Access Point com o mesmo ssid

You can use the same SSID. The problem is that your device will most likely pick the signal that is strongest when the device first attaches. Then as you roam around it will most likely not let go of that signal until it is really low. Even if the other AP is stronger. This is done so your device does not constantly jump back and forth between AP's. It is a pain though, because the signal usually has to become almost unusable before the device will automatically jump to the stronger AP signal. On some devices (like laptops) you can go into the driver details and change the parameter that controls how weak the signal is before your device will jump to the stronger AP. As far as 2.4 vs 5ghz goes, generally it is better to be on 5Ghz if your devices can support it. Not all devices can use the 5Ghz where most all wireless devices can use the 2.4Ghz band. The 2.4Ghz band has better range but the band is really crowded and thus you usually get interference that makes it slower than the 5Ghz band even though its signal is generally stronger. If using the 2.4ghz band make sure you only use channels 1, 6, or 11 (with 1 and 11 having the best chance of not having as much interference). Also make sure your two AP's are on different channels.

http://www.tomshardware.com/answers/id-2224583/access-point-ssid.html