On my iPad right now. My first-generation "Time Capsule" has four options I can set via the iOS Airport Utility. 802.11n (b/g compatible) 802.11n only (2GHz) 8

On my iPad right now. My first-generation "Time Capsule" has four options I can set via the iOS Airport Utility. 802.11n (b/g compatible) 802.11n only (2GHz) 802.11n (a compatible) 802.11n only (5GHz) I gave away my AirPort a while ago, it was also first-gen of its kind so I think it only did 802.11a