We have a a router downstairs creating our wifi network. We have 100% signal strength in a couple rooms upstairs and only 30 - 40% in the room with Xbox 360 Slim in it. It was virtually unusable and mostly terrible to unusable for laptops, smartphones and tablets. I finally got around to getting a second wifi router that extends the network created by the downstairs router. I put it in the upstairs room with 100% signal strength connection to the downstairs router and now we get 100% signal strength in the upstairs room with the Xbox 360 in it. Computers, smartphones and tablets dynamically switch to the router with the highest signal strength no matter where they are in the house, but they always think they're on the same wifi network -- because the network services and network name are the same, only there are two routers instead of one broadcasting that single network.
There's also a PS3 in that upstairs room with Xbox 360 S. The PS3 sees the one network as two networks, both with the same name. But for wifi configuration you can pick the correct router, the upstairs extender in bridge mode, simply by picking the one with 100% signal strength instead of 30%. Then the PS3 always connects to the extender, not the downstairs base wifi router. So the PS3 sees two networks when it should see only one but it you can pick the connection point.
The Xbox 360 S behaves a little more like a laptop. It only displays the one network as a connection option, but it warns me I have two networks with the same name and I need to change the name of one of them. Of course in this case I can't because it's one network extended, not two distinct wifi networks. Unfortunately, though The 360 only shows the extender in the wifi network selection screen -- with full bars signal strength -- once it's setup it mostly are always connects to the weak signal downstairs router and ignores the strong signal from the upstairs router. Meaning my network connection is terrible.
Has anyone run into this with an extended wifi network? Have you found a way to force the Xbox 360 to connect to the extender, not to the base router where the wifi network originates? I thought about turning off the main router, then connecting the 360 to the extender so it would be the only possible connection, then turning the main router back on. But that won't work because if I shut down the main router the whole network goes away.