Nace is disappointed that Sprint didn't say more. "Sprint did not respond to whether or not this heightened work on the 4G network has anything to do with an upcoming iPhone release," he says. Darn.

All this Sprint LTE activity somehow suggests to Nace that "perhaps" the carrier is "in a bid to prepare itself for a massive 4G iPhone 5 release that could be coming sooner rather than later."

"[I]f the iPhone 5 is coming soon -- June perhaps -- and it is to be 4G, Sprint may have to ramp up its 4G rollout ahead of the announcement in order to maximize on sales," Nace declares, ignoring the fact that the same would be true of AT&T and even Verizon, which, though much further along with LTE than Sprint, are still hardly pervasive.

Sprint is already selling phones that support LTE but for now run on its 3G network, as part of a strategy it calls "Phones First." Nace is skeptical that iPhone 5 users brandishing their phones in June would put up with this nonsense. "[I]t remains to be seen if [Sprint] would risk it with the iPhone 5, considering how coveted 4G capability for the next iPhone is in the U.S.," he claims.

But the previously mentioned Wall Street Journal story at least raises the question that the covetousness may be overblown, as LTE adoption at both Verizon and AT&T has been minimal. "Despite the two carriers' efforts, 4G LTE has been slow to take hold, in part because Apple's popular iPhone doesn't yet operate on them. Verizon Wireless said recently a mere 5% of its customers were using devices designed for the technology. AT&T hasn't disclosed what percentage of its users are on its LTE network."