Are you talking about your router, or a YouView box?
If the latter, what model is it, and how have you got it connected to the router? All YouView boxes except the latest, Pro, box require a wired connection, via an Ethernet cable or PLAs, and only the Pro box operates over WiFi, something you have to choose when setting it up.
(Actually, I have a T2110 working over WiFi, using a nanorouter, but you have to fool the box that it’s still on a wired connection 😛)