* Activate 4G at any time on your Sony Xperia Z5 Premium and benefit of the 4G network of BASE.
* Go to the Start screen.
* Choose *Apps*.
* Choose *Mobile networks*.
* Choose *Preferred network type*.
* Tick *4G (preferred)/WCDMA/GSM*.
* The Sony Xperia Z5 Premium has now been configured for use of 4G networks.
* Return to the Start screen.