Hi,
Outdoor APs can be installed in following positions:
Wall side
Overhead
Floor
Generally speaking, outdoor APs are mostly installed on the wallsides. advantages are that APs and terminals are visible to each other in line-of-sight distance, with penetration loss within the allowed range. They are easy to install. and APs are placed in a line. Co-channel APs are far from each other, providing good anti-interference capability.
Overhead APs are easy to install on ceilings with bridleways. APs and terminals are visible to each other in line-of-sight distance, with penetration loss within the allowed range.
For floor range, advantages can be AP signals attenuate due to obstacles. The AP coverage area can be controlled. Therefore, many APs can be deployed to connect more users. APs are deployed at the rear of the terrace, invisible to the users.
I hope it helps.