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1230AG with Omni Antenna.

Can I use two Omni directional ceiling mount AIR-ANT1728 for one Aironet 1230AG (AIR-AP1232AG-A-K9) if yes when and how?

THANX

HASSAN

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Red

Re: 1230AG with Omni Antenna.

Hi Hassan,

You can use two 1728 antennas in Diversity mode but not to cover two different cells/areas. For most installations, if you just used one 1728 antenna connected to the Right-hand/Primary, RP-TNC connector you should be good, if you have some obstacles in the cell area you can try using Diversity mode(2x1728 Antennas);

Cisco Aironet High Gain Omnidirectional Ceiling Mount Antenna (AIR-ANT1728)

From this doc;

http://www.cisco.com/en/US/products/hw/wireless/ps469/prod_installation_guide09186a0080286064.html

When you use a pair of antennas with matching characteristics to provide diversity for cell coverage in your facility, the guideline is to put those matched antennas at a distance apart from each other that is equal to a multiple of the wavelength of the frequency that is being transmitted. The 2.4 GHz wavelength is approximately 4.92 inches. Therefore, to support diversity on a 2.4 GHz radio with two separate antennas, the antennas should be spaced approximately 5 inches apart. The antenna pair could also be spaced at multiples of 5 inches, but the distance between should not exceed 4 multiples: reflected waves farther apart than that are likely to be so distorted and different in delay spread that the radio could not work with them.Because each antenna is selected by itself, both antennas must have the same radiation characteristics and be positioned to provide similar cell coverage. ***Two antennas connected to the same access point must not be used to cover two different cells.***

From this good doc;

Multipath and Diversity

http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008019f646.shtml

Hope this helps!

Rob

Please remember to rate helpful posts.....

5 REPLIES
Hall of Fame Super Red

Re: 1230AG with Omni Antenna.

Hi Hassan,

You can use two 1728 antennas in Diversity mode but not to cover two different cells/areas. For most installations, if you just used one 1728 antenna connected to the Right-hand/Primary, RP-TNC connector you should be good, if you have some obstacles in the cell area you can try using Diversity mode(2x1728 Antennas);

Cisco Aironet High Gain Omnidirectional Ceiling Mount Antenna (AIR-ANT1728)

From this doc;

http://www.cisco.com/en/US/products/hw/wireless/ps469/prod_installation_guide09186a0080286064.html

When you use a pair of antennas with matching characteristics to provide diversity for cell coverage in your facility, the guideline is to put those matched antennas at a distance apart from each other that is equal to a multiple of the wavelength of the frequency that is being transmitted. The 2.4 GHz wavelength is approximately 4.92 inches. Therefore, to support diversity on a 2.4 GHz radio with two separate antennas, the antennas should be spaced approximately 5 inches apart. The antenna pair could also be spaced at multiples of 5 inches, but the distance between should not exceed 4 multiples: reflected waves farther apart than that are likely to be so distorted and different in delay spread that the radio could not work with them.Because each antenna is selected by itself, both antennas must have the same radiation characteristics and be positioned to provide similar cell coverage. ***Two antennas connected to the same access point must not be used to cover two different cells.***

From this good doc;

Multipath and Diversity

http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008019f646.shtml

Hope this helps!

Rob

Please remember to rate helpful posts.....

Green

Re: 1230AG with Omni Antenna.

Good Answer Rob!

"Happy Holidays!"

Scott

Hall of Fame Super Red

Re: 1230AG with Omni Antenna.

Thanks Scott :)

Getting a nod like this is like getting an early Christmas present!

Funny, whenever Diversity questions pop up I think of your "Ball Park" explanation. Probably the best answer I have ever read on these forums.

Have a great Holiday season!

Rob

Green

Re: 1230AG with Omni Antenna.

Thanks again. Oddly enough, the three or four times I've been to a Major Legue game (Um, Beeer!!!!) guess where my seat was?

It was an easy analogy for me ....

Take care,

Scott

New Member

Re: 1230AG with Omni Antenna.

Dear Sir,

Thank you very much really, it was a wonderful reply and based on that I won the discussion with my colleagues.

By the way I saved your reply in my wireless folder as an important reference for this issue.

HASSAN

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