I have stored my iTunes library on my MacBook and activated home sharing. If I now want to stream some music to my iPad, I can do so from within the Music app. If I like to remotely control my MacBooks library I can do so via Apple Remote app. But what if my MacBook is asleep? After closing it and waiting for several minutes I cannot see the library any more. How can I access my library after the MacBook went to sleep? Would I need an additional app to wake my MacBook over WLAN or is it somehow build in and I just need to set something in the preferences?