How far away can the mobile station be from the reference station?

For ultra-high accuracy RTK positioning, the distance between a mobile station and a reference station should be "roughly within 10 km". If the distance is farther than that, there is a possibility that the error will be FLOAT, but if you are aiming for an error of "within 3cm", there is no practical problem even at a distance of about 20km. In some cases, users have been able to FIX even at a distance of 50km.