The languid pace of life here in downtown Atlanta belies the sense of urgency punctuating every conversation about 5G networks.

A smart city conference is as good as any to talk 5G. Both require long sales cycles, big contracts and tangled, complicated ecosystems. The nation's largest service providers -- the ones rushing to build 5G networks -- are also well placed to help cities out sort out how "smart" they want to become.

The hallway chatter here suggests that the upcoming 5G network buildout is the central conversation that one has to have to get any closer to building the cities of tomorrow. City leaders will say technology doesn't matter; it's the outcomes for citizens that they're worried about. And, indeed, the smart cities applications of the immediate future have very, very little to do with 5G -- most projects are in their early days and aren't quite ready to put 5G's unique characteristics to use. But the conversation doesn't stop there.

"5G has a ton of potential to improve the way cities operate and provide a bunch of benefits to citizens. It is not the be-all-and-end-all… so we will continue to use 4G throughout the country for many, many use cases," said Sean Harrington, vice president of city solutions for Verizon. "As we go roll out 5G … that doesn't preclude us from addressing [smart city] use cases with 4G, WiFi, Cat M and narrowband IoT [NB-IoT] for lower bandwidth use cases."