My final goal using AirMac Extreme was set Time Machine up via network.
You can't hand over previous backups using via USB to via Wi-Fi.
You must set preference for AirPort Utility.
[AirPort Utility]>(Chose your AirPort Extreme)>[Manual Setup]>[Disks]>[File Sharing]>And chose "Secure Shared Disks" to [With AirPort Extreme password].

