Here’s a hope-crusher for US mobile customers: Not all 4G LTE-capable phones are created equal. Verizon customers looking to take their high-end LTE devices and hop over to competing networks, such as AT&T, are in for the same sore surprise that customers have dealt with on 3G networks for years–the devices run on different frequencies depending on their carrier.

American wireless carriers have played this game for years. A phone may be sold in as many as three or four different carrier’s stores, but each one will be shipped with a radio that uses a frequency that the others don’t. In the case of 3G phones, this problem was most commonly experienced by iPhone owners who jumped ship and left AT&T (usually for T-Mobile). Their phones would still work, but only on EDGE, which is considerably slower than what they had to begin with.

Now, it seems that this aging practice is still in play–even with the new generation of 4G LTE networks and somewhat “open” devices. To make matters worse, the number of potential frequency bands available for LTE networks is a whopping twelve, ranging from 700MHz to 2600MHz. In this case, we’re dealing with Verizon’s use of the upper 700MHz band, while AT&T only uses the lowersegment. There’s absolutely no overlap.

The disparity between Verizon’s and AT&T’s networks goes beyond LTE, too. Because the two networks use entirely different technologies for their “3G” networks, customers would be unable to keep even the most basic of speeds if they try to switch carriers.

Frequency splitting like this is nothing but bad for consumers, but it clearly works for carriers in more ways than one. No amount of rooting has been able to affect the actual bands that a phone’s radio uses, so consumers are more or less locked into their services–even if they hate their carrier. It’s an ugly practice, but it’s unlikely to stop any time soon.