Rui CarmoApple supports 802.11n on its AirPort range of wireless devices since Feb 2006, and updated them to support simultaneous dual 5GHz/2.4GHz operation on Mar 2009, with a subsequent later upgrade to 802.11ac.
The AirPort access point in itself was also enhanced to support USB printing and bridging (which is to say relaying), becoming a full-featured repeater.