Blackberry Curve 8520 Smartphone allows users to turn off or turn on the WiFi using the Menu options. To access the menu options, press the menu button on the screen. This would display the list of menu options as shown below.
Now select Manage Connections Options from the list of available of menu options.
This would display the following screen Manage Connection screen.
Navigate to WiFi option and tick the option to turn on WiFi in Blackberry Curve 8520 Smartphone.