Correction for you and those using Straight Talk:
In order to get LTE on Straight Talk / Net10, one must have a AT&T/T-Mobile/GSM Unlocked iPhone 5/5C/5S [iPhone 5 Model A1428 | iPhone 5C Model A1532 / A1456| iPhone 5S Model A1533 / A1457] as only these models will support LTE.
Note* Verizon iPhone 5C/5S Support Full AT&T/T-Mobile LTE bands, however Verizon iPhone 5 DOES NOT.
Those getting the iPhone 5 from Straight Talk / Net10 or Walmart --- You are getting the Verizon iPhone 5 A1429 model which does not support Band 4/17 LTE therefore you will only get 3G and that too on VERIZON Network, NOT ON AT&T / T-Mobie. However you can continue paying walmart your $25/month phone fee, and cancel your 3G service, buy a AT&T Compatible SIM from Straight Talk / Net10 BYOP program and pop it in to get AT&T HSPA+ service which is faster than Verizons 3G.
hope that helps