If the 3G network isn't being used to capacity now, Sprint may be able to move LTE into that band without affecting the experience of 3G customers, Paolini said. "They might have some more room to do this," she said. But it could leave Sprint with less spectrum than other major carriers have for LTE, she added. Sprint said it could gain access to some more spectrum through LightSquared, the hybrid satellite-LTE carrier that plans to . LightSquared has yet to gain FCC approval to operate.

It's nothing new for the two companies to be out of sync. Before reaching the wholesale deal announced in April, they negotiated for months over how Sprint should compensate Clearwire for its subscribers' use of the WiMax network. And before the joint venture was even formed between Sprint and the original Clearwire, a fixed wireless broadband provider, they reached one tentative deal in 2007 that within months.

"The underlying motives are just as confused as ever," Paolini said.

One possibility is that Sprint is letting Clearwire's situation grow even more dire so it can buy out the rest of the venture at a favorable price, she said. If that is its plan, the fallout from Friday's announcement may represent progress.