Mobilitie submitted an unofficial plan in Montgomery County regarding the thousands of small cells.

From the New York Times:

"Instead of relying on large towers placed far apart, the new signals will come from smaller equipment placed an average of 500 feet apart in neighborhoods and business districts. Much of the equipment will be on streetlights or utility poles, oftenaccompanied by containers the size of refrigerators on the ground. 

More than 300,000cell stations now provide wireless connections, and 5G will bring hundreds of thousands — perhaps millions — more."

"...pushing to build the system as quickly and cheaply as possible. And they have the federal government on their side.

"Mobilitie, one of the nation’s largest cell-tower operators, submitted an unofficial plan in Montgomery County, Md., in the fall, designating where the company might want to place small cells.

https://www.nytimes.com/2018/03/02/technology/5g-cellular-service.html