Wednesday, August 14, 2013

Wall mounting vs. Ceiling mounting your access points

This post stems from the knowledge of how to properly mount your access points.  I recently went to do a validation survey for a 5 GHz WLAN, and discovered two of the three access points were mounted on the wall, perpendicular to the floor.


I decided to survey it anyway, and then remount the access points another day when I had the appropriate hardware, and re-survey.  I wanted to see what the actual coverage pattern would be – a “before and after”, if you would like to think of it that way.


Here is the coverage of the floor before making any changes.  The green and purple coverage patterns are created by two access points mounted “incorrectly”.  They’re both hanging like wall clocks, instead of being mounted on the ceiling like UFOs.  The brick colored pattern is mounted horizontally, and no change was made to this access point.



Here is the overlapping coverage in red.



I remounted the green access point horizontally about 3 feet from the telepole where it had been mounted vertically.  The “purple AP” I had to move from the hallway into the room next to the stairwell since there was no ceiling or structure to mount it to in the hallway. 



This is the “after” overlapping coverage area.



I must admit that I expected something a little more dramatic.  I used the same laptop, the same adapter, and walked the same path on both surveys.


I’m interested if anyone else has done any comparison surveys like this, what did they show?









  1. Was this an active or passive survey? Also what kind of APs were these? I'm trying to figure out if there was some beam forming involved....

  2. I've done quite a bit of 'before' and 'after' type surveys to help solve specific issues. You could also try the 'diff-view' in AirMagnet. (also turn off the white topo lines) Then you can see where RF changed based on re-orienting the Access Points.

    I would have anticipated the results you showed. By moving AP's to horizontal mounting, they are each now covering greater areas - thus more overlap.

    Also - using the 'per ap' type coloring is quite misleading. It will only show a specific color where one AP is strongest. NOT where that AP actually has coverage.

  3. I've had similar results also, although results depends on the building infrastructure are the access points mounted in an open area or closed area (reflections), also check the signal bleeding on the upper and lower adjacent floors.