Antenna Selection for High ceiling (Warehouse)

[farid nasiri]

i read nearly 500 topic on antenna selection for high ceiling and industrial warehouse environments  (~10m ceiling)

Question1 : both ant2544v4  and Ant2524 has ~60 degrees Elevation plane 3 dB beamwidth does it mean this Omni antenna could be mounted on 10m height without coverage issue ?

Question2:suppose installing plenty of 2702 with Ant2524 or Ant2544V4 in close adjacency , does CleanAir2 helps to avoid interference ?

Question3:if i want avoid directional antennas to cover aisles using dipoles is the last solution ? (if omni antenna cant afford enough elevation due to its nature )

my warehouse area is something like this : http://www.pathguide.com/Images/Content/warehouse%20aisle.jpg

thanks

[Sebastian Pusta]

If you want to receive some helpful advice, I think that you should give more details about the wireless network that you intend to design.

Will it be used for data/voice/location services?

Is uniform wireless coverage needed on all the 10 m height (from ground to ceiling) or it is required mainly at ground level?

What is the reason for installing "plenty of 2702"?

Any other info that would help us understand the needs would help you get some good ideeas :)

[farid nasiri]

Thank you Sebastian

Will it be used for data/voice/location services?

yes aim is to have unified wireless network to support Motorola Barcode laser guns,Cisco 7925G phones and some laptops

Is uniform wireless coverage needed on all the 10 m height (from ground to ceiling) or it is required mainly at ground level?

Ground level(around 1.5m from ground ) is critical area

What is the reason for installing "plenty of 2702"?

i was thinking if using dipoles may need to install more AP on warehouse ceiling , its budgeted to buy 2702E for all warehouses area

[Sebastian Pusta · Accepted solution]

As I can see this location presents challenging RF conditions: high attenuations, reflections, multipath, etc. The fact that you need to implement Voice WLAN too, introduces more difficulties.

You have to conduct a wireless site survey. I don't know how much experience do you have with this activity or if you have the equipment and site survey tools required, but it has to be done.

In the worst case scenario you have to grab at least one or two APs from the model that you intend to install, set them up in stand alone mode with some test SSIDs and install them in the warehouse in different locations. Than you walk arround and try to measure the signal quality and attenuations. You cand use some free or trial site survey applications that can be found on the Internet.

You have to find out what protocol (802.11 a/b/g/n) the barcode scanners are using and what TX power are they capable of. You should set up your APs accordingly (the AP TX power should not exceed the client power, preferably it should be about half in order to benefit of CHD). The same has to be done for the Voice clients. The survey has to be done separately for each 802.11 protocol. I recommend taht you do some futher reading on the subject.

As for the antenna type, Cisco recommends directional antennas in high ceiling environments. However, I have installed 2702e APs with standard omni antennas in warehouses and they did the job very well. The difference in my case was that I installed the APs on cable channels at ~6-7 meters, not directly on the ceiling. Maybe you can find some other mounting possibilities besides the ceiling if you want to stick to omni antennas.

The co-channel interference between adjacent APs is avoided usualy by DCA and TPC not as much by CleanAir. However in 2.4 GHz there could be some interferences.

As a conclution you have to use some real APs in order to estimate, with at least a minimal accuracy, the position and number of required APs for the deployment. Do not forget about the cabling requirements for the APs, distances to the closest switch, electrical power etc. 

[farid nasiri]

Thank you Sebastian

correct and good points you mentioned

may i ask which model of omni antenna you used ?

i hope can mount APs on ladder structure hanging from the ceiling ~2m lower the ceiling

and for the site survey hmmmm not possible due to some non technical reasons so i have to buy/install APs and WLC one time ! its crazy but nothing to do

a friend of mine had successful experience on such an environment using old 1262 and dipole antennas hoep i can

[Sebastian Pusta]

I ussed AIR-ANT2524D"X"-R.

Make sure that your APs will not swing after they are installed.

Good luck!