S3 dropping all connections

freyag

My 18 month old S3 ultra book has recently started going through a cycle of connecting to the router, then dropping it, then losing sight of all 7 available wireless networks. I thought it might be because of our new BT Homehub 4, but when we first got it it held the signal fine. My iPhone 5 has no problems with the wifi, neither do any of my housemates' phones or laptops. I was considering plugging in an Ethernet cable but of course it doesn't have the slot for it. I've googled it but everything suggests problems with the router, which obviously it isn't. Any suggestions on how to fix this? Thanks in advance

freyag

distance from the router does affect it, if I sit right next to it it hardly drops at all, but in my room (almost directly above it) it can't cope