Change 3G to LTE on iPhone 5?

I usually have LTE on my iPhone 5 when I'm out of Wi-Fi but lately it's been changing to 3G and it annoys me because it goes slower. Is there any way to have it go to LTE not 3G?

It just means that it can't get an LTE signal for whatever reason if its going to 3G. Nothing you can do about it but walk around until you get LTE