Make sure your using the right kind of injector for the nanostations and not the typical 48 volt , I think they use 24 volt poe. Make sure you have good line of sight and your settings are correct...
I have 4 4mp ip cameras going over nanostations 2.4Ghz. set at 15FPS. idon'thave any problems. about 100 feets from the NVR and cameras and annotations are 30 feets high.