You can only use your device on the LTE 700, 850, 1700/2100, 1900; WCDMA 850, 900, 1700/2100, 1900, 2100; and GSM 850, 900, 1800, 1900 MHz networks. Support for LTE networks may have been disabled on your device depending on your country or service provider. You need a subscription with a service provider.
Using some features and downloading content require a network connection and may result in data costs. You may also need to subscribe to some features.
4G/LTE might not be supported by your network service provider or by the service provider you are using when traveling. In these cases, you may not be able to make or receive calls, send or receive messages or use mobile data connections. To make sure your phone works seamlessly when full 4G/LTE service is not available, it is recommended that you change the highest connection speed from 4G to 3G. To do this, swipe left on the start screen, and tap Settings > cellular. Switch Highest connection speed to 3G.
For more info, contact your network service provider.