Ruijie Networks RG-AP320-I Series Hardware Installation And Reference Manual page 7

It is preferable to install the AP in a way that maximizes coverage.
When install the AP indoors, it is better to mount it on the ceiling rather than on the wall because the AP
provides greater coverage when it is installed on the ceiling.
Figure 1-3 and Figure 1-4 show the preferred wall-mount and ceiling-mount orientations of the AP operating in the 2.4
GHz and 5 GHz bands, respectively.
Figure 1-3 Preferred Wall-Mount and Ceiling-Mount Orientations of the RG-AP320-I (in the 2.4 GHz Band)
Figure 1-4 Preferred Wall-Mount and Ceiling-Mount Orientations of the RG-AP320-I (in the 5 GHz Band)