technology. Its advocates hope it will provide connectivity for ...