I'm going to use ANT5959 and AIR-1242AG access point while deploying wireless network at the customers warehouse. I've chosen diversity antenna because of lots of metal constructions in the warehouse. However, during the first site survey I've noticed that ANT5959 with its 2 dBi is not enough for some big rooms, so I've found ANT3213 antenna with 5 dBi at cisco.com, I have no such antenna just now that's why I have some questions:
1. How ANT3213 is mounted (if it is mounted on a pillar then how it can give an omni coverage)? Can I mount this antenna on ceiling?
2. Why ANT3213 is cheaper that ANT5959 despite it has more dBi?
Look at the vertical beam difference between the two. The 3213 may not have as much coverage from floor to ceiling as the 5959. Also, the 5959 will handle multipath distortion better than the 3213
There is also the AIR-ANT1728 antenna as well.
You may also want to consider mixing directional patches with omnidirectional placements, sort of a hybrid setup.
for more details
The 5959 is designed to clip to the metal framework of a suspended tile ceiling. Any metal will have an effect of course.
Can you be more specific in regards to "metal ceiling"
Also, check out http://en.wikipedia.org/wiki/Ground_plane
Thanks for your answers and links.
When I say metal ceiling I mean that the ceiling will be completely metal (all the surface of ceiling will be metal).
How high is the ceiling? The reason I ask is that it may be beneficial to make a bracket that puts some distance between the antenna and the ceiling, but still be high enough so that people do not bump their heads on the antenna/ap Can you temporarily mount the Ap+antenna to it to do a survey?
Here is a good link on Cisco antennae:
Eric, the ceiling will be about 3.5 meter high, unfortunately I can not conduct a survey cause the ceiling is not yet installed, I've conducted a survey without the ceiling.
So, you advise to use a bracket..., anyway I'll do one more survey when the ceiling will be on its place. As I understand, I must empirically estimate the distance between 5959 and ceiling if there will be some problems with coverage?
As I see it you are faced with two or more dilemmas, first, it would be very difficult to truly determine an accurate coverage pattern without the environment being in place, and second, getting management to be happy with the aesthetics of an antenna and/or ap as well as possibly a bracket hanging from their brand new metal ceiling.
You have not mentioned how big the area is, that too will also be a factor in regards to how many APs you will need.
This may sound a bit silly, but what if you re-did the survey with a bunch of tin foil or steel mesh stapled to the ceiling - especially around the area where the antenna will be mounted. It is not a true emulation of the final environment, but perhaps it would give you an idea of what effects the metal ceiling would have.
Have you also considered not mounting the antenna/AP to the ceiling and having it placed on a peice of furniture such as a cubicle wall, bookcase or other piece of furniture that would allow the antenna to be placed at a reasonable height?
Deploying wireless networks sometimes requires a bit of creativity
Eric, thanks for such a comprehensive answer.
Regarding the site: this is a warehouse, it consists of two parts - the old one (with standard ceiling, where 5959 fit ok) and the new part which is being constructed now and will have metal ceiling. It is a 4 floor building, during site survey I revealed that I need 20 access points, most of them will use 5959, two will use directional patches and one will use 12 dbi omni antenna. Of course management liked 5959 appearance.)
I plan to mount AP above the ceiling and then mount antenna below the ceiling (perhaps I will use 5 ft cable). Also, I must say that I see no possibility to mount antennas anywhere expect ceiling because there are no cubicle walls and bookcases there. Only ceiling, walls and pillars, moreover I must keep in mind that there will be stackers riding all over the warehouse and I must secure AP and antenna.
However, I thank you very much for the answers, I will be careful with this metal ceiling and if you are interested I will let you know about the results.