900 MHz also avoids licensing, equipment authorization, and channel availability headaches. Any time there is significant separation ("outside the immediate vicinity of") from the 462/467 MHz transmitter and the person operating it, the transmitter becomes a remote base, and there are some additional restrictions that come into play. Since 2.4 GHz is already accepted for short-range wireless microphones, 900 MHz is also fine. The question then becomes whether crossbanding to 900 MHz causes a 95.339 violation. Fixed, base, and repeater stations can be operated by remote control. Short-range 2.4 GHz microphones are designed to only operate in the immediate vicinity of the transmitter, so use on a mobile station is acceptable. Crossbanding a mobile station to something like a set of DTR650s would enable violating 95.1745, producing a 95.339 violation, as the mobile station is considered remotely controllable.