If your arris device is just a modem, then connecting this belkin will simply route that signal wirelessly (hence, giving you wifi).
If your arris device is a modem/router, you technically don't need this belkin router at all.
if your arris device is a modem/router and the wifi range sucks, and you think the belkins range is better, go ahead and try it, but this belkin device is not inherently designed to extend wifi range.