Google Chromecast can be set up by going to the setup page on a supported device. But in technical terms, what is actually happening on your device that configures the Chromecast dongle? For instance, if I have a WPA secured wireless AP, how does the dongle "listen" for configuration information?
afaik the only automatic way of doing this is Wi-Fi Protected Setup (WPS). However, that wouldn't require an additional device. So it seems like Google is doing something else.
Best Answer
Chromecast acts as an access point when first turned on.
For the initial setup, you install an app on your Android, Windows or mac device, that will find it and connect to the chromecast's AP directly. Then the chromecast scans for nearby access points, allowing you to pick one and enter in its password.
Once this is done, it will connect to that access point instead of acting as its own access point.