Last Updated: Nov 19, 2013
Depending on your coverage area, you may have:
Your HTC EVO™ 4G automatically connects to the fastest network that is available to you. If you have both 3G and 4G coverage, and your connection happens to get disrupted, your EVO can automatically switch to the other network.
When you first power on your phone, you will need to turn on 4G by using the widget or by pressing Menu, tapping Settings > Wireless & Networks and selecting the check box next to 4G when faster speeds are necessary.
The network will only go from 4G to 3G if you have 4G on AND if you are moving out of 4G coverage into a 3G coverage area. If you are not in a 4G market, you should turn off 4G.