At last week's Consumer Electronics Show, Verizon and AT&T spared no expense in spelling out their plans to aggressively roll out the next-generation of wireless networks this year.

But both carriers face a conundrum of sorts when it comes to figuring out their pricing plans for the services – which have come under the generalized label of 4G. They were relatively mute on this point, even as they touted plans to launch a range of 4G devices from handsets to tablets that promise to allow users to undertake bandwidth hogging...