No LTE is not just GSM its UMTS/4GSM. Which is wierd considering metro is cdma. Again here's a straight definition:
"Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. Soft handoffs allow the mobile telephone to communicate simultaneously with two or more cells. The best signal quality is selected until the handoff is complete. This is different from hard handoffs utilized in other cellular systems. In a hard handoff situation, as the mobile telephone approaches a handoff, signal strength may vary abruptly. In contrast, CDMA systems use the soft handoff, which is undetectable and provides a more reliable and higher quality signal."
AKA cells meaning cell towers. So i'm not really sure how the heck metro is using both, i just know they installed LTE servers on the same area as there cell sites, and process the data with those racks. So back to what I was saying about using multiple towers. Even though LTE is GSM style, the phone I think still transmits in CDMA from the cell phone point of view. I think the LTE part is when it hits the tower side, which then relays back to the phone with LTE, thus needing an LTE chip to receive and decrypt it.