Enable 4G LTE Settings Mobile Data Network Settings Mobile Devices Useful Tips
Enable 4G LTE Settings
How to enable 4G function on 4G LTE supported iOS Devices
Please follow the steps below to enable 4G LTE function on your iPhone
Step 1: Select Settings in the home screen Step 2: Select Cellular
Step 3: Tap Enable 4G  
How to enable the 4G function on the LTE supported Android Devices
This is an example of Samsung GALAXY Note3 setting. Each device may have different user interface, so the steps may be different, user may check with the device manufacturers for details.
Step 1: Go to Settings > More Networks > Mobile networks > Network mode Step 2: Select LTE/WCDMA/GSM (auto connect) to enable the 4G feature
Click here to learn more about the mobile device network settings