I couldn't get my internet to hold at home on my new MacBook Air though it worked in other places and this is what I was told (p.s. the update seems to have worked and everything is running smoothly now):
Some MacBook Air (Mid 2013) computers may encounter an issue that, in rare instances, may cause an intermittent loss in wireless connectivity. The Wi-Fi menu bar icon may or may not indicate that a wireless connection still exists.
Install MacBook Air (Mid 2013) Software Update 1.0 by running Software Update, or by downloading the update directly.