Although a highlight of the EV3 set over the older NXT is that it is advertised to be Wi-Fi capable, this is something of an exaggeration. There is a USB port that allows you to insert a Wi-Fi dongle. The current versions of the firmware do not allow compatibility with many dongles. The Wi-Fi dongle recommended by LEGO is the only one I could find that would actually work. Additionally, you will need to design your robot so the dongle does not protrude from your robot in an awkward way. In the following image, you can see that I have a Wi-Fi dongle resting just above the motor. You could also use an angled USB adaptor, so your dongle does not protrude out of the side of the robot.

In addition to only a few choices for the Wi-Fi dongle, you need to make sure that you can successfully communicate with your router. In the preceding screenshot, you can see the Netgear WNA1100 dongle, sold by LEGO. For ease of use, you may want to set your router up without encryption or with WPA2...