N017RW
Premium Pilot
That's a weird combo. 900 mHz is a good video downlink frequency with the major disadvantage of larger antennas. 5.8 GHz gets around water absorption a tad but is more susceptible to interference. It is in the ISM (Industrial, Scientific, Medical band and so there can be other more powerful transmitters roaming about as well (same as 2.4 GHz). Maybe the control signal can handle degradation better than video. It would be easier to put error correction on a control frequency with lower information density than on a video downlink.
That's what Autel's site indicates.