Originally Posted by
FanOfKOTOKO
Wireless routers as you would probably know them work by creating a local network via forwarding data packets set from the service provider wirelessly (as the name would suggest) by making itself the wireless access point in the local network. It also works as a network switch, so when multiple users are connected to the same router, they would receive only the data that they asked for.
The reason why you may or may not be granted access to your home's wireless network may very well be too many devices connected to your router (any wireless device counts, including phones, consoles, handhelds like the DS, etc.), otherwise it would just be that they're using a portion of the bandwidth in total that's large enough for you to not get optimal performance. For example, streaming videos and music and even playing some games require what's already considered a "high-speed" connection for optimal performance; having too many users doing the same thing on the same network congests the network and leaves less space for you to use it; think of it as a road or even a highway, when there's less people on the road you're more easily able to just floor the gas and go as fast as your car allows, but when there are a lot of people on the road you're more persuaded to just go at the speed limit or even might have to go under it because everyone else is so slow, right? Same idea here :P
Also you may not be connected to the router just because there are too many devices connected to the router. In this case it's nice to understand that when dealing with your IP addess, it's generally separated in to two kinds: the IP that identifies your connection to your ISP or just the internet in general (as it's really your router going onto the internet for you and not your computer itself if you can think of it that way), which is generally what people think of when they think of IP addresses, and there is the local IP address assigned to your device by the router; this is generally denoted by 192.168.x.x when you look at your IP via your computer, and there are only a certain amount that your router will assign, thus when there are too many devices connected to the router, there comes a point where it goes beyond the number the router is programmed to assign to devices, making it so that you won't be granted access to the network until another device disconnects.