Ok let's say that things are going great. You have a s ingle wifi router like the soon to be extinct Apple Time Capsule but now want a little More coverage say in your basement. What's the easiest thing to do short of living on smallnetbuilder.com.
Well, it's surprisingly easy and hard to make it all work but here's the simplest way and some of it is unintuitive.
- I'm assuming now you have a wired Ethernet jack where you want to put it. Normally you want to put it where the signal is weak from your current setup. Like your basement or attic.
Go buy an identical wifi router like the Time Capsule. You already know how to use and configure it.
Do not connect it to your home network! Instead plug it in and turn it on and connect your laptop to it. Either via Ethernet cable or on the default wifi.
Start the airport utility and go to the network tab and turn off routing. Otherwise when u plug it in it will conflict with the existing router. Now go to the wireless tab and use exactly the same network name and ssid as your. Make sure you say Create Network and not extend network. You do not want to say the seemingly logical extend because what that does is use a bunch of wireless spectrum for Backhaul. You want to use the wired Ethernet for that.
3a. If you don't have an Ethernet connection where u want to go then you do have to use extend and you want to put the router "halfway" to the dead zone. If you put it all the way in the dead zone it won't have enough signal to use wifi to get to your main router.
- Now go plug in and turn it on. What happens now is that both access points will radiate the same wifi name. Clients will connect to whichever signal is stronger. This works great as long as your PC or phone stays mainly upstairs or downstairs. They will "roam" if one signal grows weak enough which is good enough in most cases.