5:30 PM -- The Federal Communications Commission (FCC)'s move last week to open up 100MHz of 3.5GHz radar spectrum could open up interesting prospects for small cells but -- if the past is any guide -- could take more time than the agency expects.

The agency is proposing that carriers use the spectrum for high-capacity, short-range deployments using small cells. It says that deploying 10 small cells in place of a single macrocell could cause a tenfold increase in capacity. The plan for the 3.5GHz band is part of the FCC's plan to open up 275MHz of new spectrum by the end of 2015. (See FCC Shows Radar Love for Small Cells.)

The FCC's plan, however, allows for priority access for the military to use its radar in the band "when the need arises to prepare for or execute national defense missions" -- with wireless exclusion zones around radar deployments -- and more sharing with other federal users.

That's no surprise. If you remember, the U.S. military hasn't typically been particularly speedy about moving off spectrum it holds in the past.

For instance, T-Mobile USA won advanced wireless spectrum (AWS) at auction in September 2006. It didn't launch its first 3G market in NYC until May 2008 and then continued a slow rollout through 2009. (See T-Mobile: 95 Cities Will Have 3G for Android.)

Part of the delay was because T-Mobile had to wait for the U.S. military to vacate some of the AWS spectrum before it could get on the air. (See '4G' Delays Ahead?)

Using military airwaves for commercial use is often tricky. Way back in 2000, the French military wanted Bluetooth banned because it supposedly interfered with vital radio communications.

So, let's keep an eye on how this develops, but don't be surprised if moving small cells onto the 3.5GHz band takes a while.

— Dan Jones, Site Editor, Light Reading Mobile