how to turn on dual band svg2482ac

SVG2482AC is a model which require Wi-Fi customization that is changing default Wi-Fi credentials to the customized one to make interne work with Wi-Fi even the unit is activated by the service provider so after initial setup you can login to the modem GUI to enable both 2.4 and 5G Wi-Fi network.

http://arris.force.com/consumers/articles/General_FAQs/SVG2482AC-Changing-the-Wi-Fi-Name-and-Password

On the same page you can see option to enable the network.